Prospective study of recovery from copperhead snake envenomation: an observational study.

Eric J Lavonas,Charles J Gerardo,Copperhead Snakebite Recovery Outcome Group

doi:10.1186/s12873-015-0033-6

Abstract

BackgroundAlthough much is known about signs, symptoms, and management in the acute phase of crotaline snake envenomation, little is known about signs, symptoms, function, and quality of life during the recovery phase. The purpose of this observational pilot investigation is to evaluate the utility of several clinical outcome instruments in the setting of copperhead snakebite, and to characterize the clinical course of recovery.MethodsThis is a multi-center prospective, open-label, observational study of patients envenomated by copperhead snakes. We administered the Disabilities of the Arm, Shoulder, and Hand (DASH), Lower Extremity Functional Scale (LEFS), Patient-Specific Functional Scale (PSFS), Work Productivity and Ability Impairment: Special Health Problem (WPAI: SHP), Patients’ Global Impression of Change (PGIC), Patient’s Global Assessment of Recovery (PGAR), and SF-36 instruments, obtained numeric pain rating scales, and measured grip strength, walking speed, and swelling prior to hospital discharge and 3, 7, 14, 21, and 28 days after envenomation.Results20 subjects were enrolled; none were lost to follow-up. Most (80%) had moderate severity swelling, and most (75%) received antivenom. Across the broad range of measures, abnormalities of pain, swelling, impairments of physical and role function, and quality of life persisted for 7–14 days in most subjects. Validated self-reported outcome measures, such as the DASH, LEFS, PSFS, PGIC, SF-36, and the daily activities impairment portion of the WPAI: SHP were more responsive than measurements of swelling or walking speed. Data quality issues limited the utility of the work impairment portion of the WPAI: SHP. Residual signs, symptoms, and impairment in some subjects lasted through the 28-day study period. The study design precluded any assessment of the effectiveness of antivenom.ConclusionsSigns, symptoms, impaired function, and decreased quality of life typically last 7 – 14 days after copperhead envenomation. Several tools appear responsive and useful in studying recovery from pit viper envenomation.Trial registrationClinicalTrials.gov NCT01651299

Highlights

Much is known about signs, symptoms, and management in the acute phase of crotaline snake envenomation, little is known about signs, symptoms, function, and quality of life during the recovery phase
This is likely because copperhead envenomation patients rarely develop life-threatening systemic effects, such as hypotension and hematologic abnormalities that are common in rattlesnake envenomation [6,7,8]
Two potential subjects were excluded because they were unwilling or unable to complete follow-up assessments; no subjects were excluded because of distracting injuries or other comorbidities that would limit the validity of assessments

Summary

Introduction

Much is known about signs, symptoms, and management in the acute phase of crotaline snake envenomation, little is known about signs, symptoms, function, and quality of life during the recovery phase. The purpose of this observational pilot investigation is to evaluate the utility of several clinical outcome instruments in the setting of copperhead snakebite, and to characterize the clinical course of recovery. This is likely because copperhead envenomation patients rarely develop life-threatening systemic effects, such as hypotension and hematologic abnormalities that are common in rattlesnake envenomation [6,7,8]. Persistent limb dysfunction has been described in patients managed with and without antivenom [10,11,12]

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Discussion

Conclusion