Comparison of the effects of general anesthesia and combined spinal-epidural anesthesia on intraocular pressure in lower extremity surgeries employing pneumatic tourniquets: a randomized clinical trial

Abstract

Background & Objective: Induction of general anesthesia has been known to raise the intraocular pressure (IOP). The effect is more pronounced at the time of intubation. Similarly, applying pneumatic tourniquets is associated with rise in IOP. We compared the effects of general anesthesia and combined spinal-epidural anesthesia (CSEA) on IOP in lower extremity surgeries employing pneumatic tourniquets. Methodology: A total of 50 patients, aged over 18 y, completed the study. Patients were randomly divided into the general anesthesia group (Group GA) and CSEA group (Group CSE). IOP and hemodynamic parameters including systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP) and heart rate (HR),were measured at baseline (T0), and after general anesthesia induction (T1), after intubation or after initiation of CSEA (T2), after placement of tourniquet (T3), and on removal of tourniquet (T4). Results: There was no difference in IOP between the groups at T0 (P > 0.05), but it was higher at T2, T3, and T4 in Group CSE than in Group GA (P < 0.05). SAP was only higher in Group CSE at T3 (P < 0.05). İn Group GA IOP at T1, T3, and T4 was lower than that at T0 (P < 0.01) but were similar at T2 and T0 (P > 0.05). SAPs at T1, T3, and T4 were lower than those at T0 (P < 0.05) but were similar to those at T2 and T0 (P > 0.05). İn Group CSE although SAP was lower at T2, T3, and T4 than that at T0 (P < 0.05), IOP at T2 was higher than that at T0 (P < 0.01). IOP was the same at T3, T4, and T0 (P > 0.05). Abbreviations: IOP: intraocular pressure; CSEA: combined spinal-epidural anesthesia; SAP: systolic arterial pressure; DAP: diastolic arterial pressure; MAP: mean arterial pressure Key words: Intraocular Pressure; Anesthesia, Spinal; Anesthesia, General; Anesthesia, combined spinal-epidural;  Tourniquet Citation: Yildiz G, Gulec H, Ozayar E, Horasanli E. Comparison of the effects of general anesthesia and combined spinal-epidural anesthesia on intraocular pressure in lower extremity surgeries employing pneumatic tourniquets: a randomized clinical trial. Anaesth. pain intensive care 2023;27(1):09−15 DOI: 10.35975/apic.v27i1.2135 Received: December 17, 2020; Reviewed: January 27, 2021; Accepted: March 18, 2021