Cardiopulmonary bypass time as a risk factor for acute renal failure.
OBJECTIVE
Acute renal failure following heart surgery is a major complication. The aim of this study was to evaluate if duration of cardiopulmonary bypass (CPB) is an important factor that influences kidney dysfunction.


METHODS
One hundred and sixteen patients from a single center referred for heart surgery were evaluated. Demographic factors, clinical data, operative and postoperative variables were evaluated. Serum creatinine and creatinine clearance were calculated until the fifth postoperative day. Acute renal failure was defined as the requirement of dialysis therapy. Patients were divided into two groups, the CPB<70min Group, patients with CPB duration equal to or less than 70 minutes and the CPB<90min Group, patients with CPB duration equal to or more than 90 minutes.


RESULTS
The median increases in serum creatinine were 0.18 + 0.41(CPB<70min) and 0.42 + 0.44 (CPB>90min p=0.005). Dialysis was indicated in 1.3% (CPB<70min) and 12.5% 90min - p = 0.018). The odds ratio for dialysis was 1.12 (95% CI; 1.00-1.20) for CPB>90min. There was no significant difference in mortality (5.2 versus 7.5%, p = 0.631).


CONCLUSIONS
The greatest likelihood of developing kidney failure after heart surgery is observed when CPB is at least 90 minutes, although creatinine clearance was not significantly altered between the groups studied.
Taniguchi
Fábio Papa
FP
Hospital de Base de Bauru, SP. taniguchi@sbccv.org.br
Souza
Ademar Rosa de
AR
Martins
Antonio Sérgio
AS
D058186:Acute Kidney Injury / Q000209:etiology*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass; D003404:Creatinine / Q000097:blood; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D006435:Renal Dialysis; D013997:Time Factors
D003404:Creatinine