Gögenur Ismail, Middleton Benita, Burgdorf Stefan, Rasmussen Lars Simon, Skene Debra J, Rosenberg Jacob
Department of Surgical Gastroenterology D, Copenhagen University Hospital, Gentofte, Hellerup, Denmark.
J Pineal Res. 2007 Sep;43(2):179-84. doi: 10.1111/j.1600-079X.2007.00460.x.
Sleep and circadian disturbances may underlie cognitive dysfunction after major surgery. The aim of this study was to examine the association between sleep and circadian disturbances (as assessed by changes in the melatonin rhythm) and postoperative cognitive dysfunction (POCD). We measured subjective and objective sleep quality, excretion of the major metabolite of melatonin, 6-sulphatoxymelatonin (aMT6s) in urine and cognitive function before and 4 days after major abdominal surgery in 36 patients. Subjective sleep quality was measured by visual analogue scale, objective sleep quality was measured by actigraphy, and cognitive function was assessed by neuropsychological testing. Eighteen patients (50%) had POCD on day 4 after surgery. At that time, the excretion of aMT6s was disturbed with significantly higher daytime excretion and a reduced night/day ratio compared with the preoperative measure (P = 0.05). Patients with POCD had significantly worse sleep quality and more night awakenings (P < 0.05) but we found no significant differences in day time (06:00-22:00 hr), night-time (22:00-06:00 hr) or total aMT6s excretion (mug/24 hr). A significant correlation was found between the total excretion of aMT6s and actigraphically measured sleep efficiency (r(s) = 0.45, P = 0.03) and wakefulness after sleep onset (r(s) = -0.44, P = 0.04). In conclusion, POCD was associated with worse subjective sleep quality and more awakenings. Circadian rhythmicity as assessed by aMT6s excretion was disturbed after surgery but we were unable to show an association with POCD. Strategies to improve postoperative sleep quality should be investigated in the future.
睡眠和昼夜节律紊乱可能是大手术后认知功能障碍的潜在原因。本研究的目的是探讨睡眠和昼夜节律紊乱（通过褪黑素节律变化评估）与术后认知功能障碍（POCD）之间的关联。我们测量了36例患者在腹部大手术前及术后4天的主观和客观睡眠质量、褪黑素主要代谢产物6-硫酸氧褪黑素（aMT6s）的尿排泄量以及认知功能。主观睡眠质量通过视觉模拟量表测量，客观睡眠质量通过活动记录仪测量，认知功能通过神经心理学测试评估。18例患者（50%）在术后第4天出现POCD。此时，aMT6s的排泄受到干扰，与术前测量相比，白天排泄量显著增加，夜/昼比值降低（P = 0.05）。发生POCD的患者睡眠质量明显更差，夜间觉醒次数更多（P < 0.05），但我们发现白天（06:00 - 22:00时）、夜间（22:00 - 06:00时）或aMT6s总排泄量（微克/24小时）无显著差异。aMT6s总排泄量与活动记录仪测量的睡眠效率（r(s) = 0.45，P = 0.03）以及睡眠开始后的清醒时间（r(s) = -0.44，P = 0.04）之间存在显著相关性。总之，POCD与较差的主观睡眠质量和更多的觉醒有关。手术后通过aMT6s排泄评估的昼夜节律受到干扰，但我们未能证明其与POCD有关联。未来应研究改善术后睡眠质量的策略。
