Tandberg D, Murphy L C
Department of Family, Community, and Emergency Medicine, University of New Mexico School of Medicine, Albuquerque 87131.
Am J Emerg Med. 1989 May;7(3):267-70. doi: 10.1016/0735-6757(89)90167-8.
Previous studies have shown that ipecac-induced emesis, even if instituted very early, removes only a mean of 28% to 45% of an ingested tracer. Because vomiting is an ancient reflex that occurs in mammals, reptiles, and other animals, we speculated that, in humans, maintaining a sitting rather than a horizontal posture during induced emesis might decrease the efficacy of gastric emptying. To test this hypothesis, 20 normal fasting adult subjects underwent induced emesis in the knee-chest position on one day and in the sitting position on another. Twenty-five 100-micrograms tablets of cyanocobalamin were ingested as a tracer along with 250 mL tap water. Ten minutes after tracer ingestion, 30 mL ipecac syrup and 640 mL tap water were swallowed. All resulting vomitus was homogenized, frozen, and later assayed for cobalt using atomic absorption spectrophotometry. There was no difference in mean tracer recovery with the two positions: knee-chest, 47.2% v sitting, 46.9% (paired t test, P greater than .95). Analysis of cobalt recovery for all 40 episodes of emesis revealed a mean of 51.2 +/- 23.7 (SD) micrograms out of 108.7 micrograms total cobalt ingested (95% Cl, 43.6 to 58.7 micrograms). This represented 47.1% of the administered tracer dose (95% Cl, 40.1% to 54.0%). Even if initiated only ten minutes after an ingestion, ipecac-induced emesis removes an average of less than half of an ingested tracer dose, with a high degree of intersubject variability. Horizontal patient positioning does not appear to improve the efficacy of this procedure.
先前的研究表明，即使在摄入催吐剂后很快就引发呕吐，也只能平均排出摄入示踪剂的28%至45%。由于呕吐是哺乳动物、爬行动物和其他动物都有的一种古老反射，我们推测，在人类中，催吐时保持坐姿而非平躺姿势可能会降低胃排空的效果。为了验证这一假设，20名正常空腹的成年受试者在一天中处于膝胸位进行催吐，在另一天处于坐姿进行催吐。将25片100微克的钴胺素片剂作为示踪剂与250毫升自来水一起摄入。摄入示踪剂10分钟后，咽下30毫升吐根糖浆和640毫升自来水。将所有吐出物均质化、冷冻，随后使用原子吸收分光光度法测定其中的钴含量。两种姿势下示踪剂的平均回收率没有差异：膝胸位为47.2%，坐姿为46.9%（配对t检验，P大于0.95）。对所有40次呕吐事件的钴回收率分析显示，在总共摄入的108.7微克钴中，平均回收量为51.2±23.7（标准差）微克（95%置信区间，43.6至58.7微克）。这占给药示踪剂剂量的47.1%（95%置信区间，40.1%至54.0%）。即使在摄入后仅10分钟就开始催吐，吐根糖浆诱导的呕吐平均也只能排出不到一半的摄入示踪剂剂量，且个体间差异很大。患者平躺姿势似乎并不能提高该操作的效果。
