Gabapentin as an adjunct to paracervical block for perioperative pain management for first-trimester uterine aspiration: a randomized controlled trial

Local anaesthesia for pain control in first trimester surgical abortion

BACKGROUND

Abortions prior to 14 weeks are among the most common outpatient surgical procedures performed on people capable of becoming pregnant. Various methods have been used to control pain; however, many people still experience pain with the procedure.

OBJECTIVES

To evaluate the benefits and harms of local anaesthesia given for pain control during surgical abortion at less than 14 weeks' gestation.

SEARCH METHODS

We searched CENTRAL (Ovid EBM Reviews), MEDLINE (Ovid), Embase, POPLINE, and Google Scholar to December 2022 for randomized controlled trials of pain control in surgical abortion at less than 14 weeks' gestation using suction aspiration. We searched the reference lists of related reviews and articles.

SELECTION CRITERIA

We selected effectiveness and comparative effectiveness randomized controlled trials that studied local anaesthesia with common local anaesthetics and administration routes given for pain control in surgical abortion at less than 14 weeks' gestation using uterine aspiration. Outcomes included intraoperative pain, patient satisfaction, and adverse events.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We computed mean differences (MD) with 95% confidence intervals (CI) for continuous variables reporting a mean. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

Thirteen studies with 1992 participants met the inclusion criteria. Due to heterogeneity of interventions, we could not pool more than two studies for any outcome. We used 13 mm improvement on a visual/verbal analogue scale to indicate a clinically meaningful difference in pain with surgical abortion (pain with dilation, aspiration, or during procedure). Based on type of pain control, we divided studies into three groups. Paracervical block (PCB) effectiveness trials A 20 mL 1% lidocaine PCB reduced pain with dilation (MD -37.00, 95% CI -45.64 to -28.36), and aspiration (MD -26.00, 95% CI -33.48 to -18.52) compared to a sham PCB (1 RCT, 120 participants; high-certainty evidence). A PCB with 14 mL of 1% chloroprocaine resulted in a slight reduction in pain with aspiration compared to a PCB with normal saline injected at two or four sites (MD -1.50, 95% CI -2.45 to -0.55; 1 RCT, 79 participants; high-certainty evidence). PCB comparative effectiveness trials An ultracaine PCB probably results in little to no clinically meaningful difference in pain during procedure compared to topical cervical lidocaine spray (median 1 point higher, interquartile range (IQR) 0 to 3; P < 0.001; 1 RCT, 48 participants; moderate-certainty evidence). A 1000 mg dose of intravenous paracetamol probably does not decrease pain as much as ultracaine PCB during procedure (median 2 points higher, IQR 1 to 3; P < 0.001; 1 RCT, 46 participants; moderate-certainty evidence). Various local anaesthetics in PCB comparative effectiveness trials A 10 mL buffered 2% lidocaine PCB probably does not result in a clinically meaningful difference in pain with dilation compared to a plain lidocaine PCB (MD -0.80, 95% CI -0.89 to -0.71; 1 RCT, 167 participants; moderate-certainty evidence). A buffered lidocaine PCB probably does not result in a clinically meaningful difference in pain with aspiration compared to plain lidocaine PCB (MD -0.57, 95% CI -1.01 to -0.06; 2 RCTs, 291 participants; moderate-certainty evidence). Non-PCB local anaesthesia or PCB technique effectiveness trials PCB: waiting versus no waiting Waiting three to five minutes between 1% lidocaine PCB injection and dilation probably does not result in a clinically meaningful difference in pain with dilation compared to not waiting (MD -0.70, 95% CI -1.23 to -0.17; 2 RCTs, 357 participants; moderate-certainty evidence). Topical cervical analgesia Topical 10 mL 2% lignocaine gel probably does not result in a clinically meaningful difference in pain with aspiration compared to KY Jelly (MD -0.87, 95% CI -1.60 to -0.14; 1 RCT, 131 participants; moderate-certainty evidence). In participants who also received a PCB, 20 mg topical cervical lidocaine spray probably does not result in a clinically meaningful difference in pain during the procedure compared to two pumps of normal saline spray (median -1 point, IQR -2 to -1; P < 0.001; 1 RCT, 55 participants; moderate-certainty evidence). Intravenous paracetamol 1000 mg compared to two pumps of cervical lidocaine spray probably does not results in a clinically meaningful difference in pain procedure (median 1 point, IQR -2 to 2; P < 0.001; 1 RCT, 48 participants; low-certainty evidence). Non-PCB local anaesthesia or PCB technique comparative effectiveness trials Depth of PCB The evidence suggests that a 3-cm deep PCB probably does not result in a clinically meaningful difference in pain with aspiration compared to a 1.5-cm deep PCB (MD -1.00, 95% CI -1.09 to -0.91; 2 RCTs, 229 participants; low-certainty evidence). PCB: four sites versus two sites A two-site (4-8 o'clock) 20 mL 1% lidocaine PCB does not result in a clinically meaningful difference in pain with dilation compared to a four-site (2-4-8-10 o'clock) PCB (MD 8.60, 95% CI 0.69 to 16.51; 1 RCT, 163 participants; high-certainty evidence). Overall, participants reported moderately high satisfaction with pain control and studies reported few adverse events.

