Pediatric emergency medicine trisk 1383 1383
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CHAPTER 71 ■ RESPIRATORY DISTRESS
DEBRA L. WEINER, J. KATE DEANEHAN
INTRODUCTION
Respiratory distress is one of the most common chief complaints of children
seeking medical care. It accounts for nearly 10% of pediatric emergency
department visits and 20% of visits of children younger than 2 years. Twenty
percent of patients admitted to the hospital and 30% of those admitted to
intensive care units are admitted for respiratory distress. Primary respiratory
processes account for approximately 5% of deaths in children younger than 15
years and 20% in infants. In addition, respiratory distress contributes substantially
to deaths in patients with other primary processes. Respiratory arrest is one of the
five leading causes of death in pediatric patients. Respiratory distress is usually
reversible, but failure to treat the condition may result in cardiac arrest with longterm neurologic sequelae or death.
PATHOPHYSIOLOGY
The primary goals of respiration are to meet metabolic demands for O2 and to
eliminate CO2 . Secondary functions include acid–base buffering, host defense,
and hormonal regulation. Exchange of O2 and CO2 between the lungs and the
blood occurs at the alveolocapillary membrane and depends on adequate and
appropriately matched ventilation and perfusion.
Control of respiration is mediated by central and peripheral neural
mechanisms. Respiration is an intrinsic brainstem function of the respiratory
centers of the medulla. It is further influenced by the cerebellum, which alters
respiration with postural change; by the hypothalamus, which controls respiration
on a moment-to-moment basis; by the limbic system, which modulates respiration
in response to emotion; and by the motor cerebral cortex, which controls
volitional respiratory activity, including hyper- and hypoventilation and speech.
Impulses are transmitted from the brain via the vagus and spinal nerves to the
larynx, trachea, bronchi, bronchioles, and acini; the glossopharyngeal to the
pharynx; the hypoglossal (CN XII) to the tongue; and the spinal accessory (CN
XI) to accessory muscles. Cervical nerves (C2 to C4), the phrenic nerve (C3 to
C5), and the intercostal nerves (T1 to T12), innervate accessory muscles, the
respiratory diaphragm, and intercostal muscles, respectively.
