Gabapentin for Perioperative Pain Management for 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.

Pain Management in Abortion Care

Both medication and procedural abortion are associated with pain. The experiences of pain depend on both physical and emotional factors. Several pain management options are available for abortion, depending on abortion type, clinical setting, and patient considerations, and a comprehensive approach is necessary to optimize pain management.

Opioid and Nerve Block Administration in Knee Arthroplasty: An Observational Retrospective Evaluation

AIMS

Increasing opioid-related adverse events and deaths have amplified interest in non-opioid analgesic options. Peripheral nerve blocks (PNBs) are useful in pain management, especially in minimally invasive day surgeries. This evaluation sought to examine patterns of opioid use among adult patients undergoing total knee arthroplasty, stratified by use of PNBs.

DESIGN

A retrospective, observational design.

SETTINGS

A large tertiary medical center and community hospital in the Inland Northwest.

PARTICIPANTS/SUBJECTS

A dataset of 8,493 adult patients undergoing elective total knee arthroplasty, 3,432 of which received a PNB while 5,061 did not.

METHODS

A deidentified dataset was obtained to evaluate: (a) opioid use frequency, (b) average morphine milligram equivalents (MMEs) administered, (c) independent factors associated with opioid administration, and (d) time to first opioid administered in adults undergoing total knee arthroplasty while in the recovery room, stratified by use of PNBs.

RESULTS

When controlling for general anesthesia, opioid use frequency was reduced when PNBs were administered (p < .05). The amount of MMEs consumed was 15 mg less in the group receiving a PNB (p < .001). In a linear regression model, PNBs reduced the MMEs consumed by 5 mg (p = .014). Time-to-first opioid was increased in patients receiving general anesthesia and PNBs with a hazards ratio of 0.70 (p < .001).

CONCLUSIONS

Peripheral nerve blocks are an opioid-sparing technique in adult patients undergoing total knee arthroplasty.

CLINICAL IMPLICATIONS

The results confirm best practices regarding opioid-sparing PNBs. Postoperative opioids are appropriate, but regimens incorporating PNB administration for total knee arthroplasty help reduce opioid use.

Gabapentin as an adjunct for pain management during dilation and evacuation: A double-blind randomized controlled trial

OBJECTIVES

To assess the analgesic efficacy of preoperative gabapentin among patients undergoing dilation and evacuation (D&E) with moderate sedation.

STUDY DESIGN

We conducted a randomized, controlled, double-blind trial among patients undergoing same-day D&E at 14 to 19 weeks gestation under moderate sedation. We randomized participants 1:1 to gabapentin 600 mg or placebo after cervical preparation at least 1 hour prior to D&E. We assessed pain using a 100-mm visual analog scale before, during, and after the procedure. The primary outcome was postoperative recall of maximum procedural pain with a 13-mm a priori threshold for clinical significance. We standardized initial fentanyl and midazolam dosing. We assessed satisfaction with pain control, nausea, and vomiting via Likert scales and anxiety using a validated instrument.

RESULTS

We enrolled 126 participants and randomized 61 to gabapentin and 65 to placebo, with study medication administered a mean of 211 (SD 64) minutes preoperatively. Recall of maximum pain was 41 mm for gabapentin and 49 mm for placebo (p = 0.24). Gabapentin resulted in reduced pain during uterine aspiration (56 vs 71 mm, p= 0.003) compared to placebo, but not for any other time points. The gabapentin group had higher satisfaction (78% vs 65% very or somewhat satisfied, p= 0.01). Median fentanyl dose was lower in the gabapentin group (75 vs 100 mcg, p = 0.005). Midazolam dose, nausea, vomiting, and anxiety did not differ between groups. No serious adverse events occurred in the gabapentin group. Sedation reversal was not required.

CONCLUSIONS

The addition of gabapentin to moderate sedation during D&E did not result in lower maximum recalled procedural pain. Gabapentin resulted in reduced intra-operative pain during uterine aspiration and increased satisfaction with pain control.

IMPLICATIONS

Gabapentin reduces intraoperative pain and improves satisfaction with pain management when administered prior to second-trimester surgical abortion and may be considered as an adjunct to intravenous sedation. Moderate sedation may impair assessment and recall of pain. Additional research is needed to identify the most effective pain management regimens for D&E.

