For many years, the intrauterine device (IUD) has been a contraceptive choice for women. In 1995, the intrauterine device was used by 11.9% of women of reproductive age worldwide.1 The IUD is one of the safest, least expensive, and most effective contraceptive devices available. The IUD is often an excellent choice for women who do not anticipate future pregnancies but who do not wish to be sterilized. The IUD is convenient; once inserted, it is nearly maintenance-free (except for monthly self-checks to locate the IUD string) for up to a decade. In some instances, the string of the IUD cannot be observed protruding from the cervical canal. However, the string may simply be in the cervical canal or in the uterine cavity, along with the normally positioned IUD. This type of IUD is frequently called a “lost” IUD, which implies that the IUD is intrauterine, not otherwise expelled or migrated into the peritoneal cavity. An IUD needs to be removed when future childbearing is desired or in case of complications (eg, hemorrhage, uncontrolled pelvic infection, ectopic pregnancy), endometrial or cervical malignancy, and menopausal transition after long-term use of an IUD. Sometimes the string may break off its noose during removal. Removal of a “lost” IUD is generally performed easily, but it does cause patients varying degrees of uterine or pelvic pain. When a patient desires removal of the IUD, an invasive procedure may be required to retrieve the device, such as probing of the uterine cavity using a rod with a terminal hook or with a Randall stone clamp. This issue is not new and has been approached previously with the use of paracervical analgesic blocks, oral nonsteroidal anti-inflammatory medications, and anxiolytics before removal of a “lost” IUD. Different office procedures to remove an IUD without a visible string have been described, including hysteroscopy.2,3 Operative hysteroscopy has become the most effective method for removal a “lost” IUD although it is a considerably invasive and expensive procedure.
Several studies have investigated the use of topical anesthetics (ie, lidocaine, mepivacaine) to lessen the pain experienced with minor gynecologic procedures such as endometrial biopsy and/or office hysteroscopy.4,5 Local anesthetic injected into the uterine cavity has been demonstrated to be effective in decreasing patient pain associated with these intrauterine procedures.5 In most of the studies, the intrauterine use of lidocaine during certain gynecologic procedures, including first-trimester vacuum aspiration abortion, hysterosalpingography, and endometrial biopsy, has not been documented to be expedient in diminishing pain.6–8 Results of these studies might be applicable to other types of intrauterine procedures such as removal of a “lost” IUD as a mechanism for reducing the degree of discomfort to the patient. The goal of this study was to evaluate the efficacy of intrauterine lidocaine instillation in reducing patient discomfort during removal of a “lost” IUD.
MATERIALS AND METHODS
This was a randomized, double-blinded, placebo-controlled trial comparing the efficacy of intrauterine lidocaine with placebo for pain control in patients undergoing a minor gynecologic procedure for removal of a “lost” IUD. The study was conducted at the Family Planning Outpatient Clinic at Isparta Women's and Children's Hospital and Süleyman Demirel University Medical School, Department of Obstetrics and Gynecology. Patient enrollment commenced in September 2004 and ended in September 2005. The study was approved by the Human Ethics Committee of Süleyman Demirel University. Exclusion criteria included women with a history of cervical stenosis, known allergy to lidocaine, pregnancy, and acute cervicitis. A total of 68 patients were assessed for eligibility. Four patients were excluded from the study, of which 1 refused to participate in the study and 3 did not meet the inclusion criteria (1 pregnancy, 1 acute cervicitis, and 1 cervical stenosis). Before the procedure each woman completed a demographics form and was randomized with a predetermined computer-generated randomization code prepared by an investigator to receive either 5 mL of 2% lidocaine (study group) or 5 mL of saline (placebo group) topically into the uterine cavity before removal of a “lost” IUD. The trial medications were identical in physical appearance (ie, a clear colorless solution) and were contained in identical 5-mL disposable syringes without labeling. The study coordinator and the study nurse prepared all patient data sheets and study syringes without the knowledge of the investigator who was enrolling patients. The syringes and subject data sheets were labeled with, and subjects enrolled by, consecutive numbers. The administration of anesthesia and removal of a “lost” IUD was performed by the same gynecologist (M.G.) to minimize risk and technical variation. Each patient received either 5 mL of intrauterine 2% lidocaine (Jetocaine simplex ampule, Adeka Pharmaceutical Company, Istanbul, Turkey) or saline by transcervical 18-gauge angiocatheter before the procedure. None of the patients received either a paracervical block or nonsteroidal anti-inflammatory agents. The groups are shown in Figure 1. Removal of a “lost” IUD was performed with the 3-mm Novak curette, which is made up of stainless steel and is nondisposable.
