Ketamine for prehospital use: new look at an old drug

Ketamine: An emerging agent in the management of neuropsychiatric disorders

Ketamine's unique pharmacological profile, safety, modulation of multiple neurotransmitter systems, and ability to produce neuroplastic changes make it a subject of study with implications for a wide range of neuropsychiatric disorders beyond its traditional use as an anesthetic agent. This article aims to provide an overview of the pharmacology of ketamine and briefly discuss its emerging use in treating: substance use disorders (alcohol, cannabis, cocaine, and opioids); withdrawal syndromes (opioid and alcohol); acute and chronic pain syndromes; and severe psychomotor agitation. Ketamine for the treatment of depression and suicidality is well established; however, the focus of this paper is to outline less common indications.

The diverse effects of ketamine, jack-of-all-trades: a narrative review

Ketamine, an N-methyl-D-aspartic acid receptor antagonist that was first discovered in 1962, has become established in anaesthesia providing dose-dependent anaesthetic, sedative, and analgesic effects. Ketamine, however, also acts on a wide range of other cellular targets, resulting in interesting and diverse effects on both physiological and pathological processes. Potential beneficial properties of ketamine include cardiovascular stability for patients undergoing sedation or anaesthesia, analgesia in both acute and chronic pain, bronchodilation in severe refractory asthma, anti-inflammatory properties particularly in sepsis, tumour inhibition, and antidepressant properties with marked ability to reverse suicidal ideation. The reluctance to adopt ketamine into routine practice is likely attributable in part to the stigma and negative reputation associated with its perceived side-effects and potential for abuse. This review explores the diverse properties and therapeutic potentials of ketamine being investigated across different fields whilst also identifying areas for ongoing and future research. Given the diverse range of potential benefits and promising early work, ketamine should be the focus of ongoing research in multiple different specialty areas. This includes areas relevant to anaesthesia and perioperative medicine, such as acute and chronic pain management, ICU sedation, and even tumour suppression in those undergoing surgical resection of malignancies.

Fentanyl versus nebulized ketamine for prehospital analgesia: A retrospective data review

STUDY OBJECTIVE

To evaluate the comparative effectiveness of fentanyl and ketamine via Breath Actuated Nebulizer (BAN) for analgesia in the prehospital setting.

METHODS

We conducted a retrospective cross-sectional evaluation of patients receiving fentanyl or ketamine via BAN for pain management in a large suburban EMS system between 3/1/2022 and 6/1/2023. The primary outcome was change in first to last pain score. Subgroup analysis was performed on patients with traumatic pain. We used inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) to estimate the treatment effect of fentanyl vs ketamine via BAN among all patients and the subgroup of those with traumatic pain.

RESULTS

Of the total 1480 patients included, 1317 (89.0 %) received fentanyl and 163 (11.0 %) received ketamine via BAN. The unadjusted mean change in pain score was -2.9 (SD 3.0) for fentanyl and -3.5 (SD 3.4) for ketamine. In the propensity score analyses, there was no statistically significant difference in pain score change for the fentanyl group versus ketamine among all patients (mean difference, IPTW: -0.45, 95 %CI -1.18, 0.28; PSM: -0.36, 95 %CI -0.93, 0.21). Subgroup analysis of patients treated for traumatic pain showed a significant reduction in pain for patients treated with ketamine compared to fentanyl, indicating a higher degree of analgesia from ketamine for traumatic pain (unadjusted: -1.37, 95 % CI -2.20, -0.54; IPTW: -1.10, 95 % CI -1.96, -0.23; PSM: -0.92, 95 % CI -1.17, -0.12).

CONCLUSION

We found no statistically significant difference in the analgesic treatment effect for the overall fentanyl and ketamine groups. Subgroup analysis of patients treated for traumatic pain showed greater analgesia for ketamine via BAN over fentanyl. Given the ease of administration and lack of need for intravenous access, ketamine via BAN is a reasonable and effective choice for prehospital pain management.

