RESUMEN
OBJECTIVE: Renal vasoconstriction has been blamed as a cause of perioperative renal dysfunction after cardiac surgery. Endothelial function is a critical determinant of vascular tonus, including vasoconstriction. The objective of this study was to establish whether the release of the endothelial vasodilator nitric oxide (NO) or NO products is altered in patients undergoing surgery with cardiopulmonary bypass in 3 different clinical conditions. DESIGN: Observational and randomized prospective study. SETTING: University hospital. PARTICIPANTS: Adults and pediatric patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Three groups of patients were studied: group 1, 10 patients undergoing elective coronary artery surgery; group 2, 20 patients undergoing elective coronary artery surgery randomized to 2 hematocrit values during cardiopulmonary bypass, high (27%) and low (23%); and group 3, 10 pediatric patients undergoing surgical repair of noncyanotic cardiac defects. MEASUREMENTS AND MAIN RESULTS: NO products (NO2 + NO3) and cyclic guanosine monophosphate (cGMP) in urine were measured before, during hypo- and normothermic cardiopulmonary bypass, and 1 hour postoperatively. Filtration fraction was calculated. The glomerular filtration rate and effective renal plasma flow were measured with inulin and (131)I-hippuran clearances, respectively. Urinary alpha glutathione s-transferase was measured pre- and postoperatively in groups 1 and 3. NO products, as well as cGMP, decreased significantly during hypo- and normothermic cardiopulmonary bypass in all groups. This was not because of urine dilution or the degree of hemodilution. Age did not appear to alter this response. Filtration fraction decreased during cardiopulmonary bypass. Alpha glutathione s-transferase was normal pre-and postoperatively. CONCLUSIONS: Cardiac surgery with cardiopulmonary bypass is associated with a significant decrease of NO products. In the absence of kidney damage, decreased NO products could represent a physiologic response to cardiopulmonary bypass; however, endothelial dysfunction cannot be excluded.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Óxido Nítrico/orina , Adulto , Anciano , Anestesia General , Biomarcadores , Puente de Arteria Coronaria , Creatinina/sangre , GMP Cíclico/sangre , Femenino , Cardiopatías Congénitas/cirugía , Hematócrito , Humanos , Lactante , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , Tono Muscular/fisiología , Músculo Liso Vascular/fisiología , Circulación Renal/fisiologíaRESUMEN
BACKGROUND: Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation. AIM: 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. MATERIAL AND 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.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Circulación Extracorporea , Enfermedades de las Válvulas Cardíacas/cirugía , Pruebas de Función Renal , Riñón/fisiología , Adulto , Anciano , Análisis de Varianza , Nitrógeno de la Urea Sanguínea , Femenino , Tasa de Filtración Glomerular/fisiología , Humanos , Periodo Intraoperatorio , Túbulos Renales/fisiología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Circulación Renal/fisiología , Estadísticas no ParamétricasRESUMEN
Background: Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation. Aim: 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 Material and 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.