Risks of acute renal failure after cardiopulmonary bypass surgery in children: a retrospective 10-year case-control study

To our knowledge there are no case-control studies that haveexamined the main risk factors for acute renal failure (ARF)following cardiopulmonary bypass surgery in children. We thereforeevaluated the potential risk factors in a large retrospectivecase-control study. Sixty-one of 2262 children (2.7%) developedpostcardiopulmonary bypass surgery ARF requiring peritonealdialysis (PD) from 1982 to 1991. Fifty-eight of 61 cases (medianage 8.5 months) were selected by systematic sampling and matchedwith 176 controls who did not develop ARF. The four matchingvariables were age, cardiopulmonary bypass and circulatory arrestduration, and year of operation. Mortality rate was 79% in cases (controls: 18%). Forty-threeof 48 of the deceased cases did not recover renal function;no renal cause of death was found; 13 of 61 cases survived andrecovered renal function. Multiple regression analysis showedthe following significant risk factors for postcardiopulmonarybypass surgery ARF: central venous hypertension >12 h (oddsratio (OR) 9.6); systolic arterial hypotension >12 h (OR8.9); dopamine dosage >15 µg/kg/min (OR 3.0); adrenaline(OR 5.9) and isoproterenol (OR 13.5) use. High preoperativeserum creatinine, cyanosis, and vasodilator use were not significantrisk factors. We conclude that: (1) haemodynamic alterations were the maincause of postcardiopulmonary bypass surgery ARF; (2) ARF wasassociated with but was not the cause of the high mortalityrate; (3) the risk of ARF increased almost 10-fold after 12h of central venous hypertension and/or of systolic arterialhypotension; (4) effective dosages of inotropes might have beena risk factor for ARF; (5) a slight precardiopulmonary bypasssurgery reduction of renal function alone did not representan increased risk for ARF.