Paramedic Airway FISDAP Review Part 1

Ventilatory Support

**A patient who is not breathing needs artificial ventilation and 100% supplemental oxygen.** 1. Patients who are breathing inadequately are typically unable to speak in complete sentences. a. Breathing too fast or too slowly with reduced tidal volume 2. Fast, shallow breathing --> Does not allow for adequate exchange of oxygen and carbon dioxide in the alveoli **Indications for assisted ventilation: a. Altered mental status b. Inadequate minute volume -Signs of potential respiratory failure: a. Excessive accessory muscle use b. Fatigue from labored breathing --> Patients with these signs need immediate treatment. -Two treatment options: a. Assisted ventilation with a bag-mask device b.Continuous positive airway pressure (CPAP

Recognizing adequate breathing

1. An adult who is responsive, alert, and able to speak. 2. Normal breathing in an adult at rest is characterized by: i. Rate between 12 and 20 breaths/min ii. Adequate depth (tidal volume) iii. Regular pattern of inhalation and exhalation iv. Clear and equal breath sounds bilaterally 3. Changes in rate and regularity should be subtle.

Suctioning techniques

**Adequate preoxygenation is required before suctioning.** -Stimulating the back of throat can elicit a vagal response. -After suctioning, continue ventilation and oxygenation. -*Soft-tip catheters:* a. Must be lubricated when suctioning the nasopharynx b. Best used when passed through an ET tube c.Suction during extraction of the catheter. -Before inserting any suction catheter, measure for the proper size --> From the corner of the mouth to the earlobe **Never insert a catheter past the base of the tongue.** -Technique: a. Turn on the assembled suction unit. b. Measure the catheter from the corner of the mouth to the earlobe. c. Before applying suction, turn the patient's head to the side (unless you suspect cervical spine injury), open the patient's mouth by using the cross-finger technique or tongue-jaw lift, and insert the tip of the catheter to the predetermined depth. Do not suction while inserting the catheter. d. Apply suction in a circular motion as you withdraw the catheter. e. Repeat as needed.

4. Factors affecting oxygenation and respiration

*1. External factors:* a. External factors in ambient air. Examples: Atmospheric pressure, partial pressure of oxygen --> At high altitudes, the percentage of oxygen remains the same, but partial pressure decreases because total atmospheric pressure decreases. -- > Closed environments may also have decreases in ambient oxygen. Examples: Mines and trenches b. Toxic gases displace oxygen in the environment. --> CO inhibits the proper transport of oxygen to tissues *2. Internal factors:* a. Conditions that reduce the surface area for gas exchange also decrease the body's oxygen supply. b. Medical conditions may also decrease surface area of the alveoli by damaging them or by leading to an accumulation of fluid in the lungs. c. Nonfunctional alveoli inhibit the diffusion of oxygen and carbon dioxide --> Called intrapulmonary shunting d. Submersion victims and patients with pulmonary edema have fluid in the alveoli--> i. Inhibits adequate gas exchange at the alveolar membrane ii. Results in decreased oxygenation and respiration iii. Exposure to certain environmental conditions or occupational hazards. Examples: High altitudes, epoxy resins iv. Can result in anaerobic respiration and an increase in lactic acid accumulation. e. Other conditions that affect cells include: i. Hypoglycemia --> Oxygen and glucose levels decrease ii. Infection --> Increases metabolic needs, disrupts homeostasis iii. Hormonal imbalances: If insulin levels decrease, cellular uptake of glucose will decrease --> Results in ketoacidosis. *3. Circulatory compromise* a. Leads to inadequate perfusion; oxygen demands will not be met. b. Obstruction of blood is typically related to trauma emergencies, including: i. Simple or tension pneumothorax ii. Open pneumothorax iii. Hemothorax iv. Hemopneumothorax v. Pulmonary embolism c. Inhibits gas exchange at the tissue level. d. Conditions such as heart failure and cardiac tamponade inhibit the heart's ability to effectively pump oxygenated blood to the tissues. e. Blood loss and anemia reduce the oxygen-carrying ability of the blood. f. Shock - oxygen is not delivered to cells efficiently. i. Hemorrhagic shock ii. Vasodilatory shock iii.Both forms of shock result in poor tissue perfusion that leads to anaerobic metabolism.

Breath sounds

*1. Tracheal breath sounds (bronchial breath sounds)*: Heard by placing the stethoscope diaphragm over the trachea or sternum. - Assess for duration, pitch, and intensity. *2. Vesicular breath sounds:* Softer, muffled sounds - Heard in the expiratory phase: Barely audible *3. Bronchovesicular sounds:* Combination of the two - Heard in places where airways and alveoli are found - Should be assessed for duration, pitch, and intensity

Proper Airway Management

*Follow steps IN ORDER:* a. Open the airway b. Clear the airway c. Assess breathing d. Provide appropriate intervention(s)

5. Acid-base balance

*Hypoventilation, hyperventilation, and hypoxia can disrupt the acid-base balance* --> May lead to rapid deterioration and death. -Respiratory and renal systems help maintain homeostasis (Tendency toward stability in the body's internal environment): Requires a balance between acids and bases. --> Fastest way to eliminate excess acid is through the respiratory system. (a) Can be expelled as carbon dioxide from the lungs (b) Slowing respirations will increase the level of carbon dioxide. -Anything that inhibits respiratory function can lead to acid retention and acidosis. -Alkalosis can develop if the respiratory rate is too high (or the volume too much). a. Four main clinical presentations of acid-base disorders: 1. Respiratory acidosis: Fluctuations in pH due to respiratory disorders result in respiratory acidosis or alkalosis. 2. Respiratory alkalosis 3. Metabolic acidosis: Fluctuations in pH due to available bicarbonate result in metabolic acidosis or alkalosis. 4. Metabolic alkalosis

Appropriate airway management

*Steps must be performed in order. Bypass steps that do not apply.* a. Open and maintain a patent airway. b. Recognize and treat airway obstructions. c. Assess ventilation and oxygenation status. d. Administer supplemental oxygen. e.Provide ventilatory assistance.

