Nitrous oxide for pain management during in-office hysteroscopic sterilization: a randomized controlled trial

Safety reporting of Essure medical device: a qualitative and quantitative assessment on the FDA manufacturer and user facility device experience database in 2018

Background

There have been numerous cases of adverse events since the introduction of Essure medical devices for sterilization in 2002. This study analyzed the safety event reports of the Essure reported in the Manufacturer and User Facility Device Experience (MAUDE).

Methods

A retrospective analysis examined the MAUDE reports between Jan-1, 2018, and Oct-31, 2018 and focused on safety reports related to the Essure device. Safety reports were categorized and analyzed by their event type, device problem, patients' symptoms and the level of harm. Of this study cohort, 10% of samples were randomly selected for quantitative analyses. Thematic analysis was conducted for reports included death cases.

Results

A total of 4,994 eligible reports were analyzed. There were ten reports associated with individuals' deaths, and the main themes of safety reports from qualitative analysis were pains, bleeding, surgery, migraine, and infection. Quantitative analysis of 500 randomly selected samples showed that 98% of adverse event reports were associated with different injuries such as surgery, pain, bleeding, hysterectomy, and menorrhagia. Additionally, more than 90% of reports were submitted by the manufacturer.

Conclusion

These findings indicated several safety issues of Essure. More meaningful pre- and post-marketing surveillance and regulation are warranted in the medical device market to ensure safety and effectiveness, including investigating complaints, promptly sharing relevant information with regulators and users, and implementing corrective actions.

Efficacy of nitrous oxide in adults undergoing puncture biopsy: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Nitrous oxide (N2O) with rapid analgesic effect is often used to relieve pain induced by diagnostic procedures. This review was conducted to evaluate the efficacy and safety of N2O in patients undergoing puncture biopsy.

METHODS

We systematically searched PubMed, Embase, the Cochrane Library, Web of Science, Scopus and the ClinicalTrials.gov up to March, 2022. Randomized controlled trials (RCTs) were included if they investigated the effect of N2O in adults undergoing puncture biopsy. The primary outcome was pain score. Secondary outcomes included anxiety score, patient satisfaction and side effects.

RESULTS

Twelve RCTs with 1070 patients were included in the qualitative review, of which eleven RCTs were included in the meta-analysis. Pooled analysis suggested that compared with the controls (placebo, lidocaine and midazolam), N2O had better analgesic effect (MD -1.12, 95% CI -2.12 to -0.13, P = 0.03; I2 = 94%). In addition, N2O significantly alleviated patient anxiety (MD = -1.79, 95% CI -2.41 to -1.18, P<0.00001; I2 = 0%) and improved patient satisfaction (MD 1.81, 95% CI 0.11 to 3.50, P = 0.04; I2 = 92%). There was no significant difference regrading the risk of nausea (RR 2.56; 95% CI 0.70 to 9.31, P = 0.15; I2 = 0%), headache (RR 0.62, 95% CI 0.17 to 2.33, P = 0.48; I2 = 46%), dizziness (RR 1.80, 95% CI 0.63 to 5.13, P = 0.27; I2 = 0%) or euphoria (RR 2.67, 95% CI 0.81 to 8.79, P = 0.11; I2 = 8%) between the N2O group and the control group.

CONCLUSION

The present review suggested that N2O might be effective for pain management in patients undergoing puncture biopsy.

Effectiveness of Nitrous Oxide versus Pethidine/Midazolam for Pain Relief in Minor Gynecological Operative Procedures: A Randomized Controlled Trial

