Comparison of Nebulized Ketamine at Three Different Dosing Regimens for Treating Painful Conditions in the Emergency Department: A Prospective, Randomized, Double-Blind Clinical Trial

Low-dose ketamine for acute pain: A narrative review

INTRODUCTION

Acute pain management is a critical component of prehospital and emergency medical care. Opioids are effective; however, the risks and side-effects of opioids have led providers to use low-dose ketamine (LDK) for safe and effective treatment of acute pain.

METHODS

We conducted a scoping narrative review to explore the efficacy of LDK for the treatment of acute pain in the prehospital setting and emergency department (ED) setting. The prehospital review includes studies evaluating the use of LDK in both civilian and military settings. We utilized PubMed to identify prospective and retrospective clinical studies related to this topic. We limited study inclusion to quality prospective and retrospective clinical and observational studies published in the English language prior to January 30, 2024. We did not limit study inclusion based on patient population or mode of administration. We utilized the PRISMA-ScR checklist to conduct this review.

RESULTS

Using our methodology, we found 249 publications responsive to our search strategy. Of these, 178 publications were clearly outside inclusion criteria based on abstract review. Seventy-one studies were sought for retrieval and more detailed review. Of these, 22 records were excluded after review and 43 met initial inclusion criteria. An additional 22 studies were found via snowballing. In total, 64 studies met inclusion criteria for this analysis. 21 studies related to the treatment of acute pain in the prehospital setting, four of which were randomized clinical trials (RCTs). Forty-three studies evaluate the treatment of acute pain in the ED. This included 28 RCTs. Taken together, the studies suggest that LDK is non-inferior to opioids when used alone. When used as an adjunct to opioid therapy, LDK can provide an opioid-sparing effect. Ketamine doses <0.5 mg/kg were not associated with significant side effects.

CONCLUSIONS

LDK is a safe and effective option for acute pain treatment. It can be used as an alternative therapy to opioids or used in conjunction with them to reduce opioid exposure through its opioid-sparing effect. Importantly, LDK is available in a variety of formulations including intramuscular, intravenous, and intranasal, making it an effective acute pain treatment option in both the prehospital and ED settings. LDK holds promise as an emergency treatment in the evolving landscape of acute pain management.

A sequential, multiple-assignment, randomized trial of analgesic strategies for acute musculoskeletal Pain

BACKGROUND

Most methodologically rigorous, ED-based, comparative effectiveness analgesic studies completed in the last two decades failed to find a clinically important difference between the comparators. We believe that many of these comparative effectiveness studies were biased towards the null hypothesis because some ED patients with intense pain will respond to relatively mild interventions. We hypothesized that including a run-in period would alter the results of an acute pain RCT.

METHODS

We conducted a sequential, multiple-assignment, randomized study. Adults with acute moderate/severe musculoskeletal pain were randomized (3:1 ratio) to run-in period or no run-in. We administered 650 mg acetaminophen to run-in participants. Those run-in patients who reported insufficient relief one-hour later were randomized (1:1 ratio) to ibuprofen 800mg PO or ketorolac 20mg PO as were all participants randomized to no run-in. The primary outcome was achieving a clinically important improvement, defined as improvement ≥1.3 on a 0-10 scale. We built a logistic regression model including run-in/no run-in, ketorolac/ibuprofen, age and sex.

RESULTS

Of 307 participants who received acetaminophen, 100 (32.6%) reported inadequate relief and were randomized to an NSAID. Of the 100 patients randomized to no run-in, 84/100 (84%) achieved the primary outcome versus 246/287 (86%) run-in participants (95% CI for difference = 2%:-7,10%). Among run-in participants who received an NSAID, 82/99(83%) achieved the primary outcome versus 84/100(84%) no run-in participants (p = 0.82). Among all ibuprofen participants, 44/49(90%) randomized to run-in and 42/50(84%) randomized to no run-in achieved the primary outcome. Among all ketorolac participants, 38/50(76%) randomized to run-in and 42/50 (84%) randomized to no run-in achieved the primary outcome. We observed the following results in a multivariable analysis: OR for ketorolac versus ibuprofen:0.60 (95% CI: 0.28, 1.28); OR for run-in versus no run-in:0.91(95% CI: 0.43, 1.93).

CONCLUSIONS

Among patients with acute musculoskeletal pain, using an acetaminophen first strategy did not alter pain outcomes.

