Campbell W I, Kendrick R W
Department of Anaesthetics, Ulster Hospital, Dundonald.
Br J Anaesth. 1997 Nov;79(5):657-9. doi: 10.1093/bja/79.5.657.
Two studies were carried out in patients undergoing bilaterally symmetrical lower third molar surgery under general anaesthesia. In the first study observations were carried out in 40 patients, using McGill pain questionnaires and visual analogue scales (VAS), to assess the variation in pain intensity between the two sides in each individual on the morning after surgery. The within-patient variation in pain intensity indicated that a sample size exceeding 30 was required to show a difference of more than 10 mm on the VAS and achieve a power of 90% at the 5% level of significance. The second study was carried out to determine if local anaesthesia administered before rather than after tooth removal rendered any benefit. Each of the 38 patients acted as their own control; one side was allocated randomly to receive the local anaesthetic before operation and the other side after operation. The difference in pain between the pretreated and post-treated sides in each individual was assessed using a McGill pain questionnaire on the morning after surgery in addition to two VAS (one for each operation side) after operation, at 6 h, 1 and 6 days after surgery. There were no significant differences in pain at any time using any of the above methods.
两项研究针对在全身麻醉下接受双侧对称下颌第三磨牙手术的患者展开。在第一项研究中，对40名患者进行了观察，使用麦吉尔疼痛问卷和视觉模拟量表（VAS），以评估术后次日清晨每个个体两侧疼痛强度的差异。患者体内疼痛强度的差异表明，需要超过30的样本量才能在VAS上显示出超过10毫米的差异，并在5%的显著性水平上达到90%的检验效能。第二项研究旨在确定在拔牙前而非拔牙后给予局部麻醉是否有任何益处。38名患者中的每一位都作为自己的对照；一侧被随机分配在手术前接受局部麻醉，另一侧在手术后接受局部麻醉。除了在术后、术后6小时、1天和6天使用两个VAS（每个手术侧一个）外，还在术后次日清晨使用麦吉尔疼痛问卷评估每个个体预处理侧和后处理侧之间的疼痛差异。使用上述任何方法，在任何时间的疼痛都没有显著差异。
