Arterial pressure during cardiopulmonary bypass is not associated with acute kidney injury.

BACKGROUND: Acute kidney injury (AKI) after cardiac surgery is common and is associated with increased mortality. We wanted to investigate if the arterial pressure or the use of norepinephrine during cardiopulmonary bypass were associated with AKI. METHODS: A retrospective analysis of patients who underwent coronary artery bypass grafting with or without concomitant procedures was conducted. AKI was defined using the RIFLE criteria. Data on arterial pressure and use of norepinephrine during cardiopulmonary bypass were entered in a binary logistic regression model to control for possible perioperative confounders. RESULTS: A total of 623 patients were included. Mean age was 68.3 ± 9.7 years and 81% were males. AKI was observed in 198 patients (32%). Mean arterial pressure was 47 ± 6 mmHg and 45 ± 6 mmHg (P = 0.008) in the AKI and no-AKI group, respectively. Norepinephrine was used more frequently and in higher amounts, during cardiopulmonary bypass, in patients who developed AKI. These differences in arterial pressures and use of norepinephrine between the groups were not found to be significant when entered in the binary logistic regression model. CONCLUSION: No independent relationship between arterial pressure or use of norepinephrine and AKI was found.