High-Risk Pediatric Mental Health Transports-Improving Barriers to Getting Help: A Standardized Approach to High-Risk Pediatric Mental Health Transports

The Children's Mercy Hospital Critical Care Transport (CMCCT) team provides care to a sizable portion of the Midwest United States. CMCCT has seen an increased frequency of pediatric mental health transport requests for patients who are aggressive or at risk of becoming aggressive during interfacility transport. These transport requests often involve long distances and require a medical flight to accomplish safely. CMCCT's multidisciplinary approach and process focus on crew and patient safety to provide compassionate and dignified care, ensuring that this very vulnerable patient population arrives safely at their mental health care institution. This paper describes our patient population, policy, systemic process, and barriers to completing the transport.

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.

Ketamine Compared With Morphine for Out-of-Hospital Analgesia for Patients With Traumatic Pain: A Randomized Clinical Trial

Importance

Pain is a common out-of-hospital symptom among patients, and opioids are often prescribed. Research suggests that overprescribing for acute traumatic pain is still prevalent, even when limits restricting opioid prescriptions have been implemented. Ketamine hydrochloride is an alternative to opioids in adults with out-of-hospital traumatic pain.

Objective

To assess the noninferiority of intravenous ketamine compared with intravenous morphine sulfate to provide pain relief in adults with out-of-hospital traumatic pain.

Design, Setting, and Participants

The Intravenous Subdissociative-Dose Ketamine Versus Morphine for Prehospital Analgesia (KETAMORPH) study was a multicenter, single-blind, noninferiority randomized clinical trial comparing ketamine hydrochloride (20 mg, followed by 10 mg every 5 minutes) with morphine sulfate (2 or 3 mg every 5 minutes) in adult patients with out-of-hospital trauma and a verbal pain score equal to or greater than 5. Enrollment occurred from November 23, 2017, to November 26, 2022, in 11 French out-of-hospital emergency medical units.

Interventions

Patients were randomly assigned to ketamine (n = 128) or morphine (n = 123).

Main Outcomes and Measures

The primary outcome was the between-group difference in mean change in verbal rating scale pain scores measured from the time before administration of the study drug to 30 minutes later. A noninferiority margin of 1.3 was chosen.

Results

A total of 251 patients were randomized (median age, 51 [IQR, 34-69] years; 111 women [44.9%] and 140 men [55.1%] among the 247 with data available) and were included in the intention-to-treat population. The mean pain score change was -3.7 (95% CI, -4.2 to -3.2) in the ketamine group compared with -3.8 (95% CI, -4.2 to -3.4) in the morphine group. The difference in mean pain score change was 0.1 (95% CI, -0.7 to 0.9) points. There were no clinically meaningful differences for vital signs between the 2 groups. The intravenous morphine group had 19 of 113 (16.8% [95% CI, 10.4%-25.0%]) adverse effects reported (most commonly nausea [12 of 113 (10.6%)]) compared with 49 of 120 (40.8% [95% CI, 32.0%-49.6%]) in the ketamine group (most commonly emergence phenomenon [24 of 120 (20.0%)]). No adverse events required intervention.

Conclusions and Relevance

In the KETAMORPH study of patients with out-of-hospital traumatic pain, the use of intravenous ketamine compared with morphine showed noninferiority for pain reduction. In the ongoing opioid crisis, ketamine administered alone is an alternative to opioids in adults with out-of-hospital traumatic pain.

Trial Registration

ClinicalTrials.gov Identifier: NCT03236805.

Ketamine: A Practical Review for the Consultation-Liaison Psychiatrist

BACKGROUND

Ketamine is a noncompetitive N-methyl-D-aspartate-receptor antagonist often used for sedation and management of acute agitation in general hospital settings. Many hospitals now include ketamine as part of their standard agitation protocol, and consultation-liaison psychiatrists frequently find themselves treating patients who have received ketamine, despite lack of clear recommendations for management.

OBJECTIVE

Conduct a nonsystematic narrative review regarding the use of ketamine for agitation and continuous sedation, including benefits and adverse psychiatric effects. Compare ketamine to more traditional agents of agitation control. Provide consultation-liaison psychiatrists with a summary of available knowledge and recommendations for managing patients receiving ketamine.

METHODS

A literature review was performed using PubMed, querying published articles from inception to March 2023 for articles related to use of ketamine for agitation or continuous sedation and side effects including psychosis and catatonia.

