Renal function during intravenous infusion of urological irrigating fluids in the sheep

Oliguria or anuria is an important sign of the transurethral resection syndrome, but the mechanism is not clear.

We gave an intravenous infusion of 40 ml/kg of glycine 1.5%, sorbitol 2%-mannitol 1%, and isotonic saline (control) in 6 conscious ewes and studied if irrigating fluids cause acute disturbances of kidney function.

Both the electrolyte-free solutions induced an increase in urine flow and persistent hypo-osmolality. The renal clearances of p-aminohippuric acid and inulin as well as the unilateral renal blood flow, which was measured via ultrasonic flow probes, increased in response to infusion of glycine but not to sorbitol-mannitol. After the infusions, the renal clearances decreased transiently to below baseline levels. Hypertonic saline was given after half of the infusions of electrolyte-free irrigating fluid. This treatment redistributed water from the cells to the extracellular fluid, but had no effect on renal function.

We conclude that 2500 ml of electrolyte-free irrigating fluid had no detrimental effects on kidney function in sheep. The changes we observed were essentially the same as after infusion of isotonic saline.