Bawaskar Hospital and Research Centre, Mahad, Dist-Raigad, Maharashtra, India 402301.
BMJ. 2011 Jan 5;342:c7136. doi: 10.1136/bmj.c7136.
Envenomation by Mesobuthus tamulus scorpion sting can result in serious cardiovascular effects. Scorpion antivenom is a specific treatment for scorpion sting. Evidence for the benefit of scorpion antivenom and its efficacy compared with that of commonly used vasodilators, such as prazosin, is scarce. We assessed the efficacy of prazosin combined with scorpion antivenom, compared with prazosin alone, in individuals with autonomic storm caused by scorpion sting.
Prospective, open label randomised controlled trial.
General hospital inpatients (Bawaskar Hospital and Research Centre Mahad Dist-Raigad Maharashtra, India).
Seventy patients with grade 2 scorpion envenomation, older than six months, with no cardiorespiratory or central nervous system abnormalities.
Scorpion antivenom plus prazosin (n=35) or prazosin alone (n=35) assigned by block randomisation. Treatment was not masked. Analysis was by intention to treat.
The primary end point was the proportion of patients achieving resolution of the clinical syndrome (sweating, salivation, cool extremities, priapism, hypertension or hypotension, tachycardia) 10 hours after administration of study drugs. Secondary end points were time required for complete resolution of clinical syndrome, prevention of deterioration to higher grade, doses of prazosin required overall and within 10 hours, and adverse events. The study protocol was approved by the independent ethics committee of Mumbai.
Mean (SD) recovery times in hours for the prazosin plus scorpion antivenom group compared with the prazosin alone groups were: sweating 3 (1.1) v 6.6 (2.6); salivation 1.9 (0.9) v 3 (1.9); priapism 4.7 (1.5) v 9.4 (1.5). Mean (SD) doses of prazosin in the groups were 2 (2.3) and 4 (3.5), respectively. 32 patients (91.4%, 95% confidence interval 76.9% to 97.8%) in the prazosin plus antivenom group showed complete resolution of the clinical syndrome within 10 hours of administration of treatment compared with eight patients in the prazosin group (22.9%, 11.8% to 39.3%). Patients from the antivenom plus prazosin group recovered earlier (mean 8 hours, 95% CI 6.5 to 9.5) than those in the control group (17.7 hours, 15.4 to 19.9; mean difference -9.7 hours, -6.9 to -12.4). The number of patients whose condition deteriorated to a higher grade was similar in both groups (antivenom plus prazosin four of 35, prazosin alone five of 35). Hypotension was reported in fewer patients in the antivenom plus prazosin group (12 of 35, 34.3%) than in the prazosin group (19 of 35, 54.3%), but the difference was not statistically significant. No difference was noted in change in blood pressure and pulse rate over time between two groups.
Recovery from scorpion sting is hastened by simultaneous administration of scorpion antivenom plus prazosin compared with prazosin alone.
CTRI/2010/091/000584 (Clinical Trials Registry India).
噬人鳄尾蝎蜇伤可导致严重的心血管效应。蝎毒抗血清是治疗蝎蜇伤的特效药物。蝎毒抗血清与常用血管扩张剂（如哌唑嗪）相比的疗效证据稀少。我们评估了哌唑嗪联合蝎毒抗血清与单独使用哌唑嗪治疗由蝎蜇伤引起的自主风暴患者的疗效。
前瞻性、开放标签随机对照试验。
印度马哈拉施特拉邦马哈德区马瓦尔医院和研究中心综合医院的住院患者。
70 名年龄超过 6 个月、无心肺或中枢神经系统异常的 2 级噬人鳄尾蝎蜇伤患者。
按区组随机分配，患者接受蝎毒抗血清加哌唑嗪（n=35）或单独哌唑嗪（n=35）治疗。治疗未设盲法。分析采用意向治疗。
主要终点是使用研究药物治疗 10 小时后，临床综合征（出汗、流涎、四肢发凉、阳萎、高血压或低血压、心动过速）缓解的患者比例。次要结局指标包括临床综合征完全缓解所需的时间、病情恶化至更高等级的预防、总体和 10 小时内所需的哌唑嗪剂量，以及不良事件。该研究方案得到了孟买独立伦理委员会的批准。
与单独使用哌唑嗪组相比，哌唑嗪加蝎毒抗血清组的恢复时间（小时）分别为：出汗 3（1.1）比 6.6（2.6）；流涎 1.9（0.9）比 3（1.9）；阳萎 4.7（1.5）比 9.4（1.5）。两组患者使用的哌唑嗪剂量分别为 2（2.3）和 4（3.5）。在接受治疗后 10 小时内，哌唑嗪加抗血清组 32 名（91.4%，95%置信区间 76.9%至 97.8%）患者的临床综合征完全缓解，而哌唑嗪组 8 名（22.9%，11.8%至 39.3%）患者完全缓解。加用抗血清的患者恢复时间更早（平均 8 小时，95%CI 6.5 至 9.5），而对照组（17.7 小时，15.4 至 19.9；平均差异-9.7 小时，-6.9 至-12.4）。两组患者病情恶化至更高等级的人数相似（抗血清加哌唑嗪组 4 例，哌唑嗪组 5 例）。抗血清加哌唑嗪组报告低血压的患者（12/35，34.3%）少于哌唑嗪组（19/35，54.3%），但差异无统计学意义。两组间血压和脉搏率随时间的变化无差异。
与单独使用哌唑嗪相比，同时使用蝎毒抗血清加哌唑嗪可加速蝎蜇伤的恢复。
CTRI/2010/091/000584（印度临床试验注册中心）。
