Diabetes alters cardiovascular responses to anaesthetic induction agents in STZ-diabetic rats

Background: People with diabetes are at increased risk of cardiovascular (CV) morbidity and mortality during surgery. The most appropriate anaesthetic induction agent for these patients is unknown. Methods and results: We assessed the CV effects of propofol, etomidate and ketamine in streptozotocin (65 mg/kg, IP) diabetic rats. In non-diabetic rats, none of these anaesthetics significantly modified cardiac output, heart rate or stroke volume, but ketamine increased systolic blood pressure (SBP) compared to etomidate and propofol (89.6 +/- 2.4 mmHg, vs. 72.7 +/- 3.0 and 75.4 +/- 1.9; p < 0.05). In diabetic rats, by contrast, cardiac output was lower with ketamine (82.6 +/- 14 ml/min) and etomidate (78.2 +/- 15.8 ml/min) than with propofol (146 +/- 21 ml/min, N = 8, p < 0.01). SBP, however, was higher in the propofol-treated group (93.3 +/- 3.4 mmHg, p < 0.05). Conclusion: These results suggest that hyperglycaemia modifies CV responses to induction anaesthetics.