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.

Cervical dilation before first-trimester surgical abortion (<14 weeks' gestation)

First-trimester surgical abortion is a common, safe procedure with a major complication rate of less than 1%. Cervical dilation before suction abortion is usually accomplished using tapered mechanical dilators. Risk factors for major complications in the first trimester include increasing gestational age and provider inexperience. Cervical priming before first-trimester surgical abortion has been studied using osmotic dilators and pharmacologic agents, most commonly misoprostol. Extensive data demonstrate that a variety of agents are safe and effective at causing preoperative cervical softening and dilation; however, given the small absolute risk of complications, the benefit of routine use of misoprostol or osmotic dilators in first-trimester surgical abortion is unclear. Although cervical priming results in reduced abortion time and improved provider ease, it requires a delay of at least 1 to 3 h and may confer side effects. The Society of Family Planning does not recommend routine cervical priming for first-trimester suction abortion but recommends limiting consideration of cervical priming for women at increased risk of complications from cervical dilation, including those late in the first trimester, adolescents and women in whom cervical dilation is expected to be challenging.

Pain control in first trimester surgical abortion

BACKGROUND

First trimester abortions especially cervical dilation and suction aspiration are associated with pain, despite various methods of pain control.

OBJECTIVES

Compare different methods of pain control during first trimester surgical abortion.

SEARCH STRATEGY

We searched multiple electronic databases with the appropriate key words, as well as reference lists of articles, and contacted professionals to seek other trials.

SELECTION CRITERIA

Randomized controlled trials comparing methods of pain control in first trimester surgical abortion at less than 14 weeks gestational age using electric or manual suction aspiration. Outcomes included intra- and postoperative pain, side effects, recovery measures and satisfaction.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data. Meta-analysis results are expressed as weighted mean difference (WMD) or Peto Odds ratio with 95% confidence interval (CI).

MAIN RESULTS

We included forty studies with 5131 participants. Due to heterogeneity we divided studies into 7 groups:Local anesthesia: Data was insufficient to show a clear benefit of a paracervical block (PCB) compared to no PCB or a PCB with bacteriostatic saline. Pain scores during dilation and aspiration were improved with deep injection (WMD -1.64 95% CI -3.21 to -0.08; WMD 1.00 95% CI 1.09 to 0.91), and with adding a 4% intrauterine lidocaine infusion (WMD -2.0 95% CI -3.29 to -0.71, WMD -2.8 95% CI -3.95 to -1.65 with dilation and aspiration respectively).PCB with premedication: Ibuprofen and naproxen resulted in small reduction of intra- and post-operative pain.Analgesia: Diclofenac-sodium did not reduce pain.Conscious sedation: The addition of conscious intravenous sedation using diazepam and fentanyl to PCB decreased procedural pain.General anesthesia (GA): Conscious sedation increased intraoperative but decreased postoperative pain compared to GA (Peto OR 14.77 95% CI 4.91 to 44.38, and Peto OR 7.47 95% CI 2.2 to 25.36 for dilation and aspiration respectively, and WMD 1.00 95% CI 1.77 to 0.23 postoperatively). Inhalation anesthetics are associated with increased blood loss (p<0.001).GA with premedication: The COX 2 inhibitor etoricoxib, the non-selective COX inhibitors lornoxicam, diclofenac and ketorolac IM, and the opioid nalbuphine were improved postoperative pain.Non-pharmacological intervention: Listening to music decreased procedural pain.No major complication was observed.

AUTHORS' CONCLUSIONS

Conscious sedation, GA and some non-pharmacological interventions decreased procedural and postoperative pain, while being safe and satisfactory to patients. Data on the widely used PCB is inadequate to support its use, and it needs to be further studied to determine any benefit.

