[Renal function during cardiac surgery with extracorporeal circulation].
BACKGROUND
Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation.


OBJECTIVE
To describe changes in renal function parameters during surgery with extracorporeal circulation in patients with valvular heart disease and compare them with those found in patients undergoing elective coronary surgery.


METHODS
Two groups of patients were studied. Group 1 was composed by twelve patients undergoing elective coronary surgery and group 2 was composed by eleven patients undergoing surgery for heart valve replacement. Glomerular filtration rate and effective renal plasma now were estimated from inulin and the 131 I-hippuran clearance respectively, at five different times, during surgery and the postoperative period. Sodium filtration fraction and fractional excretion were calculated. Alpha and pi-glutathione s-transferase in urine were measured as markers of tubular damage in the pre and postoperative periods.


RESULTS
Effective renal plasma flow was reduced in both groups before induction of anesthesia, did not change during surgery and decreased significantly in patients with valvular disease in the postoperative period. Glomerular filtration rates were normal during all the study period. There was a non significant reduction of filtration fraction during extracorporeal circulation. Alpha and pi glutathione s-transferases were normal and did not change. Fractional excretion of sodium increased significantly postoperatively.


CONCLUSIONS
In patients with valvular disease undergoing surgery with extracorporeal circulation, renal function does not deteriorate. No significant difference was found when compared with patients undergoing coronary surgery. No evidence of functional and cellular renal disfunction or damage was found in both study groups.
Lema
Guillermo
G
Departamentos de Anestesiología, Nefrología, y Enfermedades Cardiovasculares, Pontificia Universidad Católica de Chile, Santiago, Chile. glema@med.puc.cl
Canessa
Roberto
R
Urzúa
Jorge
J
Jalil
Roberto
R
Morán
Sergio
S
Carvajal
Claudia
C
Aeschlimann
Nicolás
N
Merino
Waldo
W
Jaque
María P
MP