Internist/Associate Professor Midwestern University College of Veterinary Medicine Phoenix, Arizona, United States
Abstract:
Background: Albuterol delivered by inhalation is a common treatment for hyperkalemia in people but its effect on blood potassium concentrations in cats is unknown.
Objective: Characterize the effects of inhaled albuterol on blood potassium and glucose concentrations, heart rate (HR), and plasma insulin levels in normokalemic cats. Animals: Twenty healthy cats.
Methods: Prospective, randomized study. Cats received albuterol sulfate at a low-dose (90 µg) or high-dose (360 µg). Blood samples and HR were obtained at baseline and then at 10 timepoints after albuterol delivery. Blood potassium and glucose concentrations were measured via blood gas analyzer and plasma insulin levels were measured by radioimmunoassay.
Results: Blood potassium concentrations decreased rapidly after albuterol delivery compared to baseline for low-dose (p < 0.001) and high-dose (p < 0.001) 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 groups (low-dose: 5.10 µIU/mL , 95% CI: 2.79-7.40, p < 0.001; high-dose: 3.86 µIU/mL , 95% CI: 1.49-6.22, p = 0.002). No differences in potassium, glucose, insulin, or HR were found between dosing groups. Conclusion and Clinical Importance: 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.
