Intra-cervical versus i.v. fentanyl for abortion

E.R. Wiebe1,2, K.J. Trouton1 and E. Savoy1

1 Department of Family Practice, University of British Columbia, Canada

2 To whom correspondence should be addressed at: 1013-750 West Broadway, Vancouver, BC V5Z 1H9, Canada. Email: ellenwiebe{at}telus.net


    Abstract
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
BACKGROUND: The majority of abortions are performed using a para-cervical block (without general anaesthesia) and involve a significant amount of pain. If fentanyl was given with the lidocaine in the para-cervical block, it potentially could improve pain control while decreasing side effects and avoiding i.v. access for women having abortions. METHODS: This was a randomized double-blind placebo-controlled trial of two treatment arms: (i) para-cervical block with 100 µg of fentanyl i.v; or (ii) para-cervical block with 100 µg of fentanyl intra-cervically (i.c.) for first trimester abortion. The setting was a free-standing urban abortion clinic. The outcome measures were pain scores and side effects. RESULTS: A total of 104 women received the fentanyl i.v. and 98 received the fentanyl i.c. The two groups were similar with respect to age, gestational age, obstetric history, anxiety and depression. Pain scores (0–10) were 4.7 and 5.7 for dilation (P=0.01) and 3.8 and 5.6 for suctioning (P<0.001) in the i.v. and i.c. groups, respectively. Side effects were similar, but more women in the i.v. group received anti-emetics. More women in the i.c. group were dissatisfied with the pain control. CONCLUSION: I.v. fentanyl is more effective than i.c. fentanyl for pain control in abortion.

Key words: abortion/fentanyl/pain/paracervical block/randomized controlled trial


    Introduction
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
Surgical abortion is often done using local anaesthesia to block the nerves of the cervix with or without i.v. conscious sedation using a narcotic and/or benzodiazepine. In a survey of 236 abortion clinics in North America conducted in 1997, 58% said they used local anaesthesia with or without oral medication and 32% used local anaesthesia with i.v. conscious sedation (Lichtenberg et al., 2001Go).

In a report of 825 women having first trimester abortions, the mean pain score was 5.4 on an 11-point scale. This indicates a need for better analgesia. Depression and anxiety scores were positively related to pain perception (Rawling and Wiebe, 2001Go). A study of 109 women having first trimester abortions showed that dysmenorrhoea, depression and anxiety were positively related to pain, and age was negatively related to pain (Belanger et al., 1989Go). A report of 1055 women having first trimester abortions found that gestational age was positively related to pain, age was negatively related and women who had had previous vaginal deliveries reported less pain (Borgatta and Nickinovich, 1997).

Other studies have looked at ways to improve pain control during abortion, and the following methods reduced pain scores significantly: deep rather than superficial injections, buffering the lidocaine, pre-operative non-steroidal anti-inflammatory drug (NSAID) and adding fentanyl i.v. (Wiebe, 1992Go; Wiebe and Rawling, 1995Go; Rawling and Wiebe, 2001Go). The following methods were not helpful: different local anaesthetics, waiting between injection and procedure, and increased concentration of local anaesthetic (Wiebe, 1992Go; Wiebe et al., 1996Go, 2003Go; Glantz and Shomento, 2001Go).

Pain is subjective and difficult to quantify. A comparison of commonly used pain scales indicated that the 11-point numeric pain scale was as sensitive to changes in clinical pain as the visual analogue scale (Jensen et al., 1998Go). It is practical and valid in a setting where many patients have English as a second language and has been used in many studies on abortion (Wiebe, 1992Go; Wiebe et al., 1996Go, 2003Go). Clinically significant changes in pain are even more difficult to quantify. An emergency room study indicated that 13 points on a 101-point scale was the minimum difference patients could discriminate (Todd et al., 1996Go). One study used 18 mm on a 100 mm VAS and another used 3 points on a 11-point scale as the clinically significant difference (Tucker et al., 1993Go; Todd and Funk, 1996Go). When patients were asked what difference they would want from an analgesic, they said 2 points on an 11-point pain scale (Rawling and Wiebe, 2001Go). The outcome measure chosen for this study is the 11-point numeric pain scale. On the basis of the above evidence, the clinically important difference for this study was chosen to be 1.5 on the 11-point scale.

