Intravenous Opioids for Severe Acute Pain in the Emergency Department

As-needed opioid dosing for emergency patients with a daily use of opioids

BACKGROUND

Patients with a daily use of opioids have a higher risk of insufficient pain treatment during hospitalization than other patients. This study aimed to examine whether as-needed opioid doses (PRN) were adequately adjusted when patients were admitted to the emergency department (ED) with pain.

METHODS

Patients, with a daily use of opioids, who received PRN opioid within the first 3 h after admission at the ED at Aarhus University Hospital, Denmark, were prospectively included from February 2021 to June 2021. The primary outcome was the proportion of patients receiving an inadequate initial dose of PRN opioid, here defined as <15% of daily dose of opioids (DDO) based on sparse evidence, but aligning with the prevailing clinical practice. Secondary outcomes included risk of an inadequate PRN dose in relation to DDO (patients were dichotomized into two groups (DDO <60 or ≥60 mg/day).

RESULTS

Among 252 patients admitted to the ED with a daily use of opioids, 149 were admitted with pain and 82 received a PRN opioid dose within 3 h. Twenty-seven out of 82 (33%) patients received a PRN dose of <15% of DDO (95% CI: 23.7-43). When dichotomised; 10 out of 50 (20%) patients with a DDO <60 mg/day (95% CI: 10.0-33.7) versus 17 out of 32 (53.1%) patients with a DDO ≥60 mg/day (95% CI: 34.7-70.9) received an inadequate PRN dose (relative risk, RR: 2.65 [95% CI: 1.4-5.1]).

CONCLUSIONS

Patients with daily use of opioids presenting in the ED with acute pain had a high risk of inadequate PRN opioid dose, especially if the DDO was high. Awareness about and education focusing on sufficient PRN doses for patients with a daily use of opioids is (still) called for.

Subanaesthetic single-dose ketamine as an adjunct to opioid analgesics for acute pain management in the emergency department: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of a subanaesthetic single-dose ketamine (SDK) as an adjunct to opioids for acute pain in emergency department (ED) settings.

DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was performed in MEDLINE, Embase, Scopus and Web of Science through March 2022. Randomised controlled trials (RCTs) that investigated SDK as an adjunct to opioids in adult patients for any painful condition in ED settings were selected. Two reviewers screened studies, extracted data and assessed study quality. Data were pooled using random-effects models. The primary outcome was mean pain intensity score measured at baseline, >0-15 min, >15-30 min, >30-45 min, 60 min, 90 min and 120 min. Secondary outcomes included need for rescue analgesia, adverse events and patient satisfaction. Results were reported as mean differences (MDs) and risk ratios. Statistical heterogeneity was calculated using the I ² statistic.

RESULTS

Eight RCTs were included (n=903). Studies were judged to be at moderate to high risk of bias. Mean pain intensity scores were significantly lower 60 min after study drug administration favouring adjuvant SDK (MD -0.76; 95% CI -1.19 to -0.33), compared with opioids alone. There was no evidence of differences in mean pain intensity scores at any other time point. Patients who received adjuvant SDK were less likely to require rescue analgesia, no more likely to experience serious side effects and had higher satisfaction scores, compared with opioids alone.

CONCLUSIONS

Available evidence suggests adjuvant SDK can have an effect on lowering pain intensity scores. Although reduction of pain scores was not clinically significant, the combination of reduced pain intensity and reduced opioid requirements suggest the results could be clinically important and support the potential utility of SDK as an adjunct to opioids to treat acute pain in adult ED patients. However, current evidence is limited and higher quality RCTs are needed.

PROSPERO REGISTRATION NUMBER

CRD42021276708.

Comparing the Effects of Low-Dose Ketamine, Fentanyl, and Morphine on Hemorrhagic Tolerance and Analgesia in Humans

Hemorrhage is a leading cause of preventable battlefield and civilian trauma deaths. Ketamine, fentanyl, and morphine are recommended analgesics for use in the prehospital (i.e., field) setting to reduce pain. However, it is unknown whether any of these analgesics reduce hemorrhagic tolerance in humans. We tested the hypothesis that fentanyl (75 µg) and morphine (5 mg), but not ketamine (20 mg), would reduce tolerance to simulated hemorrhage in conscious humans. Each of the three analgesics was evaluated independently among different cohorts of healthy adults in a randomized, crossover (within drug/placebo comparison), placebo-controlled fashion using doses derived from the Tactical Combat Casualty Care Guidelines for Medical Personnel. One minute after an intravenous infusion of the analgesic or placebo (saline), we employed a pre-syncopal limited progressive lower-body negative pressure (LBNP) protocol to determine hemorrhagic tolerance. Hemorrhagic tolerance was quantified as a cumulative stress index (CSI), which is the sum of products of the LBNP and the duration (e.g., [40 mmHg x 3 min] + [50 mmHg x 3 min] …). Compared with ketamine (p = 0.002 post hoc result) and fentanyl (p = 0.02 post hoc result), morphine reduced the CSI (ketamine (n = 30): 99 [73-139], fentanyl (n = 28): 95 [68-130], morphine (n = 30): 62 [35-85]; values expressed as a % of the respective placebo trial's CSI; median [IQR]; Kruskal-Wallis test p = 0.002). Morphine-induced reductions in tolerance to central hypovolemia were not well explained by a prediction model including biological sex, body mass, and age (R2=0.05, p = 0.74). These experimental data demonstrate that morphine reduces tolerance to simulated hemorrhage while fentanyl and ketamine do not affect tolerance. Thus, these laboratory-based data, captured via simulated hemorrhage, suggest that morphine should not be used for a hemorrhaging individual in the prehospital setting.

Low-dose morphine reduces tolerance to central hypovolemia in healthy adults without affecting muscle sympathetic outflow

