High-dose intravenous infusion of irrigating fluids containing glycine andmannitol in the pig

Background. Large-scale absorption of electrolyte-free irrigating fluid dur ing endoscopic surgery may result in a "transurethral resection syndrome." The severity of the syndrome can probably be modified by using mannitol 5% instead of the most widely used glycine 1.5%. Methods. Seventeen pigs with a mean body weight of 22 (range 19-26) kg rece ived an intravenous infusion of 100 mL kg(-1) h(-1) of either glycine 1.5% or mannitol 5% over 90 min. Central hemodynamics, whole-body and brain oxyg en consumption, intracranial pressure, blood hemoglobin, and the sodium con centrations in serum and urine were monitored for 120 min. Selected measure ments were made on 6 other pigs given mannitol 3% and in 2 controls not giv en any fluid. Morphological examinations of the hearts were conducted. Results. Both glycine 1.5% and mannitol 5% transiently increased cardiac ou tput, the aortic blood flow rate, and arterial pressures, but all of these parameters fell to below baseline after the infusions were ended. The intra cranial pressure was lower (P < 0.05) and the oxygen consumption in the bra in decreased (P < 0.001) during the infusion of mannitol 5%. Glycine 1.5% e xpanded the intracellular volume more than mannitol did (P < 0.002). Signs of myocardial damage were graded glycine 1.5% > mannitol 5% > mannitol 3%. Conclusions. Massive infusion of glycine 1.5% and mannitol 5% left the pigs in a hypokinetic hypotensive state. Glycine 1.5% increased the intracrania l pressure and injured the myocardium more than mannitol 5%, which then see ms to be a more appropriate irrigating fluid to use during endoscopic surge ry. (C) 2000 Academic Press.