GLYCINE-INDUCED HYPOOSMOLAR HYPONATREMIA

Background: Hyponatremia is commonly observed following transurethral resection of the prostate or endometrial resection when the operative field is irrigated with hypotonic glycine. Although glycine-induced hy ponatremia has been associated with brain damage, the mortality is low , and it has been suggested that the condition might not be hypo-osmol ar and thus might not cause brain edema.Objective: To determine if gly cine-induced hyponatremia is a hypo-osmolar condition. Methods: The st udy was a retrospective evaluation of 13 men who underwent transurethr al resection of the prostate and 5 women who underwent transcervical e ndometrial resection at 2 university medical centers. In all patients, hypotonic glycine (200 mmol/L) was the irrigating solution. Measureme nts were made of the plasma sodium, osmolality, glucose, urea, glycine , and ammonia; and arterial pH, PO2, and PCO2. Mortality and the occur rence of respiratory arrest were recorded. Data are given as mean (+/- SE). Results: The plasma sodium in 18 patients was 106+/-2 mmol/L and the measured osmolality was 235+/-5 mOsm/kg H2O. Glycine was measured as the difference between measured and calculated plasma osmolality an d was 18+/-2 mmol/L. Four patients suffered respiratory arrest; all di ed. One patient had elevated blood ammonia (130 mu mol/L) with a plasm a sodium level of 110 mmol/L. She was treated with endotracheal intuba tion and respiratory support plus hypertonic sodium chloride, and reco vered. The other 14 surviving patients were treated with hypertonic so dium chloride. Conclusions: Patients who undergo transurethral resecti on of the prostate or endometrial resection with hypotonic glycine as the irrigating medium can experience symptomatic hyponatremia that is hypo-osmolar and can be fatal. Therapy with hypertonic sodium chloride was associated with survival in 14 of 14 patients. Ammonia intoxicati on also can develop, and can be managed with respiratory support.