Two types of hemoglobin normally found:

*a. Oxyhemoglobin (HbO2)*: Hemoglobin that is occupied by oxygen *b. Reduced hemoglobin*: Hemoglobin after oxygen has been released to cells

Uses of waveform capnography in the nonintubated patient:

1. Assess the severity of asthma, COPD, or any pathologic process that causes pulmonary air trapping 2. Gauge the effectiveness of treatment

2. Ventilation-perfusion ratio and mismatch

-Air and blood flow must be directed to the same place at the same time (ventilation and perfusion must be matched). -Failure to match ventilation and perfusion (V/Q mismatch) lies behind most abnormalities in oxygen and carbon dioxide exchange. -In most people, normal resting minute ventilation is approximately 6 L/min. a. Resting alveolar volume: Approximately 4 L/min b. Pulmonary artery blood flow: Approximately 5 L/min c. Overall ratio of ventilation to perfusion: 4:5 L/min, or 0.8 L/min -Because neither ventilation nor perfusion is distributed equally, both are distributed to dependent regions of the lungs at rest. However, an increase in gravity-dependent flow is more marked with perfusion than with ventilation. --> Ratio of ventilation to perfusion is highest at the apex of the lung and lowest at the base. -When ventilation is compromised but perfusion continues: a. Blood passes over alveolar membranes without gas exchange. b. CO2 is recirculated into the bloodstream. i. Results in V/Q mismatch ii. Could lead to severe hypoxemia if not recognized and treated -When perfusion across the alveolar membrane is disrupted: a. Less O2 is absorbed into the bloodstream; less CO2 is removed (V/Q mismatch). b. Can lead to hypoxemia --> Immediate intervention is needed to prevent further damage or death.

Flowmeters

-Allow oxygen delivered to the patient to be adjusted from 1 to 25 L/min. -Two most common types: 1. Pressure-compensated flowmeter a. Float ball rises or falls based on gas flow in the tube. b. Gas flow is controlled by a needle valve. c. Affected by gravity; must remain upright for accurate flow reading 2. Bourdon-gauge flowmeter a. Can be placed in any position b. Pressure gauge is calibrated to record the flow rate. c. Major disadvantage: Does not compensate for backpressure --> Usually records a higher flow rate when there is any obstruction to gas flow downstream.

Preparing an oxygen cylinder for use

-Before administering supplemental oxygen, prepare the oxygen cylinder and therapy regulator. -Procedure a. Inspect the cylinder and its markings. b. Remove the plastic seal covering the valve stem opening (if commercially filled). c. Inspect the opening to ensure that it is free of dirt and other debris. With the tank facing away from yourself and others, use an oxygen wrench to "crack" the cylinder. d. Attach the regulator/flowmeter to the valve stem, ensuring that the pin-index system is correctly aligned. A metal or plastic O-ring is placed around the oxygen port to optimize the airtight seal between the collar of the regulator and the valve stem. e. Place the regulator collar over the cylinder valve, with the oxygen port and indexing pins on the side of the valve stem that has three holes. f. Align the regulator so that the oxygen port and the pins fit into the correct holes on the valve stem; align the screw bolt on the opposite side with the dimpled depression. Tighten the screw bolt until the regulator is firmly attached to the cylinder. You should not see any space between the sides of the valve stem and the interior walls of the collar. g. With the regulator firmly attached, open the cylinder and read the pressure level on the regulator gauge. h. A second gauge or a selector dial on the flowmeter indicates the oxygen flow rate. Attach the oxygen connective tubing to the "Christmas tree" nipple on the flowmeter and select the oxygen flow rate that is appropriate for your patient's condition.

Peak Expiratory Flow Measurement

-Bronchoconstriction can be evaluated by measuring the peak rate of a forceful exhalation with a peak expiratory flowmeter: a. Increasing peak expiratory flow: Suggests patient is responding to treatment. b. Decreasing peak expiratory flow: Suggests patient's condition is deteriorating. -Varies based on gender, height, and age --> Healthy adults have a peak expiratory flow rate of 350 to 750 mL. -To assess peak expiratory flow: 1. Place the patient in a seated position with legs dangling. 2. Assemble the flowmeter. 3. Ensure that it reads zero. 4. Ask the patient to take a deep breath, place the mouthpiece in his or her mouth, and exhale as forcefully as possible (make sure there are no air leaks). 5. Perform the test three times. 6. Take the best peak flow rate of the three readings.

Carbon Dioxide (CO2)

-Carbon dioxide concentration in exhaled gases: 35-45 mm Hg -Typically, etco2 is approximately 2 to 5 mm Hg lower than arterial Paco2. -ETCO2 monitoring is limited with cardiac arrest: a. In a patient with a short arrest interval, exhaled carbon dioxide may be detected despite a lack of perfusion. b. Patients with prolonged cardiac arrest will have minimal to no exhaled carbon dioxide because of severe acidosis and minimal or no carbon dioxide return to the lungs.

1. Larynx

-Complex structure formed by many independent cartilaginous structures -Marks where the upper airway ends and lower airway begins

Venturi mask

-Draws room air into the mask along with oxygen -Can deliver 24%, 28%, 35%, or 40% oxygen depending on the adapter -Especially useful in the hospital management of patients with chronic respiratory diseases. --> Little advantage in prehospital care, except for long-range transport of patients with such conditions

Airway Evaluation

-Evaluation includes visual observations, palpation, and auscultation. -Visual techniques: 1. Patient position (ex. tripod position) 2. Experiencing orthopnea 3. Adequate rise and fall of the chest 4. Patient gasping for air 5. Skin: i. Color ii. Moist or clammy f. Nostrils flaring 6. Breathing through pursed lips 7. Retractions: i. Intercostal ii. At the suprasternal notch iii. At the supraclavicular fossa iv. Subcostal 8. Accessory muscle use 9. Asymmetric chest wall movement 10. Patient taking a series of quick breaths, followed by prolonged exhalation

Laryngeal Injury Obstruction

-Fracture of the larynx increases airway resistance by decreasing airway size due to: i. Decreased muscle tone ii. Laryngeal edema iii. Ventilatory effort -Penetrating and crush injuries to the larynx can compromise the airway secondary to swelling and bleeding. -Advanced airway management may be required.