RESULTS

A total of 37 articles were included. Ketamine was found to have multiple benefits, including shorter time to adequate sedation for agitated patients when compared to haloperidol ± benzodiazepines and unique advantages for continuous sedation. However, ketamine carries significant medical risks including high rates of intubation. Ketamine appears to induce a syndrome that mimics schizophrenia in healthy controls, and such effects are more pronounced and longer-lasting in patients with schizophrenia. Evidence regarding rates of delirium with ketamine for continuous sedation is mixed and requires further investigation before the agent is widely adopted for this purpose. Finally, the diagnosis of "excited delirium syndrome" and use of ketamine to treat this controversial syndrome warrants critical evaluation.

CONCLUSIONS

Ketamine carries many potential benefits and can be an appropriate medication for patients with profound undifferentiated agitation. However, intubation rates remain high, and ketamine may worsen underlying psychotic disorders. It is essential that consultation-liaison psychiatrists understand the advantages, disadvantages, biased administration, and areas of limited knowledge regarding ketamine.

A Comparison of Prehospital Pediatric Analgesic Use of Ketamine and Opioids

OBJECTIVE/INTRODUCTION

Ketamine is an opioid-alternative used for analgesia in the prehospital setting. There are knowledge gaps regarding its use during emergency medical services (EMS) encounters for pediatric patients. Our objective was to compare pain reduction, adverse events, and prehospital deaths between ketamine and opioids when used for analgesia administered by any route among pediatric patients.

METHODS

This was a retrospective review of 9-1-1 EMS records of injured pediatric patients (≤17 years of age) who received ketamine or opioids for analgesia using the ESO Data Collaborative (calendar years 2019-2020). We excluded interfacility transfers, patients receiving both medications, those with EMS clinician impressions indicating behavioral disorders, and those who received medication to facilitate advanced airway placement. EMS narrative review was performed to confirm ketamine use was for analgesia and to identify any unplanned airway placements. We assessed pain score reduction (0-10 ordinal scale) and clinician-documented patient response (improved, unchanged, worsened, unknown). Adverse events were defined as change in vital signs (GCS, SBP, RR, SpO2), bag valve mask ventilation alone, or death. Descriptive statistics were calculated to compare outcomes between groups.

RESULTS

Overall, 9,223 patients were included, 190 (2.1%) received ketamine and 9,033 (97.9%) received opioids. Mean age in years was 12.8 [SD 4.0] for ketamine and 12.7 [SD 4.0] for opioids. Patients in both groups experienced pain reduction, and more patients receiving ketamine had EMS clinician reported improvement (93.2% vs. 87.9%, p = 0.03). Ketamine was associated with a greater average reduction in pain score than opioids (mean difference: -4.4 [SD 3.5], and -3.1 [SD 2.8], p < 0.001). Adverse events were rare with few patients receiving ventilatory support following the use of ketamine or opioids, (0, [SD 0.0%] vs. 6 [SD 0.1%], p = 1). There were no unplanned airway placements or prehospital deaths identified.

CONCLUSION

We identified similar high rates of pain reduction and rare adverse events among pediatric patients who received ketamine or opioids. A greater pain reduction was noted among patients administered ketamine. Intubation as a result of medication administration did not occur and need for ventilatory assistance was rare.

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.

Treating Prehospital Pain in Children: A Retrospective Chart Review Comparing the Safety and Efficacy of Prehospital Pediatric Ketamine and Opioid Analgesia

Prior to 2020, pain management in the Washtenaw/Livingston County Medical Control Authority (W/L MCA) Emergency Medical Service (EMS) system in Southeast Michigan was limited to morphine, fentanyl, ketorolac, and acetaminophen. Based on the increasing evidence describing its safety and efficacy, ketamine was added to local protocols for pain management. This study aimed to evaluate differences in pain management and adverse effects of ketamine and opioid administration. Data from pediatric patients who received ketamine or an opioid in the W/L MCA EMS system from October 2019 to March 2021 were analyzed. The primary outcome was the difference in pain score, and the secondary outcome was adverse effects observed after analgesic administration. The decrease in pain scores was greater among ketamine patients (mean: 5.2) compared to opioid patients (mean: 2.9), p < 0.001. The prevalence of adverse effects was higher among patients in the ketamine group (28.6%) compared to patients in the opioid group (2.4%, p < 0.001). Of 14 patients who received ketamine, one 17-year-old male experienced mild anxiety (7.1%), two teenage females experienced mild dissociation (14.3%), and one 20-year-old female experienced mild nausea (7.1%). Overall, ketamine is a safe and effective option compared to opioids for pediatric patients experiencing moderate to severe prehospital pain.

