Clinical effectiveness and safety of intraoperative methadone in patients undergoing laparoscopic hysterectomy: a randomised, blinded clinical trial.

Background: Laparoscopic hysterectomy is often carried out as day-stay surgery. Minimising postoperative pain is therefore of utmost importance to ensure timely discharge from hospital. Methadone has several desirable pharmacological features, including a long elimination half-life. Therefore, a single intraoperative dose could provide long-lasting pain relief. Methods: Patients scheduled to undergo laparoscopic hysterectomy were randomly allocated to receive methadone (0.2 mg kg-1) or morphine (0.2 mg kg-1) intraoperatively, 60 min before tracheal extubation. Primary outcomes were opioid consumption (oral morphine equivalents in milligrams) at 6 and 24 h. Secondary outcomes included pain intensity at rest and during coughing, patient satisfaction, postoperative nausea and vomiting, and adverse events up to 72 h after completion of surgery. Results: The postoperative median opioid consumption was reduced in the methadone group compared with the morphine group at 6 h (35.5 [0-61] mg vs 48 [31-74.5] mg; P=0.01) and 24 h (42 [10-67] mg vs 54.5 [31-83] mg; P=0.03). On arrival at the PACU, pain at rest was significantly lower in patients receiving methadone (numeric rating scale: 3 [2-5] vs 5 [3-6]), whereas pain scores at rest and coughing were not significantly different throughout the rest of the observation period. No differences in other secondary outcomes were found. Conclusions: In this randomised, blinded, controlled trial, opioid consumption was reduced during the first 24 postoperative hours in patients receiving methadone without causing an increase in adverse events. The difference observed might be considered as small and of limited clinical relevance. Clinical trial registration: NCT03908060; EudraCT no. 2018-004351-20.

[Christmas article: Can gin with herbs induce the vision of Christmas elves?]

INTRODUCTION: The Italian Medieval doctor Thaddeus Florentinus (AD 1210-1295) claimed that herbs could cure or relieve various symptoms such as obstipation, melancholia and nervousness. Additionally, certain herbs were proposed to be able to predict the weather and induce the vision of elves. Therefore, the aim of this study was to investigate whether herbs could have medical properties as claimed. METHODS: A randomized controlled trial with three arms was conducted: 1) Gin with St. John's wort, 2) Gin with angelica and 3) Gin with sweet woodruff. Participants were 21 anesthesia registrars. The primary outcome was visual induction of elves (yes/no) whereas secondary outcomes included melancholia (VAS 0-100), nervousness (VAS 0-100), weather prediction capabilities (yes/no) obstipation (Bristol Stool Chart 1-7) and others. Baseline recordings were obtained and hourly registrations of outcomes were undertaken. Confounding factors such as alcohol intoxication and vivid imagination was controlled by the means of alcohol breathalyzers and assessment of cerebral oxygenation by near infrared spectroscopy. RRESULTS: The vision of elves was induced in 10 out of 21 participants (48.6%) and was associated with male sex (p = 0.01), young age (p = 0.03) and increase in cerebral oxygenation (p = 0.04) but not with sweet woodruff (p = 0.83) or alcohol intoxication (p = 0.26). Participants were not capable of predicting the weather forecast (p = 0.55). Melancholia and nervousness were not relieved by St. John's wort, and obstipation could not be relieved by the intake of angelica. CONCLUSION: Sweet woodruff, St. John's wort and angelica were unable to relieve relevant Christmas symptoms as proposed by a medieval doctor. Alcohol ingestion might have influenced results, and data should be interpreted in the light of these precautions. FUNDING: none. TRIAL REGISTRATION: not applicable.

Opioids for Treatment of Pre-hospital Acute Pain: A Systematic Review.

