Inhaled albuterol rapidly decreases whole blood potassium and increases plasma insulin concentrations, with peak effects 30 minutes after administration in cats.

Abstract

OBJECTIVE: To characterize the effects of inhaled albuterol on blood potassium and glucose concentrations, heart rate (HR), and plasma insulin levels in normokalemic cats. METHODS: In a prospective, randomized study between June 2023 and January 2024, 20 client-owned cats received albuterol sulfate at a low dose (90 µg) or high dose (360 µg). Blood samples and HR were obtained at baseline and 10 time points after albuterol delivery. Blood potassium and glucose concentrations were measured via blood gas analyzer and plasma insulin levels by radioimmunoassay. RESULTS: Blood potassium concentrations decreased rapidly after albuterol delivery compared to baseline for the low dose and high dose within 3 minutes and remained significantly decreased until 180 minutes. The maximal decrease in potassium concentration for albuterol at the low dose was -0.52 mmol/L (95% CI, -0.66 to -0.37) and high dose was -0.38 mmol/L (95% CI, -0.52 to -0.23) and occurred at 30 minutes for both doses. Plasma insulin levels rapidly increased, with peak effect at 30 minutes for both the low dose (5.10 µIU/mL; 95% CI, 2.79 to 7.40) and high dose (3.86 µIU/mL; 95% CI, 1.49 to 6.22). There was no correlation between nadir potassium concentration and albuterol dose (r = 0.12). CONCLUSIONS: Albuterol rapidly decreases blood potassium concentrations in part by stimulating endogenous insulin secretion in cats without dose-dependent effects or clinically meaningful changes in HR or glucose concentrations. CLINICAL RELEVANCE: Inhaled albuterol may be useful to decrease blood potassium concentrations in hyperkalemic cats.