The use of subdissociative-dose ketamine for acute pain in the emergency department

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.

Low-dose short infusion ketamine as adjunct to morphine for acute long bone fracture in the emergency department: a randomized controlled trial

BACKGROUND

Ketamine is recognized as an alternative for pain management; however, concerns about emergent adverse reactions have limited its widespread adoption. This study aimed to assess the efficacy of a short infusion of low-dose ketamine (LDK) compared to intravenous morphine (MOR) as adjunctive analgesia for acute long bone fracture pain.

METHODS

This single-blinded, randomized controlled trial was conducted in a single emergency department. Patients with acute long bone fractures and numerical rating scale (NRS) pain scores ≥ 6 following an initial dose of intravenous morphine were assigned to receive either a LDK (0.3 mg/kg) over 15 min or intravenous MOR at a dose of 0.1 mg/kg administered over 5 min. Throughout a 120-min observation period, patients were regularly evaluated for pain level (0-10), side effects, and the need for additional rescue analgesia.

RESULTS

A total of 58 subjects participated, with 27 in the MOR group and 31 in the LDK group. Demographic variables and baseline NRS scores were comparable between the MOR (8.3 ± 1.3) and LDK (8.9 ± 1.2) groups. At 30 min, the LDK group showed a significantly greater mean reduction in NRS scores (3.1 ± 2.03) compared to the MOR group (1.8 ± 1.59) (p = 0.009). Similarly, at 60 min, there were significant differences in mean NRS score reductions (LDK 3.5 ± 2.17; MOR mean reduction = 2.4, ± 1.84) with a p-value of 0.04. No significant differences were observed at other time intervals. The incidence of dizziness was higher in the LDK group at 19.4% (p = 0.026).

CONCLUSION

Short infusion low-dose ketamine, as an adjunct to morphine, is effective in reducing pain during the initial 30 to 60 min and demonstrated comparability to intravenous morphine alone in reducing pain over the subsequent 60 min for acute long bone fractures. However, it was associated with a higher incidence of dizziness.

TRIAL REGISTRATION

NMRR17318438970 (2 May 2018; www.nmrr.gov.my ).

Narrative Review: Low-Dose Ketamine for Pain Management

Pain is the leading cause of medical consultations and occurs in 50-70% of emergency department visits. To date, several drugs have been used to manage pain. The clinical use of ketamine began in the 1960s and it immediately emerged as a manageable and safe drug for sedation and anesthesia. The analgesic properties of this drug were first reported shortly after its use; however, its psychomimetic effects have limited its use in emergency departments. Owing to the misuse and abuse of opioids in some countries worldwide, ketamine has become a versatile tool for sedation and analgesia. In this narrative review, ketamine's role as an analgesic is discussed, with both known and new applications in various contexts (acute, chronic, and neuropathic pain), along with its strengths and weaknesses, especially in terms of psychomimetic, cardiovascular, and hepatic effects. Moreover, new scientific evidence has been reviewed on the use of additional drugs with ketamine, such as magnesium infusion for improving analgesia and clonidine for treating psychomimetic symptoms. Finally, this narrative review was refined by the experience of the Pain Group of the Italian Society of Emergency Medicine (SIMEU) in treating acute and chronic pain with acute manifestations in Italian Emergency Departments.

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.

Incidence of Dissociation With Low-Dose Pre-hospital Ketamine in Geriatric Patients With Trauma-Related Pain

Introduction

Sub-dissociative ketamine has been used increasingly for the treatment of acute pain in a wide variety of settings. While there are studies evaluating its use in the geriatric population, no studies have described its safety in the pre-hospital geriatric trauma patient. The objective of this study was to define the incidence of dissociation with low-dose pre-hospital ketamine in geriatric trauma patients.