Prehospital Use of Ketamine versus Benzodiazepines for Sedation among Pediatric Patients with Behavioral Emergencies

INTRODUCTION

Ketamine is an emerging alternative sedation agent for prehospital management of agitation, yet research is limited regarding its use for children. Our objective was to compare the effectiveness and safety of ketamine and benzodiazepines when used for emergent prehospital sedation of pediatric patients with behavioral emergencies.

METHODS

We performed a retrospective review of 9-1-1 EMS records from the 2019-2020 ESO Data Collaborative research datasets. We included patients ≤18 years of age who received ketamine or benzodiazepines for EMS primary and secondary impressions indicating behavioral conditions. We excluded patients with first Glasgow Coma Scale (GCS) scores ≤8, those receiving ketamine or benzodiazepines prior to EMS arrival, those receiving both ketamine and benzodiazepines, and interfacility transfers. Effectiveness outcomes included general clinician assessment of improvement, decrease in GCS, and administration of a subsequent sedative. Safety outcomes included mortality; advanced airway placement; ventilatory assistance without advanced airway placement; or marked sedation (GCS ≤8). Chi-square and t-tests were used to compare the ketamine and benzodiazepines groups.

RESULTS

Of 57,970 pediatric patients with behavioral complaints and GCS scores >8, 1,539 received ketamine (13.3%, n = 205) or a benzodiazepine (86.7%, n = 1,334). Most patients were ≥12 years old (89.2%, n = 1,372), predominantly Caucasian (48.3%, n = 744), and were equally distributed by sex (49.7% male, n = 765). First treatment with ketamine was associated with a greater likelihood of improvement (88.8% vs 70.5%, p < 0.001) and a greater average GCS reduction compared to treatment with benzodiazepines (-2.5 [SD:4.0] vs -0.3 [SD:1.7], p < 0.001). Fewer patients who received ketamine received subsequent medication compared to those who received benzodiazepines (12.2% vs 27.0%, p < 0.001). Marked sedation was more frequent with ketamine than benzodiazepines (28.8% vs 2.9%, p < 0.001). Provision of ventilatory support (1.5% vs 0.5%, p = 0.14) and advanced airway placement (1.0% vs 0.2%, p = 0.09) were similar between ketamine and benzodiazepine groups. No prehospital deaths were reported.

CONCLUSION

In this pediatric cohort, prehospital sedation with ketamine was associated with greater patient improvement, less subsequent sedative administration, and greater sedation compared to benzodiazepines. Though we identified low rates of adverse events in both groups, ketamine was associated with more instances of marked sedation, which bears further study.

Efficacy and safety of low dose oral ketamine for controlling pain and distress during intravenous cannulation in children: a double-blind, randomized, placebo-controlled trial

Background

Ketamine is widely used in infants and young children for procedural sedation and anesthesia. The aim of this study was to evaluate the efficacy and safety of low dose oral ketamine to control pain and distress in children during intravenous (IV) cannulation.

Methods

This is a prospective, randomized, double-blind study, including children aged between 3 and 6 years requiring a non-emergent IV-line placement. Children were randomly assigned to two groups, treated either with oral ketamine or a placebo. All patients were monitored for vital signs. Pain was assessed using the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and Wong-Baker Faces Pain Rating Scale (WBFS) scales and sedation using a 5-point sedation score. The facility of IV-line placement was measured by a 3-point scale. Adverse effects were recorded after 1 and 24 hours.

Results

A total of 79 and 81 children were entered in the ketamine and placebo groups, respectively. The heart and respiratory rates increased significantly in the placebo group. The median CHEOPS 4 (95% confidence interval [CI]: 3, 4, P < 0.001) and WBFS 6 (95% CI: 4, 6, P < 0.001) scores decreased statistically in the ketamine group. IV-line placement was 50% easier in the ketamine group (95% CI: 37%, 63%, P < 0.001). No serious adverse effects were observed in all cases.

Conclusions

Low dose oral ketamine effectively decreased the pain and distress during IV cannulation in children without any significant adverse reactions.

