[The effect of controlled hypotension on kidney function in spinal surgery].

The authors investigated the influence of controlled hypotension on renal function in patients operated on account of idiopathic scoliosis of the spine. The deformity was corrected by posterior fusion with Harrington instrumentation under general anaesthesia during controlled hypotension induced by sodium nitroprusside (n = 20). The control group was formed by 20 patients with the same deformity and the same surgical procedure without hypotension. The renal function was assessed before operation, during operation and continuously for 102 hours after operation. In the group of patients with controlled hypotension (median arterial pressure 8.0 kPa) during operation a significant decline of the creatinine clearance occurred (0.7 ml/s), as compared with the control group (1.3 ml/s), as well as compared with the value before operation (1.7 ml/s). After terminated hypotension the mean value of creatinine clearance rose to 2.0-2.2 ml/s for a period of 42 hours. In the control group the creatinine clearance persisted at a slightly reduced level, recorded during operation, for another 30 hours. Sodium retention as a manifestation of hyperaldosteronism was less marked in patients with controlled hypotension. During the investigation period no biochemical signs of retention of nitrogenous substances were recorded.