Methods

Using our county emergency medical services database, we identified all trauma patients greater or equal to 65 years of age who received pre-hospital ketamine for pain after the implementation of a low-dose ketamine protocol. We retrospectively reviewed pre-hospital and emergency department records for demographics, traumatic injuries, Glasgow Coma Score, emergency department length of stay and disposition, and hospital length of stay. This group was compared to a similar population of trauma patients, transported prior to the ketamine protocol. The comparison group was chosen by matching the ketamine group to more than double the number of non-ketamine patients. Records were obtained from two separate trauma centers. Our primary outcome was documentation of “ketamine-related dissociation” by either the pre-hospital, emergency department or trauma provider. Secondary outcomes included emergency department length of stay and intensive care unit admission.

Results

Seventy-nine patients received ketamine with records available for analysis. One hundred ninety-three non-ketamine patients were compared to this group. There were nosignificant differences between the two groups in regards to age, weight, gender, or mechanism of injury. The injury severity score was higher in the ketamine group. Nine patients (11%) had documented dissociation after ketamine, with six of these patients back to baseline mentation by arrival to the emergency department. The emergency department length of stay was shorter in the ketamine group. The rate of intensive care unit admission was the same between both groups.

Conclusions

Pre-hospital sub-dissociative ketamine in geriatric trauma patients is associated with brief episodes of dissociation in a small minority of patients.

A Case Report of Subanesthetic Ketamine Bolus and Infusion for Opioid Refractory Cancer Pain

Opioids and traditional adjuvant medications are frequently prescribed for the management of moderate to severe cancer pain with good effect. However, there are many cases, in which patients experience severe opioid refractory cancer pain. Ketamine is being used more frequently in the hospice and palliative setting to manage opioid refractory pain, although high-quality evidence regarding its effectiveness is lacking. It seems certain patients respond favorably to ketamine, while others experience no effect. Studies have not yet identified factors associated with a favorable response to ketamine. We present a case describing the successful treatment of high-dose opioid refractory cancer pain with a subanesthetic ketamine infusion and propose the novel use of a preinfusion test bolus of ketamine to identify patients who are likely to respond favorably to an infusion.

A randomized, noninferiority, controlled trial of two doses of intravenous subdissociative ketamine for analgesia in the emergency department

OBJECTIVE

This study aimed to determine if 0.15 mg/kg intravenous (IV) subdissociative ketamine is noninferior to 0.3 mg/kg in emergency department (ED) patients with acute pain.

METHODS

This randomized, prospective, double-blinded, noninferiority trial included patients' age 18 to 59 years presenting to the ED with acute moderate to severe pain. Subjects were randomized to IV subdissociative ketamine, 0.15 mg/kg ("low" dose) or 0.30 mg/kg ("high" dose), over 15 minutes. The primary endpoint was the 11-point numeric rating scale (NRS) pain score between groups at 30 minutes. Secondary endpoints included NRS pain scores at 15 and 60 minutes; change in NRS at 15, 30, and 60 minutes; rescue analgesia; and adverse effects. The noninferiority limit, δ₀ , was set to 1.3.

RESULTS

Forty-nine patients were included in each group. After the differences in the baseline NRS score were adjusted for, the mean NRS score at 30 minutes was 4.7 (95% confidence interval [CI] = 3.8 to 5.5) in the low-dose group and 5.0 (95% CI = 4.2 to 5.8) in the high-dose group (mean difference = 0.4, 95% CI = -0.8 to 1.5), indicating that the low-dose subdissociative ketamine was noninferior to the high dose (lower limit of 95% CI = -0.8 to ≥1.3 = -δ₀ ). Adverse effects were similar at 30 minutes. At 15 minutes, the high-dose group experienced greater change in NRS; however, more adverse effects occurred.

CONCLUSION

Our data did not detect a large difference in analgesia or adverse effect profile between 0.15 mg/kg IV ketamine and 0.30 mg/kg in the short-term treatment of acute pain in the ED.

Low-dose Ketamine For Acute Pain Control in the Emergency Department: A Systematic Review and Meta-analysis

OBJECTIVE

There has been increased interest in the use of low-dose ketamine (LDK) as an alternative analgesic for the management of acute pain in the emergency department (ED). The objective of this systematic review was to compare the analgesic effectiveness and safety profile of LDK and morphine for acute pain management in the ED.

