Intravenous infusion of amino acids in dogs attenuates hypothermia during anaesthesia and stimulates insulin secretion

ObjectiveTo evaluate the effect of intravenous infusion of amino acids on the prevention of hypothermia during anaesthesia in dogs. Study designRandomized experimental trial. AnimalsSeven healthy Beagle dogs. MethodsFour concentrations of amino acids were prepared with a 10% amino acid solution and an acetated Ringer's solution, and dogs were infused with each of the solutions at 1week intervals. Dogs were infused with amino acid solution at 12mLkg(-1)hour(-1) for 60minutes before and for 60minutes after induction of anaesthesia. Acetated Ringer's solution was infused at the same rate for the remaining 60minutes of anaesthesia. The infusion treatments were: 1) A0, nutrient-free acetated Ringer's solution; 2) A6, 0.6gkg(-1)hour(-1); 3) A9, 0.9gkg(-1)hour(-1); and 4) A12, 1.2gkg(-1) hour(-1). Rectal temperature (RT), heart rate (HR), mean arterial pressure (MAP), blood insulin, glucose, urea nitrogen (BUN) and creatinine concentrations, and time to extubation were measured. ResultsBefore anaesthesia, RT was not affected by amino acid infusion. RT decreased progressively during anaesthesia and the absolute values of RT from 30 to 120minutes were significantly higher in A12 than in A0 (p<0.05). Reductions in HR and MAP during anaesthesia were attenuated by amino acid infusion in a dose-dependent manner. Plasma insulin concentration was significantly higher in A12 than in A0 during amino acid infusion and the increase in insulin concentration was greater during than before anaesthesia. BUN increased during amino acid infusion in a dose- and time-dependent fashion. Time until extubation was shorter in A12 than in A0. Conclusions and clinical relevanceAmino acids infused at 1.2gkg(-1)hour(-1) in dogs attenuated the decrease in RT, HR, and MAP during anaesthesia, and induced a significant increase in plasma insulin concentration.