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Respiratory failure is the most common cause of cardiac arrest in pediatric patients.
It is important to recognize respiratory distress early so that actions can be taken to avoid respiratory failure whenever possible.
If respiratory failure does occur, prompt intervention will give the patient the best chance for survival with the least neurologic sequelae.
Young children have less physiologic reserve and can deteriorate very rapidly.
In a critical situation, the emergency physician has the task of not only making quick resuscitation management decisions but must also consider age-related anatomic differences, appropriate equipment (Table 18-1), and drug-dosage differences when caring for infants and children.
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Anatomy and Physiology
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Children have anatomic and physiologic differences that should be considered when evaluating a pediatric patient presenting in respiratory distress. Young infants may be obligate nose breathers, and any degree of obstruction of the nasal passages can produce respiratory difficulty.
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The chest wall of children is more flexible and the muscles are less developed compared with adults. The diaphragm is more prone to fatigue. The limitation of diaphragmatic movement by gastric distention, increased residual capacity from air trapping from asthma, bronchiolitis, or foreign body obstruction can result in reduction of tidal volume, which may produce respiratory failure. The relatively smaller lower airways are especially vulnerable to mucous plugging and ventilation–perfusion mismatch associated with common diseases of the lower airways, such as asthma and bronchiolitis.
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The actual area available for gas exchange in infants and young children is relatively limited. Alveolar space doubles by 18 months of age and triples by 3 years of age. The limited ability to recruit additional alveoli makes the infant dependent on increasing the respiratory rate to augment minute ventilation and eliminate carbon dioxide. Tachypnea, therefore, is a universal finding in infants ...