METHODS

Electronic searches of Medline and EMBASE were conducted and reference lists were hand-searched. Randomized controlled trials (RCTs) comparing LDK to morphine for acute pain control in the ED were included. Two reviewers independently screened abstracts, assessed quality of the studies, and extracted data. Data were pooled using random-effects models and reported as mean differences and risk ratios (RRs) with 95% confidence intervals (CIs). We used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the certainty of the evidence.

RESULTS

Eight RCTs were included with a total of 1,191 patients (LDK = 598, morphine = 593). There was no significant difference in reported mean pain scores between LDK and morphine within the first 60 minutes after analgesia administration and a slight difference in pain scores favoring morphine at 60 to 120 minutes. The need for rescue medication was also similar between groups (RR = 1.26, 95% CI = 0.50 to 3.16), as was the proportion of patients who experienced nausea (RR = 0.97, 95% CI = 0.63 to 1.49) and hypoxia (RR = 0.38, 95% CI = 0.10 to 1.41). All outcomes were judged to have low certainty in the evidence.

CONCLUSION

Low-dose ketamine and morphine had similar analgesic effectiveness within 60 minutes of administration with comparable safety profiles, suggesting that LDK is an effective alternative analgesic for acute pain control in the ED.

Ketamine for pain control of snake envenomation in Guinea: A case series

Snakebite envenomation is a global health crisis and is classified as a Category A neglected tropical disease by the World Health Organization (WHO). Snakebite envenomations account for a significant amount of morbidity and morbidity in tropical and subtropical regions. Recently, publications have illustrated the potential for snake envenomations causing post-traumatic stress disorder (PTSD) in a significant number of patients. Ketamine is on the WHO's list of essential medications and is used for a variety of pharmacologic applications including anesthesia and acute pain management. To date it has not been assessed for pain control in snakebite envenomations. Twelve patients who presented with severe pain secondary to Bitis, Causus, and Atractaspis envenomations were treated with low-dose intravenous ketamine. The patients included 7 males and 5 females with a median age of 37.5 (range 14-64) and a median presentation time of 5.75 h (range 5 min-96 h) after the initial bite occurred. Ten envenomations were presumed to have been caused by Bitis species resulting in extensive swelling and blistering of the affected extremities. One envenomation was presumedC. maculatus causing local swelling and pain. One envenomation was a presumed Atractaspis species causing significant local pain with minimal swelling. All patients expressed having significant pain but could not express the degree of their pain using an analogue pain scale. An initial median dose of 5 mg of ketamine (range 2.5-15 mg) was administered intravenously for pain control. Every patient expressed decreased pain and felt more comfortable within 1 min after administration of ketamine. Nine of the twelve patients only required a single dose. There were no adverse side effects. Ketamine appears to be an effective means of pain control for those suffering from painful envenomations. With minimal risk of significant side effects at acute pain management doses and the average cost per effective dose averaging between US$0.03-0.06, this may provide a cheap, safe, and effective solution for Sub-saharan Africa and other resource-limited settings. Controlled studies need to be done to critically assess our observations.

Transient amnesia following prehospital low-dose ketamine administration

Low doses of ketamine have been shown to be safe and effective for pain relief. Adverse effects are generally mild and transient. A 69-year-old woman suffered a witnessed ground-level fall without report of head injury, loss of consciousness, or intoxication. She was in severe pain despite 10 mg of intravenous morphine and paramedics provided intravenous ketamine 16 mg (0.19 mg/kg). Upon arrival to the ED, she was alert and oriented. An X-ray demonstrated an acute comminuted nondisplaced right humeral head and neck fracture. Her pain improved after an additional 4 mg of morphine and placement of a sling. Prior to discharge, the patient developed confusion, difficulty finding words, amnesia to the event, and anterograde amnesia evidenced by repetitive questioning. A head CT and a CT angiogram of the patient's head and neck demonstrated no acute abnormalities and an EEG demonstrated no epileptiform activity. The patient was admitted for observation and her mental status gradually improved overnight. She was discharged the following morning. Low dose ketamine is an important therapeutic option. Delayed or prolonged neuropsychiatric effects may be possible following combined ketamine and opioid analgesia. Clinicians utilizing low dose ketamine should be aware of this potential complication as it could result in the need for additional diagnostic testing and prolonged length of stay.

