Mechanical Ventilation

Collaborate With Respiratory Therapist (RT)

1. Auscultate breath sounds and respiratory effort, assessing for decreased ventilation or adventitious sounds. 2. • Monitor ventilator settings and alarms. 3. • Change ventilator settings as needed or ordered by HCP. 4. • Maintain appropriate cuff inflation on ET tube. 5. • Determine need for ET tube suctioning and suction patients as needed. 6. • Reposition and secure ET tube (based on agency policy). 7. • Monitor oxygenation level and signs of respiratory fatigue during weaning procedure.

Importing Monitor and Ventilator Data

1. In many ICUs, monitor data (e.g., vital signs, hemodynamic pressures, core temperature, pulse oximetry) are directly imported into the electronic health record (EHR). Ventilator data also may be sent to the EHR. 2. Depending on the information technology system, this connectivity of monitoring devices and ventilators can help drive evidence-based practice. Trends can be readily noted, and prompts can link the user to protocols. 3. Some systems can send alarms or notifications to the HCP from the EHR. 4. Always verify that correct patient data were imported into the EHR when documenting. Delete artifact or false data according to your agency's policy.

Drug Alert Oxygen

1. • O2 is considered a drug, and overexposure can lead to O2 toxicity. 2. • Mechanically ventilated patients receiving high levels of FIO2 for prolonged periods of time (e.g., 60% FIO2 for >24 hours) are at risk for O2 toxicity. 3. • Target FIO2 levels are to maintain SpO2 >92% and PaO2 between 60 and 80 mm Hg. 4. • Assess ABGs for evidence of excess O2. 5. • Monitor patient for signs of O2 toxicity: uncontrolled coughing, chest pain, and dyspnea.

Safety Alert VAP Prevention Strategies

1. • Practice good hand hygiene techniques before and after suctioning. 2. • Wear gloves when providing oral hygiene. 3. • Suction patients as needed for comfort. 4. • Keep the HOB elevated >30 to 45 degrees. 5. • Turn patient according to agency policy (e.g., side to side every 2 hours). 6. • Initiate early mobilization. 7. • Follow agency policy for limiting sedation with SAT. 8. • Perform daily SBT unless contraindicated.31

Safety Alert Alarm Fatigue

Alarm fatigue can develop in those who hear an excess number of alarms, resulting in sensory overload. This can cause a delayed response to alarms or dismissing them altogether and can lead to serious adverse events (e.g., patient death). One way to reduce alarm fatigue includes customizing alarm parameters based on patient specific needs.

Noninvasive ventilation

At times, patients may need ventilator support, without the placement of an ET tube. Noninvasive ventilation (NIV) uses a mask, instead of an ET tube, to oxygenate and ventilate a patient. These masks can be full face or a nasal piece. There are 2 common modes used for NIV.

High-pressure limit alarm

Causes • Secretions, coughing, or gagging • Patient fighting ventilator (ventilator asynchrony) • Condensate (water) in tubing • Kinked or compressed tubing (e.g., patient biting on ET tube) • ↑ Resistance (e.g., bronchospasm) • ↓ Compliance (e.g., pulmonary edema, ARDS, tension pneumothorax, atelectasis, pneumonia) • Improper alarm setting • ET tube inserted too far (e.g., right mainstem bronchus or carina)

Monitoring Oxygenation and Ventilation

Closely monitor the patient with an ET tube for adequate oxygenation by assessing clinical findings, ABGs, SpO2, and, if available, ScvO2 or SvO2. Assess for signs of hypoxemia, such as a change in mental status (e.g., confusion), dusky skin, and dysrhythmias. Periodic ABGs and continuous SpO2 provide objective data about oxygenation. Lower PaO2 values are expected in patients with some disease states, such as chronic obstructive pulmonary disease (COPD). CVP or PA catheters with ScvO2 or SvO2 capability provide an indirect measure of the patient's tissue oxygenation status (Table 65.4). Indicators of ventilation include clinical findings, PaCO2, and continuous partial pressure of EtCO2 (PETCO2). Assess the patient's respirations for rate, rhythm, and use of accessory muscles. The patient who is hyperventilating will be breathing rapidly and deeply and may have circumoral and peripheral numbness and tingling. The patient who is hypoventilating will be breathing shallowly or slowly and may appear dusky. PaCO2 is the best indicator of alveolar hyperventilation (e.g., decreased PaCO2, increased pH indicates respiratory alkalosis) or hypoventilation (e.g., increased PaCO2, decreased pH indicates respiratory acidosis). PETCO2 monitoring (capnography) is done by analyzing exhaled gas directly at the patient-ventilator circuit (mainstream sampling) or by transporting a sample of gas via a small-bore tubing to a bedside monitor (sidestream sampling). Continuous PETCO2 monitoring can assess the patency of the airway and presence of breathing. Gradual changes in PETCO2 values may accompany an increase in CO2 production (e.g., sepsis, hypoventilation, neuromuscular blockade) or a decrease in CO2 production (e.g., hypothermia, decreased CO, metabolic acidosis). In patients with normal ventilation-to-perfusion ratios (see Chapter 67), we can use PETCO2 to estimate PaCO2. PETCO2 is generally 2 to 5 mm Hg lower than PaCO2.13 However, in patients with unusually large dead air space or serious mismatch between ventilation and perfusion (e.g., COPD, pulmonary embolism), PETCO2 is not a reliable estimate of PaCO2.

Maintaining Correct Tube Placement

Continuously monitor the patient with an ET tube for proper placement. If the tube moves or is dislodged, it could end up in the pharynx or enter the esophagus or right mainstem bronchus (thus ventilating only the right lung). Observe for symmetric chest wall movement. Auscultate to confirm bilateral breath sounds. If the ET tube is not positioned properly, it is an airway emergency. Stay with the patient and try to maintain the airway. Support ventilation with a BVM and 100% O2 and call for the appropriate help to immediately assess or reposition the tube. If a dislodged tube is not repositioned, minimal or no O2 is delivered to the lungs or the entire VT is being delivered to 1 lung. This places the patient at risk for pneumothorax.

Sensitivity

Determines the amount of effort the patient must generate to initiate a ventilator breath. It may be set for pressure triggering or flow triggering. Usual setting: A pressure trigger is set 0.5-1.5 cm H2O below baseline pressure and a flow trigger is set 1-3 L/min below baseline flow

Maintaining Tube Patency

Do not routinely suction a patient.13 Regularly assess the patient to determine if suctioning is needed. Indications for suctioning include (1) visible secretions in the ET tube, (2) sudden onset of respiratory distress, (3) suspected aspiration of secretions, (4) increase in respiratory rate or frequent coughing, and (5) sudden decrease in SpO2. Other signs that indicate the patient needs suctioning include an increase in peak airway pressure and auscultating adventitious breath sounds over the trachea or bronchi.13 Table 65.8 describes 2 recommended suctioning methods, the closed-suction technique (CST) and the open-suction technique (OST). The CST uses a suction catheter that is enclosed in a plastic sleeve connected directly to the patient-ventilator circuit (Fig. 65.17). With the CST, oxygenation and ventilation are maintained during suctioning, and exposure to the patient's secretions and infection is reduced for the patient's and HCP's safety. The CST should be used for patients who (1) require PEEP, (2) have high levels of FIO2, (3) have bloody or infected pulmonary secretions, (4) require frequent suctioning, and (5) have clinical instability with the OST.13 Potential complications associated with suctioning include hypoxemia, bronchospasm, increased ICP, dysrhythmias, hypertension, hypotension, mucosal damage, pulmonary bleeding, pain, and infection. Closely assess the patient before, during, and after suctioning. If the patient does not tolerate suctioning (e.g., decreased SpO2, increased or decreased BP, sustained coughing, development of dysrhythmias), stop at once. Continue to reassess the patient until hemodynamic stability is achieved, the patient recovers, and/or the situation resolves before trying to suction again. Prevent hypoxemia by hyperoxygenating the patient before and after each suctioning pass and limiting each pass to 10 seconds or less (Table 65.8). Assess both the ECG and SpO2 before, during, and after suctioning. Causes of dysrhythmias during suctioning include (1) hypoxemia resulting in myocardial ischemia; (2) vagal stimulation caused by tracheal irritation; and (3) sympathetic nervous system stimulation caused by anxiety, discomfort, or pain. Dysrhythmias include tachydysrhythmias and bradydysrhythmias, premature beats, and asystole. Stop suctioning if any new dysrhythmias develop. Avoid excessive suctioning in patients with severe hypoxemia or bradycardia. Tracheal mucosal damage may occur due to excessive suction pressures (greater than 120 mm Hg), overly vigorous catheter insertion, and the suction catheter itself. Blood streaks or tissue shreds in aspirated secretions may indicate mucosal damage. This increases the risk for infection and bleeding, especially if the patient is receiving anticoagulants. We can prevent trauma to the mucosa by following the steps described in Table 65.8. Secretions may be thick and hard to suction because of inadequate hydration or humidification, infection, or inaccessibility of the lower airways. Maintain adequate hydration when clinically indicated (e.g., IV fluids) and provide supplemental humidification of inspired gases through the mechanical ventilator to help thin secretions. Mobilize and turn the patient (e.g., every 2 hours) to help move secretions into larger airways. If infection is the cause of thick secretions, give the patient appropriate antibiotics.

