Mechanical Ventilation
what interventions are components of the ventilator bundle of care?
- daily assess the readiness for weaning or extubation. - Elevate the head of the bed at least 30°. - Provide prophylaxis for deep vein thrombosis. - Provide stress ulcer prophylaxis.
the nurse caring for a mechanically ventilated patient understands which of the following?
-Sedation, analgesic, or neuromuscular blockade may be needed. - The head of the bed should be elevated 30°, if possible. - Turning and repositioning every two hours is part of the care plan.
Documentation for endotracheal suction
1. reason for suctioning 2. date and time of procedure 3. characteristics of secretion (amount, color, consistency, odor) 4. VS before, during, and after the procedure 5. resolution of the reason for suctioning 6. patient's comfort
A patient's ventilator settings are adjusted to treat hypoxemia. The fraction of inspired oxygen is increased from 0.6 to 0.7, and the positive end-expiratory pressure is increased from 10 to 15 cm H2O. Shortly after these adjustments, the nurse notes that the patient's blood pressure drops from 120/76 mm Hg to 90/60 mm Hg. What is the most likely cause of this decrease in blood pressure?
Decrease in cardiac output
The nurse is assisting with endotracheal intubation and understands that correct placement of the endotracheal tube in the trachea would be identified by which of the following?
Equal bilateral breath sounds upon auscultation, Position above the carina verified by chest x-ray, Positive detection of carbon dioxide (CO2) through CO2 detector devices
A patient is having difficulty weaning from mechanical ventilation. The nurse assesses the patient for which potential cause of this difficult weaning?
Hemoglobin of 8 g/dL. Normal: Male- 13.5-17.5, female- 12-15.5
A patient is admitted to the progressive care unit with a diagnosis of community-acquired pneumonia. The patient has a history of chronic obstructive pulmonary disease and diabetes. A set of arterial blood gases obtained on admission without supplemental oxygen shows pH 7.35; PaCO2 55 mm Hg; bicarbonate 30 mEq/L; PaO2 65 mm Hg.
Hypoxemia and compensated respiratory acidosis
Select all of the factors that may predispose the patient to respiratory acidosis.
Central nervous system depression, Overdose of sedatives
The nurse is caring for a mechanically ventilated patient and responds to a high inspiratory pressure alarm. Recognizing possible causes for the alarm, the nurse assesses for which of the following?
Coughing or attempting to talk, Kinks in the ventilator tubing, Need for suctioning
Causes of hypoventilation are
damage to or depression of the neurologic system (e.g., head injury, cerebral thrombosis, or hemorrhage), neuromuscular defects causing hypoventilation (e.g., myasthenia gravis, multiple sclerosis, Guillian- Barré syndrome), obstructive lung conditions (e.g., asthma, emphysema, and cystic fibrosis), restrictive lung conditions (e.g., obesity, flail chest, lung cancer, and pneumothorax)
Causes of hypoventilation
damage to or depression of the neurologic system (e.g., head injury, cerebral thrombosis, or hemorrhage), neuromuscular defects causing hypoventilation (e.g., myasthenia gravis, multiple sclerosis, Guillian- Barré syndrome), obstructive lung conditions (e.g., asthma, emphysema, and cystic fi brosis), and restrictive lung conditions (e.g., obesity, fl ail chest, lung cancer, and pneumothorax).
Management of ARDS is aimed at
determining and treating the underlying cause
Diagnosis of hypoxia
diagnosed by clinical indicators (i.e., restlessness, confusion, tachycardia, tachypnea, dyspnea, use of accessory muscles, and cyanosis)
ARDS results from
direct (i.e. pneumonia, aspiration, lung contusions, inhalation/burn injury, severe acute respiratory syndrome [SARS]) indirect lung injury (i.e., severe sepsis, trauma, pancreatitis transfusion-related lung injury [TRALI] or ventilator-associated lung injury [VALI])
Examples of anatomic shunts include
e arteriovenous (AV) shunts and shunts associated with neoplasms. Physiologic shunt examples include atelectasis, pneumothorax, pneumonias, cardiac pulmonary edema, and near drowning.
Key signs and symptoms of acute respiratory failure include
e increased respiratory rate with decreased tidal volume (i.e., rapid, shallow breaths), increase in WOB with accessory muscle use, complaints of dyspnea, hypoxemia (decreased SpO 2 and PaO 2 ), hypercapnia, anxiety, and restlessness.