Hot Off the Press: A Systematic Review And Meta-analysis of Ketamine as an Alternative to Opioids for Acute Pain in the Emergency Department

Ketamine has been studied as an alternative to opioids for acute pain in the emergency department setting. This review compares the effectives of intravenous ketamine at a dose of <0.5mg/kg to opioids for acute pain in adult patients. Measurements were taken within 60 minutes of administration. Ketamine was found to have similar effectiveness to opioids. Increased, but short-lived, side effects were seen with ketamine.

Low-Dose Oral Ketamine for Procedural Analgesia in Pediatric Cancer Patients Undergoing Lumbar Puncture at a Resource-Limited Cancer Hospital in India

Aim: The aim of this study was to evaluate the therapeutic efficacy and safety profile of orally administered low-dose ketamine for procedural pain management in pediatric cancer patients undergoing lumbar puncture (LP) in a resource-limited hospital setting. Methods: Patients between 4 and 15 years of age, with leukemia, undergoing LP were asked to participate. The study was designed as a two-armed blinded placebo-controlled trial where 0.8 mg/kg (bodyweight) of ketamine mixed in juice was given 30 minutes before the procedure to Group K (ketamine) compared with placebo, only juice, to Group P (placebo). In addition, topical analgesia (EMLA^®) was given according to established standard of care. Patients and caregivers assessed the pain using the Wong-Baker Faces Pain Rating Scale. Results: A total number of 52 patients, equally distributed between Group K and Group P, were included in the study. The placebo-controlled group had significantly higher self-reported pain score than the group receiving ketamine (p = 0.046), as well as in caregiver-assessed pain (p = 0.033). Only three incidents of mild adverse effects were reported. Conclusion: Low-dose oral ketamine can be safely administered for procedural analgesia in pediatric cancer patients undergoing LP in a resource-limited hospital setting and have significant pain-reducing effect compared with placebo.

Subdissociative Ketamine Use in the Emergency Department

Ketamine is an anesthetic known globally both for its potent dissociative properties and potential for abuse. More recently, ketamine demonstrates utility in a variety of disease states such as treatment-resistant depression, status asthmaticus, and acute agitation. In addition, ketamine has been shown to demonstrate various effects at different doses, which adds to its pharmacological benefit. As these new indications continue to come to light, it is important to stay current with the dosing for these indications as well as the adverse effects associated with ketamine's use. This review highlights the history and mechanism of ketamine as well as addressing the use of the different dosing ranges of ketamine.

Implementation of an Advanced Pharmacy Practice Model in the Emergency Department

STUDY OBJECTIVE

The objective of this retrospective descriptive study was to quantify clinical activities performed by pharmacists in an advanced pharmacy practice model in the emergency department (ED).

METHODS

Data from January 2015 to August 2017 extracted from the department of pharmacy's electronic documentation system and the hospital's electronic medical record were collected and reviewed. Cost savings was derived from the system with adaptation from the previous literature and had been validated by our institution's administration as an acceptable reflection of the impact for activity.

RESULTS

The ED pharmacy team participated in a total of 4106 clinical activities that resulted in a cumulative cost avoidance of $5 387 679. Overall, the most common clinical activities that the pharmacy team provided included pharmacotherapy consult (63.3%) and response to medical emergencies (20.7%). A total of 16 219 medication orders placed by ED clinicians were prospectively reviewed and 379 interventions were accepted by ED clinicians. Turnaround times for medication verification in median (interquartile range [IQR]) for 2015, 2016, and 2017 were 2 minutes (1-6 minutes), 3 minutes (1-6 minutes), and 2 minutes (1-5 minutes), respectively. A total of 14 peer-reviewed publications, primarily based on pharmacy practice or use of pharmacotherapy for acute pain, were published by a research program led by the ED pharmacotherapist.

CONCLUSION

We created and implemented an advanced practice model tailored to our institution's needs. The model maximized opportunities for pharmacists to provide direct patient care, practice at the top of their license, and encouraged the safe and effective use of medications.