Anesthesia Management in Emergency and Trauma Surgeries: A Narrative Review

Emergency and trauma surgeries present unique challenges for anesthesiologists due to the acuity of patient conditions and the need for rapid intervention. This review aims to provide insights into the optimal management of anesthesia in emergency and trauma surgery settings. We searched the National Institute of Health PubMed, Scopus, MEDLINE, and Web of Science databases between 2014 and 2024 to synthesize current evidence and best practices for anesthesia management during emergency and trauma surgeries. This literature review examines the evolving role of anesthesia in emergency and trauma surgeries, focusing on key considerations such as patient management, hemodynamic stability, and the choice of anesthetic agents. The review discusses recent advancements in anesthesia techniques, including the use of regional anesthesia and multimodal analgesia, to optimize patient outcomes while minimizing complications. Additionally, it discusses the importance of interdisciplinary collaboration among anesthesiologists, surgeons, and other healthcare professionals in delivering timely and effective care to critically injured patients.

Comparison of Nebulized Ketamine to Intravenous Subdissociative Dose Ketamine for Treating Acute Painful Conditions in the Emergency Department: A Prospective, Randomized, Double-Blind, Double-Dummy Controlled Trial

STUDY OBJECTIVE

We aimed to assess and compare the analgesic efficacy and adverse effects of intravenous subdissociative-dose ketamine to nebulized ketamine in emergency department (ED) patients with acute painful conditions.

METHODS

We conducted a prospective, randomized, double-blind, double-dummy clinical trial in adult patients (ages 18 and older) with a numerical rating scale pain score of ≥5. We randomized subjects to receive either a single dose of 0.3 mg/kg of intravenous (IV) ketamine or 0.75 mg/kg of nebulized ketamine through a breath-actuated nebulizer. Primary outcome was the difference in pain scores on the numerical rating scale between groups at 30 minutes postmedication administration. The secondary outcomes included the need for rescue analgesia, occurrences of adverse events in each group, and the difference in pain scores at 15, 30, 60, 90, and 120 minutes. We calculated a 95% confidence interval (CI) for a mean difference at 30 minutes, with a minimum clinically important difference set at 1.3 points.

RESULTS

We enrolled 150 subjects (75 per group). Mean pain scores through numerical rating scale were 8.2 for both groups at baseline, which decreased to 3.6 and 3.8 at 30 minutes, yielding a mean difference of 0.23 (95% CI -1.32 to 0.857). We observed no clinically concerning changes in vital signs. No serious adverse events occurred in any of the groups throughout the study period.

CONCLUSION

We found no difference between the administration of IV and nebulized ketamine for the short-term treatment of moderate to severe acute pain in the ED, with both treatments providing a clinically meaningful reduction in pain scores at 30 minutes.

Nebulized medications in the emergency department: A narrative review of nontraditional agents

PURPOSE

This article summarizes emerging nontraditional therapies administered via the nebulization route for use in the emergency department (ED).

SUMMARY

Although traditional routes of medication administration (eg, intravenous) have been the mainstay of administration modalities for decades, these routes may not be appropriate for all patients. Nowhere is this more readily apparent than in the ED setting, where patients with a variety of presentations receive care. One unique route for medication administration that has increasingly gained popularity in the ED is that of aerosolized drug delivery. This route holds promise as direct delivery of medications to the site of action could yield a more rapid and effective therapeutic response while also minimizing systemic adverse effects by utilizing a fraction of the systemic dose. Medication administration via nebulization also provides an alternative that is conducive to rapid, less invasive access, which is advantageous in the emergent setting of the ED. This review is intended to analyze the existing literature regarding this route of administration, including the nuances that can impact drug efficacy, as well as the available literature regarding novel, noncommercial nebulized medication therapy given in the ED.

CONCLUSION

Multiple medications have been investigated for administration via this route, and when implementing any of these therapies several practical considerations must be taken into account, from medication preparation to administration, to ensure optimal efficacy while minimizing adverse effects. The pharmacist is an essential bedside team member in these scenarios to assist with navigating unique and complex nuances of this therapy as they develop.

A non-inferiority randomized controlled trial comparing nebulized ketamine to intravenous morphine for older adults in the emergency department with acute musculoskeletal pain

OBJECTIVE

Our study aimed to investigate the analgesic efficacy of nebulized ketamine in managing acute moderate-to-severe musculoskeletal pain in older emergency department (ED) patients compared with intravenous (IV) morphine.

METHODS

This was a non-inferiority, double-blind, randomized controlled trial conducted at a single medical centre. The patients aged 65 and older, who presented at the ED musculoskeletal pain within 7 days and had a pain score of 5 or more on an 11-point numeric rating scale (NRS), were included in the study. The outcomes were a comparison of the NRS reduction between nebulized ketamine and IV morphine 30 minutes after treatment, incidence of adverse events and rate of rescue therapy.