Manual airway Maneuvers

-If an unresponsive patient has a pulse but is not breathing open the airway manually. -The most common cause of airway obstruction in an unresponsive patient is the tongue. -Maneuvers: 1. head tilt, chin-lift maneuver 2. jaw thrust maneuver 3. Tongue-jaw Lift maneuver

6. Trachea

-Immediately descends into the thoracic cavity -Not a straight tube, which is key to understand when placing an ET tube

Aspiration

-Increases mortality i. Potentially obstructs the airway ii. Destroys delicate bronchiolar tissue iii. Introduces pathogens into the lungs iv. Decreases the patient's ability to ventilate (or be ventilated) -Suction should be readily available for any patient who is unable to maintain his or her own airway. **Always assume patient has a full stomach.**

Normal Capnographic Waveform

-Key features: i. Contour ii. Baseline level iii. Rate and rise of the carbon dioxide level -Four distinct phases: *i. Phase I (A-B):* Known as the respiratory baseline, initial stage of exhalation. *ii. Phase II (B-C):* Expiratory upslope. *iii. Phase III (C-D):* Expiratory or alveolar plateau. *iv. Phase IV (D-E):* Inspiratory downstroke. -The duration (width) of each waveform corresponds to the duration of ventilation, and the space between waveforms corresponds with the patient's respiratory rate.

3. Cricoid cartilage (cricoid ring)

-Lies inferiorly to the thyroid cartilage -Forms the lowest portion of the larynx -More prominent in females

4. Cricothyroid membrane

-Located between the thyroid and cricoid cartilage -Site for emergency surgical and nonsurgical access to the airway -Bordered laterally and inferiorly by the highly vascular thyroid gland

Labored breathing

-May involve the use of accessory muscles i. Sternocleidomastoid ii. Chest pectoralis major iii. Abdominal

Pathophysiology of Respiration

-Multiple conditions can inhibit the body's ability to effectively provide oxygen to cells. 1. Disruption of pulmonary ventilation, oxygenation, and respiration will cause immediate effects on the body. a. Must be recognized and corrected immediately b. Important to distinguish a primary ventilation problem from a primary oxygenation or respiration problem 2. Every cell needs a constant supply of oxygen to survive. a. Some tissues are more resilient than others. b.Sufficient levels of external respiration and perfusion are required. 3. Hypoxia, ventilation-perfusion ratio and mismatch, factors affecting ventilation, factors affecting oxygenation and respiration, and acid-base balance.

5. Glottis

-Narrowest portion of the adult airway -Vocal cords are located at the lateral borders of the glottis. -Epiglottis is located at the superior border of the glottis. -ET intubation requires visualizing the epiglottis, glottis, and vocal cords before inserting the ET tube.

Oxygen humidifier

-Oxygen stored in cylinders has zero humidity --> Dry gases will rapidly dry the mucous membranes. -Small bottle of sterile water moisturizes oxygen before it reaches the patient --> Must be kept upright; practical only for the fixed oxygen unit in the ambulance -Can be a source of infection --> Use a disposable bottle.

Ventilation

-Physical act of moving air into and out of the lungs 1. *Inhalation* is the active, muscular part of breathing. 2. *Exhalation* is a passive process and does not normally require muscular effort.

Nonrebreathing mask

-Preferred device in the prehospital setting -90% and 100% Fio2 a. Good mask-to-face seal b. Flow rate of 15 L/min -Combination mask and reservoir bag system a. Oxygen fills a reservoir bag that is attached to the mask by a one-way valve. b. Permits the patient to inhale from the reservoir bag but not to exhale back into it -Before administering, ensure that the reservoir bag is completely filled. a. Oxygen flow rate is adjusted from 12 to 15 L/min to prevent collapse of the bag during inhalation. -Use a pediatric nonrebreathing mask for infants and small children. -Considerations: 1. Indications: Spontaneously breathing patients who require high-flow oxygen concentrations and are breathing adequately 2. Contraindications: Apnea and poor respiratory effort

Head tilt-chin lift maneuver

-Preferred technique with a patient who has not sustained trauma -Occasionally, the patient will resume breathing with this technique alone. -Considerations: *1. Indications* a. Unresponsive patient b. No mechanism for cervical spine injury c. Patient is unable to protect his or her own airway. *2. Contraindications* a. Responsive patient b. Possible cervical spine injury *3. Advantages* a. No equipment required b. Noninvasive *4. Disadvantages* a. Hazardous to patients with spinal injury b. No protection from aspiration -Technique i. With the patient in a supine position, position yourself beside the patient's head. ii. Place one hand on the patient's forehead, and apply firm backward pressure with your palm to tilt the patient's head back. iii. Place the tips of your fingers of your other hand under the lower jaw near the bony part of the chin. Do not compress the soft tissue under the chin because this action may block the airway. iv. Lift the chin upward, bringing the entire lower jaw with it, helping to tilt the head back. Do not use your thumb to lift the chin. Lift so that the teeth are nearly brought together, but avoid closing the mouth completely. Continue to hold.

Respiration

-Process of exchanging O2 and CO2--> 1. *External respiration (Also called pulmonary respiration)*: Process of exchanging O2 and CO2 between the alveoli and blood in pulmonary capillaries. 2. *Internal respiration (Also called cellular respiration)*: Exchange of O2 and CO2 between the systemic circulation and the body's cells.

Oxygenation

-Process of loading oxygen molecules onto hemoglobin molecules in the bloodstream -Requires adequate *FiO2 (Percentage of oxygen in inhaled air)*

Hand-operated suctioning units with disposable canisters

-Reliable, effective, relatively inexpensive -Can easily fit into your first-in bag

Abnormal Capnographic Waveforms

-Shape of the capnographic waveform can provide information about: 1. Hypoventilation 2. Hyperventilation 3. Bronchospasm 4. Rebreathing 5. Inadvertent extubation

2. Thyroid cartilage

-Shield-shaped structure formed by two plates that join in a "V" shape anteriorly to form the laryngeal prominence i. Known as the Adam's apple ii. More pronounced in men iii. Can be difficult to locate in obese or short-necked patients -Suspended from the hyoid bone by the thyroid ligament -Directly anterior to the glottic opening

Mechanical or vacuum-powered suction units

-Should be capable of generating a vacuum of 300 mm Hg within 4 seconds of clamping off the tubing -Amount of suction should be adjustable. -Check the vacuum on the mechanical suction unit at the beginning of every shift --> Ensure that all battery-charged units have fully charged batteries.

