Disturbance in venous outflow from the cerebral circulation intensifies the release of blood-brain barrier injury biomarkers in patients undergoing cardiac surgery

Abstract

Objective: Disturbances in venous outflow from the cerebral circulation may result in brain injury. Severe increases in brain venous pressure lead to brain ischemia and, subsequently, brain edema and intracranial hemorrhages. The purpose of this study was to determine the effect of changes in jugular venous bulb pressure (JVBP) on plasma blood brain-barrier biomarkers concentration and disturbances in arteriovenous total and ionized magnesium (a-vtMg and a-viMg) in brain circulation in patients undergoing coronary artery bypass grafting surgery (CABG) with cardiopulmonary bypass (CPB).

Design: Prospective observational study.

Setting: Department of Cardiac Surgery at a Medical University Hospital.

Participants: Ninety-two adult patients undergoing elective CABG with CPB under general anaesthesia were studied.

Methods: Central venous pressure (CVP) was measured using a pulmonary artery catheter. The right jugular vein was cannulized retrogradely for jugular venous bulb pressure (JVBP) measurement. Concentrations of plasma S100β protein, matrix metalloproteinase 9 (MMP-9), creatine kinase isoenzyme BB (CK-BB) a-vtMg and a-viMg were measured as the markers of blood-brain barrier dysfunction. All of them were analyzed in comparison with JVBP during surgery and the early postoperative period.

Results: Elevated JVBP was noted after CPB and after surgery. Its increase above 12 mmHg intensified release of S100β, MMP-9 and CK-BB as well as disorders in a-vtMg and a-viMg. CVP correlated with JVBP, S100β, and MMP-9. Moreover, JVBP correlated with S100β and MMP-9.

Conclusions: Cardiac surgery increased JVBP, and JVBP elevated above 12 mmHg intensified an increase in biomarkers of plasma blood-brain barrier disruption.

Keywords: S100β protein; blood-brain barrier; brain venous pressure; cardiac surgery; cardiopulmonary bypass; cerebral circulation; creatine kinase; matrix metalloproteinase 9; neurologic injury.