Cardiac arrest in a 14-year-old at an overnight camp

CMAJ | December 5, 2022 | Volume 194 | Issue 47 © 2022 CMA Impact Inc. or its licensors A previously healthy 14-year-old girl on no medications, with recent history of resolved coryza and cough, suddenly became unresponsive while sitting in her cabin at camp. A fellow camper did not feel a radial pulse and immediately initiated chest compressions while others called for help. Emergency medical services (EMS) were contacted and the camp’s health response team was activated by radio. The camp physician and 2 nurses arrived at the scene 4 minutes after cardiopulmonary resuscitation (CPR) was started. At that time, the patient had a palp able carotid pulse, absent brachial pulses and agonal respirations. The health professionals began artificial respiration (mouth-to-mouth) and restarted chest compressions 3 minutes later, after a rapid increase and then cessation in carotid pulse. An EMS team, consisting of primary care paramedics and firefighters, arrived 1 minute after chest compressions were restarted. The EMS team applied an automated external defibrillator (AED) 8 minutes after the onset of unresponsiveness. The AED detected ventricular fibrillation (Figure 1) and administered a standard 120 J shock, leading to ventricular tachycardia (Figure 2), followed by 15 seconds of narrow QRS waveform and then degeneration into ventricular fibrillation (Figure 3). Return of spontaneous circulation (ROSC) with narrow QRS waveform was ultimately achieved after an additional 2 minutes of chest compressions and delivery of a second defibrillation using 120 J (Figure 4). The total duration from unresponsiveness to ROSC was 10 minutes. Advanced care paramedics arrived 2 minutes after ROSC and secured the patient’s airway via endotracheal intubation, inserted a large-bore intravenous catheter, administered a bolus of saline and transported the patient to the local hospital. A glucometer reading taken in the advanced paramedic ambulance was 19.1 mmol/L. While updating the receiving hospital, crisis workers were dispatched to the camp to debrief and support the responders, campers and staff. On arrival to the hospital emergency department, the patient’s temperature was 36.8°C, pulse 120 beats/min, blood pressure 105/80 mm Hg, respiratory rate 28 breaths/min, oxygen saturation 100% and end-tidal CO2 30 mm Hg. Her blood glucose was 11.7 mmol/L and subsequently normalized. Initial investigations showed a normal venous blood gas, complete blood count, and electrolytes; serum ketones were not detected. A urine toxicology screen was negative. A 12-lead electrocardiogram showed normal sinus rhythm with isolated right axis deviation but no evidence of hypertrophy or ST changes (Figure 5). A chest radiograph showed no cardiomegaly or consolidation, and good endotracheal tube position. A lidocaine infusion was started after a further brief episode of spontaneously resolving ventricular tachycardia was noted on the cardiac monitor. The patient was sedated and airlifted to a tertiary children’s hospital and admitted to the intensive care unit, where a diagnosis of myocarditis was confirmed by echocardiography and cardiac magnetic resonance imaging. The patient’s ejection fraction was 33%. In addition to supportive care, intravenous methylprednisolone (2 mg/kg/d) was administered. The patient was weaned off of sedation and extubated 48 hours after arrival. When asked about previous cardiac symptoms, she indicated that she had had intermittent palpitations on the morning of her arrest but no previous chest pain, shortness of breath or syncope. The patient was discharged from hospital after 9 days on a weaning course of steroids. She had a normal neurologic examination with residual short-term memory loss. On follow-up 3 months after the arrest, her short-term memory loss had resolved and her ejection fraction was normal on repeat echocardiography. Practice | Cases CPD