Pitch of Sound

Described as higher or lower than normal (stridor or wheezing) -Intensity of sound depends on: a. Airflow rate b. Constancy of flow throughout inspiration c. Patient position/Site selected for auscultation -Less intense sounds are said to be diminished.

Nasopharyngeal Airway

-Soft, rubber tube inserted through the nose into the posterior pharynx -Allows passage of air from the nose to the lower airway -Range in size from 12 French to 32 French; length depends on size -Much better tolerated in patients with an intact gag reflex but an altered LOC -**Do not use with trauma to the nose or if you suspect a skull fracture.** -Must be inserted gently to avoid precipitating epistaxis: a. Lubricate the airway generously with a water-soluble gel, preferably one that contains a local anesthetic. b. Slide it gently, tip downward, into one nostril. c. If you meet resistance, try the other nostril. d. If the nasal airway is too long, then it may obstruct the patient's airway. e. If the patient becomes intolerant of the nasal airway, then gently remove it from the nasal passage. f. Have suction readily available. -Considerations *1. Indications* i. Unresponsive patients ii. Altered mental status who have an intact gag reflex *2. Contraindications* i. Patient intolerance ii. Facial or skull fracture *3. Advantages* i. Can be suctioned through ii. Provides a patent airway iii. Can be tolerated by responsive patients iv. Can be safely placed "blindly" v. No requirement for the mouth to be open *4. Disadvantages* i. Improper technique may result in severe bleeding. (a) Resulting epistaxis may be extremely difficult to control. ii. Does not protect from aspiration -Technique: a. To determine the correct size, measure the distance from the tip of the nostril to the earlobe or the angle of the jaw. b. Insert the prelubricated airway into the larger nostril, with the bevel facing the septum, until the flange rests on the patient's nostril.

Nasal cannula

-Two small prongs that fit into the nostrils -Oxygen flow rate: 1 to 6 L/min -Oxygen concentration: 24% to 44% -Higher flow rates will irritate the nasal mucosa. --> An oxygen humidifier should be used when giving oxygen via nasal cannula for a prolonged period. -Provides low to moderate oxygen enrichment --> Most beneficial for patients who require long-term oxygen therapy -Ineffective with: a. Apnea b. Poor respiratory effort c. Severe hypoxia d. Mouth breathing -In the prehospital setting, primarily used when patients: a. Cannot tolerate a nonrebreathing mask b. Require low concentrations of oxygen to maintain oxygen saturation greater than 94% -Generally well tolerated -Does not provide high volumes or concentrations of oxygen

Jaw-thrust maneuver

-Use if you suspect a cervical spine injury. -Considerations: *1. Indications* a. Unresponsive patient b. Possible cervical spine injury c. Patient is unable to protect his or her own airway. *2. Contraindications* a. Responsive patient with resistance to opening the mouth b. May be needed in a responsive patient who has sustained a jaw fracture *3. Advantages* a. May be used in patients with cervical spine injury b. May use with cervical collar in place c. No special equipment required *4. Disadvantages* a. Cannot maintain if patient becomes responsive or combative b. Difficult to maintain for an extended time c. Very difficult to use in conjunction with bag-mask ventilation d. Thumb must remain in place to maintain jaw displacement. e. Requires second rescuer for bag-mask ventilation f. No protection against aspiration -Technique i. Position yourself at the top of the supine patient's head. ii. Place the meaty portion of the base of your thumbs on the zygomatic arches, and hook the tips of your index fingers under the angle of the mandible, in the indentation below each ear. iii. While holding the patient's head in a neutral in-line position, displace the jaw upward and open the patient's mouth with the tips of your thumbs. Because opening and maintaining a patent airway is so critical, you should carefully perform the head tilt-chin lift maneuver if the jaw-thrust maneuver fails to adequately open the airway.

Tongue-Jaw Lift Maneuver

-Used more commonly to open a patient's airway for the purpose of suctioning or inserting an oropharyngeal airway. -Cannot be used to ventilate a patient because it will not allow for an adequate mask seal on the patient's face. -Technique i. Position yourself at the side of the patient. ii. Place the hand closest to the patient's head on the forehead. iii. With the other hand, reach into the patient's mouth and hook your first knuckle under the incisors or gum line. While holding the patient's head and maintaining the hand on the forehead, lift the jaw straight up.

2. Hyperventilation

-Waveforms are small and the etco2 value is correspondingly low (less than 35 mm Hg). -Tachypnea produces a short alveolar plateau (phase III [C-D]) and shorter-than-normal intervals between waveforms.

1. Hypoventilation

-Waveforms are tall and the etco2 value is correspondingly high (greater than 45 mm Hg). -Bradypnea produces a prolonged alveolar plateau (phase III [C-D]) and longer-than-normal intervals between waveforms.

Suctioning

-When the mouth or throat becomes filled with vomitus, blood, or secretions, a suction apparatus enables you to remove material quickly and efficiently. -Ventilating a patient with secretions in his or her mouth will force material into the lungs. **Clearing the airway with suction is your next priority after opening the airway with manual maneuvers.** Suctioning equipment: 1. Hand-operated suctioning units with disposable canisters 2. Mechanical or vacuum-powered suction units

Suction catheter

1. *Yankauer catheter (tonsil-tip catheter)* a. Option for suctioning the pharynx in adults b. Preferred device for infants and children c. Plastic-tip catheters with a large diameter d. Rigid so they do not collapse i. Capable of suctioning large volumes of fluid rapidly e. Tips with a curved contour 2. *Soft plastic, nonrigid catheters* a. French or whistle-tip catheters b. Can be placed in the oropharynx or nasopharynx or down an ET tube c. Come in various sizes d. Have a smaller diameter than rigid catheters e. Used: i. To suction the nose ii. To suction liquid secretions in the back of the mouth iii. In situations in which a rigid catheter cannot be used. Suction tubing without the attached catheter facilitates suctioning of large debris in the oropharynx and allows access to the back of the pharynx.

