Glycine-induced hypo-osmolar hyponatremia

Area of Science:

• Nephrology
• Urology
• Gynecology

Background:

• Transurethral resection of the prostate (TURP) and endometrial resection commonly use hypotonic glycine irrigation.
• Glycine-induced hyponatremia is a known complication, but its hypo-osmolar nature and potential for severe outcomes were debated.
• Previous assumptions suggested it might not be hypo-osmolar, potentially downplaying the risk of brain edema.

Purpose of the Study:

• To investigate whether glycine-induced hyponatremia following TURP or endometrial resection is a hypo-osmolar condition.
• To assess the clinical significance and potential fatality of this specific type of hyponatremia.

Main Methods:

• Retrospective analysis of 18 patients (13 male, 5 female) who underwent TURP or transcervical endometrial resection using 200 mmol/L hypotonic glycine.
• Measurement of plasma sodium, osmolality, glucose, urea, glycine, and ammonia, alongside arterial blood gases.
• Recording of mortality and respiratory arrest events.

Main Results:

• Patients presented with severe hyponatremia (plasma sodium 106 +/- 2 mmol/L) and hypo-osmolality (235 +/- 5 mOsm/kg H2O).
• Significant glycine levels (18 +/- 2 mmol/L) contributed to the measured osmolality.
• Four patients experienced fatal respiratory arrest; one case of ammonia intoxication was successfully managed with respiratory support and hypertonic saline.

Conclusions:

• Symptomatic hyponatremia following TURP or endometrial resection with glycine irrigation is indeed hypo-osmolar and potentially fatal.
• Treatment with hypertonic sodium chloride was associated with survival in all treated patients.
• Ammonia intoxication is a potential complication that can be managed with appropriate respiratory support.