A randomized, controlled clinical trial of intravenous lipid emulsion as an adjunctive treatment for permethrin toxicosis in cats.

To assess for any clinical benefit of intravenous lipid emulsion (ILE) for permethrin toxicosis in cats by comparing the progression of clinical signs of cats before and after treatment with ILE to cats treated with a saline control. To accomplish this objective, a clinical staging system for cats with permethrin toxicosis was developed and validated. Prospective, multicenter, randomized, controlled clinical trial. University veterinary teaching hospital and 12 private veterinary emergency hospitals. Thirty-four client-owned cats with permethrin toxicosis. A clinical staging system was designed based on abnormalities found on physical examination of cats with permethrin toxicosis. The clinical staging system had 6 stages, ranging from Stage A for cats with no abnormalities to Stage F for cats with grand mal seizures. The system was validated for intraviewer and interviewer variability. Cats in the clinical trial were randomized to receive 15 mL/kg of either intravenous 0.9% saline (control) or 20% ILE over 60 minutes. For each cat, a clinical stage was recorded at set time points before and after the randomized treatment was administered. The distribution of clinical stage stratified over time was compared across treatment groups. The clinical staging system showed excellent repeatability (P = 1.0) and reliability (P = 1.0). In the clinical trial, there was a significant difference in the distribution of clinical stages over time (P < 0.001) and from presentation stage to Stage B (P = 0.006), with ILE-treated cats (n = 20) having lower clinical stages earlier than control cats (n = 14). There was no significant difference in signalment, body weight, or supportive treatment between the groups. The clinical staging system was repeatable and reliable. Clinical stages of permethrin toxicosis in ILE-treated cats improved earlier compared to control cats, suggesting ILE may be a useful adjunctive therapy in the treatment of permethrin toxicosis in cats.