Methoxyflurane Analgesia in Adult Patients in the Emergency Department: A Subgroup Analysis of a Randomized, Double-blind, Placebo-controlled Study (STOP!)

Inhaled methoxyflurane (Penthrox®) as a novel pain relief for outpatient hysteroscopy and other gynaecological procedures

OBJECTIVE

Penthrox® (methoxyflurane) is a convenient, portable, self-administered disposable single-use handheld inhaler licenced as an emergency, rapid-onset, short-acting, analgesic in adult trauma patients. Outpatient hysteroscopy is one of the commonest procedures in contemporary gynecology but it can be associated with significant pain leading to poor patient experience and failed procedures. We evaluated the feasibility and acceptability of Penthrox® in women undergoing outpatient hysteroscopic procedures and its potential efficacy to reduce pain and improve patient experience.

STUDY DESIGN

We conducted a prospective observational cohort study on women undergoing hysteroscopy or other intrauterine procedures, such as coil fitting, endometrial biopsy, polypectomy, endometrial ablation and manual vacuum aspiration in an outpatient setting. Women were offered Penthrox® inhalers for pain control, instructed how to use it and asked to record the intra-procedural pain they expected and actually experienced using a 10 cm Visual Analogue Scale. The acceptability, side effects and ease of use of the Penthrox® device were also recorded.

RESULTS

122/146 (83.6 %) women chose to use Penthrox®. 116 out of the 122 (95.1 %) underwent an intrauterine procedure, including 59 hysteroscopic polypectomies and 34 global endometrial ablations. The average pain expected during the procedure was 6.0 (SD = 2.8) and the pain experienced during the procedure was 5.1 (SD = 2.8). The intended procedure was completed in 117 (96 %) women. Penthrox® was considered easy to use by 118 (97 %) women and 111 (91 %) would use it again, although 22 (18 %) women would prefer general anaesthesia in the future. No adverse events occurred but 88 (72 %) women reported mild, self-limiting side effects.

CONCLUSION

Penthrox® appears safe, feasible and acceptable as a pain relief option during outpatient hysteroscopy and other intrauterine procedures. The effectiveness of Penthrox® should be evaluated against conventional pain control in an adequately powered multicentre randomised controlled trial.

The Safety of Methoxyflurane for Emergency Pain Relief in Children and Adolescents: A Retrospective Cohort Study

OBJECTIVES

The use of methoxyflurane is becoming increasingly popular in the treatment of pain in an emergency setting, in part due to its ease of administration. However, little is known about the risk of serious adverse events in children and adolescents. The aim of this study was to examine the safety of methoxyflurane in a pediatric population.

METHODS

The study was a retrospective cohort study of pediatric prehospital events using probabilistic linked health data. All ambulance transfers in Western Australia between 1990 and 2016 involving children and adolescent patients were identified. Patients were categorized based on administered analgesia: methoxyflurane, an opioid analgesic, both methoxyflurane and an opioid analgesic, or no analgesic. Hospital and mortality data were linked to transferred patients to identify deaths, adverse drug reactions, liver and kidney toxicity, and re-admissions to hospital following ambulance transfer. Generalized linear models, adjusting for sociodemographic and ambulance transfer characteristics, were used to compare outcomes between children exposed to methoxyflurane and the other three groups.

RESULTS

The study cohort consisted of 37,211 children, including 9,472 patients (25.5%) treated with methoxyflurane alone, 2,764 (7.4%) treated with an opioid analgesic, 1,235 (3.3%) treated with both methoxyflurane and an opioid analgesic, and 23,740 (63.8%) treated with no analgesic. Death in children and adolescents was uncommon, with less than five deaths (<0.1%) observed in the 12 months following treatment with methoxyflurane and no deaths in those treated with both methoxyflurane and an opioid analgesic. Adverse drug reaction was rare (<0.1%) in patients treated with methoxyflurane, as was liver and kidney toxicity with no case observed. At 90-days follow-up, there was no significant difference in hospitalization in patients treated with methoxyflurane and those treated with methoxyflurane and an opioid analgesic (adjusted OR:1.01, 95%CI:0.85-1.21). Compared with methoxyflurane treated patients, patients treated with an opioid analgesic were more likely to be hospitalized (aOR:1.23, 95%CI:1.09-1.39), while patients treated with no analgesic were less likely to be hospitalized (aOR:0.85, 95%CI:0.79-0.92).

CONCLUSIONS

In children and adolescents transported by ambulance, the use of methoxyflurane was not associated with an increased risk of hospitalization, death, serious adverse drug reactions or liver and kidney toxicity.

MethOxyfluraNe in InTerventiOnal Radiology (MONITOR): A randomised controlled trial

INTRODUCTION

Procedural sedation and pain management in interventional radiology (IR) are of critical importance to successful outcomes but remain under-researched. Methoxyflurane has been previously used in some minor procedures with several advantages including rapid onset and offset and a good safety profile. The purpose of this study was to evaluate methoxyflurane for procedures in IR.

METHODS

A randomised, double-blind, placebo-controlled trial was performed between October 2021 and November 2022. Patients presenting for portacath insertion, portacath removal or solid organ biopsy were randomised to either methoxyflurane or placebo. Three hundred and fourteen patients were enrolled in total. Patients were supplied with one Penthrox inhaler containing either 3 mL methoxyflurane or placebo. The primary endpoints of the study were change in pain and anxiety scores compared with baseline, measured on a standardised visual analogue scale (VAS) pre-procedure, at 5-min intervals during the procedure and post-procedure. Baselines scores were controlled for in the statistical analysis. Safety analysis was also performed.

RESULTS

One hundred and sixty-nine patients received methoxyflurane and 145 received placebo. Baseline characteristics were similar between the two groups. The methoxyflurane group had lower pain and anxiety scores throughout the procedure (P < 0.001) with 2.5 times less pain (VAS 1.08/10) and 1.6 times less anxiety (VAS 0.97/10) on average. Lower post-procedure pain (mean 0.72 vs 1.44; P < 0.001) and anxiety (mean 0.55 vs 1.13; P = 0.008) were also observed with methoxyflurane. There were no drug or major procedure-related adverse events.

CONCLUSION

The results of this study suggest that methoxyflurane provides safe and effective analgesia and anxiolysis for some procedures in IR.

Wilderness Medical Society Clinical Practice Guidelines for the Treatment of Acute Pain in Austere Environments: 2024 Update

The Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded based on the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians. This is an update of the 2014 version of the "WMS Practice Guidelines for the Treatment of Acute Pain in Remote Environments" published in Wilderness & Environmental Medicine 2014; 25:41-49.

Parenteral, Non-Intravenous Analgesia in Acute Traumatic Pain-A Narrative Review Based on a Systematic Literature Search

Traumatic pain is frequently encountered in emergency care and requires immediate analgesia. Unfortunately, most trauma patients report sustained pain upon arrival at and discharge from the Emergency Department. Obtaining intravenous access to administer analgesics can be time-consuming, leading to treatment delay. This review provides an overview of analgesics with both fast onset and parenteral, non-intravenous routes of administration, and also indicates areas where more research is required.

Time to Reconsider Analgesia in Mass Casualty Incidents

The provision of analgesia in mass casualty incidents has traditionally been viewed as low-priority and reserved for later stages of care. Poor pain management is commonplace in trauma victims, and inadequate acute pain management can hinder evacuation efforts and may lead to the development of chronic pain and posttraumatic stress disorder. New, safe, and simple methods for administering quality analgesia have proven to be safe and effective in the prehospital setting and, as such, could easily be implemented into mass casualty incident protocols and allow for analgesia at earlier stages in such incidents, thereby improving patient care.