Factors that affect hypoxia
hemoglobin, SaO 2 , PaO 2 , cardiac output, and cellular demands
absorptive atelectasis
high concentrations of O 2 wash out the nitrogen that usually holds the alveoli open at the end of expiration
Patients experiencing hypoxemia or hypoxia are often hemodynamically unstable and may have
hypotension, tachycardia, arrhythmias, decreased level of consciousness, and decreased urine output
four main pathophysiologic causes of acute respiratory failure
hypoventilation, ventilation/perfusion (V/Q) mismatching, shunting, and diffusion effect
Endotracheal suctioning pressure
infant <80 mmHG, children <120 mmHg,
refractory hypoxemia
it generally refers to inadequate arterial oxygenation despite optimal levels of inspired oxygen or onset of barotrauma in mechanically ventilated patients.
Diagnosis of hypoxemia
made by analysis of the arterial blood gas.
Once the lungs have sustained an indirect or direct injury
mediators are released that cause increasing vascular and capillary permeability (leaking). Th is leads to alveolar collapse and accumulation of fluids in the pulmonary interstitium
Hypoxemia
occurs when there is a decrease in arterial blood oxygen tension (i.e., a decrease in SaO 2 and PaO 2 ).
Supportive measures include
oxygen therapy, mechanical ventilation with moderate to high levels of PEEP, low tidal volumes, and patient positioning
In V/Q mismatching, perfusion abnormalities can occur in
pulmonary embolism, excessive positive end expiratory pressure (PEEP), and decreased cardiac output
In V/Q mismatch, perfusion abnormalities can occur in
pulmonary embolism, excessive positive end expiratory pressure (PEEP), and decreased cardiac output. When there are V/Q mismatches present, such as when perfusion is greater than ventilation or vice versa, hypoxemia results.
Diagnostic tests used in ARDS include
pulmonary function studies, arterial blood gas analysis, complete blood count (CBC), coagulation profi les, tracheal-protein/plasma-protein ratio, and chest x-ray.
Patients who are hypoxic or hypoxemic may also have increased
serum lactate levels and changes in skin color and temperature.
oxygen toxicity early S& S
substernal chest pain, dry cough, dyspnea, restlessness, and lethargy
The nurse prepares to suction the endotracheal tube of an intubated patient and knows that
suction time should not exceed 10 to 15 seconds
As the condition worsens
surfactant production is decreased, protein production increases, and gas exchange decreases. Initially, hypoxemia develops and then worsens, leading to eventual hypercapnic respiratory failure. Shunt and dead space increase and lead to noncompliant, stiff lungs with derecruited alveoli. Diff use pulmonary infi ltrates and refractory hypoxemic respiratory failure defi ne the exacerbated process of ARDS, which still, despite aggressive treatment and advances in this area, leads to high mortality rates.
Decreased diffusion areas can occur with
surgical procedures such as a lobectomy as well as with destructive lung diseases such as emphysema and tumors.
In respiratory failure, typically, the patient's deterioration is reflected in
the blood gas results, which demonstrate a PaO 2 of less than 60, an FiO 2 of greater than 0.50, and a pH of less than 7.25.
In acute respiratory failure
the patient is unable to maintain the acid- base balance and the normal exchange of carbon dioxide and oxygen
In the case of hypoventilation
the patient retains carbon dioxide and becomes hypoxemic.
manifestation of acute respiratory failure
the patient's deterioration is refl ected in the blood gas results, which demonstrate a PaO 2 of less than 60, an FiO 2 of greater than 0.50, and a pH of less than 7.25
Treatment of acute respiratory failure is aimed at improving oxygenation through measures such as
treating the cause, oxygen delivery, positioning, bronchial hygiene, pharmacological therapy, and, potentially, mechanical ventilation if the patient's condition deteriorates
in caring for a patient who is intubated with an endotracheal tube, the nurse knows that a common complication is
tube placed in the right mainstem bronchus
clinical presentation of ARDS
• Cyanosis • Pallor • Accessory muscle use • Tachypnea • Tachycardia • Diaphoresis • Decreased level of consciousness • Decreased bronchial breath sounds
This ventilator mode delivers a preset number of breaths at a preset tidal volume. The patient may trigger additional breaths, and the ventilator will deliver an assisted breath at the preset tidal volume. What is the term for this ventilator mode?