RESULTS

The final study included 92 individuals, divided equally into two groups. At 30 minutes, the difference in mean NRS between the nebulized ketamine and IV morphine groups was insignificant (5.2 versus 5.7). The comparative mean difference in the NRS change from baseline between nebulized ketamine and IV morphine [-1.96 (95% confidence interval-CI: -2.45 to -1.46) and -2.15 (95% CI: -2.64 to -1.66) = 0.2 (95% CI: -0.49 to 0.89)] did not exceed the non-inferiority margin of 1.3. The rate of rescue therapy did not differ between the groups. The morphine group had considerably higher incidence of nausea than the control group (zero patients in the ketamine group versus eight patients (17.4%) in the morphine group; P = 0.006).

CONCLUSIONS

Nebulized ketamine has non-inferior analgesic efficacy compared with IV morphine for acute musculoskeletal pain in older persons, with fewer adverse effects.

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.

Ketamine decreased opiate use in US military combat operations from 2010 to 2019

BACKGROUND

Ketamine is a dissociative anaesthetic currently used in a variety of healthcare applications. Effects are dose dependent and cause escalating levels of euphoria, analgesia, dissociation and amnesia. Ketamine can be given via intravenous, intramuscular, nasal, oral and aerosolised routes. A 2012 memorandum and the 2014 Tactical Combat Casualty Care (TCCC) guidelines included ketamine as part of the 'Triple Option' for analgesia. This study investigated the effect of ketamine adoption by the US military TCCC guidelines on opioid use between 2010 and 2019.

METHODS

This was a retrospective review of deidentified Department of Defense Trauma Registry data. The study was approved by the Institutional Review Board of Naval Medical Center San Diego (NMCSD) and facilitated by a data sharing agreement between NMCSD and the Defense Health Agency. Patient encounters from all US military operations from January 2010 to December 2019 were queried. All administrations of any pain medications via any route were included.

RESULTS

5965 patients with a total of 8607 pain medication administrations were included. Between 2010 and 2019, the yearly percentage of ketamine administrations rose from 14.2% to 52.6% (p<0.001). The percentage of opioid administrations decreased from 85.8% to 47.4% (p<0.001). Among the 4104 patients who received a single dose of pain medication, the mean Injury Severity Score for those who received ketamine was higher than for those who received an opioid (mean=13.1 vs 9.8, p<0.001).

CONCLUSION

Military opioid use declined as ketamine use increased over 10 years of combat. Ketamine is generally used first for more severely injured patients and has increasingly been employed by the US military as the primary analgesic for combat casualties.

Nebulized Ketamine for Analgesia in the Prehospital Setting: A Case Series

We report the initial seven patients treated with nebulized ketamine for moderate to severe pain, via breath-actuated nebulizer, in an urban, ground-based emergency medical services (EMS) system. Ketamine for analgesia in the emergency setting has become widespread over the past decade. The addition of a non-parenteral, inexpensive, and well-tolerated ketamine delivery option is extremely desirable. We believe these initial data demonstrate promising pain reduction coupled with minimal side effects, indicating a potential role for nebulized ketamine in EMS.

Nebulized Ketamine Used for Managing Ankle Fracture in the Prehospital Emergency Setting: A Case Report

INTRODUCTION

Acute traumatic limb injury is a common complaint of patients presenting to the emergency department (ED). Ketamine is an effective analgesic administered via intravenous (IV), intranasal (IN), intramuscular (IM), and nebulized routes in the ED. It has also been used in the prehospital setting via IV, IM, and IN routes. Recent studies have proposed the prehospital use of nebulized ketamine via breath-actuated nebulizer (BAN) as a noninvasive and effective method of analgesic delivery, as well as an alternative to opioid analgesia.

CASE REPORT

We present a case of a patient with right ankle fracture after a 12-foot fall who subsequently received 0.75 milligrams per kilogram of nebulized ketamine via BAN in the prehospital setting. The patient reported improvement of pain from 8/10 to 3/10 on the pain scale without need for additional pain medication during prehospital transport. This report supports the use of nebulized ketamine via BAN in the prehospital setting for acute traumatic limb injuries.

CONCLUSION

The use of nebulized ketamine via BAN in the prehospital setting may be an effective analgesic option for the management of patients with acute traumatic limb injuries, particularly in those with difficult IV access, where mucosal atomization devices are not accessible, or where opioid-sparing treatments are preferable.