Aim and Objective: To compare the analgesic effectiveness of the patient-controlled inhaled nitrous oxide (Entonox^®) with intravenous opioids (pethidine/midazolam) in reducing pain during minor gynecological operative procedures, including manual vacuum aspiration (MVA), fractional curettage and dilatation and curettage. Materials and Methods: Patients undergoing minor gynecological procedures from August 2021 to December 2022 were randomized to receive nitrous oxide or intravenous pethidine (50-75 micrograms) plus midazolam (2 mg). Pain scores during and post-procedure, satisfaction level, and side effects were assessed and compared. Results: A total of 106 patients met the inclusion criteria, including 53 in the pethidine/midazolam group and 53 in the nitrous oxide group. Baseline characteristics were comparable (p-value > 0.05). Pain scores during, immediately and 30 min after procedures were not significantly different in two groups (4.94 ± 3.15, 2.74 ± 2.57, 1.58 ± 2.13 vs. 5.47 ± 2.80, 2.98 ± 2.70, 1.64 ± 2.70; p-value: 0.174, 0.634, 0.889, for pethidine/midazolam vs. nitrous oxide group, respectively. Satisfaction scores were comparable in both groups (p-value > 0.05). However, the rate of side effects was significantly lower in the nitrous oxide group (3.8% vs. 28.3%; p-value 0.001). Additionally, the discharge scores showed a significantly faster recovery time in the nitrous oxide group at 60 and 90 min after the procedure; median (IQR): 10 (9-10) vs. 9 (8-10) and 10 (10-10) vs. 10 (8.5-10); p-value 0.002 and 0.029, respectively). Conclusions: Nitrous oxide is as effective as pethidine/midazolam for pain relief in minor gynecological operative procedures but associated with significantly lower side effects and significantly faster recovery time.

Nitrous Oxide Use for Intrauterine System Placement in Adolescents

STUDY OBJECTIVE

To evaluate the impact of nitrous oxide on patient-reported pain for placement of intrauterine systems (IUSs) in adolescents STUDY DESIGN: : Prospective observational study SETTING: : IUS placement in an ambulatory clinic compared with placement with nitrous oxide in a hospital-based sedation unit PARTICIPANTS: : English-speaking adolescents aged 12 to 20 presenting to a pediatric and adolescent gynecologist with a medical indication for IUS placement MAIN OUTCOME MEASURES: : Patient-reported procedural pain measured on a visual analog scale 2 minutes post IUS insertion procedure. Secondary outcome measurement of likelihood of recommending an IUS to a peer.

RESULTS

Seventy-four patients agreed to participate. Forty-five patients underwent IUS placement in the clinic. Controlling for age, history of dysmenorrhea, and body mass index, a significant time (change in reported pain scores pre- vs post IUS insertion) by treatment (nitrous oxide vs standard of care) interaction was observed for patient-reported pain (b = -29.32 mm, P < 0.01). Patients receiving nitrous oxide were more likely to recommend an intrauterine placement than patients who received the current standard of care for pain management (b = 0.47, P = 0.02) after controlling for age, baseline pain score, and dysmenorrhea history.

CONCLUSION

Patient-reported pain was attenuated for patients who received nitrous oxide relative to those who received standard IUS placement. Patient-reported satisfaction was higher for patients who received nitrous oxide relative to those who received standard IUS placement.

Conscious sedation for office hysteroscopy: A systematic review and meta-analysis

OBJECTIVE

To evaluate the role of conscious sedation on pain control in office hysteroscopy.

METHODS

MEDLINE, EMBASE, CINAHL and CENTRAL were searched from inception to the 30th October 2020 in order to perform a systematic review and meta-analysis of all randomized controlled trials investigating women undergoing office hysteroscopic procedures, allocated to either conscious sedation or a suitable comparator, where the outcome was pain. Data regarding adverse events, feasibility and satisfaction/acceptability were also collected. The Risk of Bias 2 tool was used to assess study quality. Standard mean differences (SMD) or Odds Ratios (OR), and their 95% confidence intervals (CIs) were calculated for continuous (e.g. mean pain) and dichotomous (e.g. side-effects) outcomes, respectively.

