Comparison of Sleep Dose of Propofol and Induction Time in Class 1 Obese and Normal Weight Patients

Background: Anaesthetic management of obese patients is challenging. Induction of anaesthesia with propofol is achieved by intravenous injection until loss of consciousness evidenced by loss of verbal response to command and loss of eyelash reflex. Physiological responses to dose of propofol may differ in class 1 obesity compared to normal weight patients. Objectives: We aim to compare the sleep dose of propofol and induction time in class 1 obese patients to normal weight patients. Materials and Methods: This is a prospective, single blinded, controlled study, conducted in patients aged 18 – 60 years with American Society of Anesthesiologist (ASA) physical status I or II, having body mass index (BMI) of 18.50-24.99 and 30.00-34.99, undergoing elective surgeries requiring general anaesthesia. Seventy patients were randomly recruited into 2 groups based on BMI. BMI was calculated for all the patients. Patients received intravenous propofol at 40mg every 10 seconds until loss of consciousness. The induction time and dose of propofol were recorded. Results: The mean induction dose of Propofol in the obese group was 132.71 ±19.30 mg compared to 128.57 ± 27.24 mg in the normal BMI patients (p=0.13). The mean induction time was 59.23 ± 17.88 seconds in the obese group compared to 65.34 ± 22.66 seconds in the normal BMI group (p=0.15). Conclusion: There was no significant difference in induction dose of propofol, induction time, heart rate and mean arterial pressure in patients with class 1 obesity compared to normal weight patients. Administration of sleep doses therefore should be encouraged.