Patient and staff perceptions of short procedural sedation with propofol for joint and fracture reductions in the Emergency Department: A qualitative study

BACKGROUND

Emergency Department (ED) propofol sedation is widely used to facilitate reduction of fractures and dislocations, but little is known about patient and staff perceptions of the practice. Better understanding of these aspects may improve patient care.

METHODS

A qualitative exploratory study involving semi-structured patient interviews and ED healthcare professional focus groups. Interviews with adult patients (≥16 years) >1 hour after their sedation episode were audio-recorded, anonymised and transcribed verbatim to an electronic database. Thematic analysis using a general inductive method led to development of codes and themes. ED focus groups recordings were similarly transcribed and triangulated to patient interview outcomes.

RESULTS

Data saturation was reached after 16 patient interviews. Emergent central themes from a patient perspective were: 'fear of the unknown' and 'expressed relief that the procedure was comfortable.' Key themes included 'trust in the clinical team,' 'efficacy of pain management prior to sedation' and 'quality of the information delivered to patients.' Focus group discussions around patient interview outcomes identified triage, analgesia delivery, communication, and consideration of the environment as areas for improvement.

CONCLUSIONS

ED procedural sedation with propofol is generally very well accepted by patients and clinical staff but there is scope to improve patient-focus and increase satisfaction.

Ambulance nurses’ experiences of pain management with Penthrox® in Swedish ambulance care: A mixed method study

BACKGROUND

Methoxyflurane (MTX) is an inhalation agent that has several potential benefits for limiting various types of pain in ambulance care.

AIM

To elucidate how ambulance nurses experience the characteristics of MTX in an ambulance care setting.

METHOD

This cross-sectional study applied a mixed-methods approach, using a questionnaire together with complementary interviews. The questionnaire survey was analyzed using descriptive statistics (10-point Likert scale and question index values [Q-IV], range: 0-1.0). The interviews were analyzed using directed content analysis. Study results were reported following the STROBE statement.

RESULTS

The ambulance nurses' overall general satisfaction with the MTX concept had a median of 7.0 (IQR 5-8), corresponding to a mean Q-IV of 0.84 (very good experience). The qualitative part was divided into three categories: sense of security, patient participation, and general usefulness. The results revealed varying experiences of usefulness, including pain-relieving effect and the possibility of patient participation. The perceived strong odor of MTX seemed to concern the ambulance nurses and their patients.

CONCLUSION

In general, MTX was experienced as a safe and effective analgesic. However, the experiences of the overall usefulness varied, particularly since the product had a perceived strong odor. Increasing knowledge of using MTX, could likely increase the overall usefulness.

Clinical assessment and risk stratification for prehospital use of methoxyflurane versus standard analgesia in adult patients with trauma pain

Oligoanalgesia, the undertreatment of trauma-related pain using standard analgesics in prehospital and emergency departments, has been extensively documented as one of the major challenges affecting the effective treatment of trauma-related pain. When administered in low doses, methoxyflurane has been highlighted by numerous medical works of literature to provide an effective, nonopioid, nonnarcotic treatment alternative to standard analgesics for prehospital and emergency department use. Low-dose methoxyflurane has been associated with fast-pain relief in adult patients manifesting moderate-to-severe pain symptoms. This systematic review and meta-analysis aimed to assess the clinical implication of low-dose methoxyflurane use in prehospital and emergency departments in adult patients with moderate-to-severe trauma-related pain. Moreover, the review aimed at assessing the risk stratification associated with using low-dose methoxyflurane in prehospital and emergency departments. The systematic review and meta-analysis performed a comprehensive search for pertinent literature assessing the implications and risks of using low-dose methoxyflurane in adult patients exhibiting moderate-to-severe trauma-related pain in prehospital settings. A comparison between the use of low-dose methoxyflurane and standard-of-care analgesics, placebo, in prehospital settings was reported in four clinically conducted randomized controlled trials (RCTs). These RCTs included the STOP! trial, InMEDIATE, MEDIATA, and the PenASAP trials. A meta-analysis comparing the time taken to achieve first pain relief on initial treatment of patients with moderate-to-severe trauma-related pain favored the use of low-dose methoxyflurane to the standard-of-care analgesics (mean difference = -6.63, 95% confidence interval = -7.37, -5.09) on time taken to establish effective pain relief. Low-dose methoxyflurane has been associated with superior and faster pain relief in prehospital and emergency departments in adult patients exhibiting moderate-to-severe trauma-related pain compared to other standard analgesics.

Prevalence and Perinatal Outcomes Following In Utero Exposure to Prehospital Emergency Methoxyflurane: A 17-Year Retrospective Cohort Study

OBJECTIVE

To examine the prevalence of exposure and perinatal outcomes associated with in utero exposure to methoxyflurane.

DESIGN, SETTING AND POPULATION

Whole-population ambulance data in Western Australia (WA) were linked to the statutory perinatal data collection to identify pregnant women transferred by ambulance between 2000 and 2016. The proportion of neonates in WA exposed to methoxyflurane, fentanyl or no analgesia during an ambulance transfer was calculated. Perinatal outcomes of pregnancies exposed to methoxyflurane (n=1579) were compared to those exposed to fentanyl (n=203) or no analgesia (n=10524) using multivariable logistic regression modelling. Perinatal outcomes were considered overall and by trimester of exposure.

MAIN OUTCOME MEASURES

Primary outcomes were the prevalence of in utero methoxyflurane exposure and Apgar score on the day of delivery.

RESULTS

In the study period, 0.4% of all neonates born in WA were exposed to methoxyflurane in utero. Methoxyflurane exposure on the day of delivery (n=657) was not associated with an increased likelihood of a low Apgar score at five minutes compared with no analgesia (n=2667) (OR 1.23, 95% CI 0.91-1.67). Whereas fentanyl exposure (n=22) was associated with an increased likelihood of low Apgar score compared with methoxyflurane (OR 3.67, 95% CI 1.18-11.48).

CONCLUSIONS

Methoxyflurane is commonly used by ambulance services to treat pain in pregnant women in WA. While not recommended for use in pregnancy, pregnancies exposed to methoxyflurane did not have an increased risk of adverse perinatal outcomes in this study.

Inhaled methoxyflurane for the management of trauma related pain in patients admitted to hospital emergency departments: a randomised, double-blind placebo-controlled trial (PenASAP study)

BACKGROUND

Oligo-analgesia is common in the emergency department (ED). This study aimed at reporting, when initiated by triage nurse, the superior efficacy of inhaled methoxyflurane plus standard of care (m-SoC) analgesia versus placebo plus SoC (p-SoC) for moderate-to-severe trauma-related pain in the hospital ED.

METHODS

A randomised, double-blind, placebo-controlled trial was conducted at eight EDs. Adults with pain score ≥4 (11-point numerical rate scale, NRS) at admission were randomised to receive one or two inhalers containing m-SoC or p-SoC. Primary outcome measure was time until pain relief ≤30 mm, assessed on the 100-mm Visual Analogic Scale (VAS).