The respiratory and cardiovascular systems work together to ensure that:

1. A constant supply of oxygen and nutrients is delivered to every cell. 2. Waste products are removed from every cell.

Inadequate Breathing

1. An adult who is breathing at a rate of less than 12 breaths/min or more than 20 breaths/min must be evaluated for other signs of inadequate ventilation, such as: a. Shallow breathing b. Irregular pattern of breathing c. Altered mentation d. Adventitious airway sounds 2. Cyanosis is a clear indicator of low blood oxygen. 3. Preferential positioning --> a. Upright sniffing (tripod) position; b. Semi-Fowler position.

Circumstances that might produce erroneous oximetry readings:

1. Bright ambient light --> May enter the spectrophotometer and create an incorrect reading --> Cover the sensor clip with a towel or aluminum foil to protect it. 2. Patient motion 3. Poor perfusion --> If the vessels in a patient's limbs are constricted and the limbs are cold, you may need to place the clip on the earlobe or nose. 4. Nail polish 5. Venous pulsations occurring with right-sided heart failure 6. Abnormal hemoglobin 7. Normal Spo2 values may be observed in the presence of methemoglobin and carboxyhemoglobin even though the body is not receiving sufficient oxygen. a. Methemoglobin (metHb): Formed by oxidation of the iron on hemoglobin b. Carboxyhemoglobin (COHb): Hemoglobin loaded with CO

Oropharyngeal (oral) airway

1. Curved, hard plastic device that fits over the back of the tongue a. Facilitates ventilation with a bag-mask device b. An effective bite-block 2. Should be inserted in unresponsive patients who have no gag reflex a. Will stimulate gagging and retching in a responsive patient b. To assess gag reflex, use the eyelash reflex. c. If the patient gags during insertion, remove the device immediately and be prepared to suction. -Considerations *1. Indications:* Unresponsive patients who have no gag reflex *2. Contraindications* i. Responsive patients ii. Patients with a gag reflex *3. Advantages* i. Noninvasive ii. Easily placed iii. Prevents blockage of the glottis by the tongue *4. Disadvantages:* No prevention of aspiration *5. Complications* i. Unexpected gag may cause vomiting. ii. Improper technique may cause pharyngeal or dental trauma. -If the oral airway is improperly sized or is inserted incorrectly, it could push the tongue back into the pharynx, creating an airway obstruction. -->Rough insertion can injure the hard palate. -->Before insertion, suction the oropharynx as needed. -Technique a. Determine the correct size for the patient by measuring the distance from the corner of the patient's mouth to the earlobe or the angle of the jaw. b. You can insert the oral airway in one of two ways, as follows: i. Open the patient's mouth with the cross-finger technique or tongue-jaw lift, hold the airway upside down with your other hand, and insert the airway in the mouth with the tip facing the hard palate. Advance the oral airway until it reaches the soft palate and then rotate it 180°, allowing it to follow the curvature of the tongue, until the flange rests on the patient's lips. ii. Use a tongue blade to depress the tongue, ensuring that the tongue remains forward. Insert the oral airway, with the tip pointing down, and follow the curvature of the tongue until the flange rests on the patient's lips.

Assessing airway patency

1. Determine if patient's airway is patent --> An unresponsive patient has a compromised airway until that is ruled out by a careful assessment. 2. Signs of airway compromise in an unresponsive patient include: a. Snoring b. Vomitus draining from the mouth c. Gurgling sound heard during breathing 3. Secretions pooling in the patient's mouth indicate a markedly depressed or absent gag reflex --> Absence significantly increases risk of aspiration.

Emergency medical care for foreign body airway obstruction

1. If patient is responsive, ask, "Are you choking?" a. If the patient nods "yes" and cannot speak, begin treatment immediately. 2. If, after opening the airway, you are unable to ventilate the patient or you feel resistance when ventilating, reopen the airway and again attempt to ventilate the patient. 3. If large pieces of foreign body are found in the airway, sweep them forward and out of the mouth with your gloved index finger. a. Attempt to remove only foreign bodies that you can see and easily retrieve. 4. Insert your index finger along the inside of the cheek and into the throat at the base of the tongue. a. Try to hook the foreign body to dislodge it and maneuver it into the mouth. b. Do not force the foreign body deeper into the airway. c. Do not blindly insert any object other than your finger to remove a foreign body. 5. Suction as needed. 6. Abdominal thrust (Heimlich maneuver) is the most effective way to dislodge and force an object out of the airway of a responsive patient. a. Aims to create an artificial cough, thereby expelling the object. b. Perform until the object is expelled or until the patient becomes unresponsive. c. If patient is in the advanced stages of pregnancy or is morbidly obese, perform chest thrusts instead. 7. If patient becomes unresponsive, position him or her supine on the ground and begin chest compressions. a. 30 chest compressions b. 15 if two rescuers are present and the patient is an infant or a child 8. Open the airway and look in the mouth. 9. Attempt to remove any visible object. 10. Attempt a rescue breath. a. If the first breath does not produce visible chest rise, reopen the airway and reattempt to ventilate. b. If both breaths fail to produce visible chest rise, continue chest compressions. c. If these techniques do not work, proceed with direct laryngoscopy. i. Insert the laryngoscope blade into the patient's mouth. ii. If you see the foreign body, remove it with Magill forceps (see Skill Drill 15-1).

Recognition of an airway obstruction

1. Mild obstruction a. Patient is responsive. b. Able to exchange air c. Have noisy respirations and may be coughing d. Should be left alone i. Forceful cough is the most effective means of dislodging the obstruction. ii. Attempts to manually remove the object could force it farther down into the airway. e. Closely monitor the patient's condition. f. Be prepared to intervene if you see signs of severe airway obstruction. 2. Severe obstruction a. Sudden inability to breathe, talk, or cough. b. May grasp at his or her throat c. May begin to turn cyanotic d. May make frantic, exaggerated attempts to move air e. Weak, ineffective, or absent cough f. Marked respiratory distress g.Weak inspiratory stridor and cyanosis often present

Arterial blood gas analysis

1. Most comprehensive quantitative information about the respiratory system 2. Blood is obtained from a superficial artery. 3. Blood is analyzed for pH, Paco2, PaO2, Hco3−, base excess (indicating acidosis or alkalosis), and Sao2. a. pH and Hco3− are used to evaluate a patient's acid-base status. b. Paco2 indicates the effectiveness of ventilation. c. PaO2 and Sao2 are indicators of oxygenation.

