Identification of cause of sudden death during hot waterbathing

日本每年有14000名受害者在洗澡时死亡。考虑到世界猝死的统计数据，这是一个非常高的发病率，仅限于日本。为了研究猝死的真正原因，1）通过对东京消防队急救人员队长的问卷调查，研究了现场发生的浴室事故的院前情况; 2）热水浴（40和44 ℃）在日本健康年轻男性受试者中进行挑战（20-23岁），而血流动力学（体温、HR、BP、心率变异性）、血液学和内分泌生化标志物（CBC，粘附分子，内皮功能，cathecolamines，h-ANP，内皮素-1，β-内啡肽）以及神经心理功能测试（起搏听觉序列加法测试：PASAT）。在第一项研究中，分析了1775起洗澡时发生的事故。其中，现场心肺骤停者占46%（CPA受害者），而16%的受害者是无法从装满热水的浴缸中出来的人（获救的受害者）。如果他们没有被发现并从浴缸中救出，那么被召回的受害者是CPA的候选人。大多数获救的受害者有不同程度的意识障碍，而酒精，高血压和心脏症状，如胸痛的参与很少。在第二项研究中，体温上升到40.1摄氏度（44度水）和38.1摄氏度（40摄氏度水）。与体温升高相关的是心率增快、心率变异性降低、血压轻度降低或升高，诱发直立性眩晕。PASAT表明，44 ℃热水浸泡后，正确回答率显著下降，血浆β-内啡肽显著增加，而40 ℃热水浸泡后则没有。其他血液学和内分泌生化指标与热水浸泡应激反应一致。得出的结论是

Fourteen thousands Japanese victims die during their bathing annually. It is an exceptionally high incidence limited to Japan, considering the world statistics of sudden death. In order to study the actual cause of the sudden death, 1) pre-hospital situations of those accidents in bath on the scene were studied by questionnaire to captains of emergency personnel of the Tokyo fire department and 2) hot bath bathing (40 and 44 degree C) was challenged in Japanese healthy young male subjects (age 20-23) while hemodynamics (body temperature, HR, BP, heart rate variability), hematological and endocrinological biochemical markers (CBC, adhesion molecules, endothelial functions, cathecolamines, h-ANP, endothelin-1, beta endorphine) and also neuropsychological function test (Paced Auditory Serial Addition Test: PASAT). In the first study, 1775 accidents during bathing were analyzed. Among them, cardiopulmonary arrest at the scene was 46% (CPA victims), while 16% of victims were those who could not get out of hot water-filled tub (rescued victims). The recued victims were candidates of CPA if they were not found and rescued from tub. Most of rescued victims had various grade of consiousness disturbances while involvement of alcohol, hyotension and cardiac symptoms such as chest pain were rarely associated. In the second study, body temperature rose up to 40.1 degree C (44 degree water) and 38.1 degree C (40 degree C water). Associated with the high body temperature, HR increased, heart rate variability decreased, BP slightly decreased or increased, orthostatic hypotensin was induced. PASAT indicated significant decrease in the rate of correct answer following the 44 degree C hot water immersion associated with the significant increase of plasma beta-endorphin, while not following the 40 degree C hot water immersion. Other hematological and endocrinological biochemical markers were compatible with the response to stress by hot water immersion. It was concluded that