Effect of Entonox for pain management in labor: A systematic review and meta-analysis of randomized controlled trials

Inhaled analgesics for the treatment of prehospital acute pain-A systematic review

BACKGROUND

Many prehospital emergency patients receive suboptimal treatment for their moderate to severe pain. Various factors may contribute. We aim to systematically review literature pertaining to prehospital emergency adult patients with acute pain and the pain-reducing effects, adverse events (AEs), and safety issues associated with inhaled analgetic agents compared with other prehospital analgesic agents.

METHODS

As part of an initiative from the Scandinavian Society of Anaesthesia and Intensive Care Medicine, we conducted a systematic review (PROSPERO CRD42018114399), applying the PRISMA guidelines, Grading of Recommendations Assessment, Development, and Evaluation (GRADE), and Cochrane methods, searching the Cochrane Library, Epistemonikos, Centre for Reviews and Dissemination, PubMed, and EMBASE databases (updated March 2024). Inclusion criteria were the use of inhaled analgesic agents in adult patients with acute pain in the prehospital emergency care setting. All steps were performed by minimum of two individual researchers. The primary outcome was pain reduction; secondary outcomes were speed of onset, duration of effect, and relevant AEs.

RESULTS

We included seven studies (56,535 patients in total) that compared inhaled agents (methoxyflurane [MF] and nitrous oxide [N2O]) to other drugs or placebo. Study designs were randomized controlled trial (1; n = 60), randomized non-blinded study (1; n = 343), and randomized open-label study (1; n = 270). The remaining were prospective or retrospective observational studies. The evidence according to GRADE was of low or very low quality. No combined meta-analysis was possible. N2O may reduce pain compared to placebo, but not compared to intravenous (IV) paracetamol, and may be less effective compared to morphine and MF. MF may reduce pain compared to paracetamol, ketoprofen, tramadol, and fentanyl. Both agents may be associated with marked but primarily mild AEs.

CONCLUSION

We found low-quality evidence suggesting that both MF and N2O are safe and may have a role in the management of pain in the prehospital setting. There is low-quality evidence to support MF as a short-acting single analgesic or as a bridge to IV access and the administration of other analgesics. There may be occupational health issues regarding the prehospital use of N2O.

Perspectives and Practice in Eastern and Western Medicine for Pain Management in Rehabilitation Training after Orthopedic Trauma Surgery: A Qualitative Study

BACKGROUND

Despite the increasing emphasis on rehabilitation training after orthopedic surgery, little is known about the pain caused by the procedure itself. Clinical practice is driven by beliefs in pain management.

AIMS

This study aimed to explore the perspective of pain management during rehabilitation training after orthopedic trauma in China and its influencing factors from different perspectives in traditional Chinese medicine and Western medicine, respectively.

DESIGN

A phenomenological qualitative study involving semi-structured interviews.

SETTINGS

  METHODS: A qualitative study was conducted with 16 medical workers working in the Rehabilitation Medicine Department in eastern China from July 2022-February 2023. A directed method to thematic analysis was used to code the transcribed data and identify themes.

RESULTS

Four main themes emerged. (1) Inconsistent perspectives and practice: Chinese doctors majoring in Western medicine felt sympathy, helpless, and had a lack of knowledge and misconception about pain. Traditional Chinese medicine deemed that pain is a protective mechanism and attached importance to holism and unique means. (2) Consistent outcome: Insufficient pain management will have a series of negative consequences for patients' recovery, forming a vicious cycle. (3) Expectations: Though they are not optimistic about traditional analgesics, enhancement, cooperation and ideal analgesic methods still be expressed, and (4) Concept transformation: Conducting nitrous oxide is a process not only to promote analgesic technology but also to promote the awareness and concept of pain management.

CONCLUSIONS

Our study emphasized that medical workers should be aware of the importance of pain management at the same time while treating the disability. The study provides insight into pain management experiences within different educational backgrounds. The findings enable professionals to recognize the importance of pain management and its influencing factors to provide feasible and effective pain management strategies.

First alongside midwifery led unit in a high complexity public hospital in Spain: Maternal and neonatal outcomes

PROBLEM

Midwifery led units are rare in Spain.

BACKGROUND

Midwife-Led Care (MLC) is a widely extended model of care and, within this, the alongside midwifery-led units (AMLU) are those hospital-based and located in close connection with obstetric units. In Spain, CL is the first center belonging to the National Health System of these characteristics.

AIM

To evaluate the first year of activity of this pioneering unit.

METHODS

An observational cross-sectional study was carried out to assess maternal and neonatal outcomes of births facilitated at CL by comparing with those births that fulfilled the criteria to be admitted at the AMLU but were assisted at the standard obstetric care unit of the hospital.