The most commonly used drugs for abortion anaesthesia are lidocaine for para-cervical block and fentanyl with midazolam i.v. for the conscious sedation (Lichtenberg et al., 2001Go). This conscious sedation requires i.v. access and has side effects such as nausea and risks such as respiratory depression. Narcotics have been added to nerve blocks in many situations, such as axillary blocks for hand surgery (Karakaya et al., 2001Go) and spinals for obstetrics (Choi et al., 2000Go), with very good results. There are fewer side effects and risks and yet good analgesia. There was an anecdotal report of this technique of adding fentanyl to the para-cervical block at the National Abortion Federation meeting April 2003. There are no reports of the use of narcotics in para-cervical blocks in the medical literature. Potentially, we could improve analgesia without increasing side effects and risks, and we would not require i.v. access.

The goal of this study was to improve pain control in abortion by comparing para-cervical block plus either i.v. or intra-cervical (i.c.) fentanyl with respect to pain scores and side effects during surgical abortion.


    Subjects and methods
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
This was a randomized double-blinded, double dummy comparison trial of two treatment arms: para-cervical block with 100 µg of fentanyl i.v. compared with para-cervical block with 100 µg of fentanyl i.c. (mixed with the para-cervical block). The participants were women presenting for surgical abortion at a free-standing abortion clinic between February and September 2004. Inclusion criteria included age 16 years or older and termination of a pregnancy of 16 weeks gestation or less. Exclusion criteria included inability to understand the consent or allergy to the medications.

The standard procedure before a surgical abortion was applied, including a relevant medical, gynaecological and obstetric history, and a physical exam including a pelvic exam, an ultrasound and relevant laboratory testing.

After receiving information and signing the consent form, the women received a sequential study number from the study logbook. Clinic chart numbers were logged and the study number noted in the clinic chart. Randomization occurred by using a table of random numbers generated by computer and a research assistant prepared the numbered syringes for the study, which contained 100 µg of fentanyl or saline. All women received an indwelling i.v. catheter. The women in the i.v. group received 100 µg of fentanyl in the i.v and 2 ml of saline added to the lidocaine of the para-cervical block. The i.c. group received 2 ml of saline in the i.v. and 100 µg of fentanyl added to the lidocaine of the para-cervical block. Neither the operating doctor, patient or theatre nurse were aware of which syringe had the narcotic. There were five physicians involved in the study and each used their usual technique and dose of lidocaine for the para-cervical block. The dose varied from 50 to 125 mg (10–25 ml of 0.5%) and all doctors used multiple sites of injection with a combination of both deep and superficial injections (variations of the technique described in a previous study) (Borgatta and Nickinovich, 1997Go).

The abortion procedure was done as usual with vacuum curette and Berkley suction. Pre-operative misoprostol was not used for cases of <13 weeks gestation. Vasopressin (2 U) was added to the para-cervical blocks. If women still experienced pain, they were offered an additional 50 µg of i.v. fentanyl and/or more lidocaine (without fentanyl). The worst pain experienced during dilation and during the rest of the procedure was rated on an 11-point verbal pain scale by asking, ‘On a scale of 0 to 10 where 0 is no pain and 10 is pain as bad as it can be, what was that like for you?’. These scores were recorded by the theatre nurse. In the recovery room, women were asked about side effects such as nausea and acceptability of the procedure by the recovery room nurse.

Demographic information was recorded and included the factors known to influence abortion pain such as age and previous vaginal deliveries. Women were asked about dysmenorrhoea, pre-operative anxiety and depression.