I/E ratio

Duration of inspiration (I) to duration of expiration (E). Usual setting: 1:2 to 1:1.5 unless inverse ratio ventilation is desired

02 concentration FIO2

Fraction of inspired O2 (FIO2) delivered to patient. May be set between 21% (essentially room air) and 100%. Usually adjusted to maintain PaO2 level >60-80 mm Hg or SpO2 level >92%

Oral Care for Patient on Mechanical Ventilator

General Measures 1. Gather all equipment. 2. Wash hands and don personal protective equipment and gloves. 3. Explain procedure to the patient and caregiver (if present). 4. Perform oral care every 2-4 hours using a suction toothbrush and toothpaste or gel for 1-2 minutes, suctioning often. Assess for plaque buildup and any potential infection. 5. Use 0.12% chlorhexidine oral rinse twice daily. 6. Apply a mouth moisturizer to oral mucosa and lips with each cleaning. 7. Suction oral cavity and pharynx when needed. Fig. 65.18 shows an endotracheal tube that can provide continuous or intermittent subglottic suctioning.

Bilevel Positive Airway Pressure

In addition to O2, bilevel positive airway pressure (BiPAP) provides 2 levels of positive pressure support: higher inspiratory positive airway pressure and lower expiratory positive airway pressure.13 Like CPAP, the patient must be able to spontaneously breathe and cooperate with this treatment (Fig. 65.14). BiPAP is used for COPD patients with HF and acute respiratory failure and for patients with sleep apnea. Its use after extubation can help prevent reintubation. Patients with shock, altered mental status, or increased airway secretions cannot use BiPAP because of the risk for aspiration and the inability to remove the mask.

Endotracheal Tubes

In oral intubation, the ET tube is passed through the mouth and vocal cords and into the trachea with the aid of a laryngoscope or a bronchoscope. Oral ET intubation is preferred for most emergencies because the airway can be secured rapidly. A larger diameter tube is used. A larger tube reduces the WOB because of less airway resistance. It is easier to remove secretions and perform bronchoscopy, if needed. In nasal ET intubation, the ET is placed blindly (i.e., without seeing the larynx) through the nose, nasopharynx, and vocal cords. We rarely use nasal ET intubation. It may be done when oral intubation is not possible (e.g., unstable cervical spine injury, dental abscess, epiglottitis). There are risks associated with oral ET intubation. It is hard to place the tube with limited head and neck mobility (e.g., spinal cord injury). Teeth can be chipped or accidentally removed during the procedure. Salivation increases, and swallowing is difficult. Patients can obstruct the ET tube by biting down on the tube. Sedation, along with a bite block or oropharyngeal airway, may be used to prevent obstruction. Mouth care is a challenge because of limited space in the oral cavity.

Nursing Management Caring for the Patient Requiring Mechanical Ventilation

In the critically ill patient who requires mechanical ventilation, the RN and RT provide most of the care. Some patients who need chronic mechanical ventilation may be in long-term care settings or at home. In these settings, the RN and RT assess the patient and plan and evaluate care, but implementation of some activities may be delegated. • Develop plan for communication with the patient who has an ET tube or tracheostomy. • Give sedatives, analgesics, and paralytic drugs as needed. • Teach patient and caregiver about mechanical ventilation and weaning procedures. • Auscultate breath sounds and respiratory effort, assessing for decreased ventilation or adventitious sounds. • Monitor ventilator settings and alarms. • Determine need for ET tube suctioning and suction patients as needed. • Reposition and secure ET tube (based on agency policy). • Monitor oxygenation level and signs of respiratory fatigue during weaning procedure. • Provide enteral nutrition. • Oversee UAP: Obtain vital signs and report to the RN. • Provide personal hygiene, skin care, and oral care, as directed by RN. • Assist with frequent position changes, including ambulation, as directed by the RN. • Help to perform passive or active range-of-motion (ROM) exercises.

Fostering Comfort and Communication

Intubation is a major stressor for the patient.19 Intubated patients have stress from not being able to talk and communicate their needs. This can be frustrating for the patient, caregiver, and interprofessional care team. To communicate more effectively, use a variety of methods. (See Common Problems of Critical Care Patients earlier in this chapter on p. 1535.) The physical discomfort associated with ET intubation and mechanical ventilation often requires sedating the patient and giving an analgesic until the ET tube is removed. Assess the drugs' effectiveness in achieving an acceptable level of patient comfort by using a valid pain scale, sedation scale (e.g., Richmond Agitation and Sedation Scale [RASS], Sedation Agitation Scale [SAS]), and/or delirium scale.20 Consider using relaxation techniques (e.g., music therapy) to complement drug therapy.

Endotracheal Tube Placement

Maintain proper ET tube position by recording and marking the position of the tube at the lip or teeth (usually 21 cm for women, 23 cm for men). • Confirm that the mark stays constant while at rest and during patient care, repositioning, and transport.

Nursing and Interprofessional Management: Artificial Airway

Managing a patient with an artificial airway is often a shared responsibility between you and the RT. Agency policy dictates specific management tasks. Nursing responsibilities for the patient with an artificial airway may include: (1) maintaining correct tube placement, (2) maintaining proper cuff inflation, (3) monitoring oxygenation and ventilation, (4) maintaining tube patency, (5) providing oral care and maintaining skin integrity, (6) fostering comfort and communication, and (7) assessing for complications. See eNursing Care Plan 65.1 for the patient on a mechanical ventilator (available on the website for this chapter).

respiratory rate (f)

Number of breaths the ventilator delivers per minute. Usual setting: 12-20 breaths/min

Artificial Airways

Patients in the ICU often need mechanical assistance to maintain airway patency. Inserting a tube into the trachea, bypassing upper airway and laryngeal structures, creates an artificial airway. The tube is placed into the trachea via the mouth or nose past the larynx (endotracheal [ET] intubation) or through a stoma in the neck (tracheostomy). Fig. 65.15 shows the parts of an ET tube. ET intubation is common in ICU patients requiring mechanical ventilation for short periods of time (e.g., less than 2 weeks). Other indications for intubation include (1) upper airway obstruction (e.g., burns, tumor, bleeding), (2) apnea, (3) high risk for aspiration, (4) ineffective clearance of secretions, and (5) respiratory distress. ET intubation is done quickly and safely at the bedside by an HCP or RT. A tracheotomy is a surgical procedure that is done when the need for an artificial airway is expected to be prolonged. Early tracheotomy (done within 10 days) appears to have advantages over delayed tracheotomy. These include fewer ventilator dependent days, reduced length of stays, decreased pain, and improved communication.16 Chapter 26 discusses tracheostomy tubes and related nursing management.

Partial Liquid Ventilation

Perflubron is an inert, biocompatible, clear, odorless liquid derived from organic compounds that has an affinity for both O2 and carbon dioxide and surfactant like qualities Perflubron is trickled down a specially designed ET tube through a side port into the lungs of a mechanically ventilated pt Amount usually equivalent to a pt's FRC

positive end-expiratory pressure (PEEP)

Positive pressure applied at the end of expiration of ventilator breaths. Usual setting: 5 cm H2O

Pressure support

Positive pressure used to augment patient's inspiratory pressure. Usual setting: 5-10 cm H2O

High-pressure limit

Regulates the maximal pressure the ventilator can generate to deliver the VT. When the pressure limit is reached, the ventilator ends the breath and spills the undelivered volume into the atmosphere. Usual setting: 10-20 cm H2O above peak inspiratory

Settings of Mechanical Ventilation

Respiratory rate (f) Tidal volume (vt) 02 concentration (FIO2) Positive end expiratory pressure (PEEP) Pressure Support I/E ratio Inspiratory flow rate and time Sensitivity High pressure limit

Spontaneous tidal volume (VT)

Significance Amount of air exchanged during normal breathing at rest. Measure of muscle endurance. Normal Values >5-7 mL/kg Weaning indices ≥5 mL/kg

Negative inspiratory force or pressure (NIF, NIP)

Significance Amount of negative pressure that a patient can generate to initiate spontaneous respirations. Measured by clinician: After complete occlusion of inspiratory valve, a pressure manometer is attached to airway or mouth for 10-20 sec while negative inspiratory efforts are noted. Normal values <−50 cm H2O Weaning indices <−20 cm H2O The more negative the number, the better indication for weaning.