FINDINGS

174 (20,3%) women and birthing people decided to give birth at CL, whereas 684 (79,7%) gave birth at the Obstetric Unit of the Hospital. Women assisted at the AMLU had lower intervention rates (episiotomy, epidural analgesia) and a higher rate of breastfeeding practice. There were no statistical differences in maternal outcomes (postpartum hemorrhage, third-or-four-degree laceration) or neonatal outcomes (Apgar< 7 at 5 min; birth weight < 2500 gr; macrosomia; shoulder dystocia, neonatal care transfer).

DISCUSSION

There were differences in transfers from MLU to OU between nulliparous and multiparous; the main reason for transfer is the request for analgesia. Epidural analgesia should be considered when analyzing maternal outcomes.

CONCLUSION

An alongside midwifery-led unit is a safe option with a low incidence of complications. This model of care can be positively implemented at the Public Healthcare System.

Analgesic effect of nitrous oxide during manual therapy after anterior cruciate ligament reconstruction: a study protocol for a randomized controlled trial

BACKGROUND

Many patients during manual therapy after anterior ligament reconstruction will experience severe pain, which has a negative impact on their rehabilitation. However, there is rarely an analgesic method for these patients during rehabilitation. Nitrous oxide with rapid analgesic and sedative effects is often used to relieve pain in minor procedures. The purpose of this study is to determine whether or not nitrous oxide analgesia decreases pain compared to oxygen during manual therapy after anterior ligament reconstruction.

METHODS/DESIGN

This single-center, randomized, double-blind and controlled trial will recruit 120 patients. Patients ≥ 18 years old undergoing manual therapy after anterior ligament reconstruction (1 month post-operative) with acute pain (VAS ≥ 4) are included. The main exclusion criteria included the following: pulmonary embolism, intestinal obstruction, pneumothorax. Patients will be randomly allocated to the intervention group (A) and the control group (B) in a ratio of 1:1. Doctors, therapists, patients, and data collectors are all blind to the study. The manual therapy will be performed by therapists. Nurses who implemented the intervention handed the doctors envelopes containing the patients' codes and allocation of A or B. Group A will receive a pre-prepared nitrous oxide/oxygen mixture plus conventional treatment (no analgesic) given as 30-min treatment sessions, once daily, and group B will receive oxygen plus conventional treatment (no analgesic) under the same conditions. Assessments will be taken 2 min before the intervention (T0), 5 min after the beginning of the intervention (T1), and 5 min after the intervention finished (T2). The primary outcome is pain score. Secondary outcomes include vital signs, side effects, joint range of motion, adjuvant analgesia need, therapist and patient satisfaction, and whether willing to receive the same gas again.

EXPECTED OUTCOMES

We expect nitrous oxide inhalation to have a beneficial effect on the pain of patients who receive manual therapy after anterior ligament reconstruction.

DISCUSSION

If this treatment appears beneficial, it could improve patients' satisfaction and quality of life potentially and even be implemented widely in hospital and rehabilitation settings.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, ChiCTR2200061175 (Version 2.0 June 15, 2022), https://www.chictr.org.cn .

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.

Entonox® versus Pethidine in Labor Pain Relief: A Randomized Controlled Trial

BACKGROUND

Pain relief during labor is a part of standard care in modern obstetrics. Several modalities used for pain relief have their own disadvantages and benefits in terms of side effects, effectiveness, availability, and satisfaction. The objectives of this study are primarily to compare the effectiveness and patients' satisfaction for pain relief during labor between pethidine and inhaled 50% nitrous oxide (Entonox^®).

METHODS

Laboring women at 37-41 + 6 weeks of gestation were randomly allocated to receive pethidine (50 mg intravenously) or Entonox^® for reducing labor pain. Pain scores were evaluated at 0, (baseline), 30, 60, 90, and 120 min after initiation, using the visual analog scale (VAS) and also satisfaction score after delivery using the verbal rating scale (VRS). The secondary outcomes were also assessed, including APGAR scores, labor course, side effects, and cesarean section rate.

RESULTS

A total of 136 laboring women underwent randomization into two groups, but only 58 and 65 in the pethidine group and the Entonox^® group were available for analysis. The median pain scores at baseline, 30, 60, and 90 min were comparable between both groups (p-value > 0.05); however, pain score at 120 min in the pethidine group was significantly higher (p-value: 0.038). The median of satisfaction score was significantly higher in the Entonox^® group (4 vs. 3; p-value 0.043). All of the secondary outcomes were comparable between the two groups.

CONCLUSIONS

Both have comparable effectiveness, but Entonox^® has a higher satisfaction score. Entonox^® could be an alternative to pethidine for reducing labor pain, because of its efficacy, ease for self-adjustment for satisfaction, and no serious effects on the labor course and newborns.