Hemorrhage is a leading cause of preventable battlefield and civilian trauma deaths. Low-dose (i.e., an analgesic dose) morphine is recommended for use in the prehospital (i.e., field) setting. Morphine administration reduces hemorrhagic tolerance in rodents. However, it is unknown whether morphine impairs autonomic cardiovascular regulation and consequently reduces hemorrhagic tolerance in humans. Thus, the purpose of this study was to test the hypothesis that low-dose morphine reduces hemorrhagic tolerance in conscious humans. Thirty adults (15 women/15 men; 29 ± 6 yr; 26 ± 4 kg·m-2, means ± SD) completed this randomized, crossover, double-blinded, placebo-controlled trial. One minute after intravenous administration of morphine (5 mg) or placebo (saline), we used a presyncopal limited progressive lower-body negative pressure (LBNP) protocol to determine hemorrhagic tolerance. Hemorrhagic tolerance was quantified as a cumulative stress index (mmHg·min), which was compared between trials using a Wilcoxon matched-pairs signed-rank test. We also compared muscle sympathetic nerve activity (MSNA; microneurography) and beat-to-beat blood pressure (photoplethysmography) during the LBNP test using mixed-effects analyses [time (LBNP stage) × trial]. Median LBNP tolerance was lower during morphine trials (placebo: 692 [473-997] vs. morphine: 385 [251-728] mmHg·min, P < 0.001, CI: -394 to -128). Systolic blood pressure was 8 mmHg lower during moderate central hypovolemia during morphine trials (post hoc P = 0.02; time: P < 0.001, trial: P = 0.13, interaction: P = 0.006). MSNA burst frequency responses were not different between trials (time: P < 0.001, trial: P = 0.80, interaction: P = 0.51). These data demonstrate that low-dose morphine reduces hemorrhagic tolerance in conscious humans. Thus, morphine is not an ideal analgesic for a hemorrhaging individual in the prehospital setting.NEW & NOTEWORTHY In this randomized, crossover, placebo-controlled trial, we found that tolerance to simulated hemorrhage was lower after low-dose morphine administration. Such reductions in hemorrhagic tolerance were observed without differences in MSNA burst frequency responses between morphine and placebo trials. These data, the first to be obtained in conscious humans, demonstrate that low-dose morphine reduces hemorrhagic tolerance. Thus, morphine is not an ideal analgesic for a hemorrhaging individual in the prehospital setting.

Low-Dose Morphine Reduces Pain Perception and Blood Pressure, but Not Muscle Sympathetic Outflow, Responses During the Cold Pressor Test

Our knowledge about how low-dose (analgesic) morphine affects autonomic cardiovascular regulation is primarily limited to animal experiments. Notably, it is unknown if low-dose morphine affects human autonomic cardiovascular responses during painful stimuli in conscious humans. Therefore, we tested the hypothesis that low-dose morphine reduces perceived pain and subsequent sympathetic and cardiovascular responses in humans during an experimental noxious stimulus. Twenty-nine participants (14F/15M; 29±6 y; 26±4 kg•m^-2, mean ± SD) completed this randomized, crossover, placebo-controlled trial during two laboratory visits. During each visit, participants completed a cold pressor test (CPT; hand in ~0.4 °C ice bath for two minutes) before and ~35 minutes after drug/placebo administration (5 mg IV morphine or saline). We compared pain perception (100 mm visual analog scale), muscle sympathetic nerve activity (MSNA; microneurography; 14 paired recordings), and beat-to-beat blood pressure (BP; photoplethysmography) between trials (at both pre- and post-drug/placebo time points) using paired, two-tailed t-tests. Before drug/placebo infusion, perceived pain (p=0.92), Δ MSNA burst frequency (n=14, p=0.21), and Δ mean BP (p=0.39) during the CPT were not different between trials. After the drug/placebo infusion, morphine versus placebo attenuated perceived pain (morphine: 43±20 vs. placebo: 57±24 mm,p<0.001) and Δ mean BP (morphine: 10±7 vs. placebo: 13±8 mmHg,p=0.003), but not Δ MSNA burst frequency (morphine: 10±11 vs. placebo: 13±11 bursts/minute,p=0.12), during the CPT. Reductions in pain perception and Δ mean BP were only weakly related (r=0.34,p=0.07; post-morphine CPT minus post-placebo CPT). These data provide valuable information regarding how low-dose morphine affects autonomic cardiovascular responses during an experimental painful stimulus.

Low-dose fentanyl reduces pain perception, muscle sympathetic nerve activity responses, and blood pressure responses during the cold pressor test

Our knowledge about how low-dose (analgesic) fentanyl affects autonomic cardiovascular regulation is primarily limited to animal experiments. Notably, it is unknown if low-dose fentanyl influences human autonomic cardiovascular responses during painful stimuli in humans. Therefore, we tested the hypothesis that low-dose fentanyl reduces perceived pain and subsequent sympathetic and cardiovascular responses in humans during an experimental noxious stimulus. Twenty-three adults (10 females/13 males; 27 ± 7 yr; 26 ± 3 kg·m^-2, means ± SD) completed this randomized, crossover, placebo-controlled trial during two laboratory visits. During each visit, participants completed a cold pressor test (CPT; hand in ∼0.4°C ice bath for 2 min) before and 5 min after drug/placebo administration (75 μg fentanyl or saline). We compared pain perception (100-mm visual analog scale), muscle sympathetic nerve activity (MSNA; microneurography, 11 paired recordings), and beat-to-beat blood pressure (BP; photoplethysmography) between trials (at both pre- and postdrug/placebo timepoints) using paired, two-tailed t tests. Before drug/placebo administration, perceived pain (P = 0.8287), ΔMSNA burst frequency (P = 0.7587), and Δmean BP (P = 0.8649) during the CPT were not different between trials. After the drug/placebo administration, fentanyl attenuated perceived pain (36 vs. 66 mm, P < 0.0001), ΔMSNA burst frequency (9 vs. 17 bursts/min, P = 0.0054), and Δmean BP (7 vs. 13 mmHg, P = 0.0174) during the CPT compared with placebo. Fentanyl-induced reductions in pain perception and Δmean BP were moderately related (r = 0.40, P = 0.0641). These data provide valuable information regarding how low-dose fentanyl reduces autonomic cardiovascular responses during an experimental painful stimulus.

Ultrasound-Guided Nerve Blocks for Painful Hand Injuries: A Randomized Control Trial

Objectives: Traumatic hand injuries present to emergency departments frequently. Pain secondary to these injuries is typically managed with opioids, which may be inadequate and have side effects. Ultrasound (US)-guided forearm nerve blocks have emerged as an alternative modality for patients with acute pain from isolated extremity injuries.

Methods: We performed a non-blinded, consecutive, randomized pragmatic trial of US-guided forearm nerve blocks using medium and long-acting anesthetic versus usual care for a six-day period around July 4th, 2017. Adults who sustained a traumatic or blast injury of their hands were considered. Consecutive emergency department patients were consented, enrolled and randomized into a study group (block) or control (standard care). The study group received a US-guided forearm block using a 50/50 mix of 1% lidocaine and 0.5% bupivacaine. The primary outcome was median pain scores via a 100-point visual analog scale at 15, 60, and 120 minutes after the nerve block compared to the baseline pain score. The secondary outcome was mean morphine equivalents administered.

Results: Sixteen patients were screened and 12 were randomized: six to the treatment group and six to the control group. Median pain reduction from baseline at 15, 60, and 120 minutes in the forearm block group was -35 (IQR=10), -30 (IQR=50), and -20 (IQR=70, versus -5 (IQR=10), -20.5 (IQR=20), -20 (IQR=70) in the control group. At all time points, patient-reported pain scores decreased significantly over baseline in the forearm block group, whereas non-significant reductions in pain scores occurred in the control group.