INTRODUCTION: Acute pain is a frequent symptom among patients in the pre-hospital setting, and opioids are the most widely used class of drugs for the relief of pain in these patients. However, the evidence base for opioid use in this setting appears to be weak. The aim of this systematic review was to explore the efficacy and safety of opioid analgesics in the pre-hospital setting and to assess potential alternative therapies. METHODS: The PubMed, EMBASE, Cochrane Library, Centre for Reviews and Dissemination, Scopus, and Epistemonikos databases were searched for studies investigating adult patients with acute pain prior to their arrival at hospital. Outcomes on efficacy and safety were assessed. Risk of bias for each included study was assessed according to the Cochrane approach, and confidence in the evidence was assessed using the GRADE method. RESULTS: A total of 3453 papers were screened, of which the full text of 125 was assessed. Twelve studies were ultimately included in this systematic review. Meta-analysis was not undertaken due to substantial clinical heterogeneity among the included studies. Several studies had high risk of bias resulting in low or very low quality of evidence for most of the outcomes. No pre-hospital studies compared opioids with placebo, and no studies assessed the risk of opioid administration for subgroups of frail patients. The competency level of the attending healthcare provider did not seem to affect the efficacy or safety of opioids in two observational studies of very low quality. Intranasal opioids had a similar effect and safety profile as intravenous opioids. Moderate quality evidence supported a similar efficacy and safety of synthetic opioid compared to morphine. CONCLUSIONS: Available evidence for pre-hospital opioid administration to relieve acute pain is scarce and the overall quality of evidence is low. Intravenous administration of synthetic, fast-acting opioids may be as effective and safe as intravenous administration of morphine. More controlled studies are needed on alternative routes for opioid administration and pre-hospital pain management for potentially more frail patient subgroups.

Ketamine for the treatment of prehospital acute pain: a systematic review of benefit and harm.

BACKGROUND: Few publications have addressed prehospital use of ketamine in analgesic doses. We aimed to assess the effect and safety profile of ketamine compared with other analgesic drugs (or no drug) in adult prehospital patients with acute pain. METHODS: A systematic review of clinical trials assessing prehospital administration of ketamine in analgesic doses compared with other analgesic drugs or no analgesic treatment in adults. We searched PubMed, EMBASE, Cochrane Library and Epistemonikos from inception until 15 February 2020, including relevant articles in English and Nordic languages. We used the Cochrane and Grading of Recommendations Assessment, Development and Evaluation methodologies and exclusively assessed patient-centred outcomes. Two independent authors screened trials for eligibility, extracted data and assessed risk of bias. RESULTS: We included eight studies (2760 patients). Ketamine was compared with various opioids given alone, and intranasal ketamine given with nitrous oxide was compared with nitrous oxide given alone. Four randomised controlled trials (RCTs) and one cluster randomised trial included 699 patients. One prospective cohort included 27 patients and two retrospective cohorts included 2034 patients. Five of the eight studies had high risks of bias. Pain score with ketamine is probably lower than after opioids as demonstrated in a cluster-RCT (308 patients) and a retrospective cohort (158 patients) study, Δvisual analogue scale -0.4 (-0.8 to 0.0) and Δnumeric pain rating scale -3.0 (-3.86 to -2.14), respectively. Ketamine probably leads to less nausea and vomiting (risk ratio (RR) 0.24 (0.11 to 0.52)) but more agitation (RR 7.81 (1.85 to 33)) than opioids. CONCLUSIONS: This systematic literature review finds that ketamine probably reduces pain more than opioids and with less nausea and vomiting but higher risk of agitation. Risk of bias in included studies is high. OTHER: Scandinavian society of anaesthesiology and intensive care medicine funded meetings and software. The Norwegian Air Ambulance Foundation funded publication. Otherwise this research received no grant from any agency in the public, commercial or not-for-profit sectors. PROSPERO REGISTRATION NUMBER: CRD42018114399.

[Intraoperative methadone for post-operative pain].

Methadone is an opioid with several desirable pharmacological features, including a long elimination half-life. Several studies have suggested that a single intraoperative dose reduces post-operative pain and opioid consumption. In this review, we summarise the current knowledge of intraoperative methadone for the treatment of post-operative pain and propose recommendations for clinical use and future research.

Femoral nerve blocks for the treatment of acute pre-hospital pain: A systematic review with meta-analysis.

