Pediatric emergency medicine trisk 1405 1405
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (76.56 KB, 1 trang )
FIGURE 71.1 A: Approach to the child with respiratory distress. B: Approach to the child with
respiratory distress. Spo2 , percentage oxygen saturation; O2 , oxygen; EtCO2 , end-tidal carbon
dioxide; CNS, central nervous system.
Vital sign abnormalities provide important clues about the severity of illness
and adequacy of compensatory mechanisms. Tachycardia is one of the early signs
of respiratory compromise. Bradycardia in a hypoxic child is a late and ominous
sign that often signals impending cardiac arrest. Cardiac arrhythmias that
compromise cardiac output may result in respiratory distress. Respiratory rate in
children varies with age ( Table 71.7 ). Tachypnea is a compensatory mechanism
for hypoxia, hypercapnia, and acidosis, and it also occurs with pain, anxiety, and
increased activity. Fever increases respiratory rate by up to 10 breaths per degree
above normal, particularly in younger children. Although not specific for
respiratory distress, tachypnea is one of the findings most consistently present
with respiratory distress and is particularly pronounced with lower airway
processes. Tachypnea may be the only manifestation of lower respiratory
infection in children younger than 6 months. Bradypnea may reflect central
respiratory depression, increased intracranial pressure, or fatigue of respiratory
muscles. It is often an ominous sign that heralds impending respiratory arrest.
Pulsus paradoxus, an exaggeration (more than 10 mm Hg) of the normal decrease
in blood pressure during inspiration, correlates with degree of airway obstruction.
Hypotension in a child is a late and extremely worrisome finding. It suggests
profound shock, significantly decreased cardiac output, and impending
cardiorespiratory arrest. Oxygen saturation of ≥97% while awake is normal.
Central cyanosis usually reflects at least 5 g/dL of unsaturated hemoglobin and an
O2 saturation of less than 90%. Peripheral cyanosis alone is not usually associated
with a decrease in systemic O2 saturation.
On inspection, in addition to respiratory rate, one should appreciate depth,
rhythm, and symmetry of respirations; the use of accessory muscles; and
perfusion. Rapid and shallow breathing may result from air trapping in
obstructive lower airway disease. It may also result from chest pain, chest wall
musculoskeletal dysfunction, or abdominal pain and/or distention. Kussmaul
respirations (deep, regular, sighing breaths) are seen with metabolic acidosis,
particularly diabetic ketoacidosis. Cheyne–Stokes respirations (respirations with
increasing then decreasing depth alternating with periods of apnea) are seen with
CNS immaturity in otherwise normal neonates and infants, particularly during
sleep. In older children, this respiratory pattern is concerning for inadequate
cerebral perfusion, brain injury, increased intracranial pressure, and central
narcotic depression. Biot, or ataxic, respirations (breaths of irregular depth