Conclusion: US-guided forearm blocks for acute traumatic hand injuries resulted in greater pain relief when compared to usual care.

Opioid-induced analgesia among persons with opioid use disorder receiving methadone or buprenorphine: A systematic review of experimental pain studies

BACKGROUND

Treating acute pain among persons with opioid use disorder (OUD) on opioid agonist therapy (OAT) is complex, and the therapeutic benefits of opioids remain unclear when weighted against their abuse potential and respiratory depressant effects.

METHODS

We conducted a systematic review of experimental pain studies examining opioid-induced analgesia among persons with OUD on OAT. We searched multiple databases from inception to July 30, 2021. Study quality was assessed by previously established validity measures.

RESULTS

Nine studies were identified, with a total of 225 participants, of whom 63% were male, and 37% were female. Six studies included methadone-maintained persons with OUD; four studies included buprenorphine-maintained persons with OUD; and three studies included healthy persons as comparison groups. Either additional doses of OAT or other opioids - morphine, oxycodone, hydromorphone, or remifentanil - were administered. In seven studies, persons with OUD on OAT did not experience analgesia, despite receiving opioid doses up to 20 times greater than those clinically used to treat severe pain among the opioid naïve. Conversely, in two studies, high-potency opioids did produce analgesia, albeit with greater abuse potential. Notably, persons with OUD on OAT remained vulnerable to respiratory depression.

CONCLUSIONS

Although persons with OUD on OAT can derive analgesic effects from opioids, high-potency compounds may be required to achieve clinically significant pain relief. Further, persons with OUD on OAT may remain vulnerable to opioid-induced abuse potential and respiratory depression. Together, these finding have clinical, methodological, and mechanistic implications for the treatment of acute pain in the context of OAT.

Opiophobia in Emergency Department Healthcare Providers: A Survey in Western Switzerland

Opiophobia contributes to oligoanalgesia in the emergency department (ED), but its definition varies, and its association to healthcare providers’ personality traits has been scantly explored. Our purpose was to study the different definitions of opiophobia and their association with two personality traits of doctors and nurses working in EDs, namely the stress from uncertainty and risk-taking. We used three online questionnaires: the ‘Attitude Towards Morphine Use’ Score (ATMS), the Stress From Uncertainty Scale (SUS) and the Risk-Taking Scale (RTS). Doctors and nurses from nine hospital EDs in francophone Switzerland were invited to participate. The ATMS score was analyzed according to demographic characteristics, SUS, and RTS. The response rate was 56%, with 57% of respondents being nurses and 63% women. Doctors, less experienced and non-indigenous participants had a significantly higher ATMS (all p ≤ 0.01). The main contributors of the ATMS were the fear of side effects and of addiction. In multivariate analysis, being a doctor, less experience and non-indigenous status were predictive of the ATMS; each point of the SUS increased the ATMS by 0.24 point. The fear of side effects and of addiction were the major contributors of opiophobia among ED healthcare providers; opiophobia was also associated with their personality traits.

Comparison of Postoperative Renal Function between Non-Steroidal Anti-Inflammatory Drug and Opioids for Patient-Controlled Analgesia after Laparoscopic Nephrectomy: A Retrospective Cohort Study

Non-steroidal anti-inflammatory drugs (NSAIDs) can be used as opioid alternatives for patient-controlled analgesia (PCA). However, their use after nephrectomy has raised concerns regarding possible nephrotoxicity. This study compared postoperative renal function and postoperative outcomes between patients using NSAID and patients using opioids for PCA in nephrectomy. In this retrospective observational study, records were reviewed for 913 patients who underwent laparoscopic or robot-assisted laparoscopic nephrectomy from 2015 to 2017. After propensity score matching, 247 patients per group were analyzed. Glomerular filtration rate (GFR) percentages (postoperative value divided by preoperative value), blood urea nitrogen (BUN)/creatinine ratios, and serum creatinine percentages were compared at 2 weeks, 6 months, and 1 year after surgery between users of NSAID and users of opioids for PCA. Additionally, postoperative complication rates, postoperative acute kidney injury (AKI) incidences, postoperative pain scores, and lengths of hospital stay were compared between groups. Postoperative GFR percentages, BUN/creatinine ratios, and serum creatinine percentages were similar between the two groups. There were no significant differences in the rates of postoperative complications, incidences of AKI, and pain scores at 30 min, 6 h, 48 h, or 7 days postoperatively. The length of hospital stay was significantly shorter in the NSAID group than in the opioid group. This study showed no association between the use of NSAID for PCA after laparoscopic nephrectomy and the incidence of postoperative renal dysfunction.

Analgesic Effects of Hydromorphone versus Buprenorphine in Buprenorphine-maintained Individuals

BACKGROUND

Managing acute pain in buprenorphine-maintained individuals in emergency or perioperative settings is a significant challenge. This study compared analgesic and abuse liability effects of adjunct hydromorphone and buprenorphine using quantitative sensory testing, a model of acute clinical pain, in persons maintained on 12 to 16 mg sublingual buprenorphine/naloxone.

METHODS

Participants (N = 13) were enrolled in a randomized within-subject, double-blind, placebo-controlled three-session experiment. Each session used a cumulative dosing design with four IV injections (4, 4, 8, and 16 mg of hydromorphone or 4, 4, 8, and 16 mg of buprenorphine); quantitative sensory testing and abuse liability assessments were measured at baseline and after each injection. The primary analgesia outcome was change from baseline cold pressor testing; secondary outcomes included thermal and pressure pain testing, as well as subjective drug effects and adverse events.

RESULTS

A significant two-way interaction between study drug condition and dose was exhibited in cold pressor threshold (F10,110 = 2.14, P = 0.027) and tolerance (F10,110 = 2.69, P = 0.006). Compared to after placebo, participants displayed increased cold pressor threshold from baseline after cumulative doses of 32 mg of IV hydromorphone (means ± SD) (10 ± 14 s, P = 0.035) and 32 mg of buprenorphine (3 ± 5 s, P = 0.0.39) and in cold pressor tolerance after cumulative doses of 16 mg (18 ± 24 s, P = 0.018) and 32 mg (48 ± 73 s, P = 0.041) IV hydromorphone; cold pressor tolerance scores were not significant for 16 mg (1 ± 15 s, P = 0.619) or 32 mg (7 ± 16 s, P = 0.066) buprenorphine. Hydromorphone and buprenorphine compared with placebo showed greater ratings on subjective measures of high, any drug effects, good effects, and drug liking. Adverse events were more frequent during the hydromorphone compared with buprenorphine and placebo conditions for nausea, pruritus, sedation, and vomiting.

