Pulmonary and renal function following cardiopulmonary bypass is associated with systemic capillary leak

Abstract

Objective: The purpose of this study was to compare perioperative capillary permeability during cardiac surgery with subsequent pulmonary and renal function.

Design: An observational prospective comparison of capillary permeability (microalbuminuria) during and after cardiopulmonary bypass (CPB), with postoperative pulmonary and renal function.

Setting: A university teaching hospital.

Participants: Forty patients, mean (range) age 67.8 (50-85) years, undergoing elective first-time coronary artery bypass grafting (CABG).

Interventions: Urine albumin concentration (AC) and albumin creatinine ratio (ACR) were compared with PO2 /FIO2 ratio, mechanical ventilation (intermittent positive-pressure ventilation [IPPV]) duration, and renal function.

Measurements and main results: Median (range) AC and ACR increased from 8.3 (1.6-184.2) mg/L and 0.65 (0.1-18.8) mg/mmol preoperatively to 13.6 (1.6-267.2) mg/L and 4.80 (0.3-54.2) mg/mmol 10 minutes postbypass (p = 0.003 for ACR Wilcoxon rank test: not significant for AC). AC 2 hours postbypass was associated with mean PO2 /FIO2 ratio 0 to 2 hours postbypass and AC 4 hours postbypass was associated with mean PO2 /FIO2 ratio 0 to 2 and 2 to 12 hours postbypass (p < 0.05 Spearman). ACR 2 hours postbypass was associated with mean PO2 /FIO2 ratio 0 to 2 and 2 to 12 hours postbypass (p < 0.05 Spearman). AC 10 minutes and 2 hours postbypass and ACR 2 hours postbypass were associated with the duration of IPPV (p < 0.03). Day 1 serum creatinine was associated with pre- and 4 hours postbypass AC and ACR (p < 0.05). Day 2 serum creatinine was associated with 2 and 4 hours postbypass ACR (p < 0.05).

Conclusions: The magnitude of increase in capillary permeability during CABG is associated with later pulmonary and renal function.