BACKGROUND: Pain management is one of the most important interventions in the emergency medical services. The femoral nerve block (FNB) is, among other things, indicated for pre- and post-operative pain management for patients with femoral fractures but its role in the pre-hospital setting has not been determined. The aim of this review was to assess the effect and safety of the FNB in comparison to other forms of analgesia (or no treatment) for managing acute lower extremity pain in adult patients in the pre-hospital setting. METHODS: A systematic review (PROSPERO registration (CRD42018114399)) was conducted. The Cochrane and GRADE methods were used to assess outcomes. Two authors independently reviewed each study for eligibility, extracted the data and performed risk of bias assessments. RESULTS: Four studies with a total of 252 patients were included. Two RCTs (114 patients) showed that FNB may reduce pain more effectively than metamizole (mean difference 32 mm on a 100 mm VAS (95% CI 24 to 40)). One RCT (48 patients) compared the FNB with lidocaine and magnesium sulphate to FNB with lidocaine alone and was only included here for information regarding adverse effects. One case series included 90 patients. Few adverse events were reported in the included studies. The certainty of evidence was very low. We found no studies comparing FNB to inhaled analgesics, opioids or ketamine. CONCLUSIONS: Evidence regarding the effectiveness and adverse effects of pre-hospital FNB is limited. Studies comparing pre-hospital FNB to inhaled analgesics, opioids or ketamine are lacking.

Chest pain in the ambulance; prevalence, causes and outcome - a retrospective cohort study.

BACKGROUND: Chest pain is common in acute ambulance transports. This study aims to characterize and compare ambulance-transported chest pain patients to non-chest pain patients and evaluate if patient characteristics and accompanying symptoms accessible at the time of emergency call can predict cause and outcome in chest pain patients. METHODS: Retrospective, observational population-based study, including acute ambulance transports. Patient characteristics and symptoms are included in a multivariable risk model to identify characteristics, associated with being discharged without an acute cardiac diagnosis and surviving 30 days after chest pain event. RESULTS: In total, 10,033 of 61,088 (16.4%) acute ambulance transports were due to chest pain. In chest pain patients, 30-day mortality was 2.1% (95%CI 1.8-2.4) compared to 6.0% (95%CI 5.7-6.2) in non-chest pain patients. Of chest pain patients, 1054 (10.5%) were diagnosed with acute myocardial infarction, and 5068 (50.5%) were discharged without any diagnosis of disease. This no-diagnosis group had very low 30-day mortality, 0.4% (95%CI 0.2-0.9). Female gender, younger age, chronic pulmonary disease, absence of accompanying symptoms of dyspnoea, radiation, severe pain for > 5 min, clammy skin, uncomfortable, and nausea were associated with being discharged without an acute cardiac diagnosis and surviving 30 days after a chest pain event. CONCLUSION: Chest pain is a common reason for ambulance transport, but the majority of patients are discharged without a diagnosis and with a high survival rate. Early risk prediction seems to hold a potential for resource downgrading and thus cost-saving in selected chest pain patients.

Intraoperative methadone for postoperative pain after laparoscopic hysterectomy: Protocol for a randomised, double-blind trial.

BACKGROUND: Hysterectomy is often carried out as same-day surgery. Treatment of postoperative pain is, therefore, of utmost importance to ensure timely discharge from hospital. Methadone has several desirable pharmacological features, including a long elimination half-life. Theoretically, a single intraoperative dose could provide long-lasting pain relief. METHODS: This is a single-centre, investigator-initiated, randomised, double-blind study. Two-hundred and fifty women, scheduled to undergo hysterectomy at Horsens Region Hospital, Denmark, are randomized to receive methadone (0.2 mg/kg) or morphine (0.2 mg/kg) intraoperatively, 60 minutes before extubation. Primary outcomes are opioid consumption at 6 and 24 hours. Secondary outcomes include pain intensity at rest and during coughing at 1, 3, 6, 24 and 48 hours; patient satisfaction at 3 and 24 hours, postoperative nausea and vomiting at 6, 24 and 72 hours, adverse events in the postanaesthesia care unit (PACU) and time until readiness for discharge. Another outcome is persistent abdominal pain after 4 months. CONCLUSIONS: The study outlined in this protocol will provide important information about the use of methadone in same-day hysterectomy patients. The results will presumably be applicable to other types of surgery involving visceral pain.

Educational interventions to improve medical students' knowledge of acute pain management: a randomized study.

It has been consistently documented that the treatment of acute pain is inadequate. Education of medical students is an obvious strategy to improve this. We therefore conducted a study in which 217 medical students were randomized into one of three groups: a control group (no intervention) and two intervention groups (education with e-learning alone or e-learning combined with simulation-based training). We hypothesized that the combined intervention would be superior to no intervention and e-learning alone. All students completed the same multiple choice questionnaire twice with an interval of approximately 1 week. During this 1-week interval, students in the two intervention groups completed either an 45-min interactive case-based e-learning program, or the e-learning program and a simulation-based training. We showed that the theoretical knowledge about treatment of acute pain increased in both intervention groups but students who received the combined intervention felt more confident in the future handling of patients.