AUTHORS' CONCLUSIONS

Evidence from this updated review indicates that a 20 mL 1% plain lidocaine PCB decreases pain during an abortion procedure. Evidence supports forgoing buffering lidocaine and a wait time between PCB injection and cervical dilation. A 1.5-cm deep injection as opposed to a 3-cm deep injection is sufficient. A two-site PCB injection as opposed to a four-site injection has similar effectiveness. Topical cervical anaesthesia (10 mL 2% lignocaine gel or 20 mg topical cervical lidocaine spray) as compared to placebo did not decrease pain based on moderate-certainty evidence, but then when compared to PCB, pain control was similar. Due to this inconsistency in evidence regarding the effectiveness of topical anaesthesia, its routine use is presently not supported. This review did not include studies of pain management with conscious sedation but, based on the results of our prior Cochrane review and the 2022 WHO guidelines, we recommend that the option of combination of pain management using conscious sedation plus PCB and non-steroidal anti-inflammatory drugs should be offered where conscious sedation is available as it further decreases pain.

Hyoscine butylbromide in pain reduction associated with ultrasound-guided manual vacuum aspiration: a randomized placebo-controlled trial

RESEARCH QUESTION

What is the effect of adding an anti-spasmodic drug to an existing ultrasound-guided manual vacuum aspiration (USG-MVA) protocol to alleviate immediate post-procedure abdominal cramping pain in women treated for early pregnancy loss?

DESIGN

Double-blind, placebo-controlled, randomized controlled trial conducted between February 2018 and January 2020. Participants were assigned to receive a 1-ml intravenous injection containing 20-mg hyoscine butylbromide (HBB) (n=55) or saline (n =56) as a control immediately before USG-MVA. Primary outcome was reduced abdominal pain after adding a 20-mg dose of HBB to the current pain control regimen. Secondary outcomes were vaginal pain, complications and side-effects, women's pre- and post-procedure psychological state, physiological stress (saliva alpha-amylase) and procedure pain control satisfaction. Two-way mixed ANOVA was used to evaluate the main effects and interactions.

RESULTS

VAS abdominal pain scores in the HBB group were 16% lower immediately after and 21% lower 2 h after surgery (not statistically significant). Two-way ANOVA indicated that time (F[₁₁₀₈] = 83.41, P < 0.001) was the only significant main effect for reduced abdominal pain after the procedure and vaginal pain score (F[1108] = 180.1, P < 0.0001) but not drug received. No adverse events were reported. No significant difference was found for psychological state, physiological stress and procedure pain control satisfaction between the two groups.

CONCLUSIONS

Anti-spasmodic drugs can help to reduce abdominal cramping pain associated with USG-MVA; HBB produced an insignificant decrease in abdominal pain score. Further studies with longer acting or larger doses of anti-spasmodic drugs are warranted.

Auricular acupressure and auricular acupuncture as an adjunct for pain management during first trimester aspiration abortion: A randomized, double-blinded, three-arm trial

OBJECTIVES

To measure pain and anxiety during first trimester uterine aspiration when using auricular acupressure or acupuncture as an adjunct to usual care.

METHODS

This randomized, double-blinded, three-arm trial enrolled patients undergoing an aspiration procedure for an induced abortion, a miscarriage, or other abnormal intrauterine pregnancy. Trial participants received auricular acupressure, auricular acupuncture, or placebo immediately prior to their procedures. The study began with 1:1:1 randomization, but later overenrolled into the acupressure group after providing retraining for greater fidelity to that intervention. All participants received ibuprofen and a paracervical block. Participants reported pain and anxiety levels via visual analog scores (0-100). Our analysis compared pain scores of those receiving acupressure versus placebo, and those receiving acupuncture versus placebo.

RESULTS

We randomized 177 participants over nine months and excluded data from four participants. We analyzed data from 70 participants who received acupressure, 51 who received acupuncture, and 52 who received placebo. The groups had similar baseline characteristics, including baseline pain and anxiety scores. For acupressure, acupuncture, and placebo groups, respectively, immediate post-procedure median pain scores were 50, 55, 47.5 (p = 0.88); maximum pain scores during the procedure were 77, 79, 79.5 (p = 0.96); postprocedure anxiety scores were 26, 28, and 21 (p = 0.47). The acupressure group results were similar before and after retraining.

CONCLUSIONS

Receiving auricular acupressure or acupuncture did not result in lower pain or anxiety scores among women undergoing vacuum aspiration compared to a placebo group.

IMPLICATIONS

The results of this trial were null, thus differing from our previous study that had shown a benefit from auricular acupuncture. Given the conflicting results, incorporating these acupuncture techniques into abortion practice would be premature.