Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and blinding) and by imprecise results (few patients).
A Cochrane review [Abstract] 1 included 19 studies with a total of 17,20 subjects. These trials compared a variety of interventions including cervical injection with lignocaine alone, lignocaine with adrenaline, prilocaine with felypressin, oral analgesics (non-steroidal anti-inflammatory drugs (NSAIDs)), inhalation analgesia (gas mixture of isoflurane and desflurane), lignocaine spray, cocaine spray, local application of benzocaine gel, lignocaine-prilocaine cream and transcutaneous electrical nerve stimulation (TENS).
There was no significant difference in pain relief between women who received local anaesthetic infiltration (lignocaine 2%; administered as a paracervical or direct cervical injection) and a saline placebo. However, when local anaesthetic was combined with a vasoconstrictor agent (one trial used lignocaine combined with adrenaline while the second trial used prilocaine combined with felypressin), significantly less pain occurred compared with no treatment (table T1). Comparing two preparations of local anaesthetic plus vasoconstrictor, prilocaine combined with felypressin did not differ from lignocaine combined with adrenaline for its effect on pain control. The difference in mean observed blood loss score between lignocaine plus adrenaline as compared with prilocaine plus felypressin was not clinically significant.Inhalation of gas mixture (isoflurane and desflurane) in addition to standard cervical injection with prilocaine plus felypressin resulted in significantly less pain during the LLETZ (loop excision of the transformation zone) procedure (MD -7.20; 95% CI -12.45 to -1.95; 1 trial, n=389).No statistically significant difference was found in pain (VAS) between women who received oral analgesic and those who received placebo.No serious adverse events were reported in any of the trials.
| Outcome | Relative effect(95% CI) | Assumed risk - Control | Corresponding risk - Intervention | Number of participants (trials) |
|---|---|---|---|---|
| Pain scores during procedure (VAS: 0 to 100) | 13.74 lower (34.32 lower to 6.83 higher) | Saline injectionThe mean VAS score 30 to 53 | Local infiltration with lignocaine 2% The mean VAS score 27 to 29 | 130(2) |
| Pain scores during procedure (VAS: 0 to 100) | 23.73 lower(9.93 lower to 37.53 lower) | No analgesiaThe mean VAS score 42.7 to 43 | Local anaesthetic + vasoconstrictorThe mean VAS score 11.6 to 26 | 95(2) |
| Pain scores during procedure (VAS: 0 to 100) | .51 lower(10.03 lower to 3.01 higher) | PlaceboThe mean VAS score 21 to 41 | Oral analgesiaThe mean VAS score 19 to 36 | 129(2) |
Date of latest search: 23 March 2016
Primary/Secondary Keywords