The two groups were compared with respect to pain, additional pain and nausea medication, side effects and acceptability.

Statistics
Before starting the study, a 1.5 unit difference was chosen to be a clinically important difference (Rawling and Wiebe, 2001Go). A sample size of 85 per group was determined to be sufficient to detect a 1.5 unit difference (SD = 3.0) in the pain scores between the treatment groups with 90% power and 5% level of significance. The data were entered into SPSS and analysed using two-sample t-tests and Mann–Whitney tests.

The University of British Columbia Clinical Research Ethics Board approved this study (C03-0439).


    Results
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
There were 104 women in the i.v. group and 98 in the i.c. group. There were an additional 19 women who consented to be in the study but were excluded because there were eight protocol violations such as forgetting one of the pain questions or study syringe number, in one case the questions were not asked because of emotional distress, three did not have an abortion, three had initially unrecognized exclusion criteria such as allergy, three had medical complications and one i.v. could not be started, as shown in Figure 1. There were no significant differences in the two groups with respect to maternal age, gestational age, ethnicity, obstetric history, pre-operative anxiety, depression or dysmenorrhoea, as shown in Table I.



View larger version (25K):
[in this window]
[in a new window]
 
Figure 1. Randomization flow diagram.

 

View this table:
[in this window]
[in a new window]
 
Table I. Characteristics of women receiving i.v. and intra-cervical fentanyl (n=202)

 
There was more pain in the i.c. group. The mean pain score of dilation was 4.7 in the i.v. group and 5.7 in the i.c. group, while the scores for aspiration were 3.8 in the i.v. group and 5.6 in the i.c. group. (P-values 0.01 and <0.001) (Table II). The mean addition fentanyl dose used was 6.3 and 5.6 mg (NS). The total doses of lidocaine and midazolam were also similar. The only common side effects were nausea and vomiting, with post-operative nausea scores of 1.7 and 1.7 in the two groups, and emesis occurred a mean of 0.47 and 0.30 times (P=0.14). More dimenhydramine for nausea was given to women in the i.v. group (P=0.04). Women were asked if they would prefer more pain medicine if they had to have the same procedure in the future and 26 out of 103 (25.2%) said yes in the i.v. group compared with 41 out of 98 (41.8%) in the i.c. group (P=0.04).


View this table:
[in this window]
[in a new window]
 
Table II. Pain scores and side effects from i.v. and intra-cervical fentanyl

 

    Discussion
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
In this randomized, double-blinded, double dummy comparison of para-cervical block with either i.v. or i.c. fentanyl, the i.c. route of administration was not as effective as the i.v. route. The differences between the two groups are similar to the placebo-controlled trial done with i.v. fentanyl (Rawling and Wiebe, 2001Go). In that study, only one pain scale was measured for the whole procedure instead of separating the dilation from the suctioning. Lidocaine is more effective in relieving the pain in the cervix from dilation rather than the cramping pain as the uterus is emptied by suction, so one would expect, as we found, that there was more difference in the aspiration pain scale than the dilation pain scale. It may be that there are only a few opioid receptors in the uterus so that an i.c. injection has similar pharmacokinetics to i.m. injection and therefore the abortion procedure was over before the fentanyl could have been effective. The side effects of nausea and vomiting requiring dimenhydramine use were marginally greater in the i.v. group, indicating possible higher blood levels of fentanyl.

The mean pain score for dilation in the i.v. group was 4.7, which means that the amount of pain women experience during abortions is still unacceptable to many women and many women fear the pain. Since our clinic does not routinely use i.v. access if women do not request conscious sedation, we had hoped we could have a good alternative analgesic for women who are very anxious about i.v. needles.

One limitation of the study was that women who had been given midazolam may have impaired memory and not answer the questions accurately. Since they were only expected to remember the past few minutes for the pain and side effect questions, this may not have been a concern. We did not weigh the women and weight may be a factor in the effective dose of fentanyl.


