Which of the following is a common cause of subdural hematoma in infants?

Choice A rationale

The constellation of fever (101.5°F or 38.6°C), irritability, and tachycardia (160 bpm, normal for a 2-year-old is ∼80-130 bpm) in a child with a ventricular shunt is highly suggestive of a shunt infection (ventriculitis or meningitis). A shunt infection can lead to septicemia and shunt malfunction, potentially causing rapidly increased intracranial pressure (ICP). Given the high morbidity, this finding requires immediate notification of the provider for prompt diagnostic workup (e.g., shunt tap) and empiric antibiotics.

Choice B rationale

While tachycardia and irritability can sometimes be non-specific symptoms, a fever of 101.5°F is abnormal. The presence of a ventricular shunt significantly raises the index of suspicion for shunt infection, a neurosurgical emergency, which is a life-threatening condition. Documenting and observing without immediate intervention is dangerously negligent given the clinical picture.

Choice C rationale

Administering antipyretics addresses only the fever, a symptom, and does not treat the underlying potentially fatal shunt infection. Delaying notification to reassess in one hour risks rapid neurological deterioration, as shunt infections can progress quickly to sepsis, severe ventriculitis, or uncompensated increased intracranial pressure (ICP). Immediate medical evaluation is the priority.

Choice D rationale

Encouraging oral fluids is a supportive measure for fever and dehydration, but it is not the priority for a child highly suspected of having a ventricular shunt infection. Oral fluid intake can be impaired due to irritability and potential nausea/vomiting associated with increased intracranial pressure, and this action delays definitive diagnosis and treatment of the infection.

Choice A rationale

Severe retractions, involving the use of accessory muscles in the intercostal, subcostal, or supraclavicular regions, indicate an extremely high work of breathing and significant airway obstruction or severe lung compliance issues. This extreme muscular effort often signals imminent respiratory muscle fatigue, leading to eventual failure and arrest.

Choice B rationale

Bradypnea, an abnormally slow respiratory rate for the child's age, is an ominous sign in pediatric respiratory distress. It often follows a period of tachypnea and hyperventilation, indicating profound respiratory muscle fatigue and exhaustion. This decrease in effort leads to rapid hypercapnia and uncompensated respiratory acidosis, preceding arrest.

Choice C rationale

Central cyanosis, a bluish discoloration of the mucous membranes and trunk, is a late and critical sign indicating severe hypoxemia, with a significant absolute amount of deoxyhemoglobin in the arterial blood (typically >5 g/dL). This signals inadequate oxygen delivery to the vital organs, often directly preceding cardiac and respiratory failure.

Choice D rationale

Gasping or agonal breathing represents a primitive brainstem reflex that occurs when the respiratory drive center is severely compromised due to profound cerebral hypoxia or ischemia. These are infrequent, deep, reflexive breaths, often ineffective for gas exchange, and are a terminal event immediately preceding complete respiratory cessation.

Choice E rationale

While tachycardia (elevated heart rate, normal range varies by age, e.g., >100-110 bpm in a school-aged child) is a common early compensatory mechanism in respiratory distress to improve cardiac output and oxygen delivery, it is not a sign of impending arrest. Bradycardia, caused by severe hypoxemia and acidosis depressing myocardial function, is the more critical pre-arrest sign.