Prehospital Ketamine Use in Pediatrics

Introduction: Information regarding prehospital ketamine use in the pediatric population is limited as existing literature focuses primarily on critical care and air transport. Our objective was to describe patient characteristics among pediatric EMS patients who received ketamine. Secondarily, we assessed effectiveness, deviation from recommended dosing, and adverse outcomes of pediatric EMS patients who received ketamine.Methods: We conducted a retrospective data review of records from the ESO Data Collaborative for all 9-1-1 transports of pediatric patients (≤ 18 years of age) who received ketamine from 2019-2020. We categorized EMS primary impressions as a proxy for medication indication. We defined effectiveness as paramedic-identified clinical improvement, and pain relief as decrease in pain score ≥2 points between initial and final recording. Descriptive statistics were used to summarize clinical characteristics. Non-parametric Wilcoxon signed-rank test was used to assess change in pain score.Results: Out of 422,968 ground-ambulance pediatric patients, 1,291 received ketamine. They were predominately male (842, 65.2%), teenagers (median age 16, IQR: 13-17), Caucasian (810, 62.7%), and from urban areas (1,041, 80.6%). The most common EMS impressions were related to injuries (810, 62.7%) and behavior disorders (281, 21.8%). Only 980/1,291 (75.9%) had weights and identifiable routes recorded. Most patients (960, 74.4%) received single doses of ketamine, with EMS clinicians reporting improvement in 855 (89.1%) of 960 patients. Among non-behavioral emergency patients, 727/1,010 (72.0%) had pain scores recorded. Pain scores decreased significantly from a median of 8 (IQR: 4-10) to 2 (IQR: 0-6) (p < 0.001) with 59% (429) of 727 patients reporting pain score reductions of 2 or more points. Desaturation (<90% SpO₂) events were noted to be minimal (1.8%). A small number (28, 2.2%) received positive pressure ventilation without advanced airway placement. No prehospital deaths were documented.Conclusion: In this large review of pediatric prehospital ketamine use, ketamine was primarily used for analgesia, but was frequently used for other indications. Most patients were observed to improve after ketamine use, with most injured patients reporting decreases in pain scores. We observed few significant adverse events related to ketamine use in this population.

The effectiveness and safety of paediatric prehospital pain management: a systematic review

BACKGROUND

Clinically meaningful pain reduction with respect to severity and the adverse events of drugs used in prehospital pain management for children are areas that have not received sufficient attention. The present systematic review therefore aims to perform a comprehensive search of databases to examine the preferable drugs for prehospital pain relief in paediatric patients with acute pain, irrespective of aetiology.

METHODS

The systematic review includes studies from 2000 and up to 2020 that focus on children's prehospital pain management. The study protocol is registered in PROSPERO with registration no. CRD42019126699. Pharmacological pain management using any type of analgesic drug and in all routes of administration was included. The main outcomes were (1) measurable pain reduction (effectiveness) and (2) no occurrence of any serious adverse events. Searches were conducted in PubMed, Medline, Embase, CINAHL, Epistemonikos and Cochrane library. Finally, the risk of bias was assessed using the Joanna Briggs Institute (JBI) checklist and a textual narrative analysis was performed due to the heterogeneity of the results.

RESULTS

The present systematic review on the effectiveness and safety of analgesic drugs in prehospital pain relief in children identified a total of eight articles. Most of the articles reviewed identified analgesic drugs such as fentanyl (intranasal/IV), morphine (IV), methoxyflurane (inhalational) and ketamine (IV/IM). The effects of fentanyl, morphine and methoxyflurane were examined and all of the included analgesic drugs were evaluated as effective. Adverse events of fentanyl, methoxyflurane and ketamine were also reported, although none of these were considered serious.

CONCLUSION

The systematic review revealed that fentanyl, morphine, methoxyflurane and combination drugs are effective analgesic drugs for children in prehospital settings. No serious adverse events were reported following the administration of fentanyl, methoxyflurane and ketamine. Intranasal fentanyl and inhalational methoxyflurane seem to be the preferred drugs for children in pre-hospital settings due to their ease of administration, similar effect and safety profile when compared to other analgesic drugs. However, the level of evidence (LOE) in the included studies was only three or four, and further studies are therefore necessary.