Oximetry Reading

A normally oxygenated, normally perfused person should have an Spo2 of greater than 95% while breathing room air. a. Less than 95% in a nonsmoker suggests hypoxemia. b. Less than 90% signals a need for aggressive oxygen therapy.

3. Factors affecting ventilation

A patent airway is critical for the provision of O2 to tissues. Intrinsic and extrinsic factors can cause airway obstruction. *1. Intrinsic factors*: infection, allergic reactions, and unresponsiveness. a. The tongue is the most common obstruction in an unresponsive patient. b. Some factors are not necessarily directly part of the respiratory system. Ex... i. Interruptions in the central and peripheral systems. ii. Medications that depress the central nervous system. iii. Trauma to the head and spinal cord. iv. Neuromuscular disorders. v. Neuromuscular blocking agents. c. Allergic reactions i. Swelling (angioedema) can obstruct the airway. ii. Bronchoconstriction can decrease pulmonary ventilation. *2. Extrinsic factors*: trauma and foreign body airway obstruction. a. Trauma to the airway or chest --> Requires immediate evaluation and intervention b. Blunt or penetrating trauma and burns can disrupt airflow through the trachea and into the lungs --> Quickly results in oxygenation deficiencies c. Trauma to the chest wall can lead to inadequate pulmonary ventilation. Example: A patient with numerous rib fractures or a flail chest may purposely breathe shallowly in an attempt to alleviate pain from the injury (Respiratory splinting) --> Can result in decreased pulmonary ventilation **Proper ventilatory support is crucial. *3. Hypoventilation & Hyperventilation*- *a. Hypoventilation*: occurs when CO2 production exceeds CO2 elimination. *b. Hyperventilation* occurs when carbon dioxide elimination exceeds carbon dioxide production. --> Hypoventilation and hyperventilation could represent the body's attempt to compensate for various abnormal conditions. For example, if the pH of the blood alkalotic, the patient's breathing may become slow or shallow in an attempt to retain CO2 to decrease the pH<-- *4. Hypercarbia & Hypocarbia*: a. Decrease in minute volume decreases CO2 elimination --> Results in buildup of CO2 in the blood (*hypercarbia*) b. Increase in minute volume increases CO2 elimination --> Lowers CO2 in the blood (*hypocarbia*)

Sighing

A slow, deep inhalation followed by a prolonged exhalation -Periodically hyperinflates the lungs, thereby reexpanding atelectatic alveoli -Average person sighs about once per minute.

Hiccupping

A sudden inhalation, due to spasmodic contraction of the diaphragm, cut short by closure of the glottis -Serves no physiologic purpose -Persistent hiccups may be clinically significant.

Supplemental Oxygen-Delivery Devices

A. Nonrebreathing mask B. Nasal cannula C. Partial rebreathing mask D. Venturi mask E. Tracheostomy masks F. Oxygen humidifier

Adventitious Breath Sounds

Adventitious breath sounds: Usually classified as continuous or discontinuous. *a. Wheezing* *b. Rhonchi* *c. Crackles (formerly known as rales)* *d. Stridor* *e. Pleural friction rub*

Airway Management

Air reaches the lungs only through the trachea, so a patent airway is essential. -In a compromised airway, clearing the airway and maintaining patency are vital. 1. Position the patient 2. Use manual airway maneuvers

Airway Adjuncts

An artificial airway adjunct may be needed to help maintain airway patency in an unresponsive patient after manually opening the airway and suctioning. **Not a substitute for proper head positioning**--> Even after an airway adjunct has been inserted, the appropriate manual position of the head must be maintained. 1. Oropharyngeal (oral) airway 2. Nasopharyngeal airway

Assessment of Breath Sounds

Auscultate breath sounds with a stethoscope. -Should be clear and equal on both sides of the chest, anteriorly, and posteriorly -Compare each apex of the lung with the opposite apex and each base of the lung with the opposite base. -Remember: 1. Breath sounds are created as air moves through the tracheobronchial tree. a. Size of the airway determines the type of sound. b. Breath sounds: Heard over the majority of the chest, represent airflow into alveoli 2. Duration: Length of time for the inspiratory and expiratory phase of the breath 4. Pitch is described as higher or lower than normal (stridor or wheezing). 5. Always auscultate directly on skin. 6. Sounds that are present in an unexpected area can indicate an abnormal condition. 7. Adventitious breath sounds: Usually classified as continuous or discontinuous.

Recognizing inadequate breathing

Breathing does not necessarily mean adequate breathing. ** General rule: If you can see or hear a patient breathe, there is a problem.**

Airway Obstructions

Causes of airway obstruction: 1. Sudden foreign body airway obstruction usually occurs: a. During a meal in an adult b. While eating or playing with small toys in children 2. Tongue a. With altered LOC, the tongue tends to fall back against the posterior wall of the pharynx, closing off the airway. b. Partial tongue obstruction: Snoring respirations. c. Complete obstruction: No respirations d. Simple to correct using a manual maneuver 3. Laryngeal edema 4. Laryngeal spasm 5. Trauma 6. Aspiration 7. Infection or a severe allergic reaction: When obstruction is due to infection or a severe allergic reaction, repeated attempts to clear the airway will be unsuccessful and potentially harmful. -->Requires specific management and prompt transport to an appropriate medical facility

Upper airway

Consists of all anatomic airway structures above the glottic opening. *1. Tongue* a. Must be manipulated b. Tends to fall back into the posterior pharynx in unresponsive patient *2. Pharynx* a. Muscular tube that extends from the nose and mouth to the esophagus and trachea b. Composed of: i. Nasopharynx ii. Oropharynx iii. Laryngopharynx (hypopharynx)

b Rhonchi

Continuous, low-pitched sounds --> Indicate mucus or fluid in larger lower airways

Reflexes of the Airway

Coughing, sneezing, and gagging

Tracheostomy masks

Cover stoma and have a strap that goes around the neck a. Usually available in intensive care units b. May not be available in the emergency setting c. Improvise by placing a face mask over the stoma and adjusting the strap.