RESULTS

A total of 351 patients were analysed (178 m-SoC; 173 p-SoC). Median pain prior to first inhalation was 66 mm, 75% had severe pain (NRS 6-10). Median time to pain relief was 35 min [95% confidence interval (CI), 28-62] for m-SoC versus not reached in p-SoC (92 - not reached) [hazard ratio), 1.93 (1.43-2.60), P < 0.001]. Pain relief was most pronounced in the severe pain subgroup: hazard ratio, 2.5 (1.7-3.7). As SoC, 24 (7%) patients received weak opioids (6 versus 8%), 4 (1%) strong opioid and 44 (13%) escalated to weak or strong opioids (8 versus 17%, respectively, P = 0.02). Most adverse events were of mild (111/147) intensity.

CONCLUSIONS

In this study, we report that methoxyflurane, initiated at triage nurse as part of a multimodal analgesic approach, is effective in achieving pain relief for trauma patients. This effect was particularly pronounced in the severe pain subgroup.

Does Inhaled Methoxyflurane Implement Fast and Efficient Pain Management in Trauma Patients? A Systematic Review and Meta-Analysis

Introduction

Evidence on the use of inhaled methoxyflurane in the management of trauma pain is conflicting and obfuscated. This study aimed to determine the efficacy and safety of inhaled methoxyflurane for trauma pain on the basis of published randomized controlled trials (RCTs).

Methods

RCTs assessing the efficacy of methoxyflurane in adults or adolescents with acute trauma pain published in PubMed, Web of Science, Embase, Cochrane Library, and Google Scholar were searched. The control groups were those that received placebo or standard analgesic treatment (SAT). The primary outcome was the change from baseline in pain scores during the first 30 min of treatment. Secondary outcomes included time to first pain relief, the proportion of patients experiencing pain relief, rescue analgesia rate, the treatment satisfaction of patients and investigators, and the methoxyflurane-related treatment-emergent adverse events (TEAEs).

Results

A total of nine RCTs (1806 patients) were identified. Results revealed that methoxyflurane provided a clinically unimportant benefit by improving the mean difference of change from baseline in pain intensity (from − 0.44 to − 1.23 cm, p < 0.001) at various time points within the first 20 min compared to control treatment. Besides, methoxyflurane decreased the time of onset of pain relief (mean difference − 5.29 min; 95% CI − 6.97 to − 3.62) and the proportion of patients who needed rescue analgesic medication (risk ratio 1.41; 95% CI 1.17–1.70) despite it increasing the risk of non-severe TEAEs (risk ratio 3.09; 95% CI 1.72–5.57). Notably, the benefit of almost all secondary pain-related outcomes was rendered clinically nonsignificant between methoxyflurane and SAT strata besides the time of onset of pain relief. The quality of evidence was low or very low in all outcomes.

Conclusions

In emergency situations without effective therapy, this systematic review and meta-analysis provides low-quality evidence that methoxyflurane can be used as a rapid-acting and effective treatment for acute trauma pain, although its utilization is associated a risk of non-severe TEAEs. However, the current evidence does not support the notion that inhaled methoxyflurane offered superior analgesic efficacy to SAT.

Clinical Trial Number

PROSPERO registration number CRD42020223000.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-021-00258-9.

Determination of equi-analgesic doses of inhaled methoxyflurane versus intravenous fentanyl using the cold pressor test in volunteers: a randomised, double-blinded, placebo-controlled crossover study

Background

Inhaled methoxyflurane for acute pain relief has demonstrated an analgesic effect superior to placebo. Data comparing methoxyflurane to an opioid are needed. The aim of this study was to determine the equi-analgesic doses of inhaled methoxyflurane vs i.v. fentanyl. Both drugs have an onset within minutes and an analgesic effect of 20–30 min.

Methods

Twelve subjects were included in a randomised, double-blinded, placebo-controlled crossover study with four treatments: placebo (NaCl 0.9%), fentanyl 25 μg i.v., fentanyl 50 μg i.v., or inhaled methoxyflurane 3 ml. The subjects reported pain intensity using the verbal numeric rating scale (VNRS) from 0 to 10 during the cold pressor test (CPT). The CPT was performed before (CPT 1), 5 min (CPT 2), and 20 min (CPT 3) after drug administration.

Results

Inhaled methoxyflurane and fentanyl 25 μg reduced VNRS scores significantly compared with placebo at CPT 2 (–1.14 [estimated difference in VNRS between treatment groups with 95% confidence interval {CI}: –1.50 to –0.78]; –1.15 [95% CI: –1.51 to –0.79]; both P<0.001) and CPT 3 (–0.60 [95% CI: –0.96 to –0.24]; –0.84 [95% CI: –1.20 to –0.47]; both P<0.001). There were no significant differences between the two drugs. Methoxyflurane had significantly higher VNRS scores than fentanyl 50 μg at CPT 2 (0.90 [95% CI: 0.54–1.26]; P<0.001) and CPT 3 (0.57 [95% CI: 0.21–0.94]; P<0.001).

Conclusions

Inhaled methoxyflurane 3 ml was equi-analgesic to fentanyl 25 μg i.v. at CPT 2. Both resulted in significantly less pain than placebo. Fentanyl 50 μg i.v. demonstrated analgesia superior to methoxyflurane.

Clinical trial registration

NCT03894800

ANalgesic Efficacy and safety of MOrphiNe versus methoxyflurane in patients with acute myocardial infarction: the rationale and design of the ANEMON-SIRIO 3 study: a multicentre, open-label, phase II, randomised clinical trial

INTRODUCTION

The unfavourable influence of morphine on the pharmacokinetics of ticagrelor resulting in weaker and retarded antiplatelet effect in patients with acute coronary syndrome (ACS) has been previously shown. Replacing morphine with methoxyflurane, a potent, non-opioid analgesic agent, that does not weaken or delay the effect of antiplatelet agents may improve the clinical efficacy of treatment of patients with ACS.

METHODS

The ANEMON-SIRIO 3 study was designed as a multicentre, open-label, phase II, randomised clinical trial aimed to test the analgesic efficacy and safety of methoxyflurane in patients with ACS. The study population will comprise patients with ST-elevation myocardial infarction or non-ST-elevation ACS admitted to the study centres with typical chest pain requiring analgesic treatment. Before percutaneous coronary intervention (PCI) for the patients with index ACS will be randomly assigned in 1:1 ratio to receive methoxyflurane administered by inhalation, or to obtain morphine administered intravenously. Analgesic treatment will be followed by 300 mg loading dose of aspirin and 180 mg loading dose of ticagrelor. Patients will be assessed with regard to pain intensity according to the Numeric Pain Rating Scale at baseline, 3 min after study drug administration and immediately after PCI. Moreover, patients will be actively monitored with regard to the occurrence of side effects of evaluated therapies, as well as adverse events that may be related to insufficient platelet inhibition (no-reflow phenomenon assessed immediately after PCI, administration of GPIIb/IIIa inhibitors during PCI, acute stent thrombosis).

ETHICS AND DISSEMINATION

The study will be conducted in six Polish clinical centres from the beginning of in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

TRIAL REGISTRATION DETAILS

ClinicalTrials.gov, NCT04476173.

Low-Dose Methoxyflurane versus Standard of Care Analgesics for Emergency Trauma Pain: A Systematic Review and Meta-Analysis of Pooled Data

Purpose

Undertreatment of trauma-related pain is common in the pre-hospital and hospital settings owing to barriers to the use of traditional standard of care analgesics. Low-dose methoxyflurane is an inhaled non-opioid analgesic with a rapid onset of pain relief that is approved for emergency relief of moderate-to-severe trauma-related pain in adults. This analysis was performed to compare the efficacy and safety of low-dose methoxyflurane with standard of care analgesics in adults with trauma-related pain.

