Cryotherapy as a coadjuvant in crotaline snakebite management with F(ab')₂ antivenom: A randomized pilot study

Local cryotherapy induces vasoconstriction, which leads to a reduction in the inflammatory process. However, the effectiveness of local cryotherapy as a coadjuvant in the treatment of snakebite with F(ab')₂ antivenom is unknown.

To describe the clinical effectiveness of local cryotherapy as a coadjuvant in patients with snakebite treated with F(ab')₂ antivenom therapy at the Hospital Juárez de Mexico.

Patients with grade II snakebite envenomation according to the Christopher-Rodning classification system were enrolled from the Clinical Toxicology Service of the Hospital Juárez de México. One group of patients received F(ab')₂ antivenom therapy (Antivipmyn®) plus local cryotherapy, and the other group received only F(ab')₂ antivenom therapy.

Thirty-eight patients were included, of whom 86.8 % were male (n = 33). Approximately 81.5 % of the subjects were injured in an upper extremity, while 18.5 % were injured in a lower extremities; 47.3 % of the subjects reported treatment of the snakebite prior to hospitalization (suction, the application of a tourniquet, incision of the bite site, or the application of traditional medicine). No differences were found concerning edema, swelling, and pain between the groups. The group that received local cryotherapy as a coadjuvant to F(ab')₂ antivenom therapy had a shorter hospital stay (Cohen's d = 1.33; 95 % confidence interval [95 % CI] = 0.74-1.62; p < 0.01) and received fewer doses of F(ab')₂ antivenom therapy (Cohen's d = 0.69; 95 % CI = 0.19-3.80; p = 0.03).

The use of adequate local cryotherapy as a coadjuvant to F(ab')₂ antivenom therapy reduces the length of hospital stay and the number of doses of F(ab')₂ antivenom therapy used.