Pirec V, Patterson T H, Thapar P, Apfelbaum J L, Zacny J P
Department of Anesthesia, Pritzker School of Medicine, University of Chicago, IL 60637, USA.
Pharmacol Biochem Behav. 1995 Jun-Jul;51(2-3):323-9. doi: 10.1016/0091-3057(94)00388-y.
Nitrous oxide (N2O) has analgesic properties as determined in both animal and human research. In the present study, we sought to determine whether N2O given in subanesthetic concentrations would reduce cold pressor (CP)-induced pain. A crossover, double-blind study was conducted in 10 healthy volunteers. Each subject participated in four separate sessions, and in each session the effects of one of four concentrations of N2O in oxygen (0, 20, 30, and 40%) were assessed. The duration of inhalation was 40 min, and within each session, subjects immersed their nondominant arm in water (2-3 degrees C) twice for 3 min (at 10 and 30 min intrainhalation). Pain intensity, the degree to which the pain was bothersome (measured on a verbal scale of 0-10, 0 = "not at all" and 10 = "extremely" painful/bothersome), and pain quality [measured by the short-form McGill Pain Questionnaire (SF-MPQ)] were assessed during the forearm immersion. Mood effects were measured with the use of visual analogue scales (VAS) in the presence and absence of pain. Self-reported pain intensity and bothersomeness, SF-MPQ ratings of "sharp pain" and "throbbing pain," and VAS rating of "unpleasant bodily sensations" were significantly reduced by N2O (p < 0.05) in a concentration-dependent manner. Nitrous oxide had a number of effects on mood (e.g., increased VAS ratings of "stimulated," "high," "coasting," "carefree," and "having pleasant bodily sensations"). The cold-water immersion also influenced mood, but had little impact on modulating N2O effects.(ABSTRACT TRUNCATED AT 250 WORDS)
一氧化二氮（N₂O）在动物和人体研究中均已被证实具有镇痛特性。在本研究中，我们旨在确定给予亚麻醉浓度的N₂O是否会减轻冷加压（CP）诱导的疼痛。对10名健康志愿者进行了一项交叉双盲研究。每位受试者参加四个独立的实验环节，在每个环节中评估四种浓度的N₂O与氧气混合气体（0%、20%、30%和40%）之一的效果。吸入持续时间为40分钟，在每个实验环节中，受试者将非优势手臂浸入水中（2 - 3摄氏度）两次，每次3分钟（在吸入过程中的10分钟和30分钟时）。在前臂浸入过程中评估疼痛强度、疼痛困扰程度（通过0 - 10的语言量表测量，0 =“完全不”，10 =“极其”疼痛/困扰）以及疼痛性质[通过简化麦吉尔疼痛问卷（SF - MPQ）测量]。在有疼痛和无疼痛的情况下，使用视觉模拟量表（VAS）测量情绪影响。N₂O以浓度依赖性方式显著降低了自我报告的疼痛强度和困扰程度、SF - MPQ中“刺痛”和“搏动性疼痛”的评分以及VAS中“不愉快身体感觉”的评分（p < 0.05）。一氧化二氮对情绪有多种影响（例如，VAS中“兴奋”、“飘飘然”、“轻松滑行”、“无忧无虑”和“有愉悦身体感觉”的评分增加）。冷水浸泡也影响情绪，但对调节N₂O的效果影响不大。（摘要截断于250字）
