Pediatric emergency medicine trisk 2570 2570

Clinical Considerations
Clinical Recognition. Neonatal encephalopathy manifests as an acute change in
mental status and/or seizures. In its most profound presentation, the infant will
show depressed level of consciousness (as in stupor or coma) with global
hypotonia, and autonomic disturbances that include apnea, respiratory failure, or
abnormal cardiac rhythms. Moderate encephalopathy may manifest as a variable
change in alertness, with alternating periods of decreased arousal, or
hypervigilance, tremors, jitteriness, and irritability. The timing and pattern of
changes in degree of encephalopathy may help distinguish etiology; in acute
hypoxia–ischemia, there may be a period of “normalization” of the neurologic
examination 12 to 24 hours after the event or trauma. Acute intoxication or IEM
are more likely to present with progressive encephalopathy and typically do not
demonstrate this period of “pseudonormalization.”
Triage Considerations. The lethargic infant with decreased levels of alertness
should be triaged emergently, as these infants can quickly develop autonomic
instability and cardiorespiratory collapse. Additionally, if born outside a medical
setting and presenting within 6 hours of life, time-sensitive therapies are available
that offer neuroprotection.
Clinical Assessment. The clinical assessment requires detailed history regarding
the timing and onset of symptoms—initial symptoms may include decreased
arousal, increased lethargy, decreasing oral intake, and increasing irritability.
History may also reveal potential asphyxial events or trauma. Unexplained
intracranial hemorrhage should also warrant an evaluation for nonaccidental
trauma once the infant is stabilized. Given the risk of either autonomic
deterioration or a global asphyxial event that could result in multisystem
dysfunction, clinical assessment should include detailed cardiopulmonary
evaluation, including monitoring for apnea. Serum toxicology screen should be
sent, as well blood gas, BMP, liver function panel, ammonia level, and plasma
amino acids. Urine should be collected and sent for toxicology, urinalysis for
ketones, and urine for organic acids. Acute bilirubin encephalopathy (kernicterus)
is a rare cause of brain injury, but should be suspected if the infant also presents

with jaundice. Infants should also be evaluated for infection, including bacterial
and/or viral meningoencephalitis. IEM presenting with neonatal encephalopathy
are summarized in Table 96.5 . Other causes of neonatal hypotonia and weakness
are presented in Table 96.6 .