Vital capacity (VC)

Significance Maximum inspiration and then measurement of air during maximal forced expiration. Measure of respiratory muscle endurance or reserve or both. Requires patient cooperation. Normal values 65-75 mL/kg Weaning indices ≥10-15 mL/kg

Positive expiratory pressure (PEP)

Significance Measure of expiratory muscle strength and ability to cough. Measured by clinician: After complete occlusion of expiratory valve, a pressure manometer is attached to the airway or mouth for 10-20 sec while positive expiratory efforts are noted. Normal values 60-85 cm H2O Weaning indices ≥30 cm H2O

Spontaneous respiratory rate (RR)

Significance Respiratory rate/frequency over 1 min. Normal 12-20 breaths/min Weaning indices <35 breaths/min

Minute Ventilation (VE)

Significance VT multiplied by respiratory rate over 1 min. For example: 0.350 (VT) × 28 (f) = 9.8 L/min. Normal Values >10 L/min Weaning indices >10 L/min

Spontaneous breathing trial (SBT)

Significances If patient passes daily weaning screen, assess patient during SBT with little or no ventilator assistance. Trial should be at least 30 min to a maximum of 120 min. Normal values nothing Weaning indices Successful completion of trial is based on an integrated patient assessment.

Inspiratory flow rate and time

Speed with which the VT is delivered. Usual setting: 40-80 L/min and time is 0.8-1.2 sec

Weaning Assessment

Spontaneous RR Spontaneous tidal volume Minute vent. Negative inspiratory force or pressure (NIF, NIP) Positive expiratory pressure (PEP) Rapid shallow breathing index RSBI (f/Vt) Spontaneous breathing ritual (sbt) vital capacity (vc)

Maintaining Proper Cuff Inflation

The cuff is an inflatable, pliable sleeve encircling the lower, outer wall of the ET tube (Fig. 65.15). The high-volume, low-pressure cuff stabilizes and "seals" the ET tube within the trachea and prevents escape of ventilating gases. However, excess volume in the cuff can damage the tracheal mucosa. To prevent this, inflate the cuff with air and measure and monitor the cuff pressure. To ensure adequate tracheal perfusion, maintain cuff pressure at 20 to 25 cm H2O.13 Measure and record cuff pressure after intubation and on a routine basis (e.g., every 8 hours) using the minimal occluding volume (MOV) technique or the minimal leak technique (MLT). To perform the MOV technique, first, in the mechanically ventilated patient, place a stethoscope over the trachea and inflate the cuff to MOV by adding air until you hear no air at peak inspiratory pressure (end of ventilator inspiration). For the spontaneously breathing intubated patient, you inflate until you hear no sound after a deep breath or after inhalation with a BVM. Second, use a manometer to verify that cuff pressure is between 20 and 25 cm H2O and record cuff pressure in the chart. If adequate cuff pressure cannot be maintained or larger volumes of air are needed to keep the cuff inflated, there could be a leak in the cuff or tracheal dilation at the cuff site. In these situations, notify the HCP. The procedure for MLT is similar with 1 exception. You remove a small amount of air from the cuff until you hear a slight air leak at peak inflation.

Complications of Endotracheal Intubation

Two major complications of ET intubation are unplanned extubation and aspiration. Unplanned extubation (i.e., removal of the ET tube from the trachea) may complicate the patient's recovery. Unplanned extubation can be due to patient removal of the ET tube or accidental removal during movement or a procedure. Usually, the unplanned extubation is obvious (i.e., the patient is holding the ET tube). Other times, the tip of the ET tube is in the hypopharynx or esophagus and the extubation is not obvious. You are responsible for preventing unplanned extubation by ensuring that the ET tube is secured and observing and supporting the ET tube during repositioning, procedures, and patient transfers. Giving adequate sedation and analgesia and using standardized weaning protocols decrease the incidence of self-extubation.21 The use of restraints to immobilize the patient's hands is a deterrent to self-extubation.21 Be sure to explain to the patient and caregiver when you use short-term restraints for patient safety and discuss the use of alternatives. Reassess for the continued need of restraints (per agency policy) and limit restraint use when possible. Should an unplanned extubation occur, stay with the patient and call for help. Interventions are aimed at maintaining the patient's airway, supporting ventilation (e.g., manually ventilating the patient with a BVM and 100% O2), securing the appropriate help to reintubate the patient (if needed), and providing psychologic support to the patient. Aspiration is another potential hazard for the patient with an ET tube. The ET tube passes through the epiglottis, splinting it in an open position. Thus the intubated patient cannot protect the airway from aspiration. The high-volume, low-pressure ET cuff cannot totally prevent the trickle of oral or gastric secretions into the trachea.22 Further, secretions collect above the cuff. When the cuff is deflated, those secretions can move into the lungs. Some ET tubes provide continuous suctioning of secretions above the cuff (Fig. 65.18). Oral intubation increases salivation, yet swallowing is difficult, so suction the patient's mouth often. Use a Yankauer (tonsil-tip) suction catheter or a sterile single-use catheter. Other factors contributing to aspiration include improper cuff inflation, patient positioning, and decreased gastric mobility and bowel function if receiving EN. The patient with an ET tube is at risk for aspiration of gastric contents. Even when the cuff is properly inflated, take precautions to prevent vomiting, which can lead to aspiration. Often, a nasogastric (NG) or an orogastric (OG) tube is inserted and connected to low, intermittent suction when a patient is first intubated. An OG tube is preferred over an NG tube to reduce the risk for sinusitis. All intubated patients who are receiving EN should have the HOB elevated a minimum of 30 to 45 degrees, unless medically contraindicated.

Endotracheal Intubation Procedure

Unless ET intubation is emergent, consent for the procedure is obtained. Tell the patient and caregiver the reason for ET intubation and steps in the procedure. Explain that, while intubated, the patient will not be able to speak, but that you will provide other means of communication. Tell them that the patient's hands may have removable mitts placed or wrists may have soft restraints placed to remind them not to touch the airway. Have a self-inflating bag-valve-mask (BVM) (e.g., Ambu bag) attached to O2, suctioning equipment ready at the bedside, and IV access. The BVM has a reservoir that is filled with O2 so that it delivers concentrations of 90% to 95%. The slower the bag is deflated and inflated, the higher the O2 concentration that is delivered. Assemble and check the equipment, remove the patient's dentures or partial plates (for oral intubation), and give medications as ordered. Premedication varies depending on the patient's level of consciousness (e.g., awake, obtunded), urgency (e.g., emergent, nonemergent), and the HCP's preferences. For oral intubation, place the patient supine with the head extended and the neck flexed ("sniffing position"). This position allows the HCP to better see the vocal cords. For nasal intubation, the nasal passages may be sprayed with a local anesthetic and vasoconstrictor (e.g., lidocaine with epinephrine) to reduce trauma and bleeding. Before intubation is started, preoxygenate the patient using the BVM and 100% O2 for 3 to 5 minutes. Each intubation attempt is limited to less than 30 seconds. Ventilate the patient between successive attempts using the BVM and 100% O2. Rapid-sequence intubation (RSI) is the rapid, concurrent administration of both a sedative and a paralytic drug during emergency airway management to induce unconsciousness for intubation. It decreases the risks for aspiration and injury to the patient. RSI is not indicated in patients who are in cardiac arrest or have a known difficult airway. A sedative-hypnotic-amnesic (e.g., propofol, etomidate [Amidate]) is given to induce unconsciousness, along with a rapid-onset opioid (e.g., fentanyl) to blunt the pain of the procedure. This is followed with a drug (e.g., rocuronium) to produce skeletal muscle paralysis.17 Monitor the patient's O2 status during the procedure with pulse oximetry. Adhere to the agency policy about RSI medication administration. After intubation, inflate the cuff. Confirm the placement of the ET tube while continuing to manually ventilate the patient using the BVM with 100% O2. Use an EtCO2 detector to confirm proper placement by noting the presence of exhaled CO2 from the lungs (Fig. 65.16). Place the detector between the BVM and ET tube and look for a color change (indicating the presence of CO2) or a number. At least 5 or 6 exhalations with a consistent CO2 level must be present to confirm tube placement in the trachea.13 Auscultate the lungs for bilateral breath sounds and the epigastrium for the absence of air sounds. Observe the chest for symmetric chest wall movement. SpO2 should be stable or improved. If the findings support proper ET tube placement, connect the ET tube to a mechanical ventilator and secure the tube per agency policy (Fig. 65.17). Suction the ET tube and pharynx. Insert a bite block, if needed, and secure it separately from the ET tube to the face. Obtain a chest x-ray to confirm tube location (2 to 6 cm above the carina in the adult). This position allows the patient to move the neck without moving the tube or causing it to enter the right mainstem bronchus. Once proper positioning is confirmed with x-ray, record and mark the position of the tube at the lip or teeth or nose. Obtain ABGs 15 to 30 minutes after intubation to determine baseline oxygenation and ventilation status. ABG values are used to guide oxygenation and ventilation changes. Continuous pulse oximetry gives data about arterial oxygenation. EtCO2 monitoring provides data related to ventilation.

