Effect of mean arterial pressure, haemoglobin and blood transfusion during cardiopulmonary bypass on post-operative acute kidney injury

Michael Haase, Rinaldo Bellomo, David Story, Angela Letis, Katja Klemz, George Matalanis, Siven Seevanayagam, Duska Dragun, Erdmann Seeliger, Peter R. Mertens, Anja Haase-Fielitz

Research output: Contribution to journalArticleResearchpeer-review

170 Citations (Scopus)

Abstract

Background.Acute kidney injury (AKI) after cardiac surgery is a common and serious condition carrying significant costs. During cardiopulmonary bypass (CPB) surgery, modifiable factors may contribute to post-operative AKI. Their avoidance might be a potential target for nephroprotection. Methods.The objective of the present study was to identify and determine whether intraoperative hypotension, anaemia, or their combination, red blood cell transfusion or vasopressor use are independent risk factors for post-operative AKI defined by the RIFLE (renal Risk, Injury, Failure, Loss of renal function and End-stage renal disease) classification and other thresholds using a mixed logistic multivariate model. Results.We analysed 381468 mean arterial pressure (MAP) measurements from 920 consecutive on-pump cardiac surgery patients. Overall, 19.5% developed AKI which was associated with an 8.2-fold increase in-hospital mortality. Haemoglobin concentration was an independent risk factor for AKI {odds ratio [OR] 1.16 per g/dL decrease [95% confidence interval (CI) 1.05-1.31]; P = 0.018} with systemic arterial oxygen saturation and pressure values not adding further strength to such an association. MAP alone or vasopressor administration was not independently associated with AKI but volume of red blood cell transfusion was, with its effect being apparent at a haemoglobin level of >8 g/dL (>5 mmol/L). In patients with severe anaemia (<25th percentile of lowest haemoglobin), the independent effect of hypotension (>75th percentile of area under the curve MAP <50 mmHg) on AKI was more pronounced [OR 3.36 (95% CI 1.34-8.41); P = 0.010]. Conclusion.Intraoperative avoidance of the extremes of anaemia, especially during severe hypotension and avoidance of transfusion in patients with haemoglobin levels >8 g/dL (>5 mmol/L) may help decrease AKI in patients undergoing cardiac surgery and represent targets for future controlled interventions.

Original languageEnglish
Pages (from-to)153-160
Number of pages8
JournalNephrology Dialysis Transplantation
Volume27
Issue number1
DOIs
Publication statusPublished - 1 Jan 2012
Externally publishedYes

Keywords

  • acute kidney injury
  • anaemia
  • blood transfusion
  • cardiac surgery
  • hypotension

Cite this