The Efficacy of Crotaline Fab Antivenom for Copperhead Snake Envenomations
试验速览
- 阶段
- 4 期
- 状态
- 终止
- 入组人数
- 13
- 试验地点
- 8
- 主要终点
- Limb Function: AMA Disability Rating Score of Envenomated Limb
研究概览
简要总结
Most patients bitten by copperhead snakes do not currently receive antivenom. Some snakebite victims have long term problems with the function of the limb that was bitten. This study will determine whether early administration of antivenom to patients with mild to moderate copperhead snakebites reduces long-term complications.
详细描述
This study seeks to answer three important questions about the role of ovine (sheep-derived) antivenom in the treatment of people bitten by copperhead snakes (Agkistrodon contortrix):
- Although ovine antivenom has been approved by the FDA for treatment of copperhead envenomation, copperhead victims were excluded from the previous clinical trials. Animal experiments and retrospective human data suggest that the antivenom probably does work for copperhead snakebite, at least in the short term. This study will determine whether the antivenom is actually effective in reducing pain, swelling, and other immediate effects of copperhead snakebite.
- Deaths from copperhead snakebite are extremely rare, but survivors often report long term problems with pain and swelling in the envenomated limb. No study has formally measured the long-term outcomes in untreated snakebite, nor whether antivenom has any benefit in reducing the duration or severity of these complications. This study will answer this question through formal assessments of limb function up to 12 months after treatment.
- After initial control of the signs and symptoms of snakebite is achieved with antivenom therapy, some patients develop recurrent swelling or blood clotting problems. A randomized controlled trial in rattlesnake victims showed that the frequency of these problems is reduced by administration of 6 additional vials of antivenom over 18 hours ("maintenance therapy"). However, blood clotting problems are uncommon in copperhead snakebite even without antivenom treatment, and a retrospective trial suggested that maintenance therapy may have no effect on the frequency of delayed swelling in copperhead victims. In the typical copperhead victim, maintenance therapy increases the cost of treatment by more than 100%. This study will determine whether maintenance therapy is necessary in mild to moderate copperhead snakebite.
Patients are eligible for enrollment if they have been bitten by a snake positively identified as a copperhead within 6 hours of enrollment, if they have signs of mild or moderate severity envenomation, and if contraindications are not present.
After appropriate informed consent, patients are randomized to receive:
A. initial stabilizing dose of antivenom, followed by maintenance therapy,
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 12 Months 至 —（Child, Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Envenomation by copperhead snake (Agkistrodon contortrix) within 6 hours
- •Mild or moderate severity envenomation
排除标准
- •Allergy to antivenom or components
- •Severe envenomation (hypotension, severe swelling, compartment syndrome, bleeding, etc.)
- •Uncertain snake ID
- •Prior treatment with antivenom
结局指标
主要结局
Limb Function: AMA Disability Rating Score of Envenomated Limb
时间窗: 14 days
The range of possible scores is 0 - 100, and a lower score denotes less disability.
Limb Function: AAOS Normative Outcome Study Scoring for Envenomated Limb
时间窗: One year
Score ranges from 0-100 with higher scores meaning better function.
Limb Function: AAOS--time to Return to Normal Value
时间窗: 14 days
Score ranges from 0-100 with higher scores meaning better function. Time in days to return to baseline value.
次要结局
- Pain Medication Use(First 6 hours from baseline, first 18 hours from baseline, First 24 hours from baseline, 12 months)
- Swelling: % Change in Volume Compared to Contralateral (Non-envenomated) Limb(14 days)
- Limb Function: Physical or Occupational Therapy Sessions Attended(Week 4)
- Pain: Visual Analog Score(14 days)
- Swelling: Percentage (%) of Limb Spread Proximal From Bite Site(12 months)
- Hematological: Clotting Studies and Platelet Counts(12 months)
- Limb Function: Return to Work(Week 4)
- Complications of Therapy(12 months)