RESULTS

The literature search returned 339 results, of which seven studies were included for systematic review, with five studies having data suitable for meta-analysis. Intravenous conscious sedation, when compared with local anesthesia, reduced pain during (SMD -0.26, 95% CI -0.51 to -0.01), but not after (SMD -0.18, 95% CI -0.43 to 0.07) office hysteroscopy. No significant difference in side-effects were noted (OR 15.58, 95% CI 0.08 to 2891.91). Intravenous conscious sedation, when compared to an oral analgesic and antispasmodic, was associated with increased pain, both during (SMD 1.03, 95% CI 0.56 to 1.49) and after (SMD 0.49, 95% CI 0.04 to 0.93) hysteroscopy and had significantly more side-effects (OR 134.33, 95% CI 16.14 to 1118.17). Inhalational conscious sedation (70% N₂O/30% O₂), when compared to oral analgesia and anxiolysis, showed the greatest reduction in pain during hysteroscopy (SMD -1.04, 95% CI -1.57 to -0.52), however side-effects were not reported. Whilst patients and hysteroscopists were more satisfied with deeper levels of sedation, resulting side-effects, such as delirium, increased the level of post-procedural attention required, leading to a significantly lower level of satisfaction amongst nursing staff.

CONCLUSION

The routine use of conscious sedation in contemporary hysteroscopic practice should be avoided in the absence of any clear reduction in pain and a higher risk of side-effects.

Addition of Lidocaine to the Distension Medium in Hysteroscopy Decreases Pain during the Procedure-A Randomized Double-blind, Placebo-controlled Trial

STUDY OBJECTIVE

To evaluate the effect of adding a local anesthetic to the distension medium in office diagnostic hysteroscopy using the vaginoscopic approach on pain during the procedure. Secondary aims included documenting side effects, patient satisfaction, and the time needed to complete the procedure.

DESIGN

Randomized double-blind placebo-controlled study.

SETTING

University-affiliated hospital; office hysteroscopy clinic.

PATIENTS

Total of 100 patients who underwent office hysteroscopies divided in half with 50 in the intervention group and 50 in the control group.

INTERVENTIONS

Ten mL of lidocaine 2% added to 1000 mL of saline solution that was used as the distension medium for hysteroscopy in the study group vs 1000 mL of saline alone in the control group.

MEASUREMENTS AND MAIN RESULTS

A significant difference was found in the increment of pain as measured by visual analog scale after the hysteroscopy between the 2 groups. Patients receiving lidocaine had an average rise of 1.9 in the visual analog scale score after the procedure compared with 2.9 in the control group (p = .033). There was also a nonsignificant trend for shorter duration of hysteroscopy in the intervention group compared with the control group (180.1 vs 222.1 seconds, p = .08). Patients' satisfaction was high in both groups (98% for the study group and 92% for the control group). Success rates were also similar between the 2 groups at approximately 95%. No side effects were recorded in either group.

CONCLUSION

The addition of local anesthetic to the distension medium in office hysteroscopy produces significant reduction in pain during the procedure without adding time to the procedure and without side effects.

Nitrous Oxide Compared With Intravenous Sedation for Second-Trimester Abortion: A Randomized Controlled Trial

OBJECTIVE

To assess whether inhaled nitrous oxide is noninferior to intravenous (IV) sedation for pain control during outpatient surgical abortion between 12 and 16 weeks of gestation.

METHODS

We enrolled women undergoing surgical abortion at 12-16 weeks of gestation into a multisite, double-blind clinical trial. Participants were randomized to sedation with nitrous oxide (70% nitrous/30% oxygen) or IV fentanyl (100 micrograms) and midazolam (2 mg). Paracervical block was administered to both groups. The primary outcome measure was immediate postabortion recall of maximum pain on a 100-mm visual analog scale.

RESULTS

Between August 2016 and March 2017, we assessed 170 women for eligibility and enrolled 39, 19 in the nitrous group and 20 in the IV sedation group. Seven participants in the nitrous group (36.8%) required conversion to IV sedation for inadequate pain control. No participants in the IV sedation group required additional medication. The proportion of women requiring additional pain control in the nitrous group exceeded our predefined stopping rule. Intention-to-treat analysis demonstrated that immediate postabortion visual analog scale pain scores were lower by 20.1 mm (95% CI 1.6-38.6) in women randomized to IV sedation than in women randomized to nitrous.

