Microcirculatory perfusion is preserved during off-pump but not on-pump cardiac surgery

Abstract

Objective: This study investigated the perioperative course of microcirculatory perfusion in off-pump compared with on-pump surgery. Additionally, the impact of changes in systemic hemodynamics, hematocrit, and body temperature was studied.

Design: Prospective, nonrandomized, observational study.

Setting: Tertiary university hospital.

Participants: Patients undergoing coronary artery bypass grafting with (n = 13) or without (n = 13) use of cardiopulmonary bypass.

Interventions: Microcirculatory measurements were obtained at 5 time points ranging from induction of anesthesia to ICU admission.

Measurements and main results: Microcirculatory recordings were performed with sublingual sidestream dark field imaging. Despite a comparable reduction in intraoperative blood pressure between groups, the perfused vessel density decreased more than 20% after onset of extracorporeal circulation but remained stable in the off-pump group. The reduction in microvascular perfusion in the on-pump group was further paralleled by decreased hematocrit and temperature. Although postbypass hematocrit levels and body temperature were restored to similar levels as in the off-pump group, the median microvascular flow index remained reduced after bypass (2.4 [2.3-2.7]) compared with baseline (2.8 [2.7-2.9]; p = 0.021).

Conclusions: Microcirculatory perfusion remained unaltered throughout off-pump surgery. In contrast, microvascular perfusion declined after initiation of cardiopulmonary bypass and did not recover in the early postoperative phase.

Keywords: cardiopulmonary bypass; coronary artery bypass; microcirculation; off-pump cardiac surgery.

Copyright © 2014 Elsevier Inc. All rights reserved.