Prehospital intravenous fentanyl administered by ambulance personnel: a cluster-randomised comparison of two treatment protocols.

BACKGROUND: Prehospital acute pain is a frequent symptom that is often inadequately managed. The concerns of opioid induced side effects are well-founded. To ensure patient safety, ambulance personnel are therefore provided with treatment protocols with dosing restrictions, however, with the concomitant risk of insufficient pain treatment of the patients. The aim of this study was to investigate the impact of a liberal intravenous fentanyl treatment protocol on efficacy and safety measures. METHODS: A two-armed, cluster-randomised trial was conducted in the Central Denmark Region over a 1-year period. Ambulance stations (stratified according to size) were randomised to follow either a liberal treatment protocol (3 µg/kg) or a standard treatment protocol (2 µg/kg). The primary outcome was the proportion of patients with sufficient pan relief (numeric rating scale (NRS, 0-10) < 3) at hospital arrival. Secondary outcomes included abnormal vital parameters as proxy measures of safety. A multi-level mixed effect logistic regression model was applied. RESULTS: In total, 5278 patients were included. Ambulance personnel following the liberal protocol administered higher doses of fentanyl [117.7 µg (95% CI 116.7-118.6)] than ambulance personnel following the standard protocol [111.5 µg (95% CI 110.7-112.4), P = 0.0001]. The number of patient with sufficient pain relief at hospital arrival was higher in the liberal treatment group than the standard treatment group [44.0% (95% CI 41.8-46.1) vs. 37.4% (95% CI 35.2-39.6), adjusted odds ratio 1.47 (95% CI 1.17-1.84)]. The relative decrease in NRS scores during transport was less evident [adjusted odds ratio 1.18 (95% CI 0.95-1.48)]. The occurrences of abnormal vital parameters were similar in both groups. CONCLUSIONS: Liberalising an intravenous fentanyl treatment protocol applied by ambulance personnel slightly increased the number of patients with sufficient pain relief at hospital arrival without compromising patient safety. Future efforts of training ambulance personnel are needed to further improve protocol adherence and quality of treatment. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT02914678 ). Date of registration: 26th September, 2016.

Acute pain in the prehospital setting: a register-based study of 41.241 patients.

BACKGROUND: Acute pain is a frequent symptom, but little is known about the frequency and causes of acute pain in the prehospital population. The objectives of this study were to investigate the frequency of moderate to severe pain among prehospital patients and the underlying causes according to primary hospital diagnose codes. METHODS: This was a register-based study on 41.241 patients transported by ambulance. Information on moderate to severe pain [Numeric Rating Scale (NRS, 0-10) > 3 or moderate pain or higher on 4-point likert scale] was extracted from a national electronic prehospital patient record. Patient information was merged with primary hospital diagnose codes based on the 10th version of the International Classification of Diseases (ICD-10) to investigate underlying causes of pain. RESULTS: 11.430 patients (27.7%) reported moderate to severe pain during ambulance transport. As a measure of opioid demanding acute pain, 3.275 of 41.241 patients (7.9%) were treated with intravenous fentanyl. Underlying causes of pain were heterogenic according to ICD-10 chapters with injuries being the largest group of patients with moderate to severe pain (XIX: 42.8% of 8.041 patients), followed by non-specific diagnoses (XVIII: 28.5% of 7.101 patients and XXI: 31.6% of 5.148 patients), diseases of the circulatory system (IX: 22.1% of 4.812 patients) and other (20.3% of 16.139 miscellaneous patients). DISCUSSION: Due to the high frequency of moderate to severe pain affecting a wide range of patients, more attention on acute pain is necessary. Whether ambulance personnel have sufficient options for treating various pain conditions might be a subject of future evaluation. Non-specific diagnoses accounted for surprisingly many patients with moderate to severe pain, of which many were treated with intravenous fentanyl. This may be substance of further investigation. CONCLUSIONS: Moderate to severe pain is a highly frequent and probably underestimated symptom among patients transported by ambulance. Underlying causes of pain are heterogenic as described by primary hospital diagnose codes. More focus on the treatment of acute pain is needed.