Analgesia in pediatric trauma patients in physician-staffed Austrian helicopter rescue: a 12-year registry analysis

BACKGROUND

As pediatric patients are typically rare among helicopter emergency medical systems (HEMS), children might be at risk for oligo-analgesia due to the rescuer's lack of experience and the fear of side effects.

METHODS

In this retrospective analysis, data was obtained from the ÖAMTC HEMS digital database including 14 physician staffed helicopter bases in Austria over a 12-year timeframe. Primary missions involving pediatric trauma patients (< 15 years) not mechanically ventilated on-site were included. Analgesia was assessed and compared between the age groups 0-5, 6-10 and 11-14 years.

RESULTS

Of all flight missions, 8.2% were dedicated to children < 15 years. Analgetic drugs were administered in 31.4% of all primary missions (3874 of 12,324), wherefrom 2885 were injured and non-ventilated (0-5 yrs.: n = 443; 6-10 yrs.: n = 902; 11-14 yrs.: n = 1540). The majority of these patients (> 75%) suffered moderate to severe pain, justifying immediate analgesia. HEMS physicians typically chose a monotherapy with an opioid (n = 1277; 44.3%) or Esketamine (n = 1187; 41.1%) followed by the combination of both (n = 324; 11.2%). Opioid use increased (37.2% to 63.4%) and Esketamine use decreased (66.1% to 48.3%) in children < 6 vs. > 10 years. Esketamine was more often administered in extremity (57.3%) than in head (41.5%) or spine injuries (32.3%). An intravenous access was less often established in children < 6 years (74.3% vs. 90.8%; p < 0.001). Despite the use of potent analgesics, 396 missions (13.7%) were performed without technical monitoring. Particularly regarding patient data at handover in hospital, merely < 10% of all missions featured complete documentation. Therefore, sufficient evaluation of the efficacy of pain relief was not possible. Yet, by means of respiratory measures required during transport, severe side effects such as respiratory insufficiency, were barely noted.

CONCLUSIONS

In the physician-staffed HEMS setting, pediatric trauma patients liberally receive opioids and Esketamine for analgesia. With regard to severe respiratory insufficiency during transport, the application of these potent analgesics seems safe.

Hemodynamic Effects of Ketamine Versus Etomidate for Prehospital Rapid Sequence Intubation

OBJECTIVE

Rapid sequence intubation (RSI) is often required in managing critically ill patients in the prehospital setting. Although etomidate is a commonly used induction agent for RSI, ketamine has gained new interest in prehospital management with reported neutral hemodynamic effects. Limited data exist to support ketamine as an alternative to etomidate, particularly in the prehospital setting. The purpose of this study was to evaluate hemodynamic changes after the administration of ketamine versus etomidate in prehospital RSI.

METHODS

This retrospective study evaluated adult patients undergoing prehospital RSI over 13 months within a regional emergency transport medicine service. Hypotension was defined as a 20% decrease in systolic blood pressure (SBP) within 15 minutes of receiving ketamine or etomidate. Hemodynamic data were collected 15 minutes before and 15 minutes after administration or until additional sedative medications were given. Data were analyzed using SPSS software (Version 21; IBM Corp, Armonk, NY), with P < .05 considered significant.

RESULTS

One hundred thirteen patients met the inclusion criteria (ketamine, n = 33; etomidate, n = 80), with the primary reasons for intubation being respiratory failure and trauma. There was no difference between the incidence of patients who experienced a 20% decrease in SBP (16% etomidate vs. 18% ketamine, P = .79). There were no significant differences in SBP pre- to postadministration between ketamine and etomidate.

CONCLUSION

No hemodynamic differences occurred between patients who received ketamine versus etomidate for prehospital RSI. Neither drug was associated with an increased need for additional sedatives, and neither drug was associated with an increased first-pass intubation success rate. Larger, prospective, powered studies are required to identify patients who may benefit from either ketamine or etomidate.

Anesthesiology in Times of Physical Disasters-Earthquakes and Typhoons

Nepal and Hong Kong both are susceptible to natural disasters due to their geographic locations. Nepal suffers from frequent earthquakes, and Hong Kong regularly experiences typhoons of varying severity. Natural disasters may present acutely or with some advance warning. In either case, it is critical that disaster response plans are well established in advance of any incident. This article discusses the anesthetic and critical care implications of such natural disasters, using Nepal and Hong Kong as case studies.

