Effect of Gender on Propofol Requirement

Total intravenous anaesthesia (TIVA) has emerged as a viable alternative to inhalational general anaesthesia (GA). Propofol is the preferred drug for providing TIVA due to its favorable pharmacokinetic profile, such as, rapid onset of action and a short context sensitivity half -life. There is suggestion that consumption of Propofol required during TIVA is influenced by gender with females requiring higher dose due to higher volume of distribution of drug. The evidence on gender differences in Propofol requirement for TIVA is largely based on studies done using subjective (manual titration of infusions)/semi-objective (target-controlled infusions) methods of drug administration, whose initial setting and ongoing control may be affected by attending anesthesiologist discretion and action. A recent advance in Propofol TIVA delivery is development of objective automated anaesthesia delivery systems. These systems administer Propofol titrated to patients' electroencephalogram (EEG) response reflected by processed EEG monitoring, namely the Bispectral index (BIS). One such indigenously developed automated anaesthesia delivery system is the closed-loop anaesthesia delivery system (CLADS). CLADS is a more precise and robust system to facilitate administration of Propofol TIVA, which automatically regulates the dose of medication based on feedback from patient's BIS data. The present study proposes to explore if there can be any gender differences in Propofol requirements during total intravenous anaesthesia administered by CLADS. All patients undergoing elective surgery under Propofol TIVA using CLADS will be screened, and those eligible will be enrolled. Enrolled patients will receive automated Propofol TIVA using CLADS. Demographic and clinical details including gender of patient will be noted. Cumulative dose of Propofol use will be computed through algorithm executed and monitored by software built into the CLADS. The findings will then be compared between male and female gender. Other intraoperative and post- operative outcomes such as time-to-loss of consciousness, time-to-induction of anaesthesia, anaesthesia depth consistency, performance characteristic of CLADS, hemodynamic profile (heart rate, mean arterial blood pressure), time-to-early recovery from anaesthesia, and postoperative sedation scale (modified observers' assessment of alertness/sedation scale [MOAA/S]); will be noted and compared between males and females. We expect to enroll 80 patients in our study.

Inclusion Criteria:Age 18-60 years.ASA physical status I and II.Patients undergoing elective surgeries of minimum 1 hour duration.Exclusion Criteria:Uncompensated cardiovascular disease (e.g., uncontrolled hypertension, systolic and diastolic dysfunction)Hepatic dysfunction (liver enzymes > 2 times the normal range)Renal dysfunction (serum creatinine > 1.4 mg/dl)Psychiatric or neurological disorderUncontrolled endocrinology disease (diabetes mellitus, hypothyroidism)Known allergy/hypersensitivity to the study drugHistory of recent intake of sedative medication or anti-psychotic medicationDrug dependence/substance abuseRequirement of postoperative ventilationRefusal to informed consent