CONCLUSIONS

In this acute clinical pain model, high doses of IV hydromorphone (16 to 32 mg) were most effective in achieving analgesia but also displayed higher abuse liability and more frequent adverse events. Cold pressor testing was the most consistent measure of opioid-related analgesia.

APOLLO-2: A Randomized, Placebo and Active-Controlled Phase III Study Investigating Oliceridine (TRV130), a G Protein-Biased Ligand at the μ-Opioid Receptor, for Management of Moderate to Severe Acute Pain Following Abdominoplasty

Objectives

The clinical utility of conventional IV opioids is limited by the occurrence of opioid‐related adverse events. Oliceridine is a novel G protein–biased μ‐opioid receptor agonist designed to provide analgesia with an improved safety and tolerability profile. This phase III, double‐blind, randomized trial (APOLLO‐2 [NCT02820324]) evaluated the efficacy and safety of oliceridine for acute pain following abdominoplasty.

Methods

Patients received a loading dose of either placebo, oliceridine (1.5 mg), or morphine (4 mg), followed by demand doses via patient‐controlled analgesia (0.1, 0.35, or 0.5 mg oliceridine; 1 mg morphine; or placebo) with a 6‐minute lockout interval. The primary endpoint was the proportion of treatment responders over 24 hours for oliceridine regimens compared to placebo. Secondary outcomes included a predefined composite measure of respiratory safety burden (RSB, representing the cumulative duration of respiratory safety events) and the proportion of treatment responders vs. morphine.

Results

A total of 401 patients were treated with study medication. Effective analgesia was observed for all oliceridine regimens, with responder rates of 61.0%, 76.3%, and 70.0% for the 0.1‐, 0.35‐, and 0.5‐mg regimens, respectively, compared with 45.7% for placebo (all P < 0.05) and 78.3% for morphine. Oliceridine 0.35‐ and 0.5‐mg demand dose regimens were equi‐analgesic to morphine using a noninferiority analysis. RSB showed a dose‐dependent increase across oliceridine regimens (mean hours [standard deviation], 0.1 mg: 0.43 [1.56]; 0.35 mg: 1.48 [3.83]; 0.5 mg: 1.59 [4.26]; all comparisons not significant at P > 0.05 vs. placebo: 0.60 [2.82]). The RSB measure for morphine was 1.72 (3.86) (P < 0.05 vs. placebo). Gastrointestinal adverse events increased in a dose‐dependent manner across oliceridine demand dose regimens (0.1 mg: 49.4%; 0.35 mg: 65.8%; 0.5 mg: 78.8%; vs. placebo: 47.0%; and morphine: 79.3%). In comparison to morphine, the proportion of patients experiencing nausea or vomiting was lower with the 2 equi‐analgesic dose regimens of 0.35 and 0.5 mg oliceridine.

Conclusions

Oliceridine is a safe and effective IV analgesic for the relief of moderate to severe acute postoperative pain in patients undergoing abdominoplasty. Since the low‐dose regimen of 0.1 mg oliceridine was superior to placebo but not as effective as the morphine regimen, safety comparisons to morphine are relevant only to the 2 equi‐analgesic dose groups of 0.35 and 0.5 mg, which showed a favorable safety and tolerability profile regarding respiratory and gastrointestinal adverse effects compared to morphine. These findings support that oliceridine may provide a new treatment option for patients with moderate to severe acute pain where an IV opioid is warranted.

Intravenous morphine titration vs. oral hydrocodone/acetaminophen for adults with lower extremity displaced fracture in an emergency department setting: A randomized controlled trial

The objective of the present study was to test the hypothesis that intravenous morphine titration provides superior analgesia to oral hydrocodone/acetaminophen for patients with lower extremity displaced fracture in an emergency department (ED) setting. A prospective, randomized clinical trial of ED patients suffering acute lower extremity displaced fracture pain was performed with a total of 206 participants included. After application of exclusion criteria, the cohort comprised 166 patients, 85 of which were randomly allocated to the oral hydrocodone/acetaminophen (5 mg/500 mg) group and 81 to the intravenous morphine titration (every 5 min by 3-mg increments) group. The main outcome was the visual analogue scale (VAS) at different time-points after the first dose of analgesic was administered. Secondary outcomes included the VAS change during the skeletal traction operation and short-term adverse events. The results demonstrated that the initial VSA of the participants was similar at the baseline on arrival at the ED (P=0.2582). At the time-points of 5, 15, 30 min after the first dose of analgesic administered, the intravenous morphine titration group exhibited a greater VAS reduction compared with that in the oral hydrocodone/acetaminophen group (P<0.01). The differences between the 2 groups were not statistically significant at 1 h or thereafter. The incidence of short-term adverse events was similar between the 2 groups but sedation, whose incidence in the morphine group was markedly increased, may not be arbitrarily attributed to adverse events. It was concluded that, compared with oral hydrocodone/acetaminophen, intravenous morphine titration provided a rapid and sufficient pain relief and equivalent short-term adverse events for patients with lower extremity displaced fracture in an ED setting.

Pain Management in the Emergency Department: a Review Article on Options and Methods

CONTEXT

The aim of this review is to recognizing different methods of analgesia for emergency medicine physicians (EMPs) allows them to have various pain relief methods to reduce pain and to be able to use it according to the patient's condition and to improve the quality of their services.

EVIDENCE ACQUISITION

In this review article, the search engines and scientific databases of Google Scholar, Science Direct, PubMed, Medline, Scopus, and Cochrane for emergency pain management methods were reviewed. Among the findings, high quality articles were eventually selected from 2000 to 2018, and after reviewing them, we have conducted a comprehensive comparison of the usual methods of pain control in the emergency department (ED).

RESULTS

For better understanding, the results are reported in to separate subheadings including "Parenteral agents" and "Regional blocks". Non-opioids analgesics such as nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen are commonly used in the treatment of acute pain. However, the relief of acute moderate to severe pain usually requires opioid agents. Considering the side effects of systemic drugs and the restrictions on the use of analgesics, especially opioids, regional blocks of pain as part of a multimodal analgesic strategy can be helpful.

CONCLUSION

This study was designed to investigate and identify the disadvantages and advantages of using each drug to be able to make the right choices in different clinical situations for patients while paying attention to the limitations of the use of these analgesic drugs.

Satisfactory Analgesia with Minimal Emesis in Day Surgeries (SAME DayS): a protocol for a randomised controlled trial of morphine versus hydromorphone

INTRODUCTION

There has been an exponential increase in the number of ambulatory surgeries (AS). Pain and postoperative nausea vomiting (PONV) affects the recovery, discharge and overall satisfaction of patients having AS. Opioids remain the primary modality for moderate to severe pain. Since there is no perfect opioid, physicians should ideally use the opioid that optimally balances benefits and risks. Present decisions on the choice between morphine (M) and hydromorphone (HM) are based on individual experience and observation. Our primary objective is to compare the proportion of patients having AS achieving satisfactory analgesia without significant PONV when using M compared with HM. Secondarily we will compare the proportion of patients with adverse events, analgesic used, patient satisfaction, time to discharge and postdischarge symptoms.