    Acknowledgements
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
We are grateful to Dr Jonathan Berkowitz for statistical expertise, the staff of Everywoman's Health Centre for enthusiastic support, and the Department of Family Practice, University of British Columbia for financing Dr Berkowitz's time.


    References
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 Acknowledgements
 References
 
Belanger E, Melzack R and Lauzon P (1989) Pain of first-trimester abortion: a study of psychosocial and medical predictors. Contraception 36, 339–350.

Borgatta L and Nickinovich D (1997) Pain during early abortion. J Reprod Med 42, 287–293.[ISI][Medline]

Choi DH, Ahn HJ and Kim MH (2000) Bupivicaine-sparing effect of fentanyl in spinal anesthesia for cesarian delivery. Reg Anesth Pain Med 25, 240–245.[CrossRef][ISI][Medline]

Glantz JC and Shomento S (2001) Comparison of paracervical block techniques during first trimester pregnancy termination. Int J Gynecol Obstet 72, 171–178.[CrossRef][ISI][Medline]

Jensen MP, Miller L and Fisher LD (1998) Assessment of pain during medical procedures: a comparison of three scales. Clin J Pain 14, 343–349.[CrossRef][ISI][Medline]

Karakaya D, Buyukgoz F, Baris S, Guldogus F and Tur A (2001) Addition of fentanyl to bupivicaine prolongs anesthesia in axillary brachial plexus block. Reg Anesth Pain Med 26, 234–238.

Lichtenberg ES, Paul M and Jones H (2001) First trimester surgical abortion practices: a survey of National Abortion Federation members. Contraception 64, 345–352.[CrossRef][ISI][Medline]

Rawling MJ and Wiebe ER (2001) Randomized controlled trial of fentanyl for abortion pain. Am J Obstet Gynecol 185, 103–107.[CrossRef][ISI][Medline]

Todd KH and Funk JP (1996) The minimum clinically important difference in physician-assigned visual analog pain scores. Acad Emerg Med 3, 142–146.[Abstract]

Todd KH, Funk KG, Funk JP and Bonacci R (1996) Clinical significance of reported changes in pain severity. Ann Emerg Med 27, 485–489.[ISI][Medline]

Tucker N, Degnan N, Codere F and Sloan J (1993) Effect of topical anesthetic cream (EMLA) in reducing pain caused by infiltration of local anesthetic in eyelid surgery. Can J Ophthalmol 28, 167–170.[ISI][Medline]

Wiebe ER (1992) Comparison of the efficacy of different local anesthetics and techniques of local anesthesia in therapeutic abortions. Am J Obstet Gynecol 167, 131–134.[ISI][Medline]

Wiebe ER and Rawling M (1995) Pain control in abortion. Int J Gynecol Obstet 50, 41–46.[CrossRef][ISI][Medline]

Wiebe ER, Rawling M and Janssen P (1996) Comparison of the effectiveness of 0.5% and 1% lidocaine for first trimester abortions. Int J Gynecol Obstet 55, 71–72.[CrossRef][ISI][Medline]

Wiebe ER, Podhradsky L and Dijak V (2003) The effect of lorazepam on pain and anxiety in abortion. Contraception 67, 219–221.[CrossRef][ISI][Medline]

Submitted on December 8, 2004; resubmitted on February 22, 2005; accepted on March 3, 2005.





This Article
Abstract
Full Text (PDF )
All Versions of this Article:
20/7/2025    most recent
deh892v1
Alert me when this article is cited
Alert me if a correction is posted
Services
Email this article to a friend
Similar articles in this journal
Similar articles in ISI Web of Science
Similar articles in PubMed
Alert me to new issues of the journal
Add to My Personal Archive
Download to citation manager
Request Permissions
Google Scholar
Articles by Wiebe, E.R.
Articles by Savoy, E.
PubMed
PubMed Citation
Articles by Wiebe, E.R.
Articles by Savoy, E.