Turkistani A, Abdullah K M, Al-Shaer A A, Mazen K F, Alkatheri K
King Saud University, King Khalid University Hospitals, Department of Anesthesiology, Riyadh, Saudi Arabia.
Eur J Anaesthesiol. 2007 May;24(5):399-402. doi: 10.1017/S0265021506001505. Epub 2006 Nov 10.
Melatonin (N-acetyl-5-methoxytryptamine) is the main indolamine secreted by the pineal gland. Many studies showed that premedication with melatonin is associated with preoperative anxiolysis and sedation without impairment of cognitive and psychomotor skills and without prolonging recovery. We hypothesized that melatonin decreases the amount of propofol required to produce an adequate depth of hypnosis at induction time.
After approval from the research committee of the anaesthesia department, informed written consent was taken from 45 adult patients undergoing different surgical procedures. They were allocated randomly into three groups according to the premedication. At 100 min preoperatively, premedication was given in the form of oral melatonin 3 mg (M3 group), oral melatonin 5 mg (M5 group) or no premedication (P group). After preoxygenation an anaesthesiologist who was blinded to the premedication injected propofol 10 mg over 5 s every 15 s until the bispectral index (BIS) score fell to 45. The total dose of propofol required to achieve a BIS score of 45 was recorded. Response to verbal commands and eyelash reflex was evaluated and correlated to the BIS score and propofol dosage. When a BIS score of 45 was reached, tracheal intubation was accomplished after administration of a narcotic and muscle relaxant.
The mean (standard devitation (SD)) induction dose of propofol producing a BIS score of 45 was 134 (25) mg in the placebo group vs. 115 (19.5) and 114 (20.9) mg in the M3 and M5 groups, respectively (P < 0.05). The propofol dose required to achieve loss of eyelash reflex and loss of response to verbal commands was more in the placebo group. Anxiety score as assessed by visual analogue scale (VAS) scored more in the placebo group than both melatonin groups. Time spent in the recovery room did not differ between the three groups.
Melatonin premedication, in an oral dose of either 3 or 5 mg, reduced the required dose of propofol to achieve a BIS score of 45, reflecting a sufficient level of hypnosis for tracheal intubation without prolongation of postoperative recovery room stay.
褪黑素（N-乙酰-5-甲氧基色胺）是松果体分泌的主要吲哚胺。许多研究表明，术前使用褪黑素与术前抗焦虑和镇静作用相关，且不损害认知和精神运动技能，也不延长恢复时间。我们假设褪黑素可减少诱导期产生足够催眠深度所需的丙泊酚用量。
经麻醉科研究委员会批准后，对45例接受不同手术的成年患者获取了知情书面同意书。根据术前用药情况将他们随机分为三组。术前100分钟，分别给予口服3毫克褪黑素（M3组）、口服5毫克褪黑素（M5组）或不进行术前用药（P组）。在预充氧后，一位对术前用药不知情的麻醉医生每隔15秒在5秒内注射10毫克丙泊酚，直至脑电双频指数（BIS）评分降至45。记录达到BIS评分为45所需的丙泊酚总剂量。评估对言语指令和睫毛反射的反应，并将其与BIS评分和丙泊酚剂量相关联。当BIS评分为45时，在给予麻醉剂和肌肉松弛剂后进行气管插管。
安慰剂组产生BIS评分为45的丙泊酚平均（标准差（SD））诱导剂量为134（25）毫克，而M3组和M5组分别为115（19.5）毫克和114（20.9）毫克（P<0.05）。安慰剂组实现睫毛反射消失和对言语指令无反应所需的丙泊酚剂量更高。通过视觉模拟量表（VAS）评估的焦虑评分在安慰剂组高于两个褪黑素组。三组在恢复室的停留时间无差异。
口服3毫克或5毫克剂量的褪黑素进行术前用药，可减少达到BIS评分为45所需的丙泊酚剂量，这反映出足以进行气管插管的催眠水平，且不会延长术后在恢复室的停留时间。