METHODS AND ANALYSIS

This is a two-arm, multicentre, parallel group, randomised controlled trial of 400 patients having AS. Eligible patients undergoing AS of the abdominal and pelvic regions with a potential to cause moderate to severe pain will be recruited in the preoperative clinic. Using a computer-generated randomization, with a 1:1 allocation ratio, patients will be randomised to M or HM. Patients, healthcare providers and research personnel will be blinded. Study interventions will be administered in the recovery using equianalgesic doses of M or HM in concealed syringes. Patients will be followed in hospital and up to 3 months. Intention-to-treat approach will be used for analysis.

ETHICS AND DISSEMINATION

This study has been approved by the Hamilton integrated research ethics board. We plan to publish our trial findings and present our findings at scientific meetings.

TRAIL REGISTRATION NUMBER

NCT02223377; Pre-results.

Administration of intravenous morphine for acute pain in the emergency department inflicts an economic burden in Europe

BACKGROUND

Acute pain is among the leading causes of referral to the emergency department (ED) in industrialized countries. Its management mainly depends on intensity. Moderate-to-severe pain is treated with intravenous (IV) administered opioids, of which morphine is the most commonly used in the ED. We have estimated the burden of IV administration of morphine in the five key European countries (EU5) using a micro-costing approach.

SCOPE

A structured literature review was conducted to identify clinical guidelines for acute pain management in EU5 and clinical studies conducted in the ED setting. The data identified in this literature review constituted the source for all model input parameters, which were clustered as analgesic (morphine), material used for IV morphine administration, nurse workforce time and management of morphine-related adverse events and IV-related complications.

FINDINGS

The cost per patient of IV morphine administration in the ED ranges between €18.31 in Spain and €28.38 in Germany. If costs associated with the management of morphine-related adverse events and IV-related complications are also considered, the total costs amount to €121.13-€132.43. The main driver of those total costs is the management of IV-related complications (phlebitis, extravasation and IV prescription errors; 73% of all costs) followed by workforce time (14%).

CONCLUSIONS

IV morphine provides effective pain relief in the ED, but the costs associated with the IV administration inflict an economic burden on the respective national health services in EU5. An equally rapid-onset and efficacious analgesic that does not require IV administration could reduce this burden.

Pharmacokinetics and safety of fentanyl sublingual spray and fentanyl citrate intravenous: a multiple ascending dose study in opioid-naïve healthy volunteers

OBJECTIVE

Fentanyl sublingual spray, with its rapid onset for pain relief, may be efficacious in the management of acute or post-operative pain. Because patients in these settings may be opioid-naïve, the study was conducted to determine the safety, tolerability, and pharmacokinetics of multiple dose administration of fentanyl sublingual spray in an opioid-naïve population.

METHODS

Fentanyl sublingual spray (100 mcg, 200 mcg, and 400 mcg) and fentanyl citrate intravenous (IV; 50 mcg) were administered every 0.5, 1.0, 2.0, and 4.0 h for up to three doses per cohort in opioid-naïve subjects (ClinicalTrials.gov identifier: NCT02641340). Eight subjects in each cohort were randomly assigned (six subjects received fentanyl sublingual spray; two subjects received fentanyl citrate IV). Pharmacokinetic and safety-related pharmacodynamic assessments were performed through 24 h post-first dose. Safety assessments were collected through Day 7.

RESULTS

Ninety-six opioid-naïve subjects, aged 20-55 years, with a body mass index of 18.7-31.5 kg/m², participated in the study. Multiple doses of fentanyl sublingual spray (100, 200, and 400 mcg) were generally well tolerated. Hypoxia, observed in the 200-mcg and 400-mcg dose groups, increased with increasing doses and higher dosing frequency, but was readily managed by nasal cannula oxygenation. Overall, nausea increased with increasing doses, and ∼52.6% (10 out of 19) cases of nausea that occurred at the highest dose of 400 mcg were treated with concomitant medication. Overall, the reported adverse events were consistent with the known safety profile of fentanyl.

CONCLUSION

Fentanyl sublingual spray (100 mcg, 200 mg, and 400 mcg) administered every 0.5, 1, 2, and 4 h was generally well tolerated in an opioid-naïve population. The results suggest that doses of 200 mcg or lower may be safe for use in an opioid-naïve population.

Pharmacokinetics and safety of fentanyl sublingual spray and fentanyl citrate intravenous: a single ascending dose study in opioid-naïve healthy volunteers

OBJECTIVE

Fentanyl sublingual spray offers rapid pain relief in opioid-tolerant cancer patients, and may be useful in acute or post-operative pain. Both opioid-naïve and non-tolerant patients are likely to receive opioids in these settings. Understanding the relationship between systemic exposure of fentanyl sublingual spray and effects on respiratory function in opioid-naïve or non-tolerant populations is important to ensure patient safety. This study evaluated single-dose fentanyl sublingual spray in opioid-naïve participants.

RESEARCH DESIGN

Participants were randomized to receive single-dose fentanyl sublingual spray (100, 200, 400, 600, 800 mcg) or fentanyl citrate IV in one of five cohorts. Dosing occurred following a 10-h fast, with fasting continuing for 4 h post-dose. Dose proportionality was assessed using analysis of variance and linear regression techniques. PK assessments and safety monitoring were performed through 24 h post-dose. Safety assessments, including adverse event (AE) monitoring, occurred from dosing through Day 7.

RESULTS

Fifty participants (19-53 years) received fentanyl sublingual spray or fentanyl citrate IV. Mean maximum plasma concentrations were reached between 0.27-0.60 h post-dose for fentanyl sublingual spray. Peak (C_max) and total (AUC_0-t, AUC_0-∞) fentanyl exposures increased in a linear, but more than dose-proportional manner, with higher doses. The most common AEs were somnolence, nausea, and vomiting. All AEs were mild or moderate in severity. Doses at 400, 600, and 800 mcg were associated with nausea and vomiting, requiring pharmacologic intervention. Hypoxia episodes requiring nasal cannula oxygenation were observed with 600mcg and 800mcg doses.

CONCLUSIONS

Overall, single-dose fentanyl sublingual spray (100-800 mcg) was generally well tolerated, with greater incidences of AEs (e.g. nausea, vomiting, hypoxia) at higher doses. Doses up to 200 mcg may be safely administered to healthy opioid-naïve individuals with routine monitoring; doses between 400-800 mcg may be administered in settings with nasal cannula oxygenation.

