Authors: Kabbara J et al.
Journal: Cureus, Volume 18, Issue 1, Article e102502, 10.7759/cureus.102502
Summary
This case report describes a three-day-old neonate who developed intraoperative findings concerning for malignant hyperthermia (MH) during an emergent exploratory laparotomy for perforated jejunum in the setting of gram-negative sepsis. The key intraoperative change was a rapid, unexplained rise in end-tidal CO2 with tachycardia, severe mixed acidosis, and a rising temperature despite stopping active warming and maintaining stable ventilator settings. Because these changes occurred during exposure to a volatile anesthetic, the team treated presumptively for MH.
Management included immediate discontinuation of the volatile anesthetic, high-flow 100% oxygen with circuit flush/change, active cooling, and repeated intravenous dantrolene dosing. The report details profound hypercapnia and acidemia on serial blood gases during the acute event, followed by gradual improvement after treatment. During the crisis, unilateral ventilation from likely endobronchial migration was also identified and corrected, underscoring how competing problems can coexist and complicate MH recognition in neonates.
Postoperatively, the infant stabilized, CO2 levels normalized, creatine kinase remained relatively low, and urine myoglobin was negative. She later underwent an additional anesthetic using total intravenous anesthesia without incident. Confirmatory testing was limited: a formal caffeine-halothane contracture test was not performed, pathology from a muscle biopsy showed no specific myopathy, and the family declined genetic testing. The authors emphasize that MH can occur in neonates with potentially atypical or muted features, and that early recognition and treatment should proceed based on clinical suspicion rather than waiting for confirmatory labs.
What You Should Know
In neonates, suspected MH may present more as unexplained hypercarbia and severe acidosis (with modest temperature elevation) than the classic adult pattern, and prompt dantrolene treatment is appropriate when the clinical trajectory fits and trigger exposure is present.
Key Points
• Neonatal MH is rare, and concurrent sepsis or ventilation issues can cloud the picture.
• The most actionable early clue in this case was a rapid, unexplained EtCO2 rise with worsening acidosis during volatile exposure.
• Treatment steps used: stop trigger, 100% O2 with fresh circuit/flush, active cooling, and repeated dantrolene (total 10 mg/kg reported).
• Low or modest CK and absent myoglobinuria do not exclude MH, especially with early dantrolene and small neonatal muscle mass.
• Survivors should ideally be referred for definitive susceptibility testing and counseling, recognizing real-world barriers.
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