Tidal volume Vt

Volume of gas delivered to patient during each ventilator breath. Usual volume: 6-8 mL/kg, 4-8 mL/kg in ARDS

Indicators for Weaning

Weaning Readiness Patients receiving mechanical ventilation for respiratory failure should undergo a formal assessment of weaning potential if the following are satisfied∗: 1. Reversal of the underlying cause of respiratory failure 2. Adequate oxygenation • PaO2/FIO2 >150-200 • SpO2 ≥90% • PEEP ≤5-7 cm H2O • FIO2 ≤40%-50% • pH ≥7.25 3. Hemodynamically stabile • Absence of myocardial ischemia • Absence of clinically significant hypotension (low dose or no vasopressor therapy) 4. Patient ability to initiate respirations 5. Optional criteria • Hemoglobin ≥7-10 g/dL • Core temperature ≤100.4° F (38° C) to 101.3° F (38.5° C) • Mental status awake and alert or easily arousable • A SAT and an SBT are recommended in patients who meet a daily safety screen. • A SAT should be done by stopping all sedatives and, in patients without active pain, all opioids. • Sedation should be restarted at 50% of the previous dose in patients who "fail" the SAT and remain off in patients who "pass." • An SBT should last at least 30 minutes but no more than 120 minutes. • It may be done with low levels of PEEP, low levels of PSV, or FIO2. • Tolerance of the trial may lead to extubation. • Failure to tolerate an SBT should prompt a search for reversible or complicating factors and a return to a nonfatiguing ventilator modality. • The SBT should be tried daily, unless contraindicated. • All health care team members should be familiar with the weaning plan. • The use of a weaning protocol decreases ventilator days. • The ventilator settings are not as important as the use of a daily protocol to prevent delays in weaning. • The patient receiving SIMV can have the ventilator breaths gradually reduced as ventilatory status permits. • PEEP or PSV can be added to SIMV. PSV is thought to provide gentle, slow respiratory muscle conditioning. • It may be especially beneficial for patients who are deconditioned or have heart problems. • Weaning may be tried at any time of day. It is usually done after a period of time when the patient has been ventilated in a rest mode. • The rest mode should be a stable, nonfatiguing, and comfortable form of support for the patient. • It is important to allow the patient's respiratory muscles to rest between weaning trials. • Once the respiratory muscles become fatigued, they may need 12 to 24 hours to recover. • The patient and caregiver need ongoing emotional support. • Explain the weaning process to them to keep them informed of progress. • Place the patient in a comfortable sitting or semirecumbent position. • Obtain baseline vital signs and respiratory parameters. • During the weaning trial, closely monitor the patient for signs and symptoms that may signal a need to end the trial (e.g., tachypnea, dyspnea, tachycardia, dysrhythmias, sustained desaturation [SpO2 less than 90%], hypertension or hypotension, agitation, diaphoresis, anxiety, sustained VT less than 5 mL/kg, changes in mental status). • Record the patient's tolerance throughout the weaning process. • Include statements about the patient's and the caregiver's feelings. • The weaning outcome phase is the period when the patient is ready for extubation or weaning is stopped because progress is not being made. • The patient who is ready for extubation should receive hyperoxygenation and suctioning (e.g., oropharynx, ET tube) prior to extubation. • Loosen the ET tapes or commercial holder. Have the patient take a deep breath, and at the peak of inspiration, deflate the ET tube cuff and remove the tube in one motion. • After removal, encourage the patient to deep breath and cough. • Suction the oropharynx as needed. • Have the patient say their name to assess vocalization. • Give supplemental O2 and provide naso-oral care. • Carefully monitor vital signs, respiratory status, and oxygenation immediately after extubation, within 1 hour, and per agency policy. • If the patient does not tolerate extubation (e.g., decreased SpO2 levels, tachypnea or bradypnea, tachycardia, decreased level of consciousness, decrease in PaO2, increase in PaCO2), immediate reintubation or a trial of noninvasive ventilation may be needed.

Providing Oral Care and Maintaining Skin Integrity

When an oral ET tube is in place, the patient's mouth is always open. Moisten the lips, tongue, and gums with saline or water swabs to prevent mucosal drying. Proper oral care provides comfort and prevents injury to the gums and plaque formation (Table 65.9). If space is limited in the oral cavity, use smaller or pediatric-sized oral products for providing oral care. Frequent assessment and meticulous care are needed to prevent skin breakdown on the face, lips, tongue, and nares because of pressure from the ET tube or the method used to secure the ET tube to the patient's face. Ongoing assessment is shared between the RN and RT. Reposition and re-tape the ET tube (per agency policy) and as needed to prevent skin breakdown. Repositioning the ET tube may be limited to the RT. Two staff members should always perform repositioning to prevent accidental ET tube dislodgment. Monitor the patient for any signs of respiratory distress throughout the procedure. For the nasally intubated patient, remove the old tape and clean the skin around the ET tube with saline-soaked gauze. For the orally intubated patient, remove the bite block (if present) and the old tape. Provide oral hygiene, then reposition the ET tube to the opposite side of the mouth. Replace the bite block (if appropriate) and reconfirm proper cuff inflation and tube placement. Secure the ET tube again (per agency policy). We often use commercial ET holders. These may increase the risk for skin breakdown compared to tape.18 If one is used, follow the manufacturer's directions for maintaining tube position, providing skin care, and preventing skin breakdown.

Continuous positive airway pressure (CPAP)

restores functional residual capacity (FRC) and is similar to positive end-expiratory pressure (PEEP). However, the pressure in CPAP is delivered continuously during spontaneous breathing, preventing the patient's airway pressure from falling to 0. For example, if CPAP is 5 cm H2O, airway pressure during expiration is 5 cm H2O. During inspiration, we generate 1 to 2 cm H2O of negative pressure. This reduces airway pressure to 3 or 4 cm H2O. CPAP is often used to treat obstructive sleep apnea. It is a noninvasive modality, delivered through a tight-fitting face mask, nasal mask, or nasal pillows. CPAP increases work of breathing (WOB) because the patient must forcibly exhale against the CPAP. Therefore it must be used with caution in patients with myocardial compromise. The patient must be able to remove a mask independently due to the risk for vomiting. Those with increased secretions or the inability to control their airway are not good candidates for CPAP due to the risk for aspiration.13

Rapid shallow breathing index RSBI (f/VT)

significance Spontaneous respiratory rate over 1 min divided by VT (in liters). For example: 30 (f)/0.400 (VT) = 75/L Normal values <40/L Weaning indices <105/L

Assist-control (AC) or assisted mandatory ventilation (AMV)

vent. settings Requires rate, VT, inspiratory time, and PEEP set for the patient • The ventilator sensitivity is set, so when the patient initiates a spontaneous breath, a full-volume breath is delivered nursing implications • Hyperventilation can occur • To limit spontaneous breaths, sedation may be needed

Other Modes

· Advances in ventilator technology have led to the development of other pressure modes. · However, the names and features of these other options are manufacturer specific. The superiority of these modes has not been proven. · Some examples include volume-assured pressure ventilation and adaptive support ventilation.

Complications of Positive Pressure Ventilation

· Although PPV may be essential to maintain ventilation and oxygenation, it can cause adverse effects. · It may be hard to distinguish complications of mechanical ventilation from the underlying disease.

Automatic Tube Compensation

· Automatic tube compensation (ATC) is an adjunct designed to overcome WOB through an artificial airway. · It is currently available on many ventilators. · ATC is increased during inspiration and decreased during expiration. I · t is set by entering the internal diameter of the patient's airway and the desired number for compensation. · ATC may be less effective in patients with excess secretions or who need longer term ventilation.

High-Frequency Oscillatory Ventilation

· High-frequency oscillatory ventilation (HFOV) involves delivery of a small VT (usually 1 to 5 mL/kg of body weight) at rapid respiratory rates (100 to 300 breaths/min). · The goals are to recruit (e.g., alveolar expansion) and maintain lung volume and reduce intrapulmonary shunting. · While HFOV may be a useful mode for patients with life-threatening hypoxia, it has not improved survival of patients with ARDS. · Patients receiving HFOV must be sedated and may need to be paralyzed to suppress spontaneous respiration.

Neurologic System

· In patients with head injury, PPV, especially with PEEP, can impair cerebral blood flow. · The increased intrathoracic positive pressure impedes venous drainage from the brain. · This results in jugular venous distention. · The patient may have increases in ICP due to the impaired venous return and subsequent increase in cerebral volume. · Elevating the HOB and keeping the patient's head in alignment may reduce the harmful effects of PPV on ICP.