A description of pharmacological analgesia administration by public sector advanced life support paramedics in the City of Cape Town

INTRODUCTION

Emergency Medical Services are ideally placed to provide relief of acute pain and discomfort. The objectives of this study were to describe pre-hospital pain management practices by Emergency Medical Services in the Western Cape, South Africa.

METHODS

A retrospective, descriptive survey was undertaken of analgesic drug administration by advanced life support paramedics. Patient care records generated in the City of Cape Town during an 11-month period containing administrations of morphine, ketamine, nitrates and 50% nitrous oxide/oxygen were randomly sampled. Variables studied were drug dose, dose frequency, and route of administration, patient age, gender, disorder and call type as well as qualification and experience level of the provider.

RESULTS

A total of 530 patient care records were included (n = 530). Morphine was administered in 371 (70%, 95% CI 66-74) cases, nitrates in 197 (37%, 95% CI 33-41) and ketamine in 9 (1.7%, 95% CI 1-3) cases. A total of 5 mg or less of morphine was administered in 278 (75%, 95% CI 70-79) cases, with the median dose being 4 mg (IQR 3-6). Single doses were administered to 268 (72.2%, 95% CI 67-77) morphine administrations, five (56%, 95% CI 21-86) ketamine administrations and 161 (82%, 95% CI 76-87) of nitrate administrations. Chest pain was the reason for pain management in 226 (43%) cases. Advanced Life Support Providers had a median experience level of two years (IQR 2-4).

DISCUSSION

Pre-hospital acute pain management in the Western Cape does not appear to conform to best practice as Advanced Life Support providers in the Western Cape use low doses of morphine. Chest pain is an important reason for drug administration in acute pre-hospital pain. Multimodal analgesia is not a feature of care in this pre-hospital service. The development of a Clinical Practice Guideline for and training in pre-hospital pain should be viewed as imperative.

Exposure pattern influences the degree of drug-seeking behaviour after withdrawal

OBJECTIVES

The occurrence of a relapse during abstinence is an important issue that must be addressed during treatment for drug addiction. We investigated the influence of drug exposure pattern on morphine-seeking behaviour following withdrawal. We also studied the role of the hippocampus in this process to confirm its involvement in drug relapse.

METHODS

Male Sprague-Dawley rats that were trained to self-administer morphine (1.0 mg/kg) using 2, 4, 6, 8, or 10 h daily sessions underwent withdrawal in their home cages and were re-exposed to the operant chamber to evaluate morphine-seeking behaviour. During the relapse session, rats were intravenously injected with morphine (0.25 mg/kg) or saline before re-exposure to the chamber. In the second experiment, rats were administered a microinjection of saline or cobalt chloride (CoCl2, 1 mM), a synaptic blocker, into the CA1 of the hippocampus prior to the relapse test.

RESULTS

In the first experiment, more morphine-seeking behaviour was observed in the 2 h group (animals trained to self-administer morphine during a 2 h daily session spread over 21 days) during the relapse session, despite all groups being exposed to similar amounts of morphine during the training period before withdrawal. In the second experiment, pretreatment with CoCl2 markedly reduced morphine-seeking behaviour in the 2 h group.

CONCLUSIONS

The present findings suggest that the exposure pattern influences the degree of relapse and that control of memorisation is important for prevention of relapse.

Advanced Concepts and Controversies in Emergency Department Pain Management

Pain is the most common complaint for which patients come to the emergency department (ED). Emergency physicians are responsible for pain relief in a timely, efficient, and safe manner in the ED. The improvement in our understanding of the neurobiology of pain has balanced the utilization of nonopioid and opioid analgesia, and simultaneously has led to more rational and safer opioid prescribing practices. This article reviews advances in pain management in the ED for patients with acute and chronic pain as well as describes several newer strategies and controversies.

Delivering safe and effective analgesia for management of renal colic in the emergency department: a double-blind, multigroup, randomised controlled trial

BACKGROUND

The excruciating pain of patients with renal colic on presentation to the emergency department requires effective analgesia to be administered in the shortest possible time. Trials comparing intramuscular non-steroidal anti-inflammatory drugs with intravenous opioids or paracetamol have been inconclusive because of the challenges associated with concealment of randomisation, small sample size, differences in outcome measures, and inadequate masking of participants and assessors. We did this trial to develop definitive evidence regarding the choice of initial analgesia and route of administration in participants presenting with renal colic to the emergency department.

METHODS

In this three-treatment group, double-blind, randomised controlled trial, adult participants (aged 18-65 years) presenting to the emergency department of an academic, tertiary care hospital in Qatar, with moderate to severe renal colic (Numerical pain Rating Scale ≥ 4) were recruited. With the use of computer-generated block randomisation (block sizes of six and nine), participants were assigned (1:1:1) to receive diclofenac (75 mg/3 mL intramuscular), morphine (0.1 mg/kg intravenous), or paracetamol (1 g/100 mL intravenous). Participants, clinicians, and trial personnel were masked to treatment assignment. The primary outcome was the proportion of participants achieving at least a 50% reduction in initial pain score at 30 min after analgesia, assessed by intention-to-treat analysis and per-protocol analysis, which included patients where a calculus in the urinary tract was detected with imaging. This trial is registered with ClinicalTrials.gov, number NCT02187614.

FINDINGS

Between Aug 5, 2014, and March 15, 2015, we randomly assigned 1645 participants, of whom 1644 were included in the intention-to-treat analysis (547 in the diclofenac group, 548 in the paracetemol group, and 549 in the morphine group). Ureteric calculi were detected in 1316 patients, who were analysed as the per-protocol population (438 in the diclofenac group, 435 in the paracetemol group, and 443 in the morphine group). The primary outcome was achieved in 371 (68%) patients in the diclofenac group, 364 (66%) in the paracetamol group, and 335 (61%) in the morphine group in the intention-to-treat population. Compared to morphine, diclofenac was significantly more effective in achieving the primary outcome (odds ratio [OR] 1·35, 95% CI 1·05-1·73, p=0·0187), whereas no difference was detected in the effectiveness of morphine compared with intravenous paracetamol (1·26, 0·99-1·62, p=0·0629). In the per-protocol population, diclofenac (OR 1·49, 95% CI 1·13-1·97, p=0·0046) and paracetamol (1·40, 1·06-1·85, p=0·0166) were more effective than morphine in achieving the primary outcome. Acute adverse events in the morphine group occurred in 19 (3%) participants. Significantly lower numbers of adverse events were recorded in the diclofenac group (7 [1%] participants, OR 0·31, 95% CI 0·12-0·78, p=0·0088) and paracetamol group (7 [1%] participants, 0·36, 0·15-0·87, p=0·0175) than in the morphine group. During the 2 week follow-up, no additional adverse events were noted in any group.