Methods

A meta-analysis was performed on pooled data from randomized controlled trials identified via a systematic review. The primary endpoint was the pain intensity difference between baseline and various time intervals (5, 10, 15, 20, and 30 minutes) after initiation of treatment.

Results

The pain intensity difference was statistically superior with low-dose methoxyflurane compared with standard of care analgesics (overall estimated treatment effect=11.88, 95% CI=9.75–14.00; P<0.0001). The superiority of low-dose methoxyflurane was demonstrated at 5 minutes after treatment initiation and was maintained across all timepoints. Significantly more patients treated with methoxyflurane achieved response criteria of pain intensity ≤30 mm on a visual analog scale, and relative reductions in pain intensity of ≥30% and ≥50%, compared with patients who received standard of care analgesics. The median time to pain relief was shorter with methoxyflurane than with standard of care analgesics. The findings were consistent in a subgroup of elderly patients (aged ≥65 years).

Conclusion

Methoxyflurane can be considered as an alternative to standard of care analgesics in pre-hospital and hospital settings for treatment of adult patients with acute trauma-related pain.

Patient-Reported outcomes of pain care research in the adult emergency department: A scoping review

Despite more than 30 years of research, pain in the emergency department (ED) setting is frequently undertreated. EDs prioritise process measures that often have tenuous links to patient-reported outcomes. However, process measures, such as time to the administration of first analgesic medication, are neither direct objective measures of analgesia nor appropriate surrogate markers of pain relief. Since pain is a subjective symptom that lacks an objective measure, pain research in any clinical environment, including EDs, should rely upon patient-reported outcomes. This scoping review examined patient-reported outcomes (PROs) and patient-reported outcome measures (PROMs) of pain care in the adult emergency department at the micro, meso and macro-level over the last ten years. We reviewed pain care research conducted on adults in EDs over the last ten years and identified 57 articles using 14 patient-reported outcomes of pain care falling into five broad areas, most without validation or adaption to the ED setting. Despite efforts made to incorporate PROs and PROMs into acute pain care research in the ED over the last ten years, there is still no gold-standard PROM in widespread use. We recommend the adaptation of existing tools with rigorous validation in ED populations.

Approaching acute pain in emergency settings; European Society for Emergency Medicine (EUSEM) guidelines-part 2: management and recommendations

BACKGROUND

In Europe, healthcare systems and education, as well as the clinical care and health outcomes of patients, varies across countries. Likewise, the management of acute events for patients also differs, dependent on the emergency care setting, e.g. pre-hospital or emergency department. There are various barriers to adequate pain management and factors common to both settings including lack of knowledge and training, reluctance to give opioids, and concerns about drug-seeking behaviour or abuse. There is no single current standard of care for the treatment of pain in an emergency, with management based on severity of pain, injury and local protocols. Changing practices, attitudes and behaviour can be difficult, and improvements and interventions should be developed with barriers to pain management and the needs of the individual emergency setting in mind.

METHODS

With these principles at the forefront, The European Society for Emergency Medicine (EUSEM) launched a programme-the European Pain Initiative (EPI)-with the aim of providing information, advice, and guidance on acute pain management in emergency settings.

RESULTS AND CONCLUSIONS

This article provides treatment recommendations from recently developed guidelines, based on a review of the literature, current practice across Europe and the clinical expertise of the EPI advisors. The recommendations have been developed, evaluated, and refined for both adults and children (aged ≥ 1 year, ≤ 15 years), with the assumption of timely pain assessment and reassessment and the possibility to implement analgesia. To provide flexibility for use across Europe, options are provided for selection of appropriate pharmacological treatment.

Multiple criteria decision analysis approach to consider therapeutic innovations in the emergency department: The methoxyflurane organizational impact in acute trauma pain

BACKGROUND

Acute trauma pain is poorly managed in the emergency department (ED). The reasons are partly organizational: ED crowding and rare trauma care pathways contribute to oligoanalgesia. Anticipating the organizational impact of an innovative care procedure might facilitate the decision-making process and help to optimize pain management.

METHODS

We used a multiple criteria decision analysis (MCDA) approach to consider the organizational impact of methoxyflurane (self-administered) in the ED, introduced alone or supported by a trauma care pathway. A MCDA experiment was designed for this specific context, 8 experts in emergency trauma care pathways (leading physicians and pharmacists working in French urban tertiary hospitals) were recruited. The study involved four steps: (i) Selection of organizational criteria for evaluating the innovation's impact; (ii) assessment of the relative weight of each criterion; (iii) choice of appropriate scenarios for exploring the organizational impact of MEOX under various contexts; and (iv) software-assisted simulation based on pairwise comparisons of the scenarios. The final outcome measure was the expected overall organizational impact of methoxyflurane on a 0-to-100 scale (score >50: positive impact).

RESULTS

Nine organizational criteria were selected. "Mean length of stay in the ED" was the most weighted. Methoxyflurane alone obtained 59 as a total score, with a putative positive impact for eight criteria, and a neutral effect on one. When a trauma care pathway was introduced concomitantly, the impact of methoxyflurane was greater overall (score: 75) and for each individual criterion.

CONCLUSIONS

Our model highlighted the putative positive organizational impact of methoxyflurane in the ED-particularly when supported by a trauma care pathway-and the relevance of expert consensus in this particular pharmacoeconomic context. The MCDA approach could be extended to other research fields and healthcare challenges in emergency medicine.

Identifying values and preferences around the choice of analgesia for patients with acute trauma pain in emergency and prehospital settings: using group concept mapping methodology

OBJECTIVES

The main study aim was to examine the applicability of a novel method to assess the criterion of values and preferences within the Grading of Recommendation, Assessment, Development and Evaluation evidence to decision framework. The group concept mapping (GCM) approach was applied to identify, organise and prioritise values and preferences in the example of health professionals' choice of analgesia for patients with acute trauma pain.

SETTING

Prehospital and emergency care centres in the Nordic countries of Denmark, Norway, Sweden, Finland and Iceland.

PARTICIPANTS

Acute care health professionals with qualifications to administer analgesic agents to patients in emergency and prehospital settings, including advanced ambulance assistants, rescue officers, paramedics, emergency physicians and emergency nurses, participated in an online survey in which statements were generated (n=40) and structured (n=11) and finally analysed and interpreted in a validation meeting (n=4).

RESULTS

Using GCM, ideas were generated and structured through online participation. Results were interpreted at a validation meeting. In total, 111 unique ideas were identified and organised into seven clusters: drug profile, administration, context, health professionals' preferences and logistics, safety profile, patient's medical history and acute clinical situation.

CONCLUSIONS

Based on GCM, a conceptual model was developed, and values and preferences around choice of analgesia in emergency care were revealed. Health professionals within acute care can apply the conceptual model to support their decision-making when choosing the best available treatment for pain for their patients in emergency care.

Inhaled Methoxyflurane versus Intravenous Morphine for Severe Trauma Pain in the Emergency Setting: Subgroup Analysis of MEDITA, a Multicenter, Randomized, Controlled, Open-Label Trial

Purpose

Opioid analgesics remain the cornerstone of treatment for severe trauma pain in the emergency setting, but there are barriers to their use. This post hoc analysis of a previously reported trial (MEDITA) investigated the efficacy and safety of low-dose methoxyflurane versus intravenous (IV) morphine for severe trauma pain.