Success and Complications of the Ketamine-Only Intubation Method in the Emergency Department

BACKGROUND

Rapid sequence intubation (RSI), defined as near-simultaneous administration of a sedative and neuromuscular blocking agent, is the most common and successful method of tracheal intubation in the emergency department. However, RSI is sometimes avoided when the physician believes there is a risk of a can't intubate/can't oxygenate scenario or critical hypoxemia because of distorted anatomy or apnea intolerance. Traditionally, topical anesthesia alone or in combination with low-dose sedation are used when physicians deem RSI too risky. Recently, a ketamine-only strategy has been suggested as an alternative approach.

OBJECTIVE

We compared first attempt success and complications between ketamine-only, topical anesthesia alone or with low-dose sedation, and RSI approaches.

METHODS

We analyzed registry data from the National Emergency Airway Registry, comprising emergency department intubation data from 25 centers from January 2016 to December 2018. We excluded pediatric patients (<14 years of age), those in cardiac and respiratory arrest, or those with an alternate pharmacologic approach (i.e., neuromuscular blocking agent only or nonketamine sedative alone). We analyzed first attempt intubation success and adverse events across the 3 intubation approaches. We calculated differences in outcomes between the ketamine-only and topical anesthesia groups.

RESULTS

During the study period, 12,511 of 19,071 intubation encounters met inclusion criteria, including 102 (0.8%) intubated with ketamine alone, 80 (0.6%) who had intubation facilitated by topical anesthesia, and 12,329 (98.5%) who underwent RSI. Unadjusted first attempt success was 61%, 85%, and 90% for the 3 groups, respectively. Hypoxemia (defined as oxygen saturation <90%) occurred in 16%, 13%, and 8% of patients during the first attempt, respectively. At least 1 adverse event occurred in 32%, 19%, and 14% of the courses of intubation for the 3 groups, respectively. In comparing the ketamine-only and topical anesthesia groups, the difference in first pass success was -24% (95% confidence interval -37% to -12%), and the difference in number of cases with ≥1 adverse event was 13% (95% confidence interval 0-25%), both favoring the topical anesthesia group.

CONCLUSION

Although sometimes advocated, the ketamine-only intubation approach is uncommon and is associated with lower success and higher complications compared with topical anesthesia and RSI approaches.

Intranasal Ketamine as an Adjunct to Fentanyl for the Prehospital Treatment of Acute Traumatic Pain: Design and Rationale of a Randomized Controlled Trial

Objective: Acute pain management is fundamental in prehospital trauma care. Early pain control may decrease the risk of developing post-traumatic stress disorder (PTSD) and chronic pain. Fentanyl and ketamine are frequently used off-label, but there is a paucity of comparative data to guide decision-making about treatment of prehospital severe, acute pain. This trial will determine whether the addition of single dose of intranasal ketamine to fentanyl is more effective for the treatment of acute traumatic pain than administration of fentanyl alone.Methods: This two-part study consists of prehospital and 90-day follow-up components (NCT02866071). The prehospital trial is a blinded, randomized, controlled trial of adult men (age 18-65 years) rating pain ≥7/10 after an acute traumatic injury of any type. Women will be excluded due to inability to confirm pregnancy status and unknown fetal risk. Paramedics will screen patients receiving standard of care fentanyl and, after obtaining standard informed consent, administer 50 mg intranasal ketamine or matching volume saline as placebo. Upon emergency department (ED) arrival, research associates will serially assess pain, concomitant treatments, and adverse side effects. Enrolled subjects will be approached for consent to participate in the 90-day follow-up study to determine rates of PTSD and chronic pain development. The primary outcome of the prehospital study is reduction in pain on the Verbal Numerical Rating Scale between baseline and 30-minutes after study drug administration. The proportion achieving a reduction of ≥2-points will be compared between study arms using a Chi-square test. Secondary outcomes of the prehospital trial include reduction in reported pain at the time of ED arrival and at 30 minutes intervals for up to three hours of ED care, the incidence of adverse events, and additional opiate requirements prior to ED arrival and within the first three hours of ED care. The outcomes in the follow-up study are satisfaction with life and development of PTSD or chronic pain at 90 days after injury. An intention-to-treat approach will be used.Conclusion: These studies will test the hypotheses that ketamine plus fentanyl, when compared to fentanyl alone, effectively manages pain, decreases opiate requirements, and decreases PTSD at 90 days.

