Paracervical local anaesthesia for cervical dilatation and uterine intervention

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 (PLA) but its effectiveness is unclear.

To determine the effectiveness and safety of paracervical anaesthesia for cervical dilatation and uterine intervention when compared with no treatment, placebo, other methods of regional anaesthesia, systemic sedation and analgesia, or general anaesthesia (GA).

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to January 2006), EMBASE (1980 to January 2006) and reference lists of articles.

We included randomized or controlled clinical studies involving cervical dilatation and uterine intervention for obstetric and gynaecological conditions.

Two authors independently evaluated studies, extracted data, checked and entered data into Review Manager.

We included 17 studies involving 1855 participants. No study of PLA versus GA met our criteria; eight studies compared PLA versus placebo. Injection of local anaesthetic was slightly less painful than injection of saline placebo, a reduction of 0.87 points (95% CI 0.14 to 1.60) on a 10-point pain scale. Compared to placebo, PLA reduced abdominal pain during uterine intervention equivalent to two or three points on a 10-point pain scale and reduced the risk of severe pain (RR 0.16, 95% CI 0.06 to 0.74). There was no evidence that PLA reduced pain after the uterine intervention and little evidence for any effect on postoperative back or shoulder pain. Pain reduction by PLA was not confirmed in four studies that compared PLA with no treatment. Three studies compared PLA with uterosacral block; intracervical block; and 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 pain scale), which may be negligible. This benefit appeared to be greater for women who required cervical dilatation. Two 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.

No technique provided reliable pain control in the 17 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 uterine interventions.