Patients and Methods

MEDITA was a Phase IIIb, randomized, active-controlled, parallel-group, open-label study in Italian pre-hospital units and emergency departments (EudraCT: 2017-001565-25; NCT03585374). Adult patients (N=272) with moderate-to-severe trauma pain (score ≥4 on the Numerical Rating Scale [NRS]) were randomized 1:1 to inhaled methoxyflurane (3 mL) or standard analgesic treatment (SAT; IV paracetamol 1g or ketoprofen 100mg for moderate pain [NRS 4-6] and IV morphine 0.1mg/kg for severe pain [NRS ≥7]). Analyses were performed for the severe pain subgroup. The primary efficacy variable was the overall change from baseline in visual analog scale (VAS) pain intensity at 3, 5 and 10min post-randomization. Non-inferiority of methoxyflurane versus morphine was concluded if the upper 95% confidence interval (CI) for the treatment difference was <1; superiority was concluded if the upper 95% CI was <0.

Results

Ninety-three patients (methoxyflurane: 49; SAT: 44) were included in the severe pain intention-to-treat population. The reduction in VAS pain intensity over the first 10min was superior for methoxyflurane versus morphine (adjusted mean treatment difference: -5.54mm; 95% CI: -10.49, -0.59mm; p=0.029). Median time to onset of pain relief was 9min for methoxyflurane and 15min for morphine. Patients rated treatment efficacy and physicians rated treatment practicality "Excellent" or "Very good" for more methoxyflurane-treated patients (42.8% and 67.3%) than morphine-treated patients (18.1% and 22.8%). Adverse events, all non-serious, were reported in 20.4% of methoxyflurane-treated patients and in 4.8% of morphine-treated patients.

Conclusion

Methoxyflurane provided superior short-term pain relief to IV morphine in patients with severe trauma pain and offers an effective non-narcotic treatment option.

Analgesic Efficacy, Practicality and Safety of Inhaled Methoxyflurane Versus Standard Analgesic Treatment for Acute Trauma Pain in the Emergency Setting: A Randomised, Open-Label, Active-Controlled, Multicentre Trial in Italy (MEDITA)

INTRODUCTION

Inhaled low-dose methoxyflurane is approved in Europe for emergency relief of moderate-to-severe trauma-related pain in adults, but data versus active comparators are sparse. The phase IIIb Methoxyflurane in Emergency Department in ITAly (MEDITA) trial investigated the analgesic efficacy, practicality and safety of methoxyflurane versus standard analgesic treatment (SAT) for acute trauma pain.

METHODS

This was a randomised, active-controlled, parallel-group, open-label trial conducted in 15 Italian emergency units. Adults with limb trauma and pain score ≥ 4 on numerical rating scale (NRS) were randomised 1:1 to inhaled methoxyflurane 3 mL or SAT [intravenously administered (IV) morphine 0.1 mg/kg for severe pain (NRS ≥ 7); IV paracetamol 1 g or IV ketoprofen 100 mg for moderate pain (NRS 4-6)]. The primary endpoint was overall change in visual analogue scale (VAS) pain intensity from baseline (time of randomisation) to 3, 5 and 10 min. Non-inferiority and superiority of methoxyflurane versus SAT were concluded if the upper 95% confidence interval (CI) for the treatment comparison (methoxyflurane-SAT) was less than 1 and less than 0, respectively.

RESULTS

Between 8 February 2018 and 8 February 2019, 272 patients were randomised (136 per treatment group). A total of 270 patients (mean age 51 years; 49% male; 34% with severe pain; mean baseline VAS 67 mm) were treated and analysed for efficacy and safety. Superiority of methoxyflurane was demonstrated for moderate-to-severe pain (adjusted mean treatment difference - 5.94 mm; 95% CI - 8.83, - 3.06 mm), moderate pain (- 5.97 mm; 95% CI - 9.55, - 2.39 mm) and severe pain (- 5.54 mm; 95% CI - 10.49, - 0.59 mm). Median onset of pain relief was 9 min for methoxyflurane and 15 min for SAT. Practicality of methoxyflurane treatment was rated "Excellent", "Very Good" or "Good" by 90% of clinicians vs. 64% for SAT. Adverse events (all non-serious) were reported by 17% of methoxyflurane-treated patients and 3% of SAT-treated patients.

CONCLUSION

Methoxyflurane provided superior pain relief to SAT in patients with moderate-to-severe trauma pain and may offer a simple, fast, effective non-opioid treatment option.

TRIAL REGISTRATION

Trial registered with EudraCT (2017-001565-25) on 2 March 2018 and ClinicalTrials.gov (NCT03585374) on 13 July 2018.

FUNDING

Mundipharma Pharmaceuticals S.r.l.

Inhaled Methoxyflurane Provides Greater Analgesia and Faster Onset of Action Versus Standard Analgesia in Patients With Trauma Pain: InMEDIATE: A Randomized Controlled Trial in Emergency Departments

STUDY OBJECTIVE

The objective of the InMEDIATE study was to evaluate the change in intensity of traumatic pain over the first 20 min in adult patients treated with methoxyflurane versus standard analgesic treatment in Spain. This the first randomized, active-controlled, multicenter trial of methoxyflurane in the emergency setting in Europe.

METHODS

This was a randomized, controlled study that enrolled adult patients with acute moderate to severe (score ≥4 on the 11-point Numeric Rating Scale) trauma-associated pain in 14 Spanish emergency departments. Patients were randomized 1:1 to methoxyflurane (up to 2×3 mL) or standard analgesic treatment. Coprimary endpoints were the change from baseline in Numeric Rating Scale pain intensity score during the first 20 minutes of treatment and time to first pain relief.

RESULTS

Three hundred five patients were randomized (methoxyflurane 156; standard analgesic treatment 149). Most patients in the standard analgesic treatment group (70%) received intravenous first-step analgesics and 9.4% of patients were treated with opioids. Mean decrease from baseline in Numeric Rating Scale pain intensity score was greater for methoxyflurane than standard analgesic treatment at all points, with a significant treatment difference overall up to 20 minutes (repeated-measures model 2.47 versus 1.39; treatment difference 1.00; 95% confidence interval 0.84 to 1.32). Median time to first pain relief was significantly shorter for methoxyflurane than standard analgesic treatment (3 versus 10 minutes). Methoxyflurane achieved better patient and clinician ratings for pain control and comfort of treatment than standard analgesic treatment and exceeded patient and clinician expectations of treatment in, respectively, 77% and 72% of cases compared with 38% and 19% for standard analgesic treatment.

CONCLUSION

These results support consideration of methoxyflurane as a nonnarcotic, easy-to-administer, rapid-acting, first-line alternative to currently available analgesic treatments for trauma pain.

Multimodal oral analgesia for non-severe trauma patients: evaluation of a triage-nurse directed protocol combining methoxyflurane, paracetamol and oxycodone

Insufficient analgesia affects around 50% of emergency department patients. The use of a protocol helps to reduce the risk of oligoanalgesia in this context. Our objective was to describe the feasibility and efficacy of a multimodal analgesia protocol (combining paracetamol, oxycodone, and inhaled methoxyflurane) initiated by triage nurse. We performed a prospective, observational study in an emergency department (Grenoble Alpes University Hospital, France) between December 2017 and April 2018. Adult non-severe trauma patients with a numerical pain rating scale (NRS) score ≥ 4 were included. The primary efficacy criterion was the proportion of patients with an NRS score ≤ 3 at 15 min. Pain intensity was measured for 60 min and during radiography. Data on adverse events and satisfaction were recorded. A total of 200 adult patients were included (median [interquartile range (IQR)] age: 32 [23-49] years; 126 men (63%)). Sixty-six patients (33%) reported an NRS score ≤ 3 at 15 min. The time required to achieve a decrease of at least 2 points in the NRS score was 10 (5-20) min. The median [IQR] pain intensity was 4 [2-5] before radiography and 4 [2-6] during radiography. Adverse events were frequent (n = 128, 64%). No serious adverse events were reported. The patients and caregivers reported good levels of satisfaction. The administration of a nurse-driven multimodal analgesia protocol (combining paracetamol, oxycodone, and methoxyflurane) was feasible on admission to the emergency department. It rapidly produced long-lasting analgesia in adult trauma patients.Trial registration: NCT03380247.