Capnometer

Displays a numeric reading of exhaled carbon dioxide. --> More reliable than the colorimetric co2 detector

End-tidal carbon dioxide (ETCO2) assessment

ETCO2 monitors detect carbon dioxide in exhaled air --> Adjuncts for determining ventilation adequacy -Types of monitors include colorimetric, digital, and digital/waveform.

Lower airway

Extends from the glottis to the pulmonary capillary membrane. 1. *Larynx* 2. *Thyroid cartilage* 3. *Cricoid cartilage (cricoid ring)* 4. *Cricothyroid membrane* 5. *Glottis* 6. *Trachea*

a. Wheezing

High-pitched sound that may be heard on inspiration, expiration, or both.

Oxygen Regulators

High-pressure regulators are attached to the cylinder stem to deliver gas under high pressure --> Used to transfer gas from tank to tank -Pressure in a full cylinder is approximately 2,000 psi. -Gas flow from cylinder to patient is controlled by a therapy regulator--> Reduces the high pressure of gas to a safe range (about 50 psi)

d. Stridor

Loud, high-pitched sound typically heard during inspiration. -Results from foreign body aspiration, infection, swelling, disease, or trauma within or immediately above the glottic opening

Colorimetric

Provides qualitative (does not assign a numeric value) information regarding the presence of carbon dioxide in exhaled breath -After 6 to 8 positive pressure breaths, paper inside the detector should turn from purple to yellow during exhalation --> Indicates the presence of exhaled carbon dioxide -Should be used during initial confirmation of ET tube placement and replaced as soon as possible with a quantitative device -Sensitive to temperature extremes and humidity i. May be less reliable if vomitus or other secretions get into it ii. Paper inside degrades over time.

Oximetry Uses

May be useful in the following prehospital situations: a. Monitoring the oxygenation status of a patient during an intubation attempt or during suctioning b. Identifying deterioration in the condition of a trauma victim c. Identifying deterioration in the condition of a patient with cardiac disease d. Identifying high-risk patients with respiratory problems e. Assessing vascular status in orthopedic trauma i. Use with a fractured extremity to evaluate the pulse distal to the fracture. ii. Loss of a pulse means that the limb may require urgent action in the field. iii. A pulse oximeter clipped to a finger or toe on a broken limb might provide information about circulation to the limb.

CO-oximeter, or CO monitor

Measures absorption at several wavelengths to distinguish Hbo2 from COHb. -Determines HbO2 saturation (percentage of oxygenated Hb compared with the total amount of hemoglobin) including COHb, metHb, HbO2, and reduced Hb.

Pulse oximetry

Measures the percentage of hemoglobin (Hb) in arterial blood that is saturated with oxygen. a. A sensor probe transmits light through the vascular bed to a light-sensing detector --> Amount of light depends on the proportion of hemoglobin that is saturated with oxygen. b. To ensure that the instrument is measuring arterial and not venous oxygen saturation, pulse oximeters assess only pulsating blood vessels. c. Also measure pulse --> Check device functioning by comparing its pulse reading with the patient's palpated pulse

c. Crackles (formerly known as rales)

Occur when airflow causes mucus or fluid in the airways to move in the smaller lower airways --> Tend to clear with coughing - May also be heard when collapsed airways or alveoli pop open - Discontinuous sounds - May occur early or late in the inspiratory cycle 1. Early inspiratory crackles --> Usually occur when larger, proximal bronchi open. Common in patients with COPD. Tend NOT to clear with coughing. 2. Late inspiratory crackles --> Occur when peripheral alveoli and airways pop open. More common in dependent lung regions.

Capnography

Provides a graphic representation of exhaled carbon dioxide. -Capnography can indicate chest compression effectiveness and detect return of spontaneous circulation. -Two types: 1. Waveform capnography: Provides real-time information and displays a graphic waveform --> Many portable cardiac monitor/defibrillators provide a numeric reading and a waveform (digital/waveform capnography). 2. Quantitative waveform capnography: Detection of bronchospasm, hypoventilation, and hyperventilation --> Recommended method of monitoring initial and ongoing placement of an advanced airway device. -Uses of waveform capnography in the nonintubated patient: i. Assess the severity of asthma, COPD, or any pathologic process that causes pulmonary air trapping ii. Gauge the effectiveness of treatment -If inadvertent extubation occurs, then you would expect to see a complete loss of a capnographic waveform and etco2 reading. -On occasion, the sampling tubing from the in-line adaptor to the cardiac monitor/defibrillator gets obstructed with blood or other debris, blocking the flow of gas to the sensor and "zeroing out" the waveform and etco2 reading. --> Replace the in-line adaptor to restore the waveform and etco2 reading.

Pulsus Paradoxus

Systolic blood pressure drops more than 10 mm Hg during inhalation --> May detect a change in pulse quality or even the disappearance of a pulse during inhalation -Generally seen in patients with conditions that cause an increase in intrathoracic pressure; such as: i. Decompensating COPD ii. Severe pericardial tamponade iii. Tension pneumothorax iv. Severe asthma attack

Oxygen cylinders

Pure oxygen is stored in seamless steel or aluminum cylinders. --> Cylinder color may vary: silver, chrome, green, or a combination. --> Make sure that the cylinder is labeled "medical oxygen." --> Look for letters and numbers stamped on the cylinder's collar (Especially month and year (indicate last test date)) -Various cylinder sizes: You will most often use D (350 L of oxygen, typically carried from ambulance to patient) and M (3,000 L of oxygen, stays in the ambulance, main supply tank). --> Oxygen delivery is measured in liters per minute (L/min). --> Replace an oxygen cylinder with a full one when the pressure falls to 200 psi or lower. i. Safe residual pressure. ii. In some EMS systems, the safe residual pressure is 500 psi. iii. Using the pressure in the cylinder and the flow rate, you can calculate how long the supply of oxygen will last.

e. Pleural Friction Rub

Results from inflammation that causes the pleura to thicken --> Surfaces of the visceral and parietal pleura rub together. - Often creates stabbing pain with breathing or any movement of the thorax

Partial rebreathing mask

Similar to the nonrebreathing mask but lacks a one-way valve between the mask and the reservoir --> Residual exhaled air is mixed in the mask and rebreathed. -Contraindications: a. Apnea b. Inadequate tidal volume -Higher oxygen concentrations are attainable. -Flow rates of 6 to 10 L/min -Oxygen concentration of 35% to 60% -Increasing the oxygen flow rate beyond 10 L/min will not enhance the oxygen concentration. -Leakage from the mask decreases the amount of oxygen inhaled by the patient.

