[Evaluation of the Hemodynamic and Endocrino-metabolic Response to Tracheal Intubation in Patients Anesthetized with Thiopental or Propofol]

Objectives: To compare the effects of thiopental and propofol on hemodynamic and metabolic endocrine response to laryngoscopy and intubation.

Material And Methods: We selected two homogeneous groups of 14 healthy patients premedicated with midazolam i.m. (0.07 mg/kg). Induction was with diazepam (0.1 mg/kg), fentanyl (2 micrograms/kg), atropine 0.5 mg and thiopental or propofol (4-6.5 mg/kg and 1.5-2.5 mg/kg, respectively). Parameters recorded were direct arterial pressure, baseline heart rate, and heart rate after induction and at 2 and 5 minutes after intubation. We measured adrenaline (A), noradrenaline (NA), dopamine (Da), glucagon, beta-endorphines, ACTH, cortisol, glucose and amino acids in the baseline and post-intubation blood samples.

Results: We observed a significant increase (p < 0.05) in systolic and diastolic arterial pressure after intubation (10% and 22% respectively) in the thiopental group as compared with the propofol group. With both induction agents, heart rate was higher than baseline values at the three times (p < 0.001). In the thiopental group heart rate was higher after intubation than after induction (p < 0.05). Cortisol fell after intubation in the propofol group (p < 0.05); no other hormonal differences were observed. Hyperglycemia (p < 0.0001) was similar for both groups, while in the propofol group there were significant decreases in several amino acids.

Conclusions: Propofol has a greater mitigating effect on the hyperdynamic response to intubation in healthy patients. For the two induction agents we measured no significant differences in stress hormone levels, apart from the drop in cortisol with propofol. We observed a change in energy-producing metabolites.