Investigation of often-reported ten percent hysteroscopy fluid overfill: is this accurate?

A key component of hysteroscopic complications, such as fluid overload and severe dilutional hyponatremia, is the failure to anticipate and quickly recognize fluid deficits. The purpose of this study was to measure the volume and mass of irrigation fluid bags to assess the overfill of 3 common types of hysteroscopy irrigation fluids, 0.9% normal saline solution, 3% sorbitol, and 1.5% glycine, to challenge the often-quoted standard of assumption that overfill may be as high as 10% of the bag's volume.

Ten cases of irrigation fluid were tested. The volume and weight of drained fluid from 18 bags of 0.9% normal saline solution 2000 mL, 12 bags 3% sorbitol 3000 mL, 8 bags of 1.5% glycine 3000 mL, and 4 bags of 0.9% normal saline solution 5000 mL were measured. Institutional review board exemption was obtained.

Ten cases of irrigation fluid were obtained. The volume and weight of drained fluid from 18 bags of 0.9% normal saline solution 2000 mL, 12 bags of 3% sorbitol 3000 mL, 8 bags of 1.5% glycine 3000 mL, and 4 bags of 0.9% normal saline solution 5000 mL were measured. By volume, varying by the type of fluid tested, the maximum observed overfill was between 3.3% to 5.0%. For confirmation, each bag was also weighed and found to have a maximum overfill between 2.8% to 5.6%, varying with the volume and type of fluid measured. These findings were then compared with the manufacturer-provided overfill range of 1.5% to 6.0%. No underfill was observed.

Contrary to assertions over the last 25 years that overfill is 10% or higher as a rule, it appears more reasonable to assume that the degree of overfill is contingent on the type and volume of fluid used and is more likely closer to 2.8% to 5.6%. Therefore an accurate collecting system and weight measurement is more precise.