Intranasal sufentanil versus intravenous morphine for acute severe trauma pain: A double-blind randomized non-inferiority study

BACKGROUND

Intravenous morphine (IVM) is the most common strong analgesic used in trauma, but is associated with a clear time limitation related to the need to obtain an access route. The intranasal (IN) route provides easy administration with a fast peak action time due to high vascularization and the absence of first-pass metabolism. We aimed to determine whether IN sufentanil (INS) for patients presenting to an emergency department with acute severe traumatic pain results in a reduction in pain intensity non-inferior to IVM.

METHODS AND FINDINGS

In a prospective, randomized, multicenter non-inferiority trial conducted in the emergency departments of 6 hospitals across France, patients were randomized 1:1 to INS titration (0.3 μg/kg and additional doses of 0.15 μg/kg at 10 minutes and 20 minutes if numerical pain rating scale [NRS] > 3) and intravenous placebo, or to IVM (0.1 mg/kg and additional doses of 0.05 mg/kg at 10 minutes and 20 minutes if NRS > 3) and IN placebo. Patients, clinical staff, and research staff were blinded to the treatment allocation. The primary endpoint was the total decrease on NRS at 30 minutes after first administration. The prespecified non-inferiority margin was -1.3 on the NRS. The primary outcome was analyzed per protocol. Adverse events were prospectively recorded during 4 hours. Among the 194 patients enrolled in the emergency department cohort between November 4, 2013, and April 10, 2016, 157 were randomized, and the protocol was correctly administered in 136 (69 IVM group, 67 INS group, per protocol population, 76% men, median age 40 [IQR 29 to 54] years). The mean difference between NRS at first administration and NRS at 30 minutes was -4.1 (97.5% CI -4.6 to -3.6) in the IVM group and -5.2 (97.5% CI -5.7 to -4.6) in the INS group. Non-inferiority was demonstrated (p < 0.001 with 1-sided mean-equivalence t test), as the lower 97.5% confidence interval of 0.29 (97.5% CI 0.29 to 1.93) was above the prespecified margin of -1.3. INS was superior to IVM (intention to treat analysis: p = 0.034), but without a clinically significant difference in mean NRS between groups. Six severe adverse events were observed in the INS group and 2 in the IVM group (number needed to harm: 17), including an apparent imbalance for hypoxemia (3 in the INS group versus 1 in the IVM group) and for bradypnea (2 in the INS group versus 0 in the IVM group). The main limitation of the study was that the choice of concomitant analgesics, when they were used, was left to the discretion of the physician in charge, and co-analgesia was more often used in the IVM group. Moreover, the size of the study did not allow us to conclude with certainty about the safety of INS in emergency settings.

CONCLUSIONS

We confirm the non-inferiority of INS compared to IVM for pain reduction at 30 minutes after administration in patients with severe traumatic pain presenting to an emergency department. The IN route, with no need to obtain a venous route, may allow early and effective analgesia in emergency settings and in difficult situations. Confirmation of the safety profile of INS will require further larger studies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02095366. EudraCT 2013-001665-16.

Procedural sedation and analgesia practices in the emergency centre

Introduction

Procedural sedation and analgesia allows the clinician to safely and efficiently administer sedation, analgesia, anxiolysis and sometimes amnesia to facilitate the performance of various procedures in the emergency centre. The aim of this study is to determine current sedation practices, common indications and major obstacles in selected emergency centres across Southern Gauteng, South Africa, with a view to improving future standards and practices.

Methods

This was a prospective, questionnaire based, cross-sectional interview of emergency centre managers or their designee of selected private-sector and public-sector hospitals in Southern Gauteng.

Results

Overall, 17 hospitals completed the interview, nine (53%) public-sector and eight (47%) private-sector hospitals, with 36% of hospitals being aligned to an academic institute. All hospitals performed procedural sedation in their emergency centre. Forty seven percent of managers had between ten and 19 years of clinical experience post internship. Although eleven (64.7%) managers achieved a postgraduate qualification in emergency medicine, only seven (41%) were accredited with a Fellowship of the College of Emergency Medicine (FCEM) qualification and only three (17.7%) centres employed three or more specialists. The majority of centres (52.3%) performed between ten and 30 procedures per month requiring sedation. Staff training in the practice of procedural sedation was mostly obtained internally (52.9%), from in-house seniors. Essential drugs, procedure monitors, resuscitation equipment and protocols were all available in 70.6% of centres.

Conclusion

Although the safe practice and awareness of procedural sedation and analgesia in both public-sector and private-sector emergency centres in Southern Gauteng appears to be on the increase, there is still a need to enhance practitioner training and promote awareness of current local and international trends, protocols and recommendations.

Low-dose methoxyflurane analgesia in adolescent patients with moderate-to-severe trauma pain: a subgroup analysis of the STOP! study

Introduction

The undertreatment of acute pain presents a significant challenge in the Emergency Department. This post hoc subgroup analysis of a previously reported randomized controlled UK study reports the efficacy and safety of low-dose methoxyflurane analgesia in treating adolescent patients with moderate-to-severe trauma pain.

Patients and methods

Three hundred patients (96 in the adolescent subgroup) aged ≥12 years requiring analgesia for acute trauma pain (pain score of 4-7 on the Numerical Rating Scale) at triage were randomized 1:1 to methoxyflurane (up to 6 mL) or placebo (normal saline), both administered using a Penthrox^® inhaler. The patient could request rescue medication (paracetamol/opioids) at any time. The primary endpoint was the change from baseline in visual analog scale (VAS) pain intensity.

Results

Mean VAS pain score for the adolescent subgroup at baseline was ~ 61 mm. Adjusted mean change in VAS pain intensity from baseline to 5, 10, 15, and 20 minutes was -24.5, -28.1, -31.6, and -31.7 mm for methoxyflurane and -14.6, -18.8, -19.2, and -23.7 mm for placebo, with a statistically significant treatment effect in favor of methoxyflurane overall across all four time points (-9.9 mm; 95% CI: -17.4, -2.4 mm; P=0.0104). Median time to first pain relief was significantly shorter with methoxyflurane (1 minute) than placebo (3 minutes, P<0.0001). Pain relief was reported within 1-10 inhalations in 95.7% of methoxyflurane-treated patients and 64.6% of placebo-treated patients. Rescue medication was requested by two (4.3%) methoxyflurane-treated patients and three (6.3%) placebo-treated patients. Over 95% of patients, physicians, and nurses rated methoxyflurane treatment as "Excellent", "Very Good" or "Good" compared with between 64% and 68% for placebo. The incidence of adverse events was higher with methoxyflurane (51%) than placebo (42%), mostly comprising mild/transient dizziness and headache.

Conclusion

This subgroup analysis shows that low-dose inhaled methoxyflurane is a rapid-acting and effective analgesic in adolescent patients presenting with moderate-to-severe trauma pain.

