ABSTRACT
In 30 patients of rheumatic heart disease with mitral stenosis (MS) belonging to NYHA class II and III scheduled for closed mitral commissurotomy anaesthesia was induced with morphine 0.15 mg/kg followed by either thiopentone (group A, n = 15) or midazolam (group B, n = 15) titrated to produce sleep. Patients were intubated with pancuronium bromide in a dose of 0.12 mg/kg. Minimum mean arterial blood pressure following induction was significantly lower in thiopentone group (77 +/- 7 mm Hg) than midazolam group (85 +/- 6 mm Hg; P < 0.05). After intubation blood pressure was significantly higher in thiopentone group (99 +/- 8 mm Hg) than midazolam group patients (89 +/- 7 mm Hg). Heart rate was significantly higher in thiopentone treated patients both before and after endotracheal intubation. During surgery, three patients in group A had hypotensive episodes (mean arterial blood pressure 20% below basal at two successive readings 5 min apart) while one in group B had a hypotensive episode. Average duration of surgery was comparable between the two groups (102 +/- 15 and 95 +/- 18 min) and postoperatively there was no significant difference in sedation score and incidence of nausea and vomiting between the two groups.