The Effect of Induction of Anesthesia in the Leg-Elevation Position and Head-Down Position Versus Supine Position on the Incidence of Post-Induction Hypotension in Non-Cardiac Surgery: A Randomized Controlled Trial

Abstract Background: Induction of general anesthesia is associated with hypotension in nearly 50% of surgical patients. Intraop-erative hypotension leads to ischemia of vital organs and in-creases the risk of preoperative mortality; therefore, meticulous hemodynamic management to avoid pre-incision hypotension is essential to avoid serious outcomes. Various methods are used for the prevention of post-induc-tion hypotension such as preoperative fluid loading and vaso-pressors. The use of positioning protocols to augment venous return would provide a non-pharmacological option for main-taining the hemodynamic profile without the need for excessive fluids and vasopressors. Aim of Study: In this study, we aimed to evaluate the effica-cy of leg-elevation position and head-down position compared to supine position during induction of anaesthesia in reducing post-induction hypotension. Patients and Methods: This study included adult patients scheduled for elective noncardiac surgery under general anaes-thesia. Before induction of anesthesia, patients were randomly allocated into three groups who started induction of anesthesia in either supine position, leg-elevation position, or head-down position. Blood pressure and heart rate were recorded at 1-min-ute intervals after induction of anesthesia till 15-minutes after intubation. Our primary outcome was the incidence of post-in-duction hypotension (defined as systolic blood pressure <80% of the baseline reading). Other outcomes included systolic blood pressure, heart rate, and norepinephrine consumption. Results: One-hundred and twenty-one patients were avail-able for the final analysis. The incidence of post-induction hypotension was lower in each of leg-elevation group (18/41 [44%] patients) and head-down group (16/40 [40%] patients) compared to the control group (32/40 [80%] patients) (p-values <0.001 and <0.001) without significant difference between the two former groups (p-value=0.823). Furthermore, the norep-inephrine consumption and the duration of hypotension were lower in the leg-elevation group and the head-down group in comparison to the control group. Conclusion: Compared to the supine position, induction of general anesthesia in either leg-elevation position or head-down position reduced the incidence of post-induction hypo-tension and the need for vasopressor administration in adult patients undergoing elective non-cardiac surgery.