Does This Patient Have a Severe Snake Envenomation?: The Rational Clinical Examination Systematic Review.

摘要: Importance Venomous snakebite severity ranges from an asymptomatic dry bite to severe envenomation and death. The clinical evaluation aids in prognosis is essential determine the risks potential benefits of antivenom treatment. Objectives To identify historical features, examination findings, basic laboratory testing, grading scales that will risk-stratify patients with pit viper snake for systemic envenomation, tissue injury, and/or hematologic venom effects. Data Sources We conducted a structured search PubMed (1966-October 3, 2017) Embase database (1980-October English-language studies evaluated features predictive envenomation. Study Selection included test performance at least 1 finding acceptable reference standard venomous snakes Western Hemisphere. Only involving most common subfamily,Crotalinae(pit vipers), were evaluated. Seventeen data available abstraction. Extraction Synthesis assessed outcome measures extracted each original study. 3 categories: toxicity, Differences resolved by author consensus. Results pooled prevalence was 14% (95% CI, 9%-21%). injury effects 12%-16%) 18% 8%-27%), respectively. Factors increasing likelihood time care 6 or more hours (likelihood ratio [LR], 3.4 [95% 1.1-6.4]), patient younger than 12 years (LRs, 3.2 1.5-7.1] 2.9 1.3-6.2]), large size (LR, 3.1 1.5-5.7]), ptosis 1.4 1.0-2.1] 3.8 1.8-8.3]). Envenomation genusAgkistrodon(copperhead cottonmouth), as opposed rattlesnakes, decreased 0.28 0.10-0.78]). Initial hypofibrinogenemia 5.1 1.7-15.0]) thrombocytopenia 3.7 1.9-7.3]) increased Other history, physical examination, normal values not discriminative. Conclusions Clinical can risk effects, but there are few associated confidently exclude Physicians should monitor closely be wary progression nonsevere have low threshold escalate therapy needed.