A Systematic Review of the Effect of Type, Pressure, and Temperature of the Distension Medium on Pain During Office Hysteroscopy

To identify the optimal distension medium type, pressure, and temperature to minimize pain during office hysteroscopy.

MEDLINE, EMBASE, CINAHL, and CENTRAL were searched from inception to January 29, 2020.

We included randomized controlled trials in which women undergoing office hysteroscopy were randomized to either a distension medium type, pressure, or temperature against a suitable control, where pain was an outcome. Data regarding feasibility, visualization, complications, and satisfaction were also collected.

The literature search returned 847 studies, of which 18 were included for systematic review and 17 for meta-analysis. There was no significant difference in intraprocedural pain when comparing the use of normal saline against carbon dioxide (standardized mean difference [SMD], -0.12; 95% confidence interval [CI], -0.36 to 0.13). Subgroup analysis of high-quality studies revealed a statistically significant reduction in postprocedural pain with normal saline (SMD, -0.65; 95% CI, -1.14 to -0.16). Side effects were less frequent (Peto odds ratio, 0.29; 95% CI, 0.20-0.40) and patient satisfaction was higher (SMD, 1.39; 95% CI, 0.51-2.28) with normal saline compared with carbon dioxide. Pressures of ≤40 mm Hg reduced intraprocedural pain (SMD, -0.67; 95% CI, -1.09 to -0.26) at the expense of a higher proportion of unsatisfactory views (81%-89% at ≤40 mm Hg vs 95%-99% at ≥50 mm Hg). Postprocedural pain was reduced with lower filling pressures. Warming saline did not reduce intraprocedural pain (SMD, 0.59; 95% CI, -0.14 to 1.33).

Normal saline, instilled at the lowest pressure to acquire a satisfactory view, should be used for uterine distension during office hysteroscopy to minimize pain.