Gale Stephen C, Peters Jo Ann, Allen LaDonna, Creath Robert, Dombrovskiy Viktor Y
Division of Trauma, Department of Surgery, East Texas Medical Center, Tyler, TX USA ; Director of Trauma Services, East Texas Medical Center, Level 1 Trauma Center, 1020 E. Idel St., Tyler, TX 75701 USA.
Division of Trauma, Department of Surgery, East Texas Medical Center, Tyler, TX USA.
J Venom Anim Toxins Incl Trop Dis. 2016 Jan 13;22:2. doi: 10.1186/s40409-016-0056-9. eCollection 2016.
Crotalidae Polyvalent Immune Fab (Ovine) (FabAV) antivenin is commonly recommended after pit viper snakebites. Because copperhead envenomations are usually self-limited, some physicians are reluctant to use this costly treatment routinely, while others follow a more liberal approach. We hypothesized that, in practice, only patients with evidence of significant (moderate or severe) copperhead envenomation [those with snakebite severity score (SSS) > 3] receive FabAV and examined a large cohort to determine the relationship between clinical findings and FabAV administration.
All data from patients evaluated for copperhead snakebite at a rural tertiary referral center from 5/2002 to 10/2013 were compiled. Demographics, transfer status, antivenin use, and clinical findings were collected; SSS was calculated. The relationships among FabAV use, clinical findings, and SSS were analyzed using t-test, chi-square, and Pearson's coefficient (p < 0.05 was significant).
During the study period, 318 patients were treated for copperhead snakebite; 44 (13.8 %) received antivenin. Median dose was four vials (range: 1-10; IQR: 4,6). There were no deaths. Most patients receiving FabAV (63.6 %) were admitted. With regard to demographics and symptoms, only the degree of swelling (moderate vs. none/mild; p < 0.01) and bite location (hand/arm vs. leg: p < 0.0001) were associated with FabAV use. A SSS > 3, indicating moderate or severe envenomation, was only very weakly correlated with antivenin use (r = 0.217; p < 0.0001). The majority of patients with SSS > 3 (65.8 %) did not receive antivenin while most patients who did receive antivenin (70.5 %) had SSS ≤ 3 (indicating mild envenomation).
Considerable variation occurs in antivenin administration after copperhead snakebite. Use of FabAV appears poorly correlated with patients' symptoms. This practice may expose patients to the risks of antivenin and increasing costs of medical care without improving outcomes. Guidelines used for treating other pit viper strikes, such as rattlesnake or cottonmouth snakebite may be too liberal for copperhead envenomations. Our data suggests that most patients with mild or moderate envenomation appear to do well independent of FabAV use. We suggest, for patients with copperhead snakebite, that consideration be given to withholding FabAV for those without clinical evidence of severe envenomation until prospective randomized data are available.
响尾蛇科多价免疫Fab（羊）（FabAV）抗蛇毒血清常用于蝰蛇咬伤后。由于铜头蝮蛇咬伤通常具有自限性，一些医生不愿常规使用这种昂贵的治疗方法，而另一些医生则采取更宽松的方法。我们推测，在实际应用中，只有出现显著（中度或重度）铜头蝮蛇咬伤证据的患者[蛇咬伤严重程度评分（SSS）>3]才会接受FabAV治疗，并通过一个大型队列研究来确定临床发现与FabAV使用之间的关系。
汇总了2002年5月至2013年10月在一家农村三级转诊中心接受铜头蝮蛇咬伤评估的患者的所有数据。收集了人口统计学信息、转诊状态、抗蛇毒血清使用情况和临床发现；计算了SSS。使用t检验、卡方检验和皮尔逊系数分析FabAV使用、临床发现和SSS之间的关系（p<0.05具有统计学意义）。
在研究期间，318例患者接受了铜头蝮蛇咬伤治疗；44例（13.8%）接受了抗蛇毒血清治疗。中位剂量为4瓶（范围：1-10；四分位间距：4,6）。无死亡病例。大多数接受FabAV治疗的患者（63.6%）住院。在人口统计学和症状方面，只有肿胀程度（中度与无/轻度；p<0.01）和咬伤部位（手/手臂与腿部：p<0.0001）与FabAV使用相关。SSS>3表明中度或重度中毒，与抗蛇毒血清使用的相关性非常弱（r=0.217；p<0.0001）。大多数SSS>3的患者（65.8%）未接受抗蛇毒血清治疗，而大多数接受抗蛇毒血清治疗的患者（70.5%）的SSS≤3（表明轻度中毒）。
铜头蝮蛇咬伤后抗蛇毒血清的使用存在很大差异。FabAV的使用与患者症状的相关性似乎较差。这种做法可能会使患者面临抗蛇毒血清的风险，并增加医疗费用，而不会改善治疗结果。用于治疗其他蝰蛇咬伤（如响尾蛇或水蝮蛇咬伤）的指南对于铜头蝮蛇咬伤可能过于宽松。我们的数据表明，大多数轻度或中度中毒的患者似乎无需使用FabAV就能恢复良好。我们建议，对于铜头蝮蛇咬伤患者，在没有严重中毒临床证据的情况下，应考虑暂不使用FabAV，直到有前瞻性随机数据可用。
