Infants and children are more susceptible to airway obstruction because they have smaller airway structures and a proportionally larger tongue. The smaller size of airway structure makes it easier for foreign bodies to cause obstruction. With upper respiratory tract infections such as croup or epiglottis develop airway compromise more quickly than adults. Since children and infants use energy at a higher rate, they have less reserve and less able to compensate when they have difficulty breathing. The cricoid cartilage and trachea are softer structures than in adults making them more susceptible than adults to obstruction. Also, because of the smaller size of the chest wall, infants and children depend more heavily on the diaphragm for breathing.
Primary Factors:
- Rate: 12-24 bpm (adult); 15-30 bpm (children); 25-50 bpm (infants)
- Rhythm: should be regular; irregular suggests possibleCNS involvement
- Depth: depends on the tidal volume (amount of air inhaled in each breath); 500 ml (adult); some of air inhaled never reaches alveoli (dead space) which is about 150 ml
The tidal volume multiplied by the respiratory rate for 1 minute is the minute ventilation. Hypoventilation is a decrease in minute ventilation and can lead to shock.
Breath Sounds:
- Wheezing: high-pitched noise caused by air traveling through constricted bronchi. Common in asthma patients.
- Crackles: lower-pitched noises caused by a collection of fluid in the smaller airways. Course (harsh gurgling sound heard with larger amounts of fluid) crackles are a more serious sign of respiratory distress.
- Rales: heard when areas of collapsed alveoli expand with inhalation, or when fluid collects in the smaller airways. They can be simulated by rubbing hair between the thumb and fingers next to your ears.
Sign and Symptoms of Inadequate Breathing:
- Dyspnea: shortness of breath
- Nasal flaring: widening of the nostrils with inspiration
- Retractions: indentations of the skin above the clavicles, between the ribs, and below the rib cage. May produce "seesaw" breathing where the abdomen and chest move in opposite directions with each breath.
- Diaphoretic skin: sweaty, cool, pale skin
- Cyanosis: blue color, especially of lips and fingers
- Agonal respirations: occasional gasping breaths occurring just before death, usually with little or no air movement
- Apnea: complete lack of respiratory effort
Management
The most common cause of airway obstruction in the unconscious patient is the tongue.
Opening the Airway:
- head-tilt head-lift in patients without a suspected spinal injury.
- jaw thrust in patients with suspected cervical spine injury.
Suctioning:
Suctioning is used to clear an airway obstructed by oral secretions, blood, other liquids, or food particles. A patient requires suctioning when other attempts to clear the airway fail, when a gurgling sound is heard during breathing, or when fluid is seen in the airway of an unresponsive patient. Always use body substance isolation techniques while suctioning because contact with respiratory secretions is likely.
The catheter should be inserted to the base of the tongue. Suction is applied while withdrawing the catheter in a side-to-side motion for a maximum of 15 seconds.
Artificial Ventilation:
Airway adjuncts are devices used for assisting upper airway control in patients who cannot control their own airways. The main function of adjuncts is to prevent obstruction of the upper airway by the tongue.
- oropharyngeal airway: should only be used in patients who are unresponsive and do not have an intact gag reflex. It is inserted in the mouth upside down, then rotated 180 degrees so that the flange rests on the patient's teeth. Size is selected by measuring from the corner of the mouth to the angle of the jaw.
- nasopharyngeal airway: used in patients who are responsive but unable to control their own airway and cannot tolerate an oropharyngeal airway. Measure from the nose to the tip of the ear. Lubricate the airway, insert it into the nostril and advance posteriorly with the bevel side toward the base of the nose or nasal septum.
Artificial Ventilation Techniques:
- Mouth to mask: most effective for single EMT. Ventilation is performed by blowing through a one-way valve. Use an even breath with moderate pressure.
- Two person bag-valve-mask: consists of a face mask, one-way valve, self-inflating bag, and oxygen reservoir. It should be used with high-flow oxygen.
- Flow-restricted oxygen-powered ventilator device: provides 100% oxygen at a maximum flow rate of 40 liters/minute. Only use with adults.
- One person bag-valve-mask: the single EMT should form a "c" around the ventilation port with the thumb and index finger, then use the middle, ring, and little finger to lift the jaw and form a seal with the mask. Since maintaining an airtight seal is difficult, it is not recommended unless other methods are not available or possible.
Sellick Maneuver:
This maneuver is used to decrease the likelihood or regurgitation and aspiration. It is performed by applying pressure on the cricoid cartilage with the thumb and index finger just lateral to the midline. This pressure is maintained until the patient has spontaneous respirations, is intubated, or becomes responsive by moving, coughing, or gagging.
Special Situations:
A tracheostomy is a surgical opening in the neck that opens the trachea to the atmosphere. They are placed in patients who require long periods of artificial respiration or who have cancer in the neck. A tracheostomy tube is inserted in the opening. If no tracheostomy tube is available, the opening in the neck is referred to as a stoma.
Assisted Breathing:
Some patients may be breathing but have insufficient minute ventilation to maintain adequate gas exchange. The EMT should give artificial breaths with 100% oxygen at the same time the patient inhales. Patients with a depressed level of consciousness and a respiratory rate less than 12 and greater than 24 bpm may require assisted artificial ventilation to improve oxygenation.
Supplemental Oxygen:
Any cylinder that contains oxygen is green in color. Each tank is connected to a pressure regulator and flowmeter for oxygen administration. The pressure of a full cylinder is about 2000 psi. Most ambulances contain liquid oxygen tanks because they can hold more oxygen than pressurized tanks.
The nasal cannula delivers a low concentration of oxygen and should only be used in patients who are not in acute respiratory distress. The maximum flow rate for nasal cannulas is 5-6 lpm. They deliver about 35% inspired oxygen concentration.
The nonbreather mask is the best method of providing supplemental oxygen to the spontaneously breathing patient. With high slow rates (15 lpm), the mask can deliver up to 90% oxygen.
Patients who are cyanotic, cool, clammy, or extremely short of breath need oxygen in the pre-hospital situation even if they have a history of COPD, are infants or children.
Review Questions:
1. What is the most common cause of an obstructed airway in an unresponsive patient?
2. Infants and children are more susceptible than adults to airway compromise for all of the following reasons except:
a. smaller airway size
b. proportionally larger tongue
c. airway cartilage is more firm than in adults
d. upper respiratory infections are more common
3. The pulmonary arteries carry oxygenated blood from the lungs to the left atrium of the heart. (True or False)
4. Which of the following is not used to assess adequacy of breathing?
a. respiratory rate
b. depth of respiration
c. skin color
d. blood pressure
5. Which of the following is an appropriate use of artificial ventilation?
a. using a flow-restricted oxygen-powered ventilator with an infant
b. assisting ventilations in an unresponsive patient with a respiratory rate of
34 breaths per minute
c. bag-valve-mask ventilation with a single EMT
d. ventilating a semiresponsive patient with a gag reflex using an
oropharyngeal airway and bag-valve-mask
6. A patient with COPD who is in acute respiratory distress with cyanosis should be given a high concentration of supplemental oxygen. (True or False)
7. Why is care for the airway the first priority of emergency care.
8. List and describe the techniques of artificial ventilation in the recommended order of preference.
9. How does airway adjunct and suctioninghelp in airway management and artificial ventilation.
10. What are some patient conditions that would benefit from supplemental oxygen and how would you determine whether to use a nonrebreather mask or a nasal cannula?
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