Physiology Of Drowning: A Review

Abstract

Drowning physiology relates to two different events: immersion (upper airway above water) and submersion (upper airway under water). Immersion involves integrated cardiorespiratory responses to skin and deep body temperature, including cold shock, physical incapacitation, and hypovolemia, as precursors of collapse and submersion. The physiology of submersion includes fear of drowning, diving response, autonomic conflict, upper airway reflexes, water aspiration and swallowing, emesis, and electrolyte disorders. Submersion outcome is determined by cardiac, pulmonary, and neurological injury. Knowledge of drowning physiology is scarce. Better understanding may identify methods to improve survival, particularly related to hot-water immersion, cold shock, cold-induced physical incapacitation, and fear of drowning.

Deaths in triathletes: immersion pulmonary oedema as a possible cause

“…IPO is a plausible cause of triathlon death, particularly since it has been suggested as one possible mechanism in the pathophysiology of drowning 4. In contrast, due to the rarity of IPO-related deaths and lack of known history of IPO in any triathlon death, some have concluded that it is an unlikely cause of death in triathletes 10…”

“…Drowning, the process of experiencing respiratory impairment from submersion/immersion in liquid,4 is often the official reported cause of swimming death;1 however, drowning seems unlikely in experienced swimmers. Predictors of cardiac death—the overwhelming primary cause of sudden death in most other sports2 5–8—remain elusive in triathletes.…”

“…Predictors of cardiac death—the overwhelming primary cause of sudden death in most other sports2 5–8—remain elusive in triathletes. Arrhythmic causes, including prolonged QTc and autonomic conflict (simultaneous activation of sympathetic and parasympathetic),4 9 have been proposed in triathlete cardiac death. Other suggested causes include exertional heat stroke, myocardial infarction, head trauma, panic attack and arrhythmia 10.…”

Cold water immersion: kill or cure?

“…As a result of laboratory-based research, the initial responses to immersion, or 'cold shock' , were identified as particularly hazardous (Tipton, 1989), accounting for the majority of immersion deaths ). These deaths have most often been ascribed to drowning, with the physiological responses of a gasp and uncontrollable hyperventilation, initiated by the dynamic response of the cutaneous cold receptors, resulting in the aspiration of the small volume of water necessary to initiate the drowning process (Bierens et al 2016). Relatively little is known about the minimal rates of change of cold receptor temperature necessary to cause cold shock.…”

The regulation of epithelial cells volume in norm and pathology

“…Клетки мозгового вещества почек претерпевают резкие изменения осмолярности внеклеточной жидкости в процессе антидиуреза [45]. Клетки ýпителия легкого могут быть подвер-жены внеклеточным изменениям осмолярности вследствие утопления в пресной или морской воде [46], учитывая, что пресная вода являет-ся гипотонической средой в сравнении с плаз-мой крови (20 мосм/кг H 2 O), а морская вода -гипертонической (1 000 мосм/кг H 2 O) [47].В действительности клетки более часто подвер-жены изменениям во внутриклеточной осмоляр-ности, чем внеклеточной. Причинами изменения внутриклеточной осмолярности могут быть несба-лансированный транспорт ионов и органических Бюллетень сибирской медицины.…”