Chronic Mechanical Ventilation

· Mechanical ventilators are now a part of long-term and home care. · In some instances, terminally ill, ventilated patients may be discharged to hospice · . The emphasis on controlling hospital costs has increased the number of patients discharged early from the acute care setting and the need to provide highly technical care, such as mechanical ventilation, in home settings. · The success of home mechanical ventilation depends, in part, on careful predischarge assessment and planning for the patient and caregivers. · Patients must first meet criteria to be discharged on mechanical ventilation (e.g., tracheostomy, stabile mechanical ventilator settings). · Both negative pressure and positive pressure ventilators can be used in the home. · Negative pressure ventilators do not require an artificial airway and are less complicated to use. · Several types of small, portable (battery-powered) positive pressure ventilators are available. · They can be attached to a wheelchair or placed on a bedside table. · Settings and alarms on these ventilators are simpler to use than on the standard ICU ventilators. · Home mechanical ventilation has advantages and disadvantages. · Having the patient in the home eliminates the strain that the hospital setting imposes on family dynamics. · Caregivers may feel helpless when they first hear about the need for long-term mechanical ventilation. · However, these feelings are often balanced by the opportunity to take part in the patient's care in the home setting. · At home, the patient may be able to take part in more activities of daily living around a personalized schedule. · Because of the smaller size of the home ventilator, the patient may be more mobile. · Another advantage is a lower risk for HAIs. · Disadvantages include problems related to equipment, reimbursement, caregiver stress and fatigue, and the patient's complex needs. · Ventilated patients are usually dependent, requiring extensive nursing care, at least initially. · Disposable products may not be reimbursable. · Carefully assess financial resources when arranging home ventilation. · Schedule a meeting with the interprofessional care team (e.g., social worker, home health care RN, RT) before starting a discharge teaching plan. · Caregivers may seem enthusiastic about caring for their loved one in the home but may not understand the sacrifices they may have to make financially and in personal time and commitment. · Encourage caregivers to consider respite care to periodically relieve their stress and fatigue.

Negative Pressure Ventilation

· Negative pressure ventilation involves the use of chambers that encase the chest or body and surround it with intermittent subatmospheric (or negative) pressure. · The "iron lung" was the first form of negative pressure ventilation. · It was developed during the polio epidemic. · Intermittent negative pressure around the chest wall pulls the chest outward, reducing intrathoracic pressure. · Air rushes in via the upper airway, which is outside the sealed chamber. · Expiration is passive. · The machine cycles off, allowing chest retraction. · This type of ventilation is like normal ventilation in that decreased intrathoracic pressures produce inspiration, and expiration is passive. · Negative pressure ventilation is noninvasive and does not need an artificial airway. · Several portable negative pressure ventilators are available for home use. · They are mainly for patients with neuromuscular diseases, central nervous system disorders, diseases and injuries of the spinal cord, and severe COPD. · They are not routinely used for acutely ill patients.

Nitric Oxide

· Nitric oxide (NO) is a gaseous molecule that is made intravascularly and takes part in the regulation of pulmonary vascular tone · . Inhibiting NO production results in pulmonary vasoconstriction. · Administering continuous inhaled NO results in pulmonary vasodilation. · NO may be given through an ET tube, a tracheostomy, or a face mask. · Currently, NO is used as a diagnostic screening tool for pulmonary hypertension and to improve oxygenation during mechanical ventilation in this patient population. · The use of NO does not reduce mortality in patients with ARDS and may cause kidney injury.

Sedation and Analgesia

· Patients receiving PPV may need sedation (e.g., propofol) and/or analgesia (e.g., fentanyl) to help with optimal ventilation. · Before starting sedation or analgesia in the mechanically ventilated patient who is agitated or anxious, identify the cause of distress. · Common problems that can result in patient agitation or anxiety include PPV, nutritional deficits, pain, hypoxemia, hypercapnia, drugs, and environmental stressors (e.g., sleep deprivation). · At times, the decision is made to paralyze the patient with a neuromuscular blocking agent (e.g., cisatracurium [Nimbex]) to provide more effective synchrony with the ventilator and improve oxygenation. · Remember that the paralyzed patient can hear, see, and feel. · It is essential to give IV sedation and analgesia concurrently when the patient is paralyzed. · Sedated or paralyzed patients may be aware of their surroundings. · You should always address them as if they were awake and alert. · Monitoring patients receiving these drugs is challenging · . Assess the patient using train-of-four (TOF) peripheral nerve stimulation, physiologic signs of pain or anxiety (e.g., changes in HR and BP), and ventilator synchrony. · The TOF assessment involves using a peripheral nerve stimulator to deliver 4 successive stimulating currents to elicit muscle twitches · The number of twitches varies with the amount of neuromuscular blockade. · The usual goal is 1 or 2 twitches out of 4 currents. · Noninvasive electroencephalogram technology (e.g., bispectral index monitoring [BIS]) can be used to guide sedative and analgesic therapy. · Excess administration of neuromuscular blocking agents may predispose the patient to prolonged paralysis and muscle weakness even after these agents are stopped.

Pressure-Control and Pressure-Control Inverse Ratio Ventilation

· Pressure-control ventilation (PCV) provides a pressure-limited breath delivered at a set rate. It may permit spontaneous breathing. · The VT is not set. · It is determined by the pressure limit set. · Pressure-control inverse ratio ventilation (PC-IRV) combines pressure-limited ventilation with an inverse ratio of inspiration (I) to expiration (E). Some HCPs use PC without IRV. · The I/E ratio is the ratio of duration of inspiration to the duration of expiration. · This ratio is normally 1:2 or 1:3. · With IRV, the I/E ratio begins at 1:1 and may progress to 4:1. · Prolonged positive pressure is applied, increasing inspiratory time. · IRV gradually expands collapsed alveoli. · The short expiratory time has a PEEP-like effect, preventing alveolar collapse. · Because IRV imposes a nonphysiologic breathing pattern, the patient needs sedation and often paralysis. · PC-IRV is used for patients with acute respiratory distress syndrome (ARDS) who continue to have hypoxemia despite high levels of PEEP. · Not all patients with poor oxygenation respond to PC-IRV.

Sodium and Water Imbalance

· Progressive fluid retention often occurs after 48 to 72 hours of PPV, especially PPV with PEEP. · Fluid retention is associated with decreased urine output and increased sodium retention. · Fluid balance changes may be due to decreased CO, which causes decreased renal perfusion. · This stimulates the release of renin with the subsequent production of angiotensin and aldosterone · This results in sodium and water retention. It is possible that pressure changes within the thorax are associated with decreased release of atrial natriuretic peptide, which also causes sodium retention. · Less insensible water loss occurs via the airway because ventilated delivered gases are humidified with body-temperature water. · As a part of the stress response, release of antidiuretic hormone (ADH) and cortisol contributes to sodium and water retention.

Prone Positioning

· Prone positioning is the repositioning of a patient from a supine or lateral position to a prone (on the stomach, face down) position. · This repositioning improves lung recruitment through various mechanisms. · Gravity reverses the effects of fluid in the dependent parts of the lungs as the patient is moved from supine to prone. · The heart rests on the sternum, away from the lungs, contributing to an overall uniformity of pleural pressures. · The prone position requires increased sedation and is nurse-intensive. · It is an effective supportive therapy used in critically ill patients with severe ARDS to improve oxygenation.

Alveolar Hyperventilation

· Respiratory alkalosis can occur if the respiratory rate or VT is set too high (mechanical overventilation) or if the patient receiving assisted ventilation is hyperventilating. · It is easy to overventilate a patient on PPV. · Especially at risk are patients with chronic alveolar hypoventilation and CO2 retention. · For example, the patient with COPD may have a chronic PaCO2 elevation (acidosis) and compensatory bicarbonate retention by the kidneys. · When the patient is ventilated, the patient's "normal baseline" rather than the standard normal values is the therapeutic goal. · If the COPD patient is returned to a standard normal PaCO2, the patient will develop alkalosis because of the retained bicarbonate. · Such a patient could move from compensated respiratory acidosis to serious metabolic alkalosis. · The presence of alkalosis makes weaning from the ventilator difficult. · Alkalosis, especially if the onset is abrupt, can have serious consequences, including hypokalemia, hypocalcemia, and dysrhythmias. · Usually the patient with COPD who is supported on the ventilator does better with a short inspiratory and longer expiratory time. · If hyperventilation is spontaneous, it is important to determine the cause and treat it. · Common causes include hypoxemia, pain, fear, anxiety, or compensation for metabolic acidosis. · Patients who fight the ventilator or breathe out of synchrony may be anxious or in pain. · If the patient is anxious and fearful, sitting with the patient and verbally coaching the patient to breathe with the ventilator or weaning the ventilator to a more appropriate setting may help. · If these measures fail, manually ventilating the patient slowly with a BVM and 100% O2 may slow breathing enough to bring it in synchrony with the ventilator.

Types of Mechanical Ventilation

· The 2 major types of mechanical ventilation are negative pressure and positive pressure ventilation.

Psychosocial Needs

· The patient receiving mechanical ventilation often has physical and emotional stress · . In addition to the problems related to critical care patients discussed at the beginning of this chapter, the patient supported by a mechanical ventilator is unable to speak, eat, move, or breathe normally. · Tubes and machines cause pain, fear, and anxiety. Usual activities, such as eating, elimination, and coughing, are extremely complicated. · The ABCDEF Bundle is an evidence-based practice of providing care that strives to attain an environment in which all patients receiving mechanical ventilation are calm, delirium free, and able to express their needs for pain control, positioning, and reassurance. · The ABCDEF Bundle ensures (1) Assessment, (2) Both SATs and SBTs are done, (3) correct Choice of analgesia and sedation, (4) Delirium prevention and management, (5) Early mobility, and (6) Family engagement. · Feeling safe is an overpowering need of patients on mechanical ventilation. · Work to strengthen the various factors that affect feeling safe. · Encourage hope, as appropriate, and build trusting relationships with both the patient and caregiver. Involve them in decision making as much as possible.

