Division of Plastic and Reconstructive Surgery, Department of Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
Division of Infection, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
PLoS Negl Trop Dis. 2022 Feb 10;16(2):e0010066. doi: 10.1371/journal.pntd.0010066. eCollection 2022 Feb.
Naja atra bites cause wound necrosis, secondary infection, and necrotizing soft tissue infection (NSTI) requiring repetitive surgeries. Little information is known about the predictors for surgery after these bites.
We retrospectively evaluated 161 patients envenomed by N. atra, 80 of whom underwent surgery because of wound necrosis and infection. We compared the patients' variables between surgical and non-surgical groups. To construct a surgical risk score, we converted the regression coefficients of the significant factors in the multivariate logistic regression into integers. We also examined the deep tissue cultures and pathological findings of the debrided tissue.
A lower limb as the bite site, a ≥3 swelling grade, bullae or blister formation, gastrointestinal (GI) effects, and fever were significantly associated with surgery in the multivariate logistic regression analysis. The surgical risk scores for these variables were 1, 1, 2, 1, and 2, respectively. At a ≥3-point cutoff value, the model has 71.8% sensitivity and 88.5% specificity for predicting surgery, with an area under the receiver operating characteristic curve of 0.88. The histopathological examinations of the debrided tissues supported the diagnosis of snakebite-induced NSTI. Twelve bacterial species were isolated during the initial surgery and eleven during subsequent surgeries.
From the clinical perspective, swelling, bullae or blister formation, GI effects, and fever appeared quickly after the bite and before surgery. The predictive value of these factors for surgery was acceptable, with a ≥3-point risk score. The common laboratory parameters did not always predict the outcomes of N. atra bites without proper wound examination. Our study supported the diagnosis of NSTI and demonstrated the changes in bacteriology during the surgeries, which can have therapeutic implications for N. atra bites.
眼镜蛇咬伤可导致伤口坏死、继发感染和坏死性软组织感染（NSTI），需要反复手术。关于这些咬伤后手术的预测因素知之甚少。
我们回顾性评估了 161 名被眼镜蛇咬伤的患者，其中 80 名因伤口坏死和感染而接受手术。我们比较了手术组和非手术组患者的变量。为了构建手术风险评分，我们将多元逻辑回归中显著因素的回归系数转换为整数。我们还检查了清创组织的深部组织培养和病理发现。
下肢咬伤、肿胀程度≥3 级、水疱或大疱形成、胃肠道（GI）效应和发热在多变量逻辑回归分析中与手术显著相关。这些变量的手术风险评分分别为 1、1、2、1 和 2。当截断值≥3 分时，该模型对手术的预测具有 71.8%的敏感性和 88.5%的特异性，受试者工作特征曲线下面积为 0.88。清创组织的组织病理学检查支持蛇咬伤引起的 NSTI 诊断。初次手术中分离出 12 种细菌，随后的手术中分离出 11 种。
从临床角度来看，肿胀、水疱或大疱形成、GI 效应和发热在咬伤后很快出现，且在手术前出现。这些因素对手术的预测价值可以接受，风险评分≥3 分。常见的实验室参数并不总是能预测没有适当伤口检查的眼镜蛇咬伤的结果。我们的研究支持 NSTI 的诊断，并证明了手术过程中细菌学的变化，这对眼镜蛇咬伤具有治疗意义。