A Systematic Review and Meta-analysis of Ketamine as an Alternative to Opioids for Acute Pain in the Emergency Department

BACKGROUND

Opioids are commonly prescribed in the emergency department (ED) for the treatment of acute pain. Analgesic alternatives are being explored in response to an epidemic of opioid misuse. Low-dose ketamine (LDK) is one opioid alternative for the treatment of acute pain in the ED.

OBJECTIVES

This systematic review and meta-analysis sought to quantify whether LDK is an effective and safe opioid alternative for acute pain reduction in adults in the ED setting. (PROSPERO Registration Number CRD42017065303).

METHODS

This was a systematic review of randomized controlled trials comparing intravenous opioids to LDK for relief of acute pain in the ED. Studies where the control group initially received opioids prior to ketamine were excluded. A research librarian designed the electronic search strategy. Changes in visual analog scale or numeric rating scale pain scales were analyzed to determine the relative effects of LDK and opioids in the treatment of acute pain.

RESULTS

Three studies met the criteria for inclusion in this meta-analysis. Compared to pain scale reduction with morphine, ketamine was not inferior (relative reduction = 0.42, 95% confidence interval = -0.70 to 1.54). No severe adverse events were reported in any study, but higher rates of nonsevere adverse events were observed with ketamine.

CONCLUSIONS

Ketamine is noninferior to morphine for the control of acute pain, indicating that ketamine can be considered as an alternative to opioids for ED short-term pain control.

Intravenous Low-Dose Ketamine Provides Greater Pain Control Compared to Fentanyl in a Civilian Prehospital Trauma System: A Propensity Matched Analysis

Objective: A few studies report comparable analgesic efficacy between low-dose ketamine and opioids such as morphine or fentanyl; however, limited research has explored the safety and effectiveness of intravenous low-dose ketamine as a primary analgesic in a civilian prehospital setting. The objective of this study is to compare pain control between low-dose ketamine and fentanyl when administered intravenously (IV) for the indication of severe pain. Methods: This was a retrospective, observational review of prehospital adult patients (≥18 years) who presented with severe pain (numeric rating scale, 7-10) and were treated solely with either low-dose ketamine IV or fentanyl IV between January 1, 2014 and December 31, 2016. Propensity matched analysis was performed adjusting for all baseline variables with p ≤ 0.10 and for baseline pain score to match ketamine and fentanyl patients on a one-to-one ratio. The primary outcome was change in pain score from baseline to after treatment and evaluated with a paired t-test. Secondary outcomes were changes in vital signs and Glasgow coma scale (GCS) from baseline to after treatment, as well as incidence of clinically significant adverse events (AEs); AEs were followed from scene arrival through emergency department discharge. Results: Propensity matched analysis produced 79 matched pairs. Ketamine IV patients, receiving a mean (SD) dose of 0.3 (0.1) mg/kg, showed a significantly larger mean decrease in pain after treatment, compared to the fentanyl IV patients (-5.5 (3.1) vs. -2.5 (2.4), p < 0.001). A significantly greater proportion of patients receiving ketamine IV achieved at least a 50% reduction in pain compared to those receiving fentanyl IV (67% vs. 19%, p < 0.001), marking 52 ketamine IV patients as responders to treatment. Vital signs demonstrated a nonsignificant decrease in blood pressure, respiratory rate, heart rate, and GCS. No clinically significant AEs were reported for patients receiving ketamine IV. Conclusion: The significant reduction in pain, significantly high proportion of ketamine responders, and the lack of clinically significant AEs characterizing patients receiving low-dose ketamine IV compared to fentanyl IV, all provide further support for its use as an effective prehospital analgesic. Level of Evidence: Level III, therapeutic.

Acute Pain Management in Emergency Department, Low Dose Ketamine Versus Morphine, A Randomized Clinical Trial

Background

Ketamine, as an opium alternative, has been proposed for pain relief in the emergency department (ED).

Objectives

This study was carried out to compare low dose ketamine (LDK) with morphine for pain relief in trauma patients.

