Impact of mean arterial pressure on sublingual microcirculation during cardiopulmonary bypass-Secondary outcome from a randomized clinical trial.

Objective: In this substudy of a randomized, clinical trial, we explored the sublingual microcirculation during cardiac surgery at 2 different levels of blood pressure. We hypothesized that a higher map during CPB would cause higher MFI.

Methods: Thirty-six cardiac surgery patients undergoing CABG were included and randomized to either low (40-50 mm Hg) or high (70-80 mm Hg) MAP during CPB. SDF video images were recorded from the sublingual mucosa. Recordings were analyzed in a blinded fashion to quantify microcirculatory variables.

Results: MAP during CPB in the low target group was 45.0 mm Hg (SD: 5.3) vs 67.2 mm Hg (SD: 8.9) in the high target group. We found no significant difference between the 2 groups in MFI during CPB evaluated for AV: 2.91 vs 2.90 (P = .82). For sm AV (<20 μm), the corresponding values were 2.87 and 2.85 in the low and high target groups, respectively (P = .82).

Conclusions: We found no significant difference in sublingual microcirculatory flow expressed as MFI according to 2 different levels of MAP during CPB.