Prehospital triage of patients diagnosed with perforated peptic ulcer or peptic ulcer bleeding: an observational study of patients calling 1-1-2.

BACKGROUND: Triage systems are used in emergency medical services to systematically prioritize prehospital resources according to individual patient conditions. Previous studies have shown cases of preventable deaths in emergency medical services even when triage systems are used, indicating a potential undertriage among some conditions. The aim of this study was to investigate the triage level among patients diagnosed with perforated peptic ulcer (PPU) or peptic ulcer bleeding (PUB). METHODS: In a three-year period in Central Denmark Region, all patients hospitalized within 24 h after a 1-1-2 emergency call and who subsequently received either a PPU or a PUB (hereinafter combined and referred to as PPU/PUB) or a First Hour Quintet (FHQ: respiratory failure, stroke, trauma, cardiac chest pain, and cardiac arrest) diagnosis were investigated. A modified Poisson regression was used to estimate the relative risk of receiving the highest and lowest prehospital response level. Also, a linear regression analysis was used to estimate the relative risk of 30-day mortality. RESULTS: Of 8658 evaluated patients, 263 were diagnosed with PPU/PUB. After adjusting for relevant confounding variables, patients diagnosed with PPU/PUB were less likely to receive ambulance transportation compared to patients diagnosed with stroke, RR = 1.41 (CI: 1.28-1.56); trauma, RR = 1.28 (CI: 1.15-1.42); cardiac chest pain, RR = 1.47 (CI: 1.33-1.62); and cardiac arrest, RR = 1.44 (CI: 1.31-1.42). Among patients diagnosed with PPU/PUB, 6.5% (CI: 3.3-9.7) did not receive ambulance transportation. The proportion of patients not receiving ambulance transportation was higher among patients diagnosed with PPU/PUB compared to patients diagnosed with an FHQ diagnosis. The 30-day mortality rate among patients diagnosed with PPU/PUB was 7.8% (CI: 4.2-11.1). This was lower than the 30-day mortality rate among patients diagnosed with respiratory failure (P = 0.010), stroke (P = 0.001), and cardiac arrest (P < 0.001), but comparable to the 30-day mortality among patients diagnosed with cardiac chest pain (P = 0.080) and trauma (P = 0.281). CONCLUSION: Among patients calling 1-1-2, fewer patients diagnosed with PPU/PUB received ambulance transportation than patients diagnosed with FHQ diagnoses, despite a high mortality among patients diagnosed with PPU/PUB.

Prehospital triage of patients suffering severe dyspnoea using N-terminal pro-brain natriuretic peptide, the PreBNP trial: a randomised controlled clinical trial.

PURPOSE: The purpose of this study was to examine whether the addition of brain natriuretic peptide measurement to the routine diagnostic work-up by prehospital critical care team physicians improves triage in patients with severe dyspnoea. METHODS: Prehospital critical care team physicians randomly assigned patients older than 18 years with severe dyspnoea to routine diagnostic work-up or diagnostic work-up with incorporated point-of-care N-terminal pro-brain natriuretic peptide (NT-proBNP) measurement. The primary endpoint was the proportion of patients with dyspnoea of primary cardiac origin triaged directly to a department of cardiology. RESULTS: A total of 747 patients were randomly assigned and 711 patients consented to participate, 350 were randomly assigned to the NT-proBNP group and 361 to the routine work-up group. NT-proBNP was measured in 90% (315/350) of patients in the NT-proBNP group and in 19% (70/361) of patients in the routine work-up group. There was no difference in the proportion of patients with dyspnoea of primary cardiac origin triaged directly to a department of cardiology between the NT-proBNP group and the routine work-up group (75% vs. 69%, P=0.22) in the intention-to-treat analysis. Sensitivity analysis according to the de facto diagnostics performed showed results consistent with this. No differences in hospital length of stay, intensive care unit admission rates or mortality between the NT-proBNP group and the routine work-up group were observed. CONCLUSION: Routine supplementary point-of-care measurement of NT-proBNP in patients with severe dyspnoea did not improve triage of patients with dyspnoea primarily caused by heart disease. ClinicalTrials.gov identifier NCT02050282.

Acute pain in the emergency department: Effect of an educational intervention.