Before the procedure, plain X-ray and transabdominal and transvaginal ultrasonographic examinations revealed an IUD in the uterine cavity of each patient. A sterile bivalve speculum was then introduced into the vagina for visualization of the cervix. The cervix and vagina were washed with antiseptic solution (Betadine, Purdue Pharma LP, Stamford, CT), and if no string was seen, the following procedure was performed. The cervix was grasped with single-toothed tenaculum to straighten the uterine axis, and the uterine cavity was sounded and 5 mL of unlabeled test solution was instilled through the endocervix into the uterine cavity with an 18-gauge angiocatheter advanced to the hub. The angiocatheter was left in place for 10 minutes before it was withdrawn to limit backflow and to allow the anesthetic to take effect. The Novak curette was then pushed into the uterine cavity. After insertion, it was rotated and extracted in a continuous motion for a maximum of 5 attempts to retrieve the IUD strings.
Patients were asked to rate their pain levels on a visual analog scale (VAS), marking an “X” on a 10-cm line (0 cm: no pain; 10 cm: unbearable pain).9 Rating was done during, immediately after, and 20 minutes after the procedure. No further follow-up was scheduled. We recorded patient demographics such as age, parity, history of chronic pelvic pain, history of dysmenorrhea, prior curettage, menopausal status, education, socioeconomic status, and breastfeeding.
On the basis of a previous study by Dogan et al8 to determine the sample size, we concluded that lidocaine could be considered more beneficial than plain saline (mean ± standard deviation 5.9 ± 2.2) if it reduced the pain score by at least 17%. Assuming a power of 80% at a type I error of 0.05 and a standard deviation of 2.2, 34 subjects were required in each arm to detect a difference between the 2 groups of 1.5 cm on a 10-cm VAS scale. Data were analyzed using the SPSS 12.0 (SPSS Inc, Chicago, IL). Statistical analysis was performed with repeated measures analysis of variance test with Bonferroni correction (Friedman test), Student t test, and χ2, where appropriate. All P values were 2-sided, and P < .05 was considered statistically significant.
There were no statistically significant differences among groups in age, parity, history of chronic pelvic pain and dysmenorrhea, history of curettage, education, socioeconomic status, menopausal status, breastfeeding, type of IUD, and duration of IUD (Table 1). The mean pain scores during, immediately after, and 20 minutes after the procedure recorded by the subjects on the 10-cm linear VAS are shown in Figure 2. We found statistically significant differences in mean pain scores between the lidocaine group and the placebo group during and immediately after the procedure. Pain perceived by the patients in the lidocaine group during and immediately after the procedure was 18% and 18% less than the placebo, respectively. Pain perception was 2.7% more compared with the placebo group at 20 minutes after the procedure. There was a significant difference in the mean VAS pain scores between those women administered topical lidocaine (mean 4.44 ± 0.66 cm) and placebo (mean 4.32 ± 0.63 cm) at 20 minutes after the procedure. The number needed to treat was 3 (95% confidence interval 2–9). We needed to treat 3 patients with intrauterine lidocaine instillation to prevent one from having a pain score of 6 (severe pain) or more. One patient in the lidocaine group reported transient hypotension. There were no reports of adverse effects in the placebo group.
The various procedures used during removal of a “lost” IUD, such as placement of the tenaculum, traction of the cervix, and dilation of the cervical os, can cause discomfort. Patient acceptability and compliance with the procedure might be difficult because of associated pain and anxiety. We searched the PubMed database for all English-language papers published between January 1965 and January 2006 that reported on “analgesia,” “lidocaine,” and “lost IUD.” To our knowledge this is the first study comparing the effects of a local anesthetic and placebo for removal of a “lost” IUD. In the present study a significant difference was found in terms of pain reduction with the use of intrauterine topical local anesthetic either during procedure or immediately after the procedure. However, perception of patient pain at 20 minutes after the procedure was significantly higher in the lidocaine group compared with placebo group.
