A comparison of Paracervical Block Volumes before Osmotic Di
The study evaluates whether a 12-mL paracervical block is noninferior to a 20-mL block in reducing pain with osmotic dilator insertion.

In this single-blinded noninferiority trial, investigators randomized individuals undergoing insertion of osmotic dilators before the second-trimester abortion to receive either a 12-mL or 20-mL 1% lidocaine paracervical block. The primary outcome was pain immediately after insertion of osmotic dilators. Prespecified secondary outcomes included pain with paracervical block administration, overall pain, and side effects, with 88 participants being required for a noninferiority margin of 15 mm on a 100-mm visual analog scale assuming an SD of 28.

Of 232 eligible individuals, 174 were approached and 96 were randomized; 91 were available for analysis.

- The 12-mL paracervical block was noninferior to the 20-mL paracervical block for pain with osmotic dilator insertion with a difference in means of -1.36 favoring 12 mL.

- Median pain scores after dilator placement were 47 mm and 50 mm in 12-mL compared with 20-mL paracervical block, respectively.

- No difference was seen in median pain at baseline, with paracervical block administration, postprocedure, or with overall pain or experience.

- At least one lidocaine-related side effect occurred in 4% of participants in the 12-mL group compared with 13% for those receiving 20 mL, with a metallic taste, ringing in ears, and lightheadedness being most common.

To summarize, a 12-mL paracervical block is noninferior to a 20-mL block for pain reduction with osmotic dilator insertion.

Obstetrics & Gynecology
Source: https://journals.lww.com/greenjournal/Abstract/9900/A_Comparison_of_Paracervical_Block_Volumes_Before.256.aspx