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.

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

BACKGROUND

Pain management approaches during uterine aspiration vary, which include local anesthetic, oral analgesics, moderate sedation, deep sedation, or a combination of approaches. For local anesthetic approaches specifically, we continue to have suboptimal pain control. Gabapentin as an adjunct to pain management has proven to be beneficial in gynecologic surgery. We sought to evaluate the impact of gabapentin on perioperative pain during surgical management of first-trimester abortion or early pregnancy loss with uterine aspiration under local anesthesia.

OBJECTIVE

We hypothesized that adding gabapentin to local anesthesia will reduce perioperative and postoperative pain associated with uterine aspiration. Secondary outcomes included tolerability of gabapentin and postoperative pain, nausea, vomiting, and anxiety.

STUDY DESIGN

We conducted a randomized double-blinded placebo-controlled trial of gabapentin 600 mg given 1 to 2 hours preoperatively among subjects receiving a first-trimester uterine aspiration under paracervical block in an outpatient ambulatory surgery center. There were 111 subjects randomized. The primary outcome was pain at time of uterine aspiration as measured on a 100-mm visual analog scale. Secondary outcomes included pain at other perioperative time points. To assess changes in pain measures, an intention to treat mixed effects model was fit with treatment groups (gabapentin vs control) as a between-subjects factor and time point as a within-subjects factor plus their interaction term. Because of a non-normal distribution of pain scores, the area under the curve was calculated for secondary outcomes with comparison of groups utilizing Mann-Whitney U tests.

RESULTS

Among the 111 randomized, most subjects were Black or African American (69.4%), mean age was 26 years (±5.5), and mean gestational age was 61.3 days (standard deviation, 14.10). Mean pain scores at time of uterine aspiration were 66.77 (gabapentin) vs 71.06 (placebo), with a mean difference of -3.38 (P=.51). There were no significant changes in pain score preoperatively or intraoperatively. Subjects who received gabapentin had significantly lower levels of pain at 10 minutes after surgery (mean difference [standard error (SE)]=-13.0 [-5.0]; P=.01) and 30 minutes after surgery (mean difference [SE]=-10.8 [-5.1]; P=.03) compared with subjects who received placebo. Median nausea scores and incidence of emesis pre- and postoperatively did not differ between groups. Similarly, anxiety scores did not differ between groups, before or after the procedure. At 10 and 30 minutes after the procedure, most participants reported no side effects or mild side effects, and this did not differ between groups.

CONCLUSION

Preoperative gabapentin did not reduce pain during uterine aspiration. However, it did reduce postoperative pain, which may prove to be a desired attribute of its use, particularly in cases where postoperative pain may be a greater challenge.

Advances in abortion care technology and management

PURPOSE OF REVIEW

To review emerging evidence specific to abortion care, including diagnostic testing and pain management.

RECENT FINDINGS

Recent advances in abortion care include improvements in gestational age dating, Rh status testing, and pain management methods. When ultrasound technology is available, the use of crown-rump length (CRL)-based dating is more accurate up to 13 weeks and composite CRL and biometry between 13 and 14 weeks. Evidence supports using updated fetal foot length-to-gestational age reference ranges for postprocedure gestational age confirmation. Serum tests for two placental proteins, pregnancy-associated plasma protein A and a disintegrin and metalloproteinase 12, show potential for identifying pregnancies with gestational age more than 70 days. Early research using flow cytometry demonstrates that fetal RBC exposure after first-trimester uterine aspiration is insufficient to cause maternal Rh-sensitization, supporting elimination of Rh testing and anti-D-immunoglobulin provision prior to 8 weeks gestation. Recent studies exploring pain management strategies have not generated a standardized approach. Auricular acupuncture appears to be promising.

SUMMARY

Emerging data on improvements in gestational age dating and eliminating laboratory testing prior to early abortion procedures could have important implications for expanding access to early abortion care and telemedicine. Person-centered, novel pain management modalities, such as auricular acupuncture, help to improve client experience, by addressing both pain and anxiety.