Comparison of urological irrigating fluids containing glycine and mannitol in volunteers

We compared symptoms and indices of fluid distribution after experimental administration of glycine and mannitol solutions, since these irrigating fluids are sometimes absorbed by the patient during genitourinary surgery.

Glycine 1.5% and mannitol 3%, both with ethanol 1% added, were given by intravenous infusion at a rate of 0.5 ml/kg/min during 30 min to 12 male volunteers. Symptoms, cognitive status, hemodynamics, electrocardiogram during 24 hr, computerized tomography of the brain, bioimpedance, blood chemistry, and breath ethanol concentrations were recorded.

Glycine was associated with more symptoms than mannitol (P< 0.006), but the cognitive status, computerized tomography examinations, electrocardiograms, and breath ethanol concentrations did not differ between the solutions. The urinary excretion of fluid and sodium was greater after mannitol (P< 0.04), while only the glycine infusions hydrated the cells (P< 0.05). For both fluids, the intravascular and interstitial volumes were below baseline 3 hr after the experiment started (P< 0.01).

Glycine 1.5% had a higher tendency than mannitol 3% to cause symptoms and to accumulate in the cells.