Influence of the Trendelenburg position and carboxyperitoneum on cerebral tissue oximetry values

Abstract

Background. Cerebral tissue oximetry (rSO2) can be used to assess cerebral circulation. Cerebral tissue oximetry studies have been performed in the Trendelenburg position (30º), but data for 45 o are not available.Objective. To study the effect of the Trendelenburg position (45°) under carboxyperitoneum conditions on rSO2 and hemodynamic parameters.Design and methods. A single-center, prospective, descriptive study was conducted among patients (n = 30) who underwent robot-assisted laparoscopic prostatectomy. We measured rSO2 on the left and right, central venous pressure (CVP), mean arterial pressure (MAP), venous saturation at points: T1 — after induction of anesthesia and start of measurements; T2 — 5 minutes after positioning the patient in the Trendelenburg position of 45o; T3 — 15 minutes; T4 — 30 minutes; T5 — after returning to a horizontal position. Cerebral perfusion was assessed using cerebral perfusion pressure (CPP).Results. rSO2 on the right and left at points T2, T3 and T5 significantly exceeded T1. There was a significant increase in BP mean at T2 and T3, as well as a significant increase in CVP at T2, T3 and T4 compared to T1. The CPP significantly decreased compared to T1 at points T3, T4 and T5.Conclusions. The Trendelenburg position with a tilt angle of 45º in combination with carboxyperitoneum is accompanied by an increase in rSO2, blood pressure and CVP.