Ketamine as a Prehospital Analgesic: A Systematic Review

OBJECTIVE

Analgesia in the prehospital setting is an extremely important, yet controversial topic. Ketamine, a N-methyl D-aspartate (NMDA) receptor antagonist, has been commonly used in the prehospital setting, including recommendations by the US Department of Defense and by the Royal Australian College of Pain Medicine, despite the paucity of high-level evidence.

METHODS

Accordingly, a review of the literature was conducted using several electronic medical literature databases from the earliest available records to the time at which the search was conducted (October 2018).

RESULTS

The search strategy yielded a total of 707 unique papers, of which 43 were short-listed for full review, and ultimately, ten papers were identified as meeting all the relevant inclusion criteria. The included studies varied significantly in the prehospital context and in the means of administering ketamine. There was only low-grade evidence that ketamine offered a safe and effective analgesia when used as the only analgesic, and only low-grade evidence that it was as effective as alternative opioid options. However, there was moderate evidence that co-administration of ketamine with morphine may improve analgesic efficacy and reduce morphine requirement.

CONCLUSIONS

Overall, ketamine as a prehospital analgesic may be best used in combination with opioids to reduce opioid requirement. It is suggested that future studies should use a standardized approach to measuring pain reduction. Future studies should also investigate short-term side effects and long-term complications or benefits of prehospital ketamine.

Alternatives to Rapid Sequence Intubation: Contemporary Airway Management with Ketamine

Endotracheal intubation (ETI) is a high-risk procedure commonly performed in emergency medicine, critical care, and the prehospital setting. Traditional rapid sequence intubation (RSI), the simultaneous administration of an induction agent and muscle relaxant, is more likely to harm patients who do not allow appropriate preparation and preoxygenation, have concerning airway anatomy, or severe hypoxia, acidemia, or hypotension. Ketamine, a dissociative anesthetic, can be used to facilitate two alternatives to RSI to augment airway safety in these scenarios: delayed sequence intubation - the use of ketamine to allow airway preparation and preoxygenation in the agitated patient; and ketamine-only breathing intubation, in which ketamine is used without a paralytic to facilitate ETI as the patient continues to breathe spontaneously. Ketamine may also provide hemodynamic benefits during standard RSI and is a valuable agent for post-intubation analgesia and sedation. When RSI is not an optimal airway management strategy, ketamine's unique pharmacology can be harnessed to facilitate alternative approaches that may increase patient safety.

Low-dose intravenous ketamine versus intravenous ketorolac in pain control in patients with acute renal colic in an emergency setting: a double-blind randomized clinical trial

BACKGROUND

This study was conducted to compare the effectiveness of low-dose ketamine versus ketorolac in pain control in patients with acute renal colic presenting to the emergency department (ED).

METHODS

This is a double-blind randomized clinical trial. The initial pain severity was assessed using the numerical rating scale (NRS). Then, ketamine or ketorolac was administered intravenously at a dose of 0.6 mg/kg and 30 mg respectively. The pain severity and adverse drug reactions were recorded 5, 15, 30, 60, and 120 min thereafter.

RESULTS

The data of 62 subjects in the ketamine group and 64 patients in the ketorolac group were analyzed. The mean age of the patients was 34.2 ± 9.9 and 37.9 ± 10.6 years in the ketamine and ketorolac group, respectively. There was no significant difference in the mean NRS scores at each time point, except for the 5 min, between the two groups. Despite a marked decrease in pain severity in the ketamine group from drug administration at the 5 min, a slight increase in pain was observed from the 5 min to the 15 min. The rate of adverse drug reactions, including dizziness (P = 0.001), agitation (P = 0.002), increased systolic blood pressure (> 140 mmHg), and diastolic blood pressure (> 90 mmHg) was higher in the ketamine group.

CONCLUSIONS

Low dose ketamine is as effective as ketorolac in pain management in patients with renal colic presenting to the ED. However, it is associated with a higher rate of adverse drug reactions.

Effect of Intramuscular Ketamine versus Haloperidol on Short-Term Control of Severe Agitated Patients in Emergency Department; A Randomized Clinical Trial

Objective