Cervical dilation before first-trimester surgical abortion (<14 weeks' gestation). SFP Guideline 20071

First-trimester surgical abortion is a common, safe procedure with a major complication rate of less than 1%. Cervical dilation before suction aspiration is usually accomplished using tapered mechanical dilators. Risk factors for major complications in the first trimester are increasing gestational age and provider inexperience. Use of laminaria for cervical priming reduces the risk of cervical laceration and, to a lesser extent, uterine perforation. While pharmacological priming agents may potentially have the same effects, no published studies to date have been large enough to assess these outcomes. Given an experienced provider, the risk of these injuries during suction aspiration is very small. Cervical priming can be achieved with osmotic dilators or pharmacological agents. The advantages of osmotic dilators such as laminaria, Dilapan-S and Lamicel are their ability to produce wide cervical dilation, and for the synthetic types, their advantages include predictable effects and rapid onset of action. A disadvantage of osmotic dilators is that they require a speculum examination and a trained clinician to perform the insertion. When cervical priming is performed, misoprostol is the prostaglandin analogue most commonly used worldwide. Compared to laminaria, vaginal misoprostol requires a shorter period of time to achieve the same dilatation, is associated with less discomfort and is preferred by women. The sublingual route appears as effective as vaginal administration and requires less time for priming (2 h), but it is associated with more side effects. Oral administration can produce equivalent dilation to vaginal or sublingual administration, but higher doses and longer treatment periods (8 to 12 h) are required. Buccal administration of misoprostol appears to have a pharmacokinetic and physiologic profile similar to vaginal administration; however, there are no published studies of buccal misoprostol prior to first-trimester suction abortion. While extensive data demonstrate that a variety of agents are safe and effective at causing cervical softening and dilation preoperatively, there are not enough data to conclude that routine cervical priming is necessary to reduce complications of first-trimester surgical abortion. Cervical priming increases preoperative cervical dilation, making the procedure easier and quicker for the physician. However, in order to preoperatively dilate the cervix, the woman must receive the agent at least 3 to 4 h prior to her procedure. Besides the additional waiting, the woman might experience bleeding and cramping prior to the procedure. There are insufficient data evaluating how cervical priming affects women's quality of life in relation to abortion. Based on existing evidence, the Society of Family Planning does not recommend routine cervical priming for suction aspiration procedures. The Society of Family Planning further recommends that providers consider cervical priming only for women who may be at increased risk of complications from cervical dilation, including those late in the first trimester, adolescents and women in whom cervical dilation is expected to be difficult due to either patient factors or provider experience.

Surgical abortion

This review of surgically-induced abortion focuses on conventional first trimester suction evacuation. Manual vacuum aspiration at early gestations and dilatation and evacuation at more advanced gestation are also considered. The place of surgical abortion in contemporary abortion practice is reviewed alongside developments in medical abortion. There is still debate about the best method for later abortions. Patient choice and pre-procedure assessment are considered fundamental to practice. The importance of antibiotic prophylaxis or infection screening is highlighted. The value of ultrasound emerges. The need for cervical priming is considered along with choice of suitable pharmacological agents. Current practice and the procedure of surgical abortion is outlined. Complications and strategies to minimize risk are detailed. The overview concludes with consideration of the impact on future reproductive health.

General anaesthesia, a risk factor for complication following induced abortion?

Of the 10,000 abortions performed at the Regional hospital at Modena in Italy between 1982 and 1986, 199 (2%) led to early complications. Investigation of the relationship between the risk of haemorrhage, injury, other complications and all complications and eight explanatory variables revealed that the adjusted odds ratio associated with the use of general anaesthetic compared with local anaesthetic was 4.6 (95% CI, 2.2-9.5) for haemorrhage, 1.3 (95% CI, 0.78-2.2) for injury, 1.6 (95% CI, 1.0-2.6) for other complications and 1.8 (95% CI, 1.4-2.5) for all complications. It is speculated that if the relationship between use of general anaesthetic and risk of complication is causal there could be about 40% fewer cases of complications and 75% fewer cases of haemorrhage following induced abortion if local anaesthesia were used rather than general anaesthesia.