INTERPRETATION

Intramuscular non-steroidal anti-inflammatory drugs offer the most effective sustained analgesia for renal colic in the emergency department and seem to have fewer side-effects.

FUNDING

Hamad Medical Corporation Medical Research Center, Doha, Qatar.

Morphine Glucuronidation and Elimination in Intensive Care Patients: A Comparison with Healthy Volunteers

BACKGROUND

Although morphine is used frequently to treat pain in the intensive care unit, its pharmacokinetics has not been adequately quantified in critically ill patients. We evaluated the glucuronidation and elimination clearance of morphine in intensive care patients compared with healthy volunteers based on the morphine and morphine-3-glucuronide (M3G) concentrations.

METHODS

A population pharmacokinetic model with covariate analysis was developed with the nonlinear mixed-effects modeling software (NONMEM 7.3). The analysis included 3012 morphine and M3G concentrations from 135 intensive care patients (117 cardiothoracic surgery patients and 18 critically ill patients), who received continuous morphine infusions adapted to individual pain levels, and 622 morphine and M3G concentrations from a previously published study of 20 healthy volunteers, who received an IV bolus of morphine followed by a 1-hour infusion.

RESULTS

For morphine, a 3-compartment model best described the data, whereas for M3G, a 1-compartment model fits best. In intensive care patients with a normal creatinine concentration, a decrease of 76% was estimated in M3G clearance compared with healthy subjects, conditional on the M3G volume of distribution being the same in intensive care patients and healthy volunteers. Furthermore, serum creatinine concentration was identified as a covariate for both elimination clearance of M3G in intensive care patients and unchanged morphine clearance in all patients and healthy volunteers.

CONCLUSIONS

Under the assumptions in the model, M3G elimination was significantly decreased in intensive care patients when compared with healthy volunteers, which resulted in substantially increased M3G concentrations. Increased M3G levels were even more pronounced in patients with increased serum creatinine levels. Model-based simulations show that, because of the reduction in morphine clearance in intensive care patients with renal failure, a 33% reduction in the maintenance dose would result in morphine serum concentrations equal to those in healthy volunteers and intensive care patients with normal renal function, although M3G concentrations remain increased. Future pharmacodynamic investigations are needed to identify target concentrations in this population, after which final dosing recommendations can be made.

Safety of an ED High-Dose Opioid Protocol for Sickle Cell Disease Pain

INTRODUCTION

A nurse-initiated high dose, opioid protocol for vaso-occlusive crisis (VOC) was implemented. Total intravenous morphine sulfate equivalents (IVMSE) in mgs] and safety was evaluated.

METHODS

A medical record review was conducted for all ED visits in adult patients with VOC post protocol implementation. Opioids doses and routes administered during the ED stay, and six hours into the hospital admission were abstracted and total IVMSE administered calculated. Oxygen saturation (SPO2), respiratory rate (RR), administration of naloxone or vasoactive medications, evidence of respiratory arrest, or any other types of resuscitation effort were abstracted. A RR of <10 or SPO2 <92% were coded as abnormal. Descriptive statistics report the total dose. Logistic regression was used to predict abnormal events. Predictors were age, gender, ED dose (10 mg increments) administered, and time from 1st dose to discharge from ED.

RESULTS

72 patients, 603 visits, 276 admitted. The total (ED & hospital dose) mean (95% CI) mg IVMSE administered for all visits was 93 mg (CI 86, 100), ED visit 63 mg (CI 59, 67) and hospital 66 mg (CI 59, 72). The mean (SD) time from administration of 1st analgesic dose to discharge from the ED was 203 (143) minutes, (range = 30-1396 minutes). During two visits, patients experienced a RR <10; while 61 visits were associated with a SPO2 <92%. No medications were administered, or resuscitative measures required. Controlling for demographics and evaluated at the average total ED dose, the longer patients were in the ED, patients were 1.359 times more likely to experience an abnormal vital sign. Controlling for demographics and evaluated at the average total time in the ED, for every 10 mg increase in IVMSE, patients were 1.057 times more likely to experience an abnormal vital sign. The effect of ED dose on the odds of experiencing an abnormal vital sign decreased by a multiplicative factor of 0.0970 for every 1 hour increase in time until discharge. The larger the dose administered in less time, the more likely patients experienced an abnormal vital sign.

DISCUSSION

High opioid doses were safely administered to patients with sickle cell disease.

Comparison of pain-relieving effects of fentanyl versus ketorolac after eye amputation surgery

Purpose

To investigate the analgesic effect and incidence of postoperative nausea and vomiting (PONV) between the opioid fentanyl and the non-steroidal anti-inflammatory drug ketorolac in patients who underwent eye amputation surgery.

Methods

Retrospective observational case series. Eighty-two patients underwent evisceration or enucleation surgery by one surgeon over a 2-year period. Fentanyl by intravenous patient-controlled analgesia (IV-PCA) at 20 µg/kg with 12 mg/kg ondansetron or intravenous ketorolac at 2 mg/kg/day was administered to patients at postoperative days 0, 1, and 2. The pain score was measured using an 11-point visual analog scale (VAS). The incidence of severe nausea requiring anti-emetics and the incidence of vomiting were reviewed.

Results

The mean postoperative VAS in the fentanyl group was significantly lower than that in the ketorolac group on the day of operation for both types of surgery (p = 0.001 and p = 0.004, respectively). At postoperative days 1 and 2, the mean VAS was not different between the two groups for either surgical type (p > 0.05 for both days). The mean VAS was significantly higher in eviscerated patients than in enucleated patients at postoperative days 0 and 1 in the fentanyl group (p = 0.023 and p = 0.016, respectively). However, this was not observed in the ketorolac group. The incidence of PONV was higher in the fentanyl group than in the ketorolac group, although this was not statistically significant for either surgical type (p > 0.05 for both groups).

Conclusions

Fentanyl was more effective as an analgesic than was ketorolac on the day of operation for both surgical types. There was no difference between the two analgesics on postoperative day 1. The analgesic effect of fentanyl in enucleated patients was significantly higher than in eviscerated patients at postoperative days 0 and 1. The use of fentanyl by IV-PCA was associated with greater PONV despite co-administration with anti-emetics, although this finding was not significant.

The 90% effective dose of a sufentanil bolus for the management of painful positioning in intubated patients in the ICU

CONTEXT

Pain and discomfort arising from the routine care of intubated patients in the ICU is managed by continuous infusion of narcotic and sedative drugs. There is benefit in keeping infusion rates low because lightening sedation improves clinical outcome, but this risks breakthrough pain. Management of this discomfort by bolus administration could permit lower background infusion rates, but the lowest effective bolus dose of sufentanil to achieve this is unknown.

