Increasing mean arterial pressure improves jugular venous oxygen saturation in patients with and without preexisting stroke during normothermic cardiopulmonary bypass

Abstract

Study objective To examine whether increasing mean arterial pressure (MAP) with the administration of phenylephrine would improve internal jugular venous oxygen saturation (SjvO2) during normothermic cardiopulmonary bypass (CPB) in patients with preexisting stroke. Design Prospective, controlled study. Setting Cardiovascular center and university hospital. Patients 17 patients with preexisting stroke who were scheduled for elective coronary artery bypass graft (CABG) surgery, and a control group of 17 age-matched patients without preexisting stroke. Interventions After the induction of anesthesia, a fiberoptic oximetry catheter was inserted into the right jugular bulb to monitor SjvO 2. After measuring the baseline partial pressure of the arterial and jugular venous blood gases and cardiovascular hemodynamic values immediately before the start of the study protocol, MAP was increased by the repeated administration of a 10 μg bolus of phenylephrine, until it reached 200% of baseline values. Measurements Partial pressure of the arterial and jugular venous blood gases and cardiovascular hemodynamic values before and after the treatment were recorded. Main results There was no significant difference between the groups in SjvO 2 values at baseline (Mann-Whitney U test: p = 0.22). SjvO 2 values in both groups were increased after the administration of phenylephrine (SjvO 2 values in the control group: 60 ± 5%, SjvO 2 values in the stroke group: 57 ± 5%). There was no significant difference between the stroke and control groups in SjvO 2 values after the administration of phenylephrine (Mann-Whitney U test: p = 0.08). Conclusions Increasing MAP improves SjvO 2 in patients with or without preexisting stroke during normothermic CPB.