Assist-control ventilation.
The nurse is caring for a patient whose ventilator settings include 15 cm H2O of positive end-expiratory pressure (PEEP). What complication does the nurse assess the patient for?
Low cardiac output secondary to increased intrathoracic pressure
The nurse is caring for a mechanically ventilated patient and notes the high pressure alarm sounding. The nurse cannot quickly identify the cause of the alarm and notes the patient's oxygen saturation is decreasing and heart rate and respiratory rate are increasing. The nurse's priority action is to
Manually ventilate the patient while calling for a respiratory therapist.
three levels of hypoxemia
Mild hypoxemia = PaO 2 , 80 mmHg (SaO 2 , 95) Moderate hypoxemia = PaO 2 , 60mmHg (SaO 2 , 90) Severe hypoxemia = PaO 2 , 40mm Hg (SaO 2 , 75)
Pulse oximetry measures
Oxygen saturation
Oxygen saturation (SaO2) represents
Oxygen that is chemically combined with hemoglobin.
The primary mode of action of neuromuscular blocking agents is
Paralysis
Documentation of the artificial airway
Patient and family education Type of airway inserted Size and location of airway inserted Respiratory assessment Any difficulties with insertion How the patient tolerated the procedure Vital signs and pain assessment before and after the procedure Verification of proper placement Appearance of secretions (amount, nature, color)
What is an adjunct to mechanical ventilation that helps decrease the work of breathing?
Pressure support.
A patient is being mechanically ventilated in the synchronized intermittent mandatory ventilation mode at a rate of 4 breaths/min. His spontaneous respirations are 12 breaths/min. He receives a dose of morphine sulfate, and his spontaneous respirations decrease to 4 breaths/min. Which acid-base disturbance will likely occur?
Respiratory acidosis
Current guidelines recommend the oral route for endotracheal intubation. The rationale for this recommendation is that nasotracheal intubation is associated with a greater risk for
Sinusitis and infection.
The nurse is caring for a mechanically ventilated patient. The providers are considering performing a tracheostomy because the patient is having difficulty weaning from mechanical ventilation. Related to tracheostomy, the nurse understands which of the following?
The greatest risk after a percutaneous tracheostomy is accidental decannulation.
Positive end-expiratory pressure (PEEP) is a mode of ventilatory assistance that produces the following condition:
There is pressure remaining in the lungs at the end of expiration that is measured in cm H2O.
e development of a shunt
When blood bypasses the alveolar-capillary unit (anatomic shunt) or blood goes through the alveolar-capillary unit but it is nonfunctional (physiologic shunt), oxygenation does not take place
Hypoxia
a decrease in tissue oxygenation
Increased diffusion pathways can occur with
accumulation of fluid, such as with pulmonary edema and pulmonary fibrosis.
diff usion abnormalities can cause
acute respiratory failure
Oxygen toxicity may cause
alveolar collapse, seizures, and retinal detachment in the eyes.
If the low exhaled volume alarm is sounding on a mechanical ventilator, the nurse should
assess to see that the ventilator is attached to the endotracheal tube.
In V/Q mismatching, Ventilation abnormalities can occur in
asthma, pneumonia, and when tumors are present
In V/Q mismatching, Ventilation abnormalities can occur in
asthma, pneumonia, and when tumors are present,
ARDS has an acute onset and demonstrates
bilateral lung opacities with pulmonary edema on the chest x-ray.
the nurse is caring for a patient who has positive end-expiratory pressure, PEEP, as an adjunct to the ventilation. The nurse understands that as PEEP is increased
cardiac output may decrease
Later signs of oxygen toxicity include
chest x-ray changes, refractory hypoxemia, and progressive ventilator diffi culty
Patients may develop oxygen-induced hypoventilation, particularly if they are
chronic obstructive pulmonary disease (COPD) patients
Respiratory failure
condition in which your blood doesn't have enough oxygen or has too much carbon dioxide Respiratory failure is a syndrome in which the respiratory system fails in one or both of its gas exchange functions: oxygenation and carbon dioxide elimination. In practice, it may be classified as either hypoxemic or hypercapnic.
