Sorbitol 2.5% mannitol 0.54% irrigation solution for hysteroscopic endometrial ablation surgery

To determine if systemic absorption of sorbitol 2.5%/mannitol 0.54% irrigation solution (165 mosm.L-1) during hysteroscopic endometrial ablation with diathermy is associated with hyponatraemia and hypoosmolality.

In 35 day surgery patients in a university hospital we measured baseline preoperative variables: serum sodium and creatinine concentrations and osmolality, haematocrit, haemoglobin, urine osmolality and sodium concentration, and weight. Fractional excretion of sodium (FENa) was calculated. The same observations were obtained postoperatively before discharge (one hour post resection). Volumes of intraoperative fluid irrigation intravasation and perioperative intravenous fluid absorption (lactated Ringer's solution) were estimated clinically (volumetric).

The mean (+/-SD) serum sodium concentration preoperatively was 140.3 +/- 2.4 mmol.L-1; and postoperatively, 139.7 +/- 2.2 mmol.L-1 (P = NS). The serum osmolality decreased from 285.4 +/- 4.5 to 282.6 +/- 4.1 mmol.kg-1 (P < 0.001). The mean volume of intravasated irrigation fluid was 26.4 ml (range 0-300). During the same time, the FENa increased from 0.57% to 0.79% (P < 0.001).

In these patients, closely and continuously observed for imbalance between infused and collected irrigation fluid, these was no clinical evidence for hyponatraemic hypoosmolality. However, there was a small 1% +/- 1.5% (mean +/- SD; range -3.4 to 3.6%) decrease in plasma osmolality despite adequate blood volumes as shown by urinary sodium indices.