McKenna Helen T, Reiss Irwin Km, Martin Daniel S
University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.
Critical Care Unit, The London Clinic, London, UK.
J Intensive Care Soc. 2017 May;18(2):121-129. doi: 10.1177/1751143717692603. Epub 2017 Feb 13.
Many physiological and cellular processes cycle with time, with the period between one peak and the next being roughly equal to 24 h. These circadian rhythms underlie 'permissive homeostasis', whereby anticipation of periods of increased energy demand or stress may enhance the function of individual cells, organ systems or whole organisms. Many physiological variables related to survival during critical illness have a circadian rhythm, including the sleep/wake cycle, haemodynamic and respiratory indices, immunity and coagulation, but their clinical significance remains underappreciated. Critically ill patients suffer from circadian dysrhythmia, manifesting overtly as sleep disturbance and delirium, but with widespread covert effects on cellular and organ function. Environmental and pharmacological strategies that ameliorate or prevent circadian dysrhythmia have demonstrated clinical benefit. Harnessing these important biological phenomena to match metabolic supply to demand and bolster cell defenses at the apposite time may be a future therapeutic strategy in the intensive care unit.
许多生理和细胞过程会随时间循环，一个峰值与下一个峰值之间的周期大致等于24小时。这些昼夜节律是“允许性稳态”的基础，据此，对能量需求增加或压力期的预期可能会增强单个细胞、器官系统或整个生物体的功能。许多与危重病期间生存相关的生理变量都有昼夜节律，包括睡眠/觉醒周期、血流动力学和呼吸指标、免疫和凝血，但它们的临床意义仍未得到充分认识。危重病患者会出现昼夜节律紊乱，明显表现为睡眠障碍和谵妄，但对细胞和器官功能有广泛的隐性影响。改善或预防昼夜节律紊乱的环境和药物策略已显示出临床益处。利用这些重要的生物学现象，使代谢供应与需求相匹配，并在适当的时候增强细胞防御，可能是重症监护病房未来的治疗策略。
