Epidemiology and hospital course of rattlesnake envenomations cared for at a tertiary referral center in Central Arizona.

Abstract

To describe the demographics and primary inpatient treatment of victims of rattle-snake bites (RSBs) referred to a teritiary referral poison treatment center in central Arizona, and to compare the frequency of local tissue complications and hematologic toxicity during hospitalization in children with those for adults. This was a chart review of patients diagnosed as having RSB by a toxicology service between July 1994 and April 2000. Data collected included: age, sex, date, bite location, time to and length of hospitalization, time to and amount of antivenin, serial hematologic studies, and inpatient complications. Of 241 patients admitted, 236 charts met inclusion criteria. The majority of RSB victims were male (81%). Children (< or =13 years) represented 22%. Most RSBs (78%) occurred between April and September. Mean time (+/-SEM) to presentation was 1.7 +/- 0.2 hours. Antivenin was administered to 77% of patients, with an average (+/-SEM) of 28.5 +/- 0.9 vials administered. Hematologic abnormalities included: coagulopathy (60%), hypofibrinogenemia (49%), and thrombocytopenia (33%). No statistically significant difference in the above parameters was detected between upper- and lower-extremity envenomations, or between children and adults. Immediate antivenin reactions occurred in 36% of patients. Hemorrhagic bullae formation occurred in 22%, occurring most frequently in upper extremities. Operative procedures were required in 3.4% of patients. Hospitalization averaged 2.5 +/- 0.1 days. There was no fatality. In Arizona, RSB victims were typically adult males with upper-extremity bites. Hematologic abnormalities were common. Local tissue complications were more common with upper-extremity envenomations. No statistically significant difference was detected in frequency of hematologic disorders or local tissue complications when children were compared with adults.