Ventilator-Associated Pneumonia

· The risk for HAI pneumonia is highest in patients requiring mechanical ventilation because the ET or tracheostomy tube bypasses normal upper airway defenses. · Poor nutrition, immobility, and the underlying disease process (e.g., immunosuppression, organ failure) make the patient more prone to infection. · Ventilator-associated pneumonia (VAP) is pneumonia that occurs 48 hours or more after ET intubation. · It occurs in as many as 27% of all intubated patients. · Patients who develop VAP have significantly longer hospital stays and higher mortality rates than those who do not. · Half of the patients develop early VAP (VAP that occurs within 96 hours of mechanical ventilation). · In those with early VAP, sputum cultures often grow gram-negative bacteria (e.g., E coli, Klebsiella, Streptococcus pneumoniae, H influenzae). · Organisms associated with late VAP include antibiotic-resistant organisms, such as Pseudomonas aeruginosa and oxacillin-resistant Staphylococcus aureus. · These organisms are abundant in the hospital environment and the patient's GI tract. · They can spread in a number of ways, including contaminated respiratory equipment, inadequate hand washing, adverse environmental factors (e.g., poor room ventilation, high traffic flow), and decreased patient ability to cough and clear secretions. · Colonization of the oropharynx tract by gram-negative organisms predisposes the patient to gram-negative pneumonia. · Clinical signs that suggest VAP include fever, high white blood cell count, purulent or odorous sputum, crackles or wheezes on auscultation, and pulmonary infiltrates noted on chest x-ray. · The patient is given antibiotics after appropriate cultures are taken by tracheal suctioning or bronchoscopy and when infection is evident. · Guidelines for VAP prevention include (1) minimizing sedation, including daily spontaneous awakening trials (SATs) and daily spontaneous breathing trials (SBTs), (2) early exercise and mobilization, (3) use of ET tubes with subglottic secretion drainage ports for patients likely to be intubated greater than 48 to 72 hours, (4) HOB elevation at a minimum of 30 to 45 degrees unless medically contraindicated, (5) oral care with chlorhexidine, and (6) no routine changes of the patient's ventilator circuit tubing. · Other preventive measures include strict hand washing before and after suctioning, whenever ventilator equipment is touched, and after contact with any respiratory secretions · Always wear gloves when in contact with the patient and change gloves between activities (e.g., emptying urinary catheter drainage, hanging an IV drug). · Last, always drain the water that collects in the ventilator tubing away from the patient as it collects.

Modes of Volume Ventilation

· The ways by which the patient and ventilator interact to deliver effective ventilation are called ventilator modes. · The selected ventilator mode is based on how much WOB the patient should or can perform. · WOB is the inspiratory effort needed to overcome the elasticity and viscosity of the lungs along with the airway resistance. · The mode is determined by the patient's ventilatory status, respiratory drive, and ABGs. · Generally, ventilator modes are controlled or assisted. · With controlled ventilatory support, the ventilator does all the WOB for the patient. · With assisted ventilatory support, the ventilator and patient share the WOB. · Historically, volume modes, such as controlled mandatory ventilation (CMV), assist-control ventilation (ACV), and synchronized intermittent mandatory ventilation (SIMV), have been used to treat critically ill patients. · Pressure modes, such as pressure support ventilation (PSV), pressure-control ventilation (PCV), and inverse ratio ventilation (PC-IRV) are becoming more common.

Pressure Support Ventilation

· With pressure support ventilation (PSV), positive pressure is applied to the airway only during inspiration and is used with the patient's spontaneous respirations. · The patient must be able to initiate a breath in this modality. · The level of positive airway pressure is preset so that the gas flow rate is greater than the patient's inspiratory flow rate. · As the patient starts a breath, the machine senses the spontaneous effort and supplies a rapid flow of gas at the initiation of the breath and variable flow throughout the breath. · With PSV, the patient determines inspiratory length, VT, and respiratory rate. · VT depends on the pressure level and airway compliance. · PSV is used with continuous ventilation and during weaning. · It also may be used with SIMV during weaning. · PSV is not often used as ventilatory support during acute respiratory failure because of the risk for hypoventilation and apnea. · Advantages include increased patient comfort, decreased WOB (because inspiratory efforts are augmented), decreased O2 consumption (because inspiratory work is reduced), and increased endurance conditioning (because the patient is exercising respiratory muscles).

Airway Pressure Release Ventilation

• Airway pressure release ventilation (APRV) permits spontaneous breathing at any point during the respiratory cycle with a preset CPAP with short timed pressure releases. • The CPAP level (pressure high, pressure low) is adjusted to keep oxygenation goals while the timed releases (time high, time low) are increased or decreased to meet ventilation goals.25 VT is not set. • It varies depending on the CPAP level, the patient's compliance and resistance, and spontaneous breathing effort. • This mode is best for patients who need high pressure levels for alveolar recruitment (open collapsed alveoli). • An advantage is that it allows for spontaneous respirations. • This may reduce the need for deep sedation or paralytics.

Alveolar Hypoventilation

• Alveolar hypoventilation can be caused by inappropriate ventilator settings, leakage of air from the ventilator tubing or around the ET tube or tracheostomy cuff, lung secretions or obstruction, and low ventilation/perfusion ratio. • A low VT or respiratory rate decreases minute ventilation. • This results in hypoventilation, atelectasis, and respiratory acidosis. • A leaking cuff or tubing that is not secured may cause air leakage and lower VT. • Mobilizing the patient, turning the patient at least every 2 hours, encouraging deep breathing and coughing, and suctioning (as needed) may limit lung secretions. • Increasing the VT, adding small increments of PEEP, and adding a preset number of sighs to the ventilator settings (i.e., a deeper than normal breath incorporated into the respiratory cycle) can help reduce the risk for atelectasis.

Pulmonary System Barotrauma

• As lung inflation pressures increase, risk for barotrauma increases. • Barotrauma results when the increased airway pressure distends the lungs and possibly ruptures fragile alveoli or emphysematous blebs. • Patients with noncompliant lungs (e.g., COPD) are at greatest risk for barotrauma. • Patients with stiff lungs (e.g., ARDS) who are given high inspiratory pressures and high levels of PEEP (greater than 5 cm H2O) or have a lung abscess from necrotizing organisms (e.g., staphylococci) are also at risk. • Air can escape into the pleural space from alveoli or the interstitium and become trapped. • Pleural pressure increases and collapses the lung, causing a pneumothorax • The lungs receive air during inspiration but cannot expel it during expiration. • Respiratory bronchioles are larger on inspiration than expiration. • They may close on expiration, and air becomes trapped. • With PPV, a simple pneumothorax can become a life-threatening tension pneumothorax. • The mediastinum and contralateral lung are compressed, reducing CO. • Immediate treatment of the pneumothorax is required. • Pneumomediastinum usually begins with rupture of alveoli into the lung interstitium. • Progressive air movement occurs into the mediastinum and subcutaneous neck tissue, and a pneumothorax often follows. • New, unexplained subcutaneous emphysema is an indication for immediate chest x-ray. • Pneumomediastinum and subcutaneous emphysema may be too small to detect on x-ray or clinically before the development of a pneumothorax.

Collaborate With Dietitian

• Assess and monitor patient's nutritional status. • Recommend formulations for enteral and/or parenteral nutrition as needed.

Low VT or minute ventilation alarm interventions

• Assess patients respiratory and neurologic status. Reduce sedation. • Assess ventilator circuit for leaks • Reassess cuff to ensure cuff is adequately inflated • Check ventilator settings

Low VT or minute ventilation alarm cause

• Change in patient's breathing efforts (e.g., rate and volume) • Patient disconnection, loose connection, or leak in circuit • ET tube or tracheotomy cuff leak (e.g., air leak) • Insufficient gas flow

Low-pressure limit alarm interventions

• Check connections • Confirm adequate tidal volume and ET tube position with chest x-ray • Reinflate cuff

High-pressure limit alarm interventions

• Clear secretions and ↑ sedation • Reassure patient • Remove water from ventilator tubing • Unkink tubing, insert bite block, or reposition patient • Give bronchodilator • Assess breath sounds, obtain chest x-ray • Adjust ET tube

Pressure-control inverse ratio ventilation (PC-IRV)

• Combines pressure-limited ventilation with an inverse ratio of inspiration to expiration • HCP selects the pressure level, rate, inspiratory time (1:, 2:1, 3:1, 4:1), and PEEP level • With the prolonged inspiratory times, auto-PEEP may result • Auto-PEEP may be a desirable outcome of the inverse ratios nursing • Requires sedation and/or pharmacologic paralysis to oxygenate and ventilate patient due to discomfort • Air trapping can occur due to ↑ intrathoracic pressure, leading to a ↓ cardiac output

Ventilator inoperative or low battery alarm interventions

• Ensure mechanical ventilator is plugged into right power source • Disconnect patient from mechanical ventilator and use bag- valve-mask to ventilate until machine is properly functioning

Extracorporeal Membrane Oxygenation

• Extracorporeal membrane oxygenation (ECMO) is an alternative form of pulmonary support for the patient with severe respiratory failure • It is used most often in the pediatric and neonatal populations but is increasingly being used in adults. • ECMO is a modification of cardiac bypass. It involves partially removing blood from a patient with large-bore catheters, infusing O2, removing CO2, and returning the blood to the patient. • This intensive therapy requires systemic anticoagulation and is a time-limited intervention. • A skilled team of specialists, including a perfusionist, must be continuously at the bedside.

