Takahashi H, Nishikawa T, Mizutani T, Handa F
Department of Anaesthesiology, Institute of Clinical Medicine, University of Tsukuba, Japan.
Can J Anaesth. 1997 Mar;44(3):268-72. doi: 10.1007/BF03015364.
Clonidine not only stops postoperative shivering and decreases oxygen consumption, but also decreases energy expenditure with or without a reduction in shivering during recovery from anaesthesia. It is important to see if clonidine decreases energy expenditure at rest since this may contribute to a postoperative decrease in energy expenditure. The authors tested the hypothesis that oral clonidine decreases energy expenditure at rest.
Twenty healthy male volunteers were randomly assigned to one of two groups. Ten volunteers received oral clonidine approximately 5 micrograms.kg-1 (clonidine group), while the remaining 10 volunteers received placebo (control group). Blood pressure, heart rate, body temperature at the tympanic membrane, sedation score graded from 1 (alert) to 5 (sleeping and difficult to be aroused by tactile stimulation) were measured before and at 30-min intervals for three hours after administration of clonidine or placebo. Measurements of energy expenditure and respiratory quotient were made with a head canopy system at one-minute intervals and averaged over 15 min before, and at 30, 60, 90, 120, and 180 min after administration of clonidine or placebo.
Sedation score increased from 1 to 3 (median) after clonidine administration. Energy expenditure decreased from 1452 +/- 225 kcal.24hr-1 (mean +/- SD) at baseline to 1258 +/- 175 kcal.24hr-1 at 180 min after clonidine administration (P < 0.05).
This study suggests that oral clonidine at a dose of 5 micrograms.kg-1 decreases energy expenditure at rest.
可乐定不仅能阻止术后寒战并降低氧耗，而且在麻醉恢复期间，无论寒战是否减轻，它都能降低能量消耗。了解可乐定是否能降低静息时的能量消耗很重要，因为这可能有助于术后能量消耗的减少。作者检验了口服可乐定可降低静息时能量消耗这一假设。
20名健康男性志愿者被随机分为两组。10名志愿者口服约5微克·千克-1的可乐定（可乐定组），其余10名志愿者服用安慰剂（对照组）。在给予可乐定或安慰剂之前以及给药后3小时内，每隔30分钟测量血压、心率、鼓膜温度以及从1级（清醒）到5级（睡眠且难以被触觉刺激唤醒）的镇静评分。使用头部面罩系统每隔1分钟测量一次能量消耗和呼吸商，并在给予可乐定或安慰剂之前以及给药后30、60、90、120和180分钟时取15分钟的平均值。
服用可乐定后，镇静评分从1级升至3级（中位数）。能量消耗从基线时的1452±225千卡·24小时-1（平均值±标准差）降至服用可乐定后180分钟时的1258±175千卡·24小时-1（P<0.05）。
本研究表明，剂量为5微克·千克-1的口服可乐定可降低静息时的能量消耗。