OBJECTIVE

The aim of this study was to determine the effective analgesic dose in 90% of intubated patients (ED90) in the ICU given bolus sufentanil. Pain was assessed using a Behavioural Pain Scale (BPS) requiring a score of 3-4 during moving to the lateral decubitus position.

DESIGN

Prospective, dose response study.

SETTING

A 16-bed multidisciplinary ICU in a French university hospital. Study period was from January to June 2010.

PATIENTS

Intubated and ventilated patients were eligible for the study once they had reached a BPS of 3 or 4 and Ramsay score of 3-5 within 48 h of admission to the ICU.

INTERVENTION

The analgesic efficacy of a sufentanil bolus was measured during successive lateral decubitus positioning over a 72-h study period, using the BPS scale. The dose was increased with each subsequent turn to lateral decubitus until a BPS score of 3-4 was obtained (dose escalation, starting at zero).

MAIN OUTCOME MEASURES

BPS, Ramsay score, heart rate and mean arterial pressure were collected before and during each procedure.

RESULTS

A total of 25 patients were enrolled over 6 months. The ED90 bolus for sufentanil was 0.15 μg kg, but 40% of the patients subsequently demonstrated increased BPS with this dose.

CONCLUSION

The effective dose in 90% was 0.15 μg kg during the first 5 days of sedation. There were no adverse effects. A pre-emptive sufentanil bolus can be used to treat anticipated pain in the ICU. Regular and frequent assessments of acute pain and sedation are essential for adjusting the dose, on a case-by-case basis. This strategy may help clinicians to keep background infusions of sedatives and narcotics as low as possible and may improve clinical outcome.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01356732.

Efficacy of patient-controlled analgesia for patients with acute abdominal pain in the emergency department: a randomized trial

OBJECTIVES

The objective was to assess the efficacy of patient-controlled analgesia (PCA) in the emergency department (ED) and to compare two PCA dosing regimens.

METHODS

A randomized controlled trial with three treatment arms was performed in an urban ED. A convenience sample of ED patients ages 18 to 65 years with abdominal pain of 7 days or less duration requiring intravenous (IV) opioid analgesia was enrolled between April 2009 and June 2010. All patients received an initial dose of 0.1 mg/kg IV morphine followed by physician-managed analgesia as needed. Patients in the PCA arms also received IV morphine with on-demand doses of 1 or 1.5 mg, with a 6-minute lockout between doses. Pain intensity was rated by patients on an 11-point numeric rating scale (NRS). Satisfaction with pain treatment, desire for the same treatment in the future, and need for additional analgesia were assessed at study end. Adverse events (O(2) sat < 92%, respiratory rate [RR] < 10/min, systolic blood pressure [sBP] < 90 mm Hg, and naloxone use) were counted. One-way analysis of variance was used to test the difference among groups in short-term pain relief, as assessed by mean change in NRS pain intensity from baseline to 30 minutes and pain over the entire 2-hour study period measured by area under the curve (AUC) of NRS pain ratings. A post hoc hierarchical linear model was used to test the observed difference in NRS between the groups between 30 and 120 minutes.

RESULTS

A total of 211 patients were enrolled. A sharp, nearly identical decline in mean NRS scores occurred from baseline to 30 minutes in the three groups (p = 0.82). Between 30 and 120 minutes, there was little further decline in the non-PCA NRS scores, while both PCA groups continued to decline (p = 0.004). The net treatment effect over the entire 2 hours was smallest in the non-PCA group and largest in the group receiving 1.5 mg of morphine (p = 0.06). The mean decline in pain from baseline to 120 minutes postbaseline in both PCA groups was 1.4 NRS units (95% confidence interval [CI] = 0.3 to 2.4) greater than the decline in patients treated without PCA. More patients in the PCA arms reported satisfaction, wanting the same pain management in the future, and not wanting further analgesics at 120 minutes than patients who did not receive PCA. There were no clinically or statistically significant differences in any outcomes between the two PCA groups. One PCA patient had a transient oxygen saturation of 88% after the initial bolus only, and one non-PCA patient had a brief drop in sBP to 87 mm Hg.

CONCLUSIONS

This study provides support for efficacy of PCA when applied to the ED setting. Future studies designed to assess implementation of this modality in the context of conditions of actual ED staffing and competing patient demands are warranted.

Parenteral opioids in emergency medicine - A systematic review of efficacy and safety

Introduction and aim Pain is a frequent symptom in emergency patients and opioids are commonly used to treat it at emergency departments and at pre-hospital settings. The aim of this systematic review is to examine the efficacy and safety of parenteral opioids used for acute pain in emergency medicine. Method Qualitative review of randomized controlled trials (RCTs) on parenteral opioids for acute pain in adult emergency patients. Main outcome measures were: type and dose of the opioid, analgesic efficacy as compared to either placebo or another opioid and adverse effects. Results Twenty double-blind RCTs with results on 2322 patients were included. Seven studies were placebo controlled. Majority of studies were performed in the emergency department. Only five studies were in prehospital setting. Prehospital studies Four studies were on mainly trauma-related pain, one ischemic chest pain. One study compared two different doses of morphine in mainly trauma pain showing faster analgesia with the larger dose but no difference at 30 min postdrug. Three other studies on the same pain model showed equal analgesic effects with morphine and other opioids. Alfentanil was more effective than morphine in ischemic chest pain. Emergency department studies Pain models used were acute abdominal pain seven, renal colic four, mixed (mainly abdominal pain) three and trauma pain one study. Five studies compared morphine to placebo in acute abdominal pain and in all studies morphine was more effective than placebo. In four out of five studies on acute abdominal pain morphine did not change diagnostic accuracy, clinical or radiological findings. Most commonly used morphine dose in the emergency department was 0.1 mg/kg (five studies). Other opioids showed analgesic effect comparable to morphine. Adverse effects Recording and reporting of adverse effects was very variable. Vital signs were recorded in 15 of the 20 studies (including all prehospital studies). Incidence of adverse effects in the opioid groups was 5-38% of the patients in the prehospital setting and 4-46% of the patients in the emergency department. Nausea or vomiting was reported in 11-25% of the patients given opioids. Study drug was discontinued because of adverse effects five patients (one placebo, two sufentanil, two morphine). Eight studies commented on administration of naloxone for reversal of opioid effects. One patient out of 1266 was given naloxone for drowsiness. Ventilatory depression defined by variable criteria occurred in occurred in 7 out of 756 emergency department patients. Conclusion Evidence for selection of optimal opioid and dose is scarce. Opioids, especially morphine, are effective in relieving acute pain also in emergency medicine patients. Studies so far are small and reporting of adverse effects is very variable. Therefore the safety of different opioids and doses remains to be studied. Also the optimal titration regimens need to be evaluated in future studies. The prevention and treatment of opioid-induced nausea and vomiting is an important clinical consideration that requires further clinical and scientific attention in this patient group.