Hyperthermic perfusion during cardiopulmonary bypass and postoperative temperature are independent predictors of acute kidney injury following cardiac surgery

Abstract

Acute kidney injury (AKI) following cardiopulmonary bypass (CPB) is associated with increased mortality, requirement for dialysis, and longer intensive care unit (ICU) and hospital length of stay. Rewarming during CPB and poor oxygen delivery have been associated with AKI; however, the role of temperature management on AKI has not been clearly defined. This study aims to evaluate the role of hyperthermia during CPB and the temperature upon admission to the ICU on AKI following cardiac surgery, using the RIFLE (renal Risk, Injury, Failure, Loss of renal function and End-stage renal disease) criteria.

To determine whether CPB hyperthermia (measured as the cumulative time the arterial outlet temperature >37°C) and ICU admission temperature were independent risk factors for AKI, data from 1393 consecutive adult patients undergoing isolated on-pump coronary artery bypass graft (CABG), valve repair and/or replacement and valve/CABG procedures was analysed using a logistic multivariate model. After testing for interaction, we incorporated covariates having a p-value <0.1. AKI was defined according to the RIFLE criteria as an increase in serum creatinine >50% from baseline to peak value postoperatively. Overall, 12.3% of patients developed AKI with a 4.5-fold increase in in-hospital mortality. Variables found to be independent predictors of AKI included CPB hyperthermia (Odds ratio [OR] 1.03 per minute increase [95% confidence interval (CI) 1.01-1.05]; p = 0.01), ICU admission temperature ([OR] 1.44 per degree increase [(CI) 1.13-1.85]; p<0.001), minimum CPB haemoglobin ([OR] 0.83 per g/dL increase [(CI) 0.71-0.97]; p = 0.02), use of intra-aortic balloon pump ([OR] 2.69 [(CI) 1.24-5.82]; p = 0.01) and ICU readmission ([OR] 3.13 [(CI) 1.73-5.64]; p<0.001).

Avoiding arterial outlet hyperthermia may help decrease AKI following cardiac surgery using CPB. Both intraoperative and postoperative temperature management strategies should be the focus of future randomised studies to determine optimal interventions.

Keywords

cardiopulmonary bypass rewarming hyperthermia acute kidney injury cardiac surgery

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References

Boodhwani

Rubens

Wozny

Nathan

. Effects of mild hypothermia and rewarming on renal function after coronary artery bypass grafting. Ann Thorac Surg 2009; 87: 489–495.

Garwood

. Cardiac surgery – associated acute renal injury: new paradigms and innovative therapies. JCVA 2010; 24: 990–1001.

Bellomo

Ronco

Kellum

Mehta

Palevsky

. Acute renal failure – definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group. Critical Care 2004; 8: 204–212.

Moore

Nichol

Bernard

Bellomo

. Therapeutic hypothermia: benefits, mechanisms and potential clinical applications in neurological, cardiac and kidney injury. Injury 2011; 42: 843–854.

Karkouti

Wijeysundera

Yau

. Acute kidney injury after cardiac surgery: focus on modifiable risk factors. Circulation 2009; 119: 495–502.

Haase

Bellomo

Story

. Effect of mean arterial pressure, haemoglobin and blood transfusion during cardiopulmonary bypass on post-operative acute kidney Injury. Nephrol Dial Transplant 2012; 27: 153–60.

de Somer

Mulholland

Bryan

Aloisio

van Nooten

Ranucci

. O₂ delivery and CO₂ production during cardiopulmonary bypass as determinants of acute kidney injury: time for a goal-directed perfusion management? Crit Care 201; 15: R192.

Zager

Gmur

Bredl

Eng

. Degree and time sequence of hypothermic protection against experimental ischemic acute renal failure. Circ Res 1989; 65: 1263–1269.

Insler

OConnor

Leventhal

. Association between postoperative hypothermia and adverse outcome after coronary artery bypass surgery. Ann Thorac Surg 2000; 70: 175–181.

10.

Newland

Baker

Stanley

. Electronic data processing: the pathway to automated quality control of cardiopulmonary bypass. J Extra Corpor Technol 2006; 38: 139–143.

11.

Kourliouros

Valencia

Phillips

Collinson

. Low cardiopulmonary bypass perfusion temperatures are associated with acute kidney injury following coronary artery bypass surgery. Eur J Cardiothorac Surg 2010; 37: 704–709.

12.

Shann

Likosky

Murkin

. An evidence-based review of the practice of cardiopulmonary bypass in adults. A focus on neurological injury, glycemic control, hemodulation, and the inflammatory response. J Thorac Cardiovasc Surg 2006; 132: 283–290.

13.

Grocott

Mackensen

Grigore

. Postoperative hyperthermia is associated with cognitive dysfunction after coronary artery bypass graft surgery. Stroke 2002; 33: 537–541.

14.

Huybregts

de Vroege

Jansen

. The association of haemodilution and transfusion of red blood cells with biochemical markers of splanchnic and renal injury during cardiopulmonary bypass. Anesth Analg 2009; 109: 331–339.

15.

Ferraris

Brown

Despotis

. 2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines. Ann Thorac Surg 2011; 91: 944–982.

16.

Haase

Bellomo

Matalanis

. A comparison of the RIFLE and Acute Kidney Injury Network classifications for cardiac surgery-associated acute kidney injury: a prospective cohort study. J Thorac Cardiovasc Surg 2009; 138: 1370–1376

17.

Newland

Sanderson

Baker

. Accuracy of temperature measurement in the cardiopulmonary bypass circuit. J Extra Corpor Technol 2005; 37: 32–37.

18.

Newland

Baker

Sanderson

Tuble

Tully

. Oxygenator safety evaluation: a focus on connection grip strength and arterial temperature measurement accuracy. J Extra Corpor Technol 2012; 44: 53–59.

19.

Cohen

. Statistical power analysis for the behavioral sciences (2nd ed.) 1988.