Intracervical block with 2% lidocaine reduces pain associated with LNG-IUS placement

Référence

De Nedai MN, Poli-Neto OB, Franceschini SA, et al. Intracervical block for levonorgestrel -releasing intrauterine system placement among nulligravid women: a randomized double-blind controlled trial. Am J Obstet Gynecol 2020;222(3):245e.1-245e.10.

Sommaire

This well-designed and well-executed study was conducted at 2 Brazilian academic medical centers. The investigators included 302 nulligravid women who chose LNG-IUS (Mirena, R) as their method of contraception. The included women were aged 18 years to 45 years and had never before used any intrauterine contraceptive method. Women were ineligible if they had medical conditions for which the method was contraindicated, an allergy to or contraindication for lidocaine, chronic pelvic pain, prior cervical surgery or abnormality, illicit drug use, known psychiatric disorders, chronic use of medications that could interfere with pain perception, or current use of analgesics. The participants were randomized to receive 3.6 mL 2% lidocaine, sham dry needle procedure, or no treatment. The investigators used a 27-gauge dental carpule syringe and 2 ampules of lidocaine, 1.8 mL each, administered in equal parts deep into the cervix at 3, 6, 9, and 12 o'clock. The sham procedure used the same needle at the same locations without the administration of any solution. To preserve masking for the main outcome of pain at device insertion, the clinician who provided the medication or sham procedure was different from the obstetrician-gynecologist who placed the device. Ease of insertion was not different among groups. Vagal reactions trended to be lower in the lidocaine group compared with the sham and no treatment groups (1.1% vs 7.1% vs 6.9%; P = .08). Severe pain (more than 7 on a 10 -point visual analog scale) at tenaculum placement was less frequent in the lidocaine group (2% vs 30% vs 15%; P < .0001; author-calculated number needed to treat [NNT] = 2; 95% CI 1 - 6). The main outcome—severe pain at LNG-IUS insertion—was also reduced in the lidocaine-treated group (27% vs 59% vs 51%; P < .0001; author-calculated NNT = 4; 2 - 8). Shortly after the procedure 63% of the women treated with lidocaine reported that they experienced less pain than expected as compared with 25% of women who were treated with the sham procedure and 37% who were not treated (P <.0001). During telephone follow-up the day after the procedure the proportion of women who reported that they would be unwilling to undergo the procedure again was reduced in the lidocaine group (5% vs 18% and 10%, respectively; P = .01).