Methods

In this randomized double-blinded clinical trial, 300 trauma patients from the ED of 2 teaching hospitals in Tehran, Iran were enrolled and randomly divided into 2 equal groups. The 1st group received 0.2 mg/kg of ketamine while the 2nd group received 0.1 mg/kg of intravenous morphine. The pain intensity and complications were measured and compared every 15 minutes to 1 hour.

Results

Fifteen minutes after drug injection in both groups, a significant reduction was found in average pain intensity compared to the initial pain (P = 0.01). At 15 minutes, no significant difference was found in both groups in regards to average pain intensity (P = 0.23). The average pain intensity at 30, 45, and 60 minutes in the group receiving morphine was lower than the ketamine group (P = 0.01, P < 0.001, P < 0.001 respectively). Two complications (drop in O₂ saturation below 90% and flushing) were significantly greater in the morphine group.

Conclusions

The results of this study suggest that LDK, at a dose of 0.2 mg/kg, in the earlier minutes leads to significant reduction of pain when compared to that of intravenous morphine. It also created fewer complications than morphine.

Randomized Controlled Feasibility Trial of Intranasal Ketamine Compared to Intranasal Fentanyl for Analgesia in Children with Suspected Extremity Fractures

OBJECTIVES

We compared the tolerability and efficacy of intranasal subdissociative ketamine to intranasal fentanyl for analgesia of children with acute traumatic pain and investigated the feasibility of a larger noninferiority trial that could investigate the potential opioid-sparing effects of intranasal ketamine.

METHODS

This randomized controlled trial compared 1 mg/kg intranasal ketamine to 1.5 μg/kg intranasal fentanyl in children 4 to 17 years old with acute pain from suspected isolated extremity fractures presenting to an urban Level II pediatric trauma center from December 2015 to November 2016. Patients, parents, treating physicians, and outcome assessors were blinded to group allocation. The primary outcome, a tolerability measure, was the frequency of cumulative side effects and adverse events within 60 minutes of drug administration. The secondary outcomes included the difference in mean pain score reduction at 20 minutes, the proportion of patients achieving a clinically significant reduction in pain in 20 minutes, total dose of opioid pain medication in morphine equivalents/kg/hour (excluding study drug) required during the emergency department (ED) stay, and the feasibility of enrolling children presenting to the ED in acute pain into a randomized trial conducted under U.S. regulations. All patients were monitored until 6 hours after their last dose of study drug or until admission to the hospital ward or operating room.

RESULTS

Of 629 patients screened, 87 received the study drug and 82 had complete data for the primary outcome (41 patients in each group). The median (interquartile range) age was 8 (6-11) years and 62% were male. Baseline pain scores were similar among patients randomized to receive ketamine (73 ± 26) and fentanyl (69 ± 26; mean difference [95% CI] = 4 [-7 to 15]). The cumulative number of side effects was 2.2 times higher in the ketamine group, but there were no serious adverse events and no patients in either group required intervention. The most common side effects of ketamine were bad taste in the mouth (37; 90.2%), dizziness (30; 73.2%), and sleepiness (19; 46.3%). The most common side effects of fentanyl were sleepiness (15; 36.6%), bad taste in the mouth (9; 22%), and itchy nose (9; 22%). No patients experienced respiratory side effects. At 20 minutes, the mean pain scale score reduction was 44 ± 36 for ketamine and 35 ± 29 for fentanyl (mean difference = 9 [95% CI = -4 to 23]). Procedural sedation with ketamine occurred in 28 ketamine patients (65%) and 25 fentanyl patients (57%) prior to completing the study.

CONCLUSIONS

Intranasal ketamine was associated with more minor side effects than intranasal fentanyl. Pain relief at 20 minutes was similar between groups. Our data support the feasibility of a larger, noninferiority trial to more rigorously evaluate the safety, efficacy, and potential opioid-sparing benefits of intranasal ketamine analgesia for children with acute pain.

