Connolly E, Worthley L I
Department of Critical Care Medicine, Flinders Medical Centre, Adelaide, South Australia.
Crit Care Resusc. 2000 Mar;2(1):22-9.
To review human thermoregulation and the pathophysiology and management of induced and accidental hypothermia.
A review of studies reported over ten years from 1990 to 2000 and identified through a MEDLINE search of the English-language literature on thermoregulation and induced and accidental hypothermia.
Hypothermia is defined as a core temperature less than 35 degrees C, and may be therapeutic (i.e. induced for clinical benefit) or accidental. Hypothermia induced prior to cardiovascular or neurosurgical procedures (i.e. therapeutic hypothermia) allows for a greater hypotensive operative period with less risk of cerebral or cardiac ischaemic injury. Hypothermia induced following tissue injury (e.g. closed head injury, cerebrovascular accident, adult respiratory distress syndrome) has also been used to reduce ischaemic tissue injury, although significant clinical benefits have not yet been demonstrated. Inadvertent hypothermia (i.e. accidental hypothermia) is classed as mild from 33 degrees C-35 degrees C, moderate from 30 degrees C-33 degrees C and severe if less than 30 degrees C. Treatment includes surface and core warming methods, all of which have a valid basis from experimental studies. However, no prospective, randomised controlled clinical trials exist that have compared the various rewarming methods. Currently, passive rewarming methods (e.g. reflective metalloplastic sheets, blankets) are recommended for patients with mild hypothermia (> 33 degrees C), active surface rewarming (e.g. heated blankets, hot air circulators) for moderate hypothermia (> 30 degrees C), active core rewarming (e.g. heated haemodialysis, haemodiafiltration or peritoneal dialysis) for severe hypothermia (< 30 degrees C), and heated cardiopulmonary bypass for severe hypothermia with cardiopulmonary arrest.
Operative hypothermia reduces ischaemic injury during cardiac and neurosurgical procedures. Hypothermia induced following tissue injury has not yet been shown to be of benefit. Management of accidental hypothermia requires passive and active warming methods, the indication of each depending on the availability of the method and severity of hypothermia.
综述人体体温调节以及诱导性和意外性低温的病理生理学与处理方法。
回顾1990年至2000年这十年间报道的研究，并通过对关于体温调节以及诱导性和意外性低温的英文文献进行MEDLINE检索来确定。
低温被定义为核心体温低于35摄氏度，可分为治疗性（即为临床益处而诱导）或意外性。在心血管或神经外科手术前诱导的低温（即治疗性低温）可使手术期间低血压时间延长，同时降低脑或心脏缺血性损伤的风险。在组织损伤（如闭合性颅脑损伤、脑血管意外、成人呼吸窘迫综合征）后诱导的低温也已用于减少缺血性组织损伤，尽管尚未证明有显著的临床益处。意外低温（即意外性低温）分为轻度（33摄氏度至35摄氏度）、中度（30摄氏度至33摄氏度），若低于30摄氏度则为重度。治疗方法包括体表复温和核心复温方法，所有这些方法都有实验研究的有效依据。然而，尚无前瞻性、随机对照临床试验比较各种复温方法。目前，对于轻度低温（>33摄氏度）的患者，建议采用被动复温方法（如反射性金属塑料片、毛毯）；对于中度低温（>30摄氏度），采用主动体表复温（如加热毛毯、热空气循环器）；对于重度低温（<30摄氏度），采用主动核心复温（如加热血液透析、血液滤过或腹膜透析）；对于伴有心跳骤停的重度低温，则采用加热体外循环。
手术性低温可减少心脏和神经外科手术期间的缺血性损伤。组织损伤后诱导的低温尚未显示有益处。意外性低温的处理需要被动和主动复温方法，每种方法的选择取决于该方法的可获得性和低温的严重程度。