Trial registration

Clinicaltrials.gov identifier: NCT01420159, EudraCT number: 2011-000338-12.

Penthrox: a breath of PHEC air for the military?

Prehospital analgesia is vital to good clinical care and inhaled methoxyflurane (Penthrox) would be a valuable addition to the armed forces medical armoury. Penthrox would provide strong, fast-acting, self-administered and safe analgesia to patients with moderate to severe injuries. In addition, it would provide an option for strong analgesia which would not be subject to the regulations that govern controlled or accountable drugs which gives it a unique position as the military moves its focus from large enduring operations to small short-term training teams supported by lone combat medics in remote locations across the globe.

Methoxyflurane Versus Standard of Care for Acute Trauma-Related Pain in the Emergency Setting: Protocol for a Randomised, Controlled Study in Italy (MEDITA)

Introduction

Low-dose methoxyflurane, administered via a hand-held inhaler, has been used for short-term pain relief in emergency medicine in Australia and New Zealand for over 40 years, and was recently approved in Europe for the rapid relief of moderate-to-severe trauma-related pain in adults. There is currently a lack of data for methoxyflurane versus active comparators, therefore this trial will investigate the efficacy and safety of inhaled methoxyflurane compared with standard of care (SoC) in the treatment of acute trauma-related pain in pre-hospital and ED settings in Italy.

Methods

MEDITA (Methoxyflurane in Emergency Department in ITAly) is a Phase IIIb, prospective, randomised, active-controlled, parallel-group, open-label, multicentre trial. A total of 272 adult patients with moderate-to-severe pain [score ≥ 4 on the Numerical Rating Scale (NRS)] due to limb trauma will be randomised 1:1 to receive 3 mL methoxyflurane (self-administered by the patient via inhalation under supervision of a trained person) or medications that currently comprise the SoC in Italy [intravenous (IV) morphine for severe pain (NRS ≥ 7); IV paracetamol or ketoprofen for moderate pain (NRS 4–6)], administered as soon as possible after randomisation.

Planned Outcomes

Pain intensity will be measured using a 100-mm visual analogue scale (VAS) at baseline (time of randomisation) and at intervals up to 30 min. Time of onset of pain relief as reported by the patient and use of rescue medication will be recorded. The patient will rate the efficacy and the healthcare professional will rate the practicality of study treatment at 30 min after randomisation using a 5-point Likert scale. Adverse events will be recorded until safety follow-up at 14 ± 2 days. Vital signs will be measured at baseline, 10 and 30 min. The primary aim is to demonstrate non-inferiority of methoxyflurane versus SoC for the change in VAS pain intensity from baseline (randomisation) to 3, 5 and 10 min.

Trial Registration

EudraCT number: 2017-001565-25. Clinicaltrials.gov identifier: NCT03585374.

Funding

Mundipharma Pharmaceuticals srl.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0830-x) contains supplementary material, which is available to authorized users.

Rédiger un protocole douleur : quelle méthode atraumatique pour l’urgentiste ?

Les protocoles « antalgie » sont des outils incontournables pour tous les services d’urgence dans le cadre de l’amélioration de la prise en charge de la douleur. Suivre les recommandations d’experts ne peut suffire. Un protocole doit proposer des conduites à tenir ciblées sur des situations définies, validées scientifiquement, adaptées au contexte du service et au personnel concerné, dans un cadre réglementaire et légal précis. Mais l’élaboration d’un protocole peut s’avérer une expérience pénible pour l’urgentiste, même si c’est une des missions extracliniques essentielles à la professionnalisation du métier. Pour le non-algologue, sa conception et sa rédaction peuvent être perçues comme fastidieuses et non prioritaires, mais cette inertie retarde dangereusement la mise à jour de nos stratégies thérapeutiques globales, en particulier en traumatologie. L’optimisation de cette tâche et un gain de temps sont pourtant possibles grâce à un guide méthodologique, des modèles, des documents types, tous accessibles, mais parfois mal référencés : l’expert pourra ainsi consacrer son temps au contenu et à l’adhésion des équipes plutôt qu’à la forme et, in fine, au patient. Une « protocolisation » de l’élaboration de nos protocoles est sans doute le moyen de les réaliser et de les mettre à jour plus efficacement, plus vite et sans douleur. Se doter d’un protocole d’antalgie est en fait une opportunité pour les équipes davantage qu’une contrainte, à condition de proposer une méthodologie adaptée à la culture de la médecine d’urgence, transversale, accessible, priorisée.

Prospective, Multicentre Trial of Methoxyflurane for Acute Trauma-Related Pain in Helicopter Emergency Medical Systems and Hostile Environments: METEORA Protocol

Introduction

The inhalational analgesic low-dose methoxyflurane has been widely used by Australian ambulance services since 1975 and is now approved in Europe for emergency relief of moderate-to-severe trauma-related pain in conscious adult patients. The use of methoxyflurane in hostile environments is of special interest given its portability, ease of use and rapid onset of action. This trial will investigate the efficacy, tolerability and practicality of use of inhaled methoxyflurane in patients with moderate-to-severe trauma-related pain rescued from hostile mountainous environments by the Helicopter Emergency Medical Service (HEMS) in Italy.

Methods

METEORA is a phase IIIb, prospective, single-arm, multicentre trial. Approximately 200 adult patients with a pain score of at least 4 on the numerical rating scale (NRS) due to limb trauma rescued by HEMS will be enrolled. Patients will receive up to 2 × 3 mL methoxyflurane, self-administered by the patient by inhalation under medical supervision. Rescue medication will be permitted if required.

Planned Outcomes

Pain intensity will be measured using a 100-mm visual analogue scale (VAS) at baseline, at 5, 10, 15, 20, 30, 45 and 60 min after the start of methoxyflurane inhalation and when positioning the patient on a spinal board or stretcher; and also using the NRS at enrolment and at 10 min. Use of rescue medication (yes/no) will be recorded. The patient will rate efficacy and the healthcare professional will rate practicality of methoxyflurane treatment at 30 and 60 min using a 5-point Likert scale. Vital signs will be measured at baseline, 10, 30 and 60 min. Assessments after 30 min will only be performed for patients using a second inhaler. Adverse events will be recorded until safety follow-up at 3 ± 1 days. The primary endpoint is the percentage of patients achieving at least 30% improvement from baseline in VAS pain intensity within the first 10 min of methoxyflurane administration.

Trial Registration

EudraCT number: 2017-004601-40.

Funding

Mundipharma Pharmaceuticals, srl.

Plain Language Summary

Plain language summary available for this article.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0816-8) contains supplementary material, which is available to authorized users.

The treatment of pain is an essential part of the management of injured patients. In emergency rescue situations, rapid and effective pain relief can reduce the patient’s stress and discomfort, making it easier to assess, treat and extricate them. Currently available painkillers have limitations such as being slow to work (oral medications), requiring needles (intravenous medications) or prolonged monitoring and observation (e.g. opioids). An inhaled painkiller (methoxyflurane) is now available in Europe for emergency relief of moderate-to-severe pain in conscious adult patients with trauma (injury) and associated pain. Methoxyflurane is administered via a hand-held inhaler, which provides pain relief within 6–10 inhalations and lasts for 25–30 min, on average, when used continuously. The patient can control his/her own level of pain relief and a second inhaler may be used if required. Methoxyflurane has been widely used by Australian ambulance services since 1975 and its effectiveness and safety are well established. Considering its ease of use and rapid action, inhaled methoxyflurane may be useful in emergency situations in remote and hostile environments. A new trial (METEORA) will assess the use of methoxyflurane in 200 patients with limb injuries who are rescued from mountainous environments by the Helicopter Emergency Medical Service (HEMS) in Italy. Patients with moderate-to-severe pain will receive inhaled methoxyflurane under medical supervision. A second inhaler and/or additional pain-relieving medication will be provided if necessary. The trial will assess the reduction in pain intensity and whether additional pain-relieving medication is needed. The practicality of use of methoxyflurane in the emergency rescue situation and any side effects will also be evaluated.