Ketamine for pain

The efficacy of the N-methyl-D-aspartate receptor antagonist ketamine as an analgesic agent is still under debate, especially for indications such as chronic pain. To understand the efficacy of ketamine for relief of pain, we performed a literature search for relevant narrative and systematic reviews and meta-analyses. We retrieved 189 unique articles, of which 29 were deemed appropriate for use in this review. Ketamine treatment is most effective for relief of postoperative pain, causing reduced opioid consumption. In contrast, for most other indications (that is, acute pain in the emergency department, prevention of persistent postoperative pain, cancer pain, and chronic non-cancer pain), the efficacy of ketamine is limited. Ketamine's lack of analgesic effect was associated with an increase in side effects, including schizotypical effects.

Systematic review of the use of low-dose ketamine for analgesia in the emergency department

Objectives

The aim of the study is to determine the performance of low-dose ketamine (LDK) as an analgesic for acute pain management in adult patients in the emergency department (ED).

Methods

We systematically reviewed electronic databases, grey literature, conference abstracts, and clinical trial registries. Two independent reviewers identified eligible studies. These selections were subsequently reviewed by one reviewer who identified the final eligible studies, using refined inclusion and exclusion criteria. Our outcome measures included the analgesic effect of LDK, need for rescue analgesia, and neuropsychological adverse events secondary to LDK use. We assessed inter-rater agreement using kappa statistics and proposed a treatment recommendation using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) software. Heterogeneity among studies precluded meta-analysis.

Results

Our electronic search identified 1,408 records; 44 were selected for full evaluation (kappa=0.70), and 8 were included after the final review. All six randomized controlled trials and two observational studies were set in the ED where LDK was administered to adult patients ( >18 years old) exclusively for pain management. All studies had an overall low risk of bias. There was extensive variation in the dose and route of LDK used (0.1-0.7 mg/kg SC/IV/IM), administration protocols, and use of adjunct analgesia. Overall, most studies reported a significant analgesic effect of LDK with occasional need for rescue analgesia and mild-to-moderate adverse events (dizziness, dysphoria, and confusion).

Conclusion

There are moderate to low quality data supporting LDK as an alternative analgesic in the ED with the potential for minimal requirement of rescue analgesia and self-limited neuropsychological adverse events.

Low dose ketamine use in the emergency department, a new direction in pain management

There is a need for alternative non-opioid analgesics for the treatment of acute, chronic, and refractory pain in the emergency department (ED). Ketamine is a fast acting N-methyl-d-aspartate (NMDA) receptor antagonist that provides safe and effective analgesia. The use of low dose ketamine (LDK) (<1mg/kg) provides sub-dissociative levels of analgesia and has been studied as an alternative and/or adjunct to opioid analgesics. We reviewed 11 studies using LDK either alone or in combination with opioid analgesics in the ED. Ketamine was shown to be efficacious at treating a variety of painful conditions. It has a favorable adverse effect profile when given at sub-dissociative doses. Studies have also compared LDK to opioids in the ED. Although ketamine's analgesic effects were not shown to be superior, they were comparable to opioids. LDK has the benefit of causing less respiratory depression. It likely has less wide spread potential for abuse. Nursing protocols for the administration of LDK have been studied. We believe that LDK has the potential to be a safe and effective alternative and/or adjunct to opioid analgesics in the ED. Additional studies are needed to expand upon and determine the optimal use of LDK in the ED.

BET 2: Low-dose ketamine for acute pain in the ED

A short cut review was carried out to establish whether low-dose ketamine is better than morphine at safely and effectively reducing pain scores in ED patients with acute pain who do not respond to conventional therapies. One hundred and thirty-two papers were found using the reported searches, of these three presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. It is concluded that the evidence is limited, but that ketamine can be an effective alternative or adjunct to intravenous opioid pain medications and in some instances may provide more effective pain relief when compared with opioids.

The Effects of Low-Dose Ketamine on Acute Pain in an Emergency Setting: A Systematic Review and Meta-Analysis

OBJECTIVES

Currently ketamine is not used often as an analgesic in the emergency department (ED). Nonetheless, it can increase the efficiency of opioids and decrease their side effects. The purpose of this systematic review and meta-analysis was to evaluate whether low-dose ketamine in the ED provides better analgesia with fewer adverse effects.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched by two reviewers independently (last search performed on January 2016). Data were also extracted independently.

