Dept. Psychology, University of Westminster, London, United Kingdom.
Auton Neurosci. 2011 Feb 24;160(1-2):53-8. doi: 10.1016/j.autneu.2010.09.009. Epub 2010 Oct 30.
The experienced smoker maintains adequate nicotine levels by 'puff-by-puff self-control' which also avoids symptomatic nauseating effects of nicotine overdose. It is postulated that there is a varying 'dynamic threshold for nausea' into which motion sickness susceptibility provides an objective toxin-free probe. Hypotheses were that: (i) nicotine promotes motion sickness whereas deprivation protects; and (ii) pleasurable effects of nicotine protect against motion sickness whereas adverse effects of withdrawal have the opposite effect.
Twenty-six healthy habitual cigarette smokers (mean ± SD) 15.3 ± 7.6 cigs/day, were exposed to a provocative cross-coupled (coriolis) motion on a turntable, with sequences of 8 head movements every 30s. This continued to the point of moderate nausea. Subjects were tested after either ad-lib normal smoking (SMOKE) or after overnight deprivation (DEPRIV), according to a repeated measures design counter-balanced for order with 1-week interval between tests.
Deprivation from recent smoking was confirmed by objective measures: exhaled carbon monoxide CO was lower (P<0.001) for DEPRIV (8.5 ± 5.6 ppm) versus SMOKE (16.0 ± 6.3 ppm); resting heart rate was lower (P<0.001) for DEPRIV (67.9 ± 8.4 bpm) versus SMOKE (74.3 ± 9.5 bpm). Mean ± SD sequences of head movements tolerated to achieve moderate nausea were more (P = 0.014) for DEPRIV (21.3 ± 9.9) versus SMOKE (18.3 ± 8.5).
Tolerance to motion sickness was aided by short-term smoking deprivation, supporting Hypothesis (i) but not Hypothesis (ii). The effect was was approximately equivalent to half of the effect of an anti-motion sickness drug. Temporary nicotine withdrawal peri-operatively may explain why smokers have reduced risk for postoperative nausea and vomiting (PONV).
有经验的吸烟者通过“一口一口的自我控制”来保持足够的尼古丁水平，这也避免了尼古丁过量的症状性恶心作用。据推测，存在一个变化的“恶心动态阈值”，其中晕动病易感性提供了一种客观的无毒探针。假设是：（i）尼古丁促进晕动病，而剥夺则保护；（ii）尼古丁的愉悦作用可以预防晕动病，而戒断的不良反应则有相反的效果。
26 名健康习惯性吸烟的吸烟者（平均值±标准差）15.3±7.6 支/天，在转盘上接受刺激性交叉耦合（科里奥利）运动，每 30 秒进行 8 个头动序列。这一直持续到中度恶心的程度。根据重复测量设计，根据顺序平衡，在测试之间间隔 1 周，受试者在正常吸烟（SMOKE）或通宵剥夺（DEPRIV）后进行测试。
通过客观测量证实了近期吸烟的剥夺：DEPRIV （8.5±5.6 ppm）的呼出一氧化碳 CO 水平较低（P<0.001），而 SMOKE （16.0±6.3 ppm）；DEPRIV （67.9±8.4 bpm）的静息心率较低（P<0.001），而 SMOKE （74.3±9.5 bpm）。达到中度恶心的可耐受头动序列的平均值±标准差为 DEPRIV （21.3±9.9）高于 SMOKE （18.3±8.5）（P=0.014）。
短期吸烟剥夺有助于晕动病的耐受性，支持假设（i）但不支持假设（ii）。这种效果大约相当于抗晕动病药物效果的一半。围手术期短暂的尼古丁戒断可能解释了为什么吸烟者术后恶心和呕吐（PONV）的风险降低。
