The surgical correction of scoliosis and open reduction of spinal fractures involve considerable trauma to bone and muscles, together with hypotensive anaesthesia, it might be expected to compromise renal function. In our clinics, 36 spinal operations with CD instrumentation were performed from december 1988 to december 1989. 30 of the anaesthesia. Induced hypotension reduces bleeding during the operation so that surgeon can operate easily on surgical hypotension, muscle damage and evidence of fat embolism, renal function was unaltered in all patients, and attention was paid to the meintenance of circulating volume which is essential to protect renal function.