RESULTS

A total of 6 trials involving 438 patients were included in the current analysis. Our subgroup analysis of pain reduction indicates that the favorable effects of ketamine were similar or superior to those of placebo or opioids, although these effects were heterogeneous. However, low-dose ketamine was associated with a higher risk of neurological (relative risk [RR] = 2.17, 95% confidence interval [CI] = 1.37-3.42, P < 0.001) and psychological events (RR = 13.86, 95% CI = 4.85-39.58, P < 0.001). In contrast, the opioid group had a higher risk of major cardiopulmonary events (RR = 0.22, 95% CI = 0.05-1.01, P = 0.05).

CONCLUSIONS

The efficiency of ketamine varies depending on the pain site, but low-dose ketamine may be a key agent for pain control in the ED, as it has no side effects. It may also help to reduce the side effects of opioids.

HEMS in Alpine Rescue for Pediatric Emergencies

OBJECTIVE

The objective of this study was to describe the pediatric emergencies encountered by the Christophorus-1 helicopter emergency medical service (HEMS) during a period of 2 years.

METHODS

Emergency treatment of pediatric casualties by HEMS was evaluated at a helicopter base. Children up to 14 years who were treated by HEMS emergency physicians from Christophorus-1 during primary missions in the alpine region were retrospectively enrolled.

RESULTS

Of the 1314 HEMS operations conducted during a 2-year investigation period, pediatric emergencies accounted for 114 (8.7%). Trauma was the most common emergency indication (91.3%) in alpine areas, and 77.5% of the indications were related to skiing and snowboarding; 11.3% of the prehospital pediatric emergencies were classified as life-threatening. Interventions on site were rendered in 46.3% of cases. Mean and SD intervals for approach were 11.0 ± 3.0 minutes; for treatment, 14.0 ± 6.0 minutes; and for transport, 8.0 ± 4.0 minutes. Intervals on site were significantly longer whenever it was necessary to search for an interim landing place (P < .001) or perform rope extrication (P < .001). Aggravating environmental conditions such as low temperature (78.8%), rocky terrain (18.8%), or precipitation (12.5%) were common.

CONCLUSIONS

Rapid procedures are preferred to sustained on-scene treatment, particularly when surrounding conditions are hostile. HEMS emergency physicians attempt to keep on-site intervals short and treatment and monitoring to the essential to minimize delay in rescue.

Trends in Opioid Analgesic Use in Encounters Involving Physician Trainees in U.S. Emergency Departments

BACKGROUND

Opioid analgesic use has increased dramatically in emergency departments (EDs), but the relative contribution of physician trainees has not been explored. We assessed trends in opioid utilization focusing on ED encounters where a physician trainee was involved.

METHODS

We studied ED visits from the National Hospital Ambulatory Medical Care Survey, 2001-2011. Adult ED visits in which an opioid was administered in the ED or prescribed at discharge were stratified by whether or not there was trainee involvement. Trends in use over time for five common opioids (codeine, hydrocodone, hydromorphone, morphine, oxycodone) were tested using survey-weighted logistic regression.

RESULTS

From 2001-02 to 2009-11, the proportion of ED visits where an opioid analgesic was used increased 31.5% from 21.9% (95% CI: 20.3-23.6) of visits to 28.8% (95% CI: 27.5-30.1). Trainee involvement in ED visits was stable, with 9.3% (95% CI: 7.7-11.3) seen by a trainee in 2001-02 vs. 10.2% (95% CI: 8.1-12.7) in 2010-11. Opioid use in visits with trainee involvement did not change significantly over time relative to visits without a trainee (increase of 36.8% compared to 31.2% without trainees, P = 0.652). Trends in opioid utilization for trainee visits paralleled non-trainee visits. Hydromorphone had the greatest relative increase in use for all providers. Adjusted for patient- and hospital-level factors, the probability of receiving opioids when a trainee was involved increased to a greater extent than among non-trainee visits (30.9% vs. 24.0%).

CONCLUSION

Opioid utilization patterns for visits involving trainees reflect similar trends in attending practice, and highlights the more liberal opioid prescribing climate over time.