CONCLUSION

Intravenous sedation is a better choice than inhaled nitrous oxide for pain control in second-trimester abortion.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02755090.

Managing pain and anxiety during transabdominal chorionic villus sampling. A noninferiority randomized trial of nitrous oxide vs local anesthesia

INTRODUCTION

Transabdominal chorionic villus sampling (CVS) is an invasive procedure for prenatal diagnosis reported to be associated with anxiety and pain. In this context, the need for analgesia during CVS has been considered useful. Even though several authors have been interested in pain management during amniocentesis, no study has been published on pain reduction during CVS. Our objective was to evaluate pain and anxiety management during transabdominal CVS using nitrous oxide (N₂ O) and local anesthesia.

MATERIAL AND METHODS

In a randomized controlled noninferiority trial, self-administered nitrous oxide (N₂ O) inhalation (equimolar premix of oxygen and nitrous oxide) was compared with local anesthesia (1% lidocaine) before CVS. Primary outcome was pain and secondary outcome was anxiety, both measured on a visual analog scale 30-60 minutes before, immediately after (5-10 minutes) and 30-60 minutes after CVS. With a statistical power of 90%, type I error of 5% and two-sided test and potential exclusions, a sample size of 96 patients per group was enrolled and randomized. No patient was enrolled before the trial registration date.

RESULTS

From 13 March 2013 through 10 February 2015, 192 patients (96 per group) were screened and randomized. Most characteristics were similar across groups. Pain in the N₂ O group was 2.65 ± 0.22 vs 3.32 ± 0.26 in local anesthesia group [mean ± standard error of mean  (SEM)]. Mean anxiety in the N₂ O group was 3.17 ± 0.27 vs 5.19 ± 0.30 in the local anesthesia group.

CONCLUSION

N₂ O was as efficient and even superior to local anesthesia for both pain and anxiety reduction during CVS, as the 95% confidence intervals were both below the prespecified noninferiority margin of 0.8 and below zero.

Nitrous oxide versus oral sedation for pain management of first-trimester surgical abortion - a randomized study

OBJECTIVE

The objective of the study was to compare nitrous oxide with oxygen (N₂O/O₂) to oral hydrocodone/acetaminophen and lorazepam for analgesia during first-trimester surgical abortion.

STUDY DESIGN

This double-blind randomized trial assigned women undergoing first-trimester surgical abortion at<11 weeks' gestation to inhaled N₂O/O₂ vs. oral sedation for pain management. The N₂O/O₂ group received up to 70:30 ratio during the procedure and placebo pills preprocedure; the oral group received inhaled oxygen during the procedure and oral hydrocodone/acetaminophen 5 mg/325 mg and lorazepam 1 mg preprocedure. The primary outcome was maximum procedural pain, assessed on a 100-mm visual analog scale (VAS; anchors 0=no pain and 100=worst pain) at 2 min postprocedure. A difference of 13 mm on the VAS was considered clinically significant. Satisfaction with pain management was measured on a 100-mm VAS (anchors 0=very unsatisfied, 100=very satisfied).

RESULTS

We randomized 140 women, 70 per study arm. Mean age of participants was 26±6.6 years; mean gestational age was 7.3±1.5 weeks. Mean maximum procedure pain scores were 52.5±26.7 and 60.8±24.4 for N₂O/O₂ and oral groups, respectively (p=.09). Satisfaction with pain management was 69.3±28.4 and 61.5±30.4 for N₂O/O₂ and oral groups. respectively (p=.15).

CONCLUSION

We found no difference in mean procedural pain scores between women assigned to N₂O/O₂ vs. those assigned to oral sedation for first-trimester surgical abortion. Satisfaction with both options was high.

IMPLICATIONS

Women undergoing early surgical abortion experienced no differences in pain and satisfaction between those who used inhaled nitrous oxide and oral sedation. Nitrous oxide, with side effects limited to the duration of inhalation and no need for a ride home, is a viable alternative to oral sedation for first-trimester abortion pain management.