Evaluation of pain as a symptom is difficult because it is a subjective feeling and composed of sensory, emotional, and cognitive components. Pain tolerance is deeply influenced by culture. Pain perception from the cervix and the corpus of the uterus appears to pass through two distinct neural pathways. Innervation to the cervix arises from parasympathetic fibers from the pelvic splanchnic nerves (S2–4), which also supply the lower portion of the uterus and travel up to hypogastric nerves to the lower thoracic spinal cord.10 The paracervical block aids in decreasing pain of cervical origin, but the extent of its effect on pain arising from uterine activity is controversial. Paracervical lidocaine was found to be ineffective in reducing pain and carried a risk of inducing bradycardia, hypotension, convulsion, respiratory arrest, and death.11,12
Studies of intrauterine topical anesthesia evaluated its use with combined hysteroscopy and endometrial biopsy, fractional curettage, and hysterosalpingography (HSG), which are potentially more uncomfortable procedures than removal of a “lost” IUD. Several studies have investigated the use of intrauterine local anesthetics to lessen the pain experienced with HSG.7,13,14 It is interesting that a trend was seen in two of the studies of more pain after the procedure in the lidocaine group as in our study.7,13 However, our results during and immediately after the procedure differed from the results of HSG studies. This may be related to the underlying nature of our procedure, which physically traumatizes the uterine cavity and possibly causes pain via contractions, whereas HSG induces discomfort via a stretching phenomenon and pain caused by peritoneal irritation as a result of contrast spill into peritoneal cavity. The time interval that had been allowed for the local anesthetic to become effective is also important. The waiting time was 2 minutes in several studies in the literature.7,13 The peak anesthetic effect after topical application of 1% lidocaine occurs within 10 minutes.6 As explained in Materials and Methods, we waited 10 minutes after injection of 5 mL 2% lidocaine before removing the angiocatheter.
Edelman et al6 randomly assigned 80 women to receive 10 mL 1% lidocaine or saline with a 3-minute delay in first-trimester abortions and did not observe a reduction of pain during or after suction aspiration. The 3-minute waiting period may be too short. It is also possible that tubal extravasation of high-dose lidocaine might have caused peritoneal irritation. The volume of lidocaine used in our study was 5 mL. Rattanachaiyanont et al15 found statistically significant reductions in pain when a combination of paracervical block and intrauterine anesthesia was used before fractional curettage. We did not apply paracervical block because no cervical dilation was necessary in our patients.
None of the studies that included a combination of hysteroscopy and endometrial biopsy found statistically significant differences between case and placebo groups in patient-reported pain experience.4,16,17 These were not in agreement with our results, in which the lidocaine group did have significant pain relief over placebo during and immediately after procedure. The possible explanation of this contradiction could be that hysteroscopy involves uterine distention, and combined hysteroscopy and endometrial biopsy is potentially more uncomfortable than our procedure. Another explanation could be the ethnic and cultural differences between the patient population, which may affect pain perception and tolerance. Another possible explanation could be that pain is difficult to evaluate because it is a symptom and therefore subjective, and anxiety may be a potential confounder. In the present study, we chose 2% lidocaine for intrauterine anesthetic because it has a quicker onset and shorter duration of action than mepivacaine, which was used in previous studies, and 2% lidocaine might have a theoretically greater efficacy than 1%.4,5,16,17 The study by Dogan et al8 found that the combination of local lidocaine and oral naproxen sodium significantly reduced patient discomfort during an endometrial biopsy. However, when either lidocaine or naproxen sodium were given individually, there was no improvement in outcome. This was inconsistent with our results. However, their population was older (mostly postmenopausal), and cervical stenosis and genital atrophy were felt to play a role in their findings.
In conclusion, transcervical intrauterine topical instillation of 5 mL of 2% plain lidocaine brings about pain relief during and immediately after removal of a “lost” IUD. Therefore, it appears to be a beneficial method. We believe that further studies are needed to evaluate the effectiveness of intrauterine anesthesia, using either a higher concentration or more volume and longer waiting time. This will increase patient acceptability and compliance with the procedure. The results of future studies may prove this method beneficial, especially in younger women who undergo minor gynecologic procedures.
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© 2006 The American College of Obstetricians and Gynecologists
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