Cervical dilatation and uterine intervention can be performed under sedation, local or general anaesthesia for obstetrics and gynaecological conditions. Many gynaecologists use paracervical local anaesthesia but its effectiveness is unclear. This review was originally published in 2009 and was updated in 2013.
The objectives of this review were to determine the effectiveness and safety of paracervical local anaesthesia for cervical dilatation and uterine intervention, versus no treatment, placebo, other methods of regional anaesthesia, sedation and systemic analgesia, and general anaesthesia.
We reran our search to August 2013. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 8), MEDLINE (1966 to August 2013), EMBASE (1980 to August 2013), and reference lists of articles. The original search was performed in January 2006.
We included randomized or controlled clinical studies involving women who underwent cervical dilatation and uterine intervention for obstetrics and gynaecological conditions. We included studies which compared paracervical anaesthesia with no treatment, placebo, other methods of regional anaesthesia, systemic sedation and analgesia, or general anaesthesia.
Data collection and analysis
Two authors independently evaluated the studies, extracted data, and checked and entered data into Review Manager.
This updated review includes nine new studies, in total 26 studies with 28 comparisons and involving 2790 participants. No study of local paracervical versus general anaesthesia met our criteria. Ten studies compared local anaesthetic versus placebo. Paracervical local anaesthetic (PLA) reduced pain on cervical dilatation with a standardized mean difference (SMD) of 0.37 (95% CI 0.17 to 0.58) and a relative risk (RR) of severe pain of 0.16 (95% CI 0.06 to 0.74). PLA also reduced abdominal pain during, but not after, uterine intervention (SMD 0.74, 95% CI 0.28 to 1.19); there was no evidence of any effect on postoperative back or shoulder pain. Comparisons against no treatment did not demonstrate any effect of PLA. Five studies compared paracervical block with uterosacral block, intracervical block, or intrauterine topical anaesthesia. Two of these studies showed no significant difference in pain during the procedure. Compared to intrauterine instillation, PLA slightly reduced severe pain (from 8.3 to 7.6 on a 10-point scale), which may be negligible. Six studies compared PLA with sedation. There were no statistically significant differences in pain during or after the procedure, postoperative analgesia requirement, adverse effects, patient satisfaction, and the operator's perception of analgesia. We performed risk of bias assessment using six domains and found that more than half of the included studies had low risk of bias.
We found that no technique provided reliable pain control in the 26 included studies. Some studies reported that women experienced severe pain (mean scores of 7 to 9 out of 10) during uterine intervention, irrespective of the analgesic technique used. We concluded that the available evidence fails to show whether paracervical block is inferior, equivalent, or superior to alternative analgesic techniques in terms of efficacy and safety for women undergoing cervical dilatation and uterine interventions. We suggest that woman are likely to consider the rates and severity of pain during uterine interventions when performed awake to be unacceptable in the absence of neuraxial blockade, which are unaltered by paracervical block.