Ventilator inoperative or low battery alarm cause

• Machine malfunction • Unplugged, power failure, or internal battery not charged

Mechanical Ventilation

• Mechanical ventilation is the process by which the FIO2 (21% [room air] or more) is moved in and out of the lungs by a mechanical ventilator. • Mechanical ventilation is not curative. • It is a means of supporting patients until they recover the ability to breathe independently. • It can also serve as a bridge to long-term mechanical ventilation or until a decision is made to stop ventilatory support. • Indications for mechanical ventilation include (1) apnea, (2) inability to breathe or protect the airway, (3) acute respiratory failure (4) severe hypoxia, and (5) respiratory muscle fatigue. • Patients with chronic lung disease and their caregivers should be given the opportunity to discuss mechanical ventilation before end-stage respiratory failure develops. • Encourage all patients, especially those with chronic illnesses, to discuss the subject of life-sustaining measures, including mechanical ventilation, with their families and HCPs. • The patient's wishes about end-of-life treatment should be recorded in an advance directive. • The decision to use, withhold, or stop mechanical ventilation must be made carefully, respecting the wishes of the patient. • When the interprofessional care team, patient, and/or caregiver disagree over the treatment plan that the patient desires, conferences are essential to keep the lines of communication open and discuss options. • You may need to consult the agency's ethics committee for assistance.

Settings of Mechanical Ventilators

• Mechanical ventilator settings regulate rate, VT, O2 concentration, and other characteristics of ventilation • Settings are based on the patient's status (e.g., ABGs, ideal body weight, current physiologic state, level of consciousness, respiratory muscle strength). • Settings are evaluated and adjusted until oxygenation and ventilation targets have been reached. • It is important that you check that all ventilator alarms are always on. • Alarms alert the staff to potentially dangerous situations, such as mechanical malfunction, apnea, unplanned extubation, or patient asynchrony with the ventilator • On many ventilators, the alarms can be temporarily suspended or silenced for up to 2 minutes for suctioning or testing while a staff member is in the room. • After that time, the alarm system automatically turns back on.

Ventilator Alarms

• Mechanical ventilators may become disconnected or malfunction. • Most deaths from accidental ventilator disconnection occur while the alarm is off. • Most accidental disconnections are discovered by low-pressure alarms. • The most frequent site for disconnection is between the tracheal tube and the adapter. • Push connections together and then twist to secure more tightly. • Be certain that alarms are always set and activated. • Chart that this is the case. • You can pause alarms (not inactivate) during suctioning or removal from the ventilator, but you must reactivate them before leaving the patient's bedside. • Ventilator malfunction may occur. • Although most agencies have emergency generators in case of a power failure and newer ventilators may have battery backup, power failure is always a possibility. • Have a plan for manually ventilating all patients who depend on a ventilator. • If, at any time, you decide the ventilator is malfunctioning (e.g., failure of O2 supply), disconnect the patient from the machine and manually ventilate with a BVM and 100% O2 until the ventilator is fixed or replaced.

Nutritional Therapy: Patient Receiving Positive Pressure Ventilation

• PPV and the hypermetabolism associated with critical illness can contribute to inadequate nutrition. • Critical illness, trauma, and surgery are associated with hypermetabolism, anxiety, pain, and increased WOB, which greatly increase caloric expenditure. • The presence of an ET tube eliminates the normal route for eating. • Inadequate nutrition makes the patient receiving prolonged mechanical ventilation prone to poor O2 transport from anemia and to poor tolerance of minimal exercise. • It can delay mechanical ventilation weaning, decrease resistance to infection, and slow recovery • . Critically ill patients have frequent EN interruptions. • We often hold feedings due to procedures and during routine nursing care. • Poor nutrition and the disuse of respiratory muscles contribute to decreased respiratory muscle strength. • Serum protein levels (e.g., albumin, prealbumin, transferrin, total protein) are usually decreased. • Patients unlikely to be able to eat independently for 3 to 5 days should have a nutritional assessment and EN started within 24 to 48 hours of admission. • EN is the preferred method to meet caloric needs of mechanically ventilated patients • Consult the dietitian to determine the caloric and nutrient needs of these patients. • When eating with a tracheostomy tube in place, the patient should tilt the head slightly forward to assist with swallowing and to prevent aspiration. • The diet may be restricted to soft foods (e.g., puddings, ice cream) and thickened liquids. • Patients with a long-term tracheostomy will likely have a tube placed in the stomach (gastrostomy) or small bowel (jejunostomy) for nutritional support • Patients may be able to eat normally once the tracheostomy site heals and they meet criteria that will allow them to take oral intake. • Swallowing studies and a speech therapy consultation are done to assess the patient's readiness for oral intake.

Cardiovascular System

• PPV can affect circulation because of the transmission of increased mean airway pressure to various structures in the thorax. • Increased intrathoracic pressure compresses the thoracic vessels. • This compression causes decreased venous return to the heart, left ventricular end-diastolic volume (preload), and CO, resulting in hypotension. • Mean airway pressure is further increased if PEEP is being titrated (greater than 5 cm H2O) to improve oxygenation. • If the lungs are noncompliant (e.g., ARDS), airway pressures are not as easily transmitted to the heart and blood vessels. • Thus effects of PPV on CO are reduced. Conversely, with compliant lungs (e.g., COPD), there is increased danger of transmission of high airway pressures and negative effects on hemodynamics. • Hypovolemia (e.g., hemorrhage) and decreased venous tone (e.g., sepsis, spinal shock) can further compromise venous return. • Restoring and maintaining the circulating blood volume are important in minimizing cardiovascular complications.

High VT, minute ventilation, or respiratory rate alarm cause

• Pain, anxiety • Change in patient condition (e.g., ↑ metabolic demand, fever, hypoxia, hypercapnia) • Excess condensate or secretions in tubing (i.e., false reading)

Gastrointestinal System

• Patients receiving PPV are stressed because of the serious illness, immobility, or discomforts associated with the ventilator. • This places the patient at risk for developing stress ulcers and GI bleeding. • Patients with a preexisting ulcer or those receiving corticosteroids have a higher risk. • Any circulatory compromise, including reduced CO caused by PPV, may contribute to ischemia of the gastric and intestinal mucosa and increase the risk for translocation of GI bacteria. • Stress ulcer prophylaxis includes giving histamine (H2)-receptor blockers (e.g., ranitidine), proton pump inhibitors (PPIs) (e.g., esomeprazole), or EN to decrease gastric acidity and reduce the risk for stress ulcer and hemorrhage. • PPIs may increase the risk for Clostridium difficile infection. • Gastric and bowel dilation may occur because of gas accumulation in the GI tract from swallowed air. • The irritation of an artificial airway may cause excessive air swallowing and gastric dilation. • Gastric or bowel dilation may put pressure on the vena cava, decrease CO, and prohibit adequate diaphragmatic excursion during spontaneous breathing. • Elevation of the diaphragm from a paralytic ileus or bowel dilation leads to compression of the lower lobes of the lungs. • This may cause atelectasis and compromise respiratory function. • Decompression of the stomach is done by inserting an OG or NG tube. • Immobility, sedation, circulatory impairment, decreased oral intake, use of opioid pain medicines, and stress contribute to decreased peristalsis. • The patient's inability to exhale against a closed glottis may make defecation difficult. • As a result, the ventilated patient is at risk for constipation. • A bowel regimen should be started to help with motility. Musculoskeletal System • Maintaining muscle strength and preventing complications associated with immobility are important. • Adequate analgesia and nutrition can enhance exercise tolerance. • Plan for early and progressive mobility of appropriate patients receiving PPV. • In collaboration with physical and occupational therapy, perform passive and active exercises to maintain muscle tone in the upper and lower extremities. • Simple maneuvers, such as leg lifts, knee bends, or arm circles, are appropriate. • Prevent contractures, pressure injuries, footdrop, and external rotation of the hip and legs by proper positioning and using specialized mattresses or beds. • Use a portable ventilator or provide manual ventilation with a BVM and 100% O2 when ambulating patients who are mechanically ventilated.

Collaborate With Physical and Occupational Therapist

• Perform ROM exercises. • Assist with early and progressive ambulation as directed by the RN.