The role of inhaled methoxyflurane in acute pain management

Methoxyflurane is an inhaled analgesic administered via a disposable inhaler which has been used in Australia for over 40 years for the management of pain associated with trauma and for medical procedures in children and adults. Now available in 16 countries worldwide, it is licensed in Europe for moderate to severe pain associated with trauma in conscious adults, although additional applications are being made to widen the range of approved indications. Considering these ongoing developments, we reviewed the available evidence on clinical usage and safety of inhaled analgesic methoxyflurane in trauma pain and in medical procedures in both adults and children. Published data on methoxyflurane in trauma and procedural pain show it to be effective, well tolerated, and highly rated by patients, providing rapid onset of analgesia. Methoxyflurane has a well-established safety profile; adverse events are usually brief and self-limiting, and no clinically significant effects on vital signs or consciousness levels have been reported. Nephrotoxicity previously associated with methoxyflurane at high anesthetic doses is not reported with low analgesic doses. Although two large retrospective comparative studies in the prehospital setting showed inhaled analgesic methoxyflurane to be less effective than intravenous morphine and intranasal fentanyl, this should be balanced against the administration, supervision times, and safety profile of these agents. Given the limitations of currently available analgesic agents in the prehospital and emergency department settings, the ease of use and portability of methoxyflurane combined with its rapid onset of effective pain relief and favorable safety profile make it a useful nonopioid option for pain management. Except for the STOP! study, which formed the basis for approval in trauma pain in Europe, and a few smaller randomized controlled trials (RCTs), much of the available data are observational or retrospective, and further RCTs are currently underway to provide more robust data.

A Review of the Burden of Trauma Pain in Emergency Settings in Europe

Trauma pain represents a large proportion of admissions to emergency departments across Europe. There is currently an unmet need in the treatment of trauma pain extending throughout the patient journey in emergency settings. This review aims to explore these unmet needs and describe barriers to the delivery of effective analgesia for trauma pain in emergency settings. A comprehensive, qualitative review of the literature was conducted using a structured search strategy (Medline, Embase and Evidence Based Medicine Reviews) along with additional Internet-based sources to identify relevant human studies published in the prior 11 years (January 2006-December 2017). From a total of 4325 publications identified, 31 were selected for inclusion based on defined criteria. Numerous barriers to the effective treatment of trauma pain in emergency settings were identified, which may be broadly defined as arising from a lack of effective pain management pan-European and national guidelines, delayed or absent pain assessment, an aversion to opioid analgesia and a delay in the administration of analgesia. Several commonly used analgesics also present limitations in the treatment of trauma pain due to the routes of administration, adverse side effect profiles, pharmacokinetic properties and suitability for use in pre-hospital settings. These combined barriers lead to the inadequate and ineffective treatment of trauma pain for patients. An unmet need therefore exists for novel forms of analgesia, wider spread use of available analgesic agents which overcome some limitations associated with several treatment options, and the development of protocols for pain management which include patient assessment of pain.Funding: Mundipharma International Ltd.

A review of the safety and efficacy of inhaled methoxyflurane as an analgesic for outpatient procedures

Methoxyflurane delivered via a hand-held inhaler is a proven analgesic which has been used in Australasia for emergency relief of trauma associated pain since the 1970s. The agent is self-administered by the patient under the supervision of trained personnel. More than 5 million patients have received inhaled methoxyflurane without significant side effects. Methoxyflurane is also licensed in Australasia for the relief of pain in monitored conscious patients requiring analgesia for minor surgical procedures. Recent clinical studies undertaken in a variety of outpatient settings, including colonoscopy, prostate biopsy, dental procedures, bone marrow biopsy, and the management of burns dressings, indicate that inhaled methoxyflurane has significant analgesic activity, without producing deep sedation or respiratory depression. Return to full psychomotor activity is rapid. Thus, methoxyflurane may be a suitable and well-tolerated alternative to traditional i.v. sedative agents for outpatient medical and surgical procedures. There are direct advantages to the patient in terms of rapid recovery and an early return to normal activities, and significant benefits for outpatient departments in terms of cost saving and rate of throughput. Further randomised controlled trials comparing the efficacy, safety, and cost-effectiveness of inhaled methoxyflurane against traditional i.v. sedative techniques are currently in progress.

Management of trauma pain in the emergency setting: low-dose methoxyflurane or nitrous oxide? A systematic review and indirect treatment comparison

Background

Low-dose methoxyflurane and nitrous oxide (N₂O; 50:50 with oxygen) are both self-administered, self-titrated, rapid-acting, nonnarcotic, and noninvasive inhalational agents with similar onset times of pain relief. The aim of this review was to compare the clinical efficacy, safety, and tolerability of these analgesics in emergency care.

Materials and methods

A systematic literature search and review according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were performed using Embase, Medline, the Cochrane Library, several clinical trial registers, and emergency-medicine conference material.

Results

Although both compounds have been used for many years in emergency care, the search found only a few controlled studies and no head-to-head trials performed in this setting. Two double-blind, randomized studies comparing their respective study medication (low-dose methoxyflurane or N₂O) to placebo were identified that could be compared in an indirect approach by using placebo as a bridging comparator. Both agents provided rapid pain relief to trauma patients, with no significant differences between them; both treatments were generally well tolerated.

Conclusion

Both low-dose methoxyflurane and N₂O are suitable options for the pain treatment of trauma patients in the emergency setting. Due to the ease of administration and portability, inhaled low-dose methoxyflurane, however, may not only offer advantages in emergency situations in remote or difficult-to-reach locations and mass-casualty situations but also be of significant value in urban and rural environments.

Methoxyflurane: A Review in Trauma Pain

Methoxyflurane (Penthrox^®) is a halogenated ether first used clinically as a volatile inhalational anaesthetic. It has been used as an analgesic in Australia and New Zealand for the past 30 years. In the UK and Europe, methoxyflurane has been approved for the emergency relief of moderate to severe trauma pain in conscious adult patients. Methoxyflurane is self-administered using a hand-held inhaler. This article reviews the pharmacological properties of methoxyflurane and its clinical efficacy and tolerability in these patients. In the phase III STOP! trial, methoxyflurane was effective and generally well tolerated for the management of acute pain due to minor trauma, with a rapid onset of analgesia. In a prospective study, methoxyflurane was more effective than intramuscular tramadol when administered for the treatment of acute musculoskeletal pain in the pre-hospital setting (i.e. by paramedics). Methoxyflurane had a more rapid onset of action than tramadol when administered for the treatment of pain related to ankle injuries in the emergency department. Although methoxyflurane is known to be potentially nephrotoxic at anaesthetic doses, the much lower doses used for pain relief were not associated with nephrotoxicity or an increased risk of renal disease. Inhaled methoxyflurane may offer advantages over other analgesics administered via the intravenous, intramuscular or intranasal routes in terms of its non-invasive self-administration, ease of use and/or rapid onset of action. As such, it is a useful additional treatment option for the management of trauma pain in the pre-hospital or emergency department setting.