The role of ammonia toxicity in the post transurethral prostatectomy syndrome

To investigate the aetiology of altered mental status following transurethral prostatectomy (TURP), serum electrolyte and blood ammonia levels were measured in 33 patients before and immediately after TURP. The irrigating fluid was 3% sorbitol in 12 patients and 1.5% glycine in 21. Serum electrolyte changes were similar in both groups. Elevated blood ammonia levels were observed in eight of the 21 patients receiving glycine irrigation. Three of these eight patients demonstrated clinical signs of encephalopathy. Absorption of glycine during transurethral prostatectomy appears to produce hyerammonaemia in some patients and may contribute to the encephalopathy.