Positive End-Expiratory Pressure

• Positive end-expiratory pressure (PEEP) is a ventilatory maneuver, or mechanical ventilator setting, in which positive pressure is applied to the airway during exhalation. • Normally during exhalation, airway pressure drops to near 0, and exhalation occurs passively. • With PEEP, exhalation is passive but pressure falls to a preset level, often 3 to 20 cm H2O. • Lung volume during expiration and between breaths is greater than normal with PEEP. • This increases FRC and often improves oxygenation by restoring the lung volume that normally remains at the end of passive exhalation. • The mechanisms by which PEEP increases FRC and oxygenation include increased aeration of patent alveoli, aeration of previously collapsed alveoli, and prevention of alveolar collapse throughout the respiratory cycle. • PEEP is titrated to the point that oxygenation improves without compromising hemodynamics. • We call this optimal PEEP. Often 5 cm H2O PEEP (referred to as physiologic PEEP) is used prophylactically to replace the glottic mechanism, help maintain a normal FRC, and prevent alveolar collapse. • PEEP of 5 cm H2O is used for patients with a history of alveolar collapse during weaning. • PEEP improves gas exchange, vital capacity, and inspiratory force when used during weaning. • In contrast, auto-PEEP is not purposely set on the ventilator but is a result of inadequate exhalation time. • Auto-PEEP is more PEEP over what is set by the HCP • . This added PEEP may result in increased WOB, barotrauma, and hemodynamic instability. • Interventions to limit auto-PEEP include sedation and analgesia, large-diameter ET tube, bronchodilators, short inspiratory times, and decreased respiratory rates. • Reducing water accumulation in the ventilator circuit by frequent emptying or use of heated circuits also limits auto-PEEP. • In patients with short exhalation times and early airway closure (e.g., asthma), setting PEEP above auto-PEEP can offset auto-PEEP effects by splinting the airway open during exhalation and preventing "air trapping." • FIO2 often can be reduced when PEEP is used. • PEEP is generally indicated in all patients who are mechanically ventilated. • The classic indication for PEEP therapy is ARDS • PEEP is used with caution in patients with increased ICP, low CO, and hypovolemia • In these cases, the adverse effects of high PEEP may outweigh the benefits.

Positive Pressure Ventilation

• Positive pressure ventilation (PPV) is the main method used with acutely ill patients • During inspiration the ventilator pushes air into the lungs under positive pressure. • Unlike spontaneous ventilation, intrathoracic pressure is raised during lung inflation rather than lowered. • Expiration occurs passively as in normal expiration. • There are 2 categories of PPV: volume and pressure ventilation.

Airway pressure release ventilation (APRV)

• Provides 2 levels of continuous positive airway pressure (CPAP) with timed releases • Permits spontaneous breathing throughout the respiratory cycle • HCP selects both pressure (high, low) and time (high, low). VT is not a set variable and depends on the CPAP level, the patient's compliance and resistance, and spontaneous breathing effort nursing • Monitor for hypercapnia

Pressure support ventilation (PSV)

• Provides an augmented inspiration to a spontaneously breathing patient • HCP selects inspiratory pressure level, PEEP, and sensitivity • When the patient initiates a breath, a high flow of gas is delivered to the preselected pressure level, and pressure is maintained throughout inspiration • Patient determines VT, rate, and inspiratory time nursing • Reduces patients work of breathing and ↑ ventilator synchrony • Monitor patient for hypercapnia

Intermittent mandatory ventilation (IMV) and synchronized intermittent mandatory ventilation (SIMV)

• Requires rate, VT, inspiratory time, sensitivity, and PEEP set for the patient • Between "mandatory breaths," patients spontaneously breathe at their own rates and VT • With SIMV, the ventilator synchronizes the mandatory breaths with the patient's own inspirations nursing • Muscle fatigue may occur due to ↑ work of breathing

Apnea alarm cause

• Respiratory arrest • Oversedation • Change in patient condition • Loss of airway (e.g., total or partial extubation)

Volutrauma

• The concept of volutrauma in PPV relates to the lung injury that occurs when a large VT is used to ventilate noncompliant lungs. • Volutrauma results in alveolar rupture and movement of fluids and proteins into the alveolar spaces. • Low-volume ventilation should be used in patients with ARDS to protect the lungs.

Low-pressure limit alarm causes

• Total or partial ventilator disconnect • Loss of airway (e.g., total or partial extubation) • ET tube or tracheotomy cuff leak (e.g., patient speaking, grunting)

High VT, minute ventilation, or respiratory rate alarm interventions

• Treat pain • Assess patient for change in condition • Obtain an ABG • Remove water or secretions from tubing

Weaning From Positive Pressure Ventilation and Extubation

• Weaning is the process of reducing ventilator support and resuming spontaneous breathing. • The weaning process differs for patients on short-term ventilation (up to 3 days) versus long-term ventilation (longer than 3 days). • Those with short-term ventilation (e.g., after heart surgery) have a linear weaning process. • Patients with prolonged PPV (e.g., patients with COPD who develop respiratory failure) often have a weaning process that consists of alternating gains and losses. • Preparation for weaning begins when PPV is started and involves a team approach (e.g., HCP, RT, RN, patient). • Weaning consists of 3 phases: the preweaning phase, the weaning process, and the outcome phase. • The preweaning, or assessment phase, looks at the patient's ability to breathe spontaneously. • Assessment depends on a combination of respiratory and nonrespiratory factors • Note the resolution of the primary problem that prompted patient admission. • The patient's lungs should be reasonably clear on auscultation and chest x-ray. • Weaning assessment parameters should include criteria to assess muscle strength (negative inspiratory force) and endurance (spontaneous VT, vital capacity, minute ventilation, rapid shallow breathing index). • There should be minimal secretions, the ability to cough and gag, and a cuff leak when the ET tube cuff is deflated. • Nonrespiratory factors include the patient's neurologic status; hemodynamics; fluid, electrolytes, and acid-base balance; nutrition; and hemoglobin. • It is important to have an alert, well-rested, and well-informed patient relatively free from pain and anxiety who can cooperate with the weaning plan. • This does not mean complete withdrawal from sedatives or analgesics. • Instead, drugs should be titrated to achieve comfort without causing excessive drowsiness.

Assist-Control Ventilation

• With assist-control ventilation (ACV), the ventilator delivers a preset VT at a preset frequency. • When the patient initiates a spontaneous breath, the ventilator senses a decrease in intrathoracic pressure and then delivers the preset VT. • The patient can breathe faster than the preset rate but not slower. • ACV has the advantage of allowing the patient some control over ventilation while providing some assistance. • It is used in patients with a variety of conditions, including neuromuscular disorders (e.g., Guillain-Barré syndrome), pulmonary edema, and acute respiratory failure. • With ACV, the patient has the potential for hyperventilation. • The spontaneously breathing patient can easily be overventilated, resulting in hyperventilation. • If the volume or minimum rate is set too low and the patient is apneic or weak, the patient can be hypoventilated. • Thus these patients need vigilant assessment and monitoring of ventilatory status, including respiratory rate, ABGs, SpO2, and ScvO2 or SvO2. • It is important that the sensitivity, or amount of negative pressure needed to start a breath, is appropriate to the patient's condition. • For example, if it is too hard for the patient to begin a breath, the WOB is increased and the patient may tire (i.e., the patient "rides" the ventilator) or develop ventilator dyssynchrony (i.e., the patient "fights" the ventilator)

Pressure Ventilation

• With pressure ventilation, the peak inspiratory pressure is predetermined. • The VT delivered to the patient varies based on the selected pressure and compliance and resistance factors of the patient-ventilator system. • Careful attention must be given to the VT to prevent unplanned hyperventilation or hypoventilation. • For example, when the patient breathes out of synchrony with the ventilator, the pressure limit may be reached quickly, and the volume of gas delivered may be small.

Synchronized Intermittent Mandatory Ventilation

• With synchronized intermittent mandatory ventilation (SIMV), the ventilator delivers a preset VT at a preset frequency in synchrony with the patient's spontaneous breathing. Between ventilator-delivered breaths, the patient can breathe spontaneously through the ventilator circuit. • Thus the patient receives the preset FIO2 during the spontaneous breaths but self-regulates the rate and VT of those breaths. • SIMV is used during continuous ventilation and during weaning from the ventilator. • It may be combined with PSV (described later). Potential benefits of SIMV include improved patient-ventilator synchrony, lower mean airway pressure, and prevention of muscle atrophy as the patient takes on more of the WOB. • SIMV has disadvantages. • If spontaneous breathing decreases when the preset rate is low, ventilation may not be adequately supported. • Only patients with regular, spontaneous breathing should use low-rate SIMV. • Weaning with SIMV demands close monitoring and may take longer because the rate of breathing is gradually reduced. Patients being weaned with SIMV may have increased muscle fatigue associated with spontaneous breathing efforts.

Volume Ventilation

• With volume ventilation, a predetermined VT is delivered with each inspiration. • The amount of pressure needed to deliver the breath varies based on compliance and resistance factors of the patient-ventilator system. • So, the VT is consistent from breath to breath, but airway pressures vary.

Collaborate With Social Worker

• Work with the patient and caregiver to identify care needs. • Help the patient with transitions through the health care system. • Teach the patient the various levels of care and seek to optimize outcomes in a cost-effective manner.

Apnea alarm interventions

• ↓ Sedation • ↓ Analgesia • Reverse sedation or analgesia • Confirm ET tube placement or reintubate