BACKGROUND AND AIMS: Pain management is often inadequate in emergency departments (ED) despite the availability of effective analgesics. Interventions to change professional behavior may therefore help to improve the management of pain within the ED. We hypothesized that a 2-h educational intervention combining e-learning and simulation would result in improved pain treatment of ED patients with pain. METHODS: Data were collected at the ED of Horsens Regional Hospital during a 3-week study period in March 2015. Pain intensity (NRS, 0-10) and analgesic administration were recorded 24h a day for all patients who were admitted to the ED during the first and third study weeks. Fifty-three ED nurses and 14 ED residents participated in the educational intervention, which took place in the second study week. RESULTS: In total, 247 of 796 patients had pain >3 on the NRS at the admission to the ED and were included in the data analysis. The theoretical knowledge of pain management among nurses and residents increased as assessed by a multiple choice test performed before and after the educational intervention (P=0.001), but no change in clinical practice could be observed: The administration for analgesics [OR: 1.79 (0.97-3.33)] and for opioids [2.02 (0.79-5.18)] were similar before and after the educational intervention, as was the rate of clinically meaningful pain reduction (NRS >2) during the ED stay [OR: 0.81 (CI 0.45-1.44)]. CONCLUSIONS: Conduction of a 2-h educational intervention combining interactive case-based e-learning with simulation-based training in an ED setting was feasible with a high participation rate of nurses and residents. Their knowledge of pain management increased after completion of the program, but transfer of the new knowledge into clinical practice could not be found. Future research should explore the effects of repeated education of healthcare providers on pain management. IMPLICATIONS: It is essential for nurses and residents in emergency departments to have the basic theoretical and practical skills to treat acute pain properly. A modern approach including e-learning and simulation lead to increased knowledge of acute pain management. Further studies are needed to show how this increased knowledge is transferred into clinical practice.

Prehospital intravenous fentanyl to patients with hip fracture: an observational cohort study of risk factors for analgesic non-treatment.

BACKGROUND: Patients with proximal femoral neck fracture have a high short-term mortality, a high risk of postoperative complications, and impaired quality of life. One of the challenges related to the prehospital treatment of these patients is to administer systemic opioids fast and properly. Effective analgesic prehospital treatment ought be initiated rapidly in order to alleviate the stress that follows acute pain, to facilitate transportation, and to improve quality of care. The objectives of this study were to explore the prevalence of prehospital administration of intravenous fentanyl to patients with proximal femoral neck fracture in the ambulances and to assess risk factors for analgesic non-treatment. METHODS: This was a register-based observational cohort study of patients with proximal femoral neck fracture from the North Denmark Region transported by ambulance. The patients were identified via the Danish Interdisciplinary Hip Fracture Registry over a 3-year period from 1 July 2011 to 30 June 2014. This hospital registry contains data on several patient characteristics used for the risk factor analysis. Data on prehospital treatment (intravenous fentanyl) and patient monitoring were registered in an electronic prehospital patient record. A modified Poisson regression with robust standard errors was carried out with intravenous fentanyl as the primary binary outcome and the following explanatory variables: age, sex, Charlson Comorbidity Index score, housing, body mass index, type of fracture, fracture displacement, prior consultation with general practitioner, dispatch triage level, and time with ambulance personnel. RESULTS: In total, 2,140 patients with proximal femoral neck fracture were transported by ambulance, of which 584 (27.3%, 95% CI: 25.4-29.2) were treated with intravenous fentanyl. Risk factors for non-treatment were: older age, male sex (RR 0.77, 95% CI: 0.64-0.91), institutional housing (RR 0.72, 95% CI: 0.56-0.92), medial fracture (RR 0.74, 95% CI: 0.60-0.92), short time with ambulance personnel, Charlson Comorbidity Index score > 1, year of fracture (2011), low levels of urgency at dispatch, and if seen by general practitioners prior to transport. DISCUSSION: Education of ambulance personnel in assessing and treating patients with hip fracture seems to be required. Also, future studies should consider alternative or supportive pain treatment options with suitable analgesic effects and side effects. CONCLUSIONS: Few patients with proximal femoral neck fracture were treated with intravenous fentanyl, and several risk factors were associated with prehospital analgesic non-treatment. Future prospective studies should explore covariates of socioeconomic, cultural, and psychological origin to provide further insight into the multifactorial causes of non-treatment of acute pain.