Clinical scenario: shoulder dystocia | elevated troponin-I | cerebral edema
A term male infant is born following a prolonged shoulder dystocia. He requires endotracheal intubation and positive-pressure ventilation for 8 minutes before spontaneous respiration is established. At 18 hours of age, he develops generalized seizures and is admitted to the NICU.
Investigations reveal:
- Serum creatinine: 1.8 mg/dL
- Urine output: 0.4 mL/kg/hour
- ALT: 210 U/L
- Platelet count: 85 × 10⁹/L
- Troponin-I: Elevated
Cranial ultrasound shows diffuse cerebral edema.
Which of the following organ systems is most commonly affected after the central nervous system in infants with moderate-to-severe perinatal asphyxia?
A. Cardiovascular system
B. Gastrointestinal system
C. Hematological system
D. Renal system
E. Respiratory system
Correct answer & Explanation:
Correct Answer
D. Renal system
Explanation
Perinatal asphyxia causes multisystem hypoxic-ischemic injury. Although neurological injury determines long-term outcome, the kidneys are the most commonly affected extracerebral organ because of their high metabolic demand and redistribution of blood flow during hypoxia.
Renal manifestations include:
- Acute kidney injury
- Oliguria (<1 mL/kg/hour)
- Rising serum creatinine
- Electrolyte disturbances
Approximately 50–70% of infants with moderate-to-severe HIE develop renal dysfunction.
Why the other options are incorrect
A. Cardiovascular system
- Myocardial ischemia and ventricular dysfunction are common, but less frequent than renal injury.
B. Gastrointestinal system
- Feeding intolerance and necrotizing enterocolitis may occur but are less common.
C. Hematological system
- Thrombocytopenia and coagulopathy can occur secondary to hypoxia but are not the most frequently affected extracerebral system.
E. Respiratory system
- Respiratory failure is often secondary to neurological depression rather than primary hypoxic injury.
High-Yield Pearl
The typical order of organ involvement after significant perinatal asphyxia is:
- Central nervous system
- Renal system
- Cardiovascular system
- Pulmonary system
- Gastrointestinal system
- Hematological system
Renal dysfunction is therefore an important reason to monitor urine output, serum creatinine, fluid balance, and electrolytes closely in all infants with moderate-to-severe HIE.