Novel uses of ketamine in the emergency department

INTRODUCTION

: Ketamine is gaining renewed interest among healthcare providers due to its novel clinical applications in the emergency department (ED) setting.

AREAS COVERED

: This article provides a comprehensive discussion of ketamine's pharmacological properties, including safety profile and adverse effects, in addition to an overview of current evidence for ketamine (racemic formulation) in the management of ED patients with acute agitation, pain, and depression/suicide ideation.

EXPERT OPINION

: Ketamine is an effective adjunct to opioids, providing greater pain relief than morphine alone. As an analgesic agent, administration of ketamine (0.1-0.3 mg/kg IV) alone can provide analgesia similar to that of morphine in patients with acute visceral and musculoskeletal pain. Moreover, ketamine provides equal analgesic efficacy to morphine in a variety of chronic painful conditions including pain associated with cancer, vaso-occlusive pain crisis associated with sickle cell disease, and in patients with high opioid tolerance and/or opioid dependency. Available literature shows that ketamine (1-2mg/kg IV or 4-5 mg/kg IM) is a safe, rapid (<5 minutes) and effective tranquilization agent for ED patients with acute agitation. Finally, there is growing evidence that suggests ketamine may have a potential utility in the management of patients with self-harm ideation or acute depressive episodes. Intravenous infusion of ketamine (0.5 mg/kg over 40 mins) has been shown to produce an antidepressant effect and decrease in suicidal ideation within 4 hours with effects lasting up to one week.

Recent advances in drug delivery to the central nervous system by inhalation

INTRODUCTION

Drugs need to enter the systemic circulation efficiently before they can cross the blood-brain barrier and reach the central nervous system. Although the respiratory tract is not a common route of administration for delivering drugs to the central nervous system, it has attracted increasing interest in recent years for this purpose.

AREAS COVERED

In this article, we compare pulmonary delivery to three other common routes (parenteral, oral, and intranasal) for delivering drugs to the central nervous system, followed by summarising the devices used to aerosolise neurological drugs. Recent studies delivering drugs for different neurological disorders via inhalation are then discussed to illustrate the strengths of pulmonary delivery.

EXPERT OPINION

Recent studies provide strong evidence and rationale to support inhaling neurological drugs. Since inhalation can achieve improved pharmacokinetics and rapid onset of action for multiple drugs, it is a non-invasive and efficient method to deliver drugs to the central nervous system. Future research should focus on delivering other small and macro-molecules via the lungs for different neurological conditions.

Paraphimosis Pain Treatment with Nebulized Ketamine in the Emergency Department

BACKGROUND

Paraphimosis is an acute urological emergency occurring in uncircumcised males that can lead to strangulation of the glans and painful vascular compromise. Ketamine has been used in the emergency department (ED) as an anesthetic agent for procedural sedation, and when administrated in a sub-dissociative dose (low dose) at 0.1-0.3 mg/kg, ketamine has been utilized in the ED and prehospital settings for pain control as an adjunct and as an alternative to opioid, as well as for preprocedural sedation. This report details the case of a pediatric patient who presented to our Pediatric ED with paraphimosis and had his procedural pain treated with ketamine administrated via a breath-actuated nebulizer (BAN).

CASE REPORT

This case report illustrates the potential use of ketamine via BAN to effectively achieve minimal sedation for a procedure in pediatric patients in the ED. The patient was a 15-year-old boy admitted to the Pediatric ED complaining of groin pain due to paraphimosis. The patient was given 0.75 mg/kg of nebulized ketamine via BAN, and 15 min after the medication administration the pain score was reduced from 5 to 1 on the numeric pain rating scale. The patient underwent a successful paraphimosis reduction without additional analgesic or sedative agents 20 min after the administration of nebulized ketamine. The patient was subsequently discharged home after 60 min of monitoring, with a pain score of 0. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The use of nebulized ketamine via BAN might represent a viable, noninvasive way to provide a mild sedative and be an effective analgesic option for managing a variety of acute painful conditions and procedures in the pediatric ED.

Pain management in the emergency department: a clinical review

Pain is one of the most common reasons for patients to visit the emergency department. The ever-growing research on emergency department analgesia has challenged the current practices with respect to the optimal analgesic regimen for acute musculoskeletal pain, safe and judicious opioid prescribing, appropriate utilization of non-opioid therapeutics, and non-pharmacological treatment modalities. This clinical review is set to provide evidence-based answers to these challenging questions.