Prospective study of morbidity associated with snakebite envenomation

Abstract

Background: The morbidity associated with snakebite envenomation has not been well documented.

Method: Using a standardized questionnaire all patients with snakebite reported to a regional poison center during the year 2001 were followed after hospital discharge by telephone until resolution of symptoms.

Results: One hundred and twenty-eight snakebite cases were reported, of which 16 (12.5%) were lost to follow-up and 31 (24.2%) reported no progression of symptoms beyond puncture and were deemed "dry bites." Eighty-one (63.3%) patients were followed for the duration of symptoms. Age ranged from 1 to 86 years with a mean of 32 years. There were 64 males (79%). The snakes were identified as copperhead (n = 57), unidentified venomous (n = 17), timber rattlesnake (n = 6), and cottonmouth (n = 1). All patients were initially evaluated in a hospital emergency department of which 51 were admitted. Nine patients received antivenin. Of the 37 patients who had a job, 33 lost a mean of 14 days of work (SD +/- 18.1). Mean duration of edema was reported as 11.4 days (S.D +/- 12). Recurrent edema frequently occurred with limb activity. Pain was scored on a scale of 1 to 10, with a mean score of 4.8 (SD +/- 2.7). Mean duration of pain was reported as 7.8 days (SD +/- 6.4). Thirty patients required accommodation for ambulation including crutches (n = 11), limp (n = 11), and no shoes or loose shoes (n = 14). Of the 26 patients bitten on the hand or finger, duration of reduced function persisted for a mean of 14.3 days (SD +/- 10.4) and reduction of hand strength persisted for a mean of 22 days (SD +/- 25.5). Five patients had poorly healing wounds at the bite site which persisted from 14 to 77 days with a mean of 45 days (SD +/- 22.8)

Conclusion: In this study snakebite resulted in significant duration and extent of morbidity in a majority of patients.