Minimum induction dose (MID) of thiopentone in Pakistani patients.

The thiopentone dose needed for abolition of eyelash reflex was studied in 505 Pakistani patients who were divided in three subgroups, i.e., age less than 16 years, between 16 and 60 years, and over 60 years. The minimum induction dose for thiopentone was then determined in the three groups and the effect of sex, ASA classification, premedication and advancing age were seen. The minimum induction dose in the adult patients (16-60) was 215.8 +/- 66 mgs (3.48 mgs/kg). Both the adult groups and the elderly showed a statistical difference in the dose required by the males and females, but this difference was not seen in children. Thiopentone dose also showed a steady decline as the age progressed. A statistical correlation existed between ASA I and II patients compared to ASA III who required less thiopentone. The premedicated patients required less thiopentone compared to those who did not receive a premedication. Our patients required a lesser dosage for abolition of eyelash reflex than the figures recommended for British population. We recommend a dose of 3.5 mg/kg for adult Pakistani males and 3.3 mg/kg for adult females.