Submersion injury and hypothermia — branching viva

Opening (candidate)

This is a profound hypothermic submersion cardiac arrest, and my priorities are to continue high-quality cardiopulmonary resuscitation, manage the ventricular fibrillation by the hypothermic rules, and escalate to extracorporeal rewarming. The core is 25 degrees, which is Swiss stage four, so I continue compressions, deliver a single shock for the ventricular fibrillation, and withhold further shocks and adrenaline until the core rises above thirty degrees. I remove the wet clothes, dry and insulate him, handle him gently, and arrange extracorporeal rewarming as early as the system allows, because nobody is dead until warm and dead. [5] [9]

Branch A — The defibrillation and drug rules

Examiner: Walk me through your defibrillation and adrenaline strategy in this arrest. [5]

Candidate: The core is below thirty degrees, so the cold myocardium is refractory. I deliver a single shock at the standard paediatric energy of four joules per kilogram for the ventricular fibrillation, and if it fails I do not repeat the shock immediately. Instead I continue chest compressions and active rewarming, and I withhold adrenaline and antiarrhythmics until the core rises above thirty degrees, because drug clearance is slowed and the drugs are ineffective at this temperature. Once above thirty degrees I resume standard shocks and adrenaline, but I lengthen the interval between adrenaline doses. The whole time I am rewarming actively and preparing extracorporeal support. [5] [6]

Branch B — The rewarming ladder

Examiner: How do you rewarm him, and when is extracorporeal rewarming indicated? [6]

Candidate: I match the rewarming to the Swiss stage. For stage one I would use passive rewarming; for stage two I add forced warm air at thirty-eight to forty-two degrees; for stage three I add active internal rewarming with warmed humidified oxygen at forty-two to forty-six degrees and warmed intravenous crystalloid at approximately forty degrees. This child is stage four, in cardiac arrest, so the treatment is extracorporeal rewarming with extracorporeal membrane oxygenation or cardiopulmonary bypass, which rewarms fastest, supports the circulation, and carries the best survival. The Saczkowski meta-analysis showed meaningful survival after extracorporeal rewarming, which is why I escalate early. I watch for the afterdrop and rewarming shock with warmed fluids and monitoring. [6] [8]

Branch C — The cold-water exception and prognosis

Examiner: This child has been submerged for thirty minutes. Why are you resuscitating him at all? [9]

Candidate: Because this is cold-water submersion, where the diving response and rapid cerebral cooling protect the brain by lowering its metabolic oxygen demand, extending the window of cerebral tolerability to hypoxia far beyond a warm-water drowning. Case reports of children surviving prolonged hypothermic submersion cardiac arrest with good neurological outcome after extracorporeal rewarming underpin the principle that the duration alone does not futility make, provided the water was cold. So I continue resuscitation until the core reaches at least thirty-two degrees before considering stopping — nobody is dead until warm and dead. [9]

Branch D — The drowning lung in the child who recovers a pulse

Examiner: He regains a pulse at a core of 31 degrees. How do you manage the lung injury over the next hours? [3]

Candidate: I continue rewarming gently to normothermia, avoiding overshoot into hyperthermia, and I hold a neuroprotective bundle — normothermia, normoxia with saturations 94 to 99 per cent, and normocapnia guided by capnography. The drowning lung is managed with oxygen titrated up the support ladder to high-flow nasal cannula, non-invasive ventilation, or intubation and lung-protective ventilation for failing gas exchange, because pulmonary oedema can evolve and worsen over the first hours. I check the glucose and electrolytes, surveil for seizures, and admit him to the paediatric intensive care unit. [3] [6]

Branch E — Definition and prevention

Examiner: Returning to first principles — define drowning, and tell me how you would prevent this in the community. [1]

Candidate: Drowning is the process of experiencing respiratory impairment from submersion or immersion in liquid, with outcomes of death, morbidity, or no morbidity — the van Beeck definition, which retires the obsolete terms near-drowning, secondary, dry and wet. Prevention is the public-health core: four-sided isolation pool fencing with self-closing self-latching gates, constant supervision of children around all water, life jackets on and near open water, learn-to-swim programmes from around one year of age, and bystander CPR training, because bystander rescue breaths and CPR improve outcome. These are the interventions that stop the next child reaching my resuscitation bay. [1]

Close

Continue high-quality cardiopulmonary resuscitation, deliver a single shock for the ventricular fibrillation below thirty degrees and withhold further shocks and adrenaline until the core rises, rewarn actively and escalate to extracorporeal rewarming, and continue resuscitation until the core is at least thirty-two degrees — because nobody is dead until warm and dead. Debrief the team, document the sequence and the time intervals, and speak honestly and early with the family about the prognostic uncertainty of the first days. [5] [9]