Supplemental Oxygen Therapy

Supplemental oxygen should be administered to any patient with potential hypoxia. 1. Indications: a. Respiratory distress b. Suspected or documented hypoxemia c. As determined by EMS system protocols 2. Oxygen-delivery method a. Must be appropriate for the patient's ventilatory status b. Reassess frequently. c. Adjust based on clinical condition and breathing adequacy.

Patient Assessment: Airway Evaluation

The importance of carefully assessing a patient's airway and ventilatory status cannot be overemphasized. -The quality of your assessment determines the quality of care.

1. Hypoxia

Tissues and cells do not receive enough oxygen --> Death may occur quickly if not corrected. - Varying signs and symptoms a. Onset and degree of tissue damage often depend on the quality of ventilations. b. Early signs include restlessness, irritability, apprehension, tachycardia, and anxiety. c. Late signs include mental status changes, a weak pulse, and cyanosis. d. Responsive patients often report dyspnea and may not be able to speak in complete sentences. -Best to administer oxygen before signs and symptoms appear

Positioning the patient

Unresponsive patients found in a prone position must be positioned in a supine position. a. Log roll the person as a unit. b. Once the patient is supine, quickly assess for breathing by visualizing the chest for visible movement. c. If the patient is breathing adequately and is not injured, move to recovery position (Left lateral recumbent position): --> Use in all nontrauma patients with decreased LOC who can maintain their airway spontaneously and are breathing adequately.

Ambulances should carry

a. Fixed suction unit b. Portable suction unit

Safety Reminders: O2 Cylinders

a. Keep combustible materials away from the cylinder, regulators, fittings, valves, and tubing. b. No smoking near cylinders. c. Store in a cool, well-ventilated area with temperature below 125°F (approximately 50°C). d. Use only with a safe, properly fitting regulator valve. e. Close all valves when the cylinder is not in use, even if the tank is empty. f. Secure cylinders so they will not topple over. g. When working with an oxygen cylinder, always position yourself to its side. --> Never place any part of your body over the cylinder valve. h. Have the cylinder hydrostat tested every 10 years to make sure it can sustain the high pressures required.

Laryngeal spasm and edema

a. Laryngeal spasm results in spasmodic closure of the vocal cords, completely occluding the airway. b. Often caused by trauma during an intubation attempt or immediately on extubation c. Laryngeal edema causes the glottic opening to become extremely narrow or totally closed --> Common causes include: (a) Epiglottitis (b) Anaphylaxis (c) Inhalation injury e. May be relieved by aggressive ventilation or a forceful upward pull of the jaw f. Muscle relaxant medications may be effective g. Laryngospasm may recur. h.Transport patient to the hospital for evaluation.

Duration of Breath

a. Normally, expiration is at least twice as long as inspiration: Relationship is expressed by I/E ratio (inspiratory/expiratory ratio) --> I/E ratio is 1:2. b. When the lower airway is obstructed, expiratory phase may be four to five times as long as inspiration --> I/E ratio is 1:4 or 1:5. c. In patients who are tachypneic, the expiratory phase is short and approaches that of inspiration --> I/E ratio may be 1:1.

Ask questions to determine the evolution of the current problem:

a. Onset sudden or gradual? b. Known cause or "trigger"? c. Duration: Constant or recurrent? d. Does anything alleviate or exacerbate the problem? e. Other symptoms, such as a productive cough (color of sputum), chest pain or pressure, or fever? f. Any interventions attempted before EMS arrival? g. Has the patient been evaluated by a physician or admitted to the hospital for this condition in the past? i. Was the patient hospitalized or seen in the emergency department and released? ii. If hospitalized, admitted to intensive care (clinically significant) or a regular, unmonitored floor? h. Is the patient currently taking any medications? If so, determine overall compliance by asking: i. Have you been able to take all of your pills as directed? ii. Is there anything that has stopped you from taking your pills as directed? iii. Is there something that bothers you about taking a certain pill? iv. Look at the prescription date and directions to verify information. v. Were there any changes in the current prescription, such as a new medication or changes in the prescribing directions of an existing medication? i. Any risk factors that could cause or exacerbate the condition

Signs of inadequate ventilation

a. Respiratory rate of fewer than 12 breaths/min or more than 20 breaths/min in the presence of dyspnea b. Irregular rhythm c. Diminished, absent, or noisy breath sounds d. Abdominal breathing e. Reduced flow of exhaled air at the nose and mouth f. Unequal or inadequate chest expansion g. Increased effort of breathing h. Shallow depth of breathing i. Pale, cyanotic, cool, moist, or mottled skin j. Retractions k. Staccato speech patterns (one- or two-word dyspnea)

Potential Causes of Inadequate Breathing

a. Severe infection (sepsis) b. Trauma c. Brainstem insult d. Noxious or oxygen-poor environment e. Renal failure f. Upper and/or lower airway obstruction g. Respiratory muscle impairment h. Central nervous system impairment

Foreign Body Obstruction

a. Typical victim i. Middle-aged or older ii. Wears dentures iii. Has consumed alcohol --> Depresses protective reflexes --> Adversely affects judgment about size of pieces of food b. Increased risk with conditions that decrease airway reflexes (such as stroke) c. Obstruction may be mild or severe depending on the object's size and location d. Signs may include: i. Choking ii. Gagging iii. Stridor iv. Dyspnea v. Aphonia (inability to speak) vi. Dysphonia (difficulty speaking) e. Treatment depends on whether the patient is effectively moving air.

Readily accessible at the patient's head:

a. Wide-bore, thick-walled, nonkinking tubing b. Soft and rigid suction catheters c. Nonbreakable, disposable collection bottle d. Supply of water for rinsing the catheters

Maximum suctioning time

i. 15 seconds in an adult ii. 10 seconds in children iii. 5 seconds in infants