Preventing febrile complications of suction curettage abortion

To identify risk factors for febrile complications after suction curettage abortion, we analyzed the data of 26,332 women who underwent suction curettage abortion at five participating centers in the Joint Program for the Study of Abortion, Part III, from 1975 to 1978. We defined febrile morbidity as an oral temperature of greater than or equal to 38 degrees C for 2 days or longer. The febrile morbidity rate was 0.34 per 100 abortions. We performed a multivariate analysis using a linear logistic regression model. Prophylactic antibiotics proved to be the most protective factor, reducing the rate of febrile complications to about one third that of women who received no prophylactic antibiotics (relative risk 0.36; 95% confidence interval 0.18 to 0.70). Patients who had had one or more previous births also had a significantly lower risk of febrile morbidity (relative risk 0.54; 95% confidence interval 0.33 to 0.88). Other factors did not significantly affect the febrile complication rate.

Uterine perforation following medical termination of pregnancy by vacuum aspiration

Out of 9344 first trimester elective abortions performed by vacuum aspiration, 37 uterine perforation cases occurred. The suction cannula was responsible for more than 50% of perforations. All cases were multiparous. In 56.8%, the duration of gestation was 6 weeks or less. One third of the cases had a history of child birth within the previous 6 months. Fundal and anterior wall perforations were most common. Cases with a retroverted uterus had a higher incidence of perforation (59.4%) than those with an anteverted uterus (32.4%). Exact pelvic assessment and proper technique and case management are important for preventing perforation.

The risks associated with teenage abortion

the risks of morbidity and mortality affect a teenager's choice between termination of a pregnancy through induced abortion and continuation of the pregnancy. To identify these risks, we analyzed information from two separate sets of data collected by the Centers for Disease Control: that of the Joint Program for the Study of Abortion, a multicenter prospective study of nearly 165,000 legally induced abortions; and that of a national surveillance of abortion-related mortality. The rates of major complications associated with abortions in teenagers were 1 to 3 per 1000 suction-curettage procedures and approximately 13 per 1000 saline-administration procedures. The death-to-case rate for teenage women was 1.3 per 100,000 procedures. When the data on procedures were adjusted according to gestational age, teenagers generally had lower rates of morbidity and mortality from induced abortion than older women.

Comparative risk of death from induced abortion at less than or equal to 12 weeks' gestation performed with local versus general anesthesia

Although complications of anesthesia are now the leading cause of death from abortion at less than or equal to 12 weeks' gestation, the comparative risk of death from abortions performed with local versus general anesthesia is unknown. To estimate this risk for both anesthesia-related and nonanesthesia-related legal abortion deaths at less than or equal to 12 weeks' gestation, we used 1972-1977 data from the Center for Disease Control and the Alan Guttmacher Institute. When adjusted for preexisting disease and concurrent sterilization, the death-to-case rate for abortions at less than or equal to 12 weeks' gestation associated with general anesthesia was 0.37/100,000 abortions, and the rate with local anesthesia was 0.15/100,000. For nonanesthesia-related deaths, the comparable adjusted rates were 0.49 and 0.28, respectively. Use of general anesthesia is associated with a twofold to fourfold increased risk of death from abortion at less than or equal to 12 weeks' gestation.

Local versus general anesthesia: which is safer for performing suction curettage abortions?

The relative safety of suction curettage abortions performed with either local or general anesthesia has not been clearly established. To compare the safety of these two anesthetic techniques, we studied 36,430 women who received local anesthetics and 17,725 who received general anesthetics for this operation in the United States from 1971 through 1975. The aggregated major complication rates for the two groups were similar, but there were significant differences between local and general anesthesia for specific complications and treatments. Local anesthesia was associated with higher rates of febrile and convulsive morbidity; however, general anesthesia was associated with higher rates of hemorrhage, cervical injury, and uterine perforation. Both anesthetic techniques appear to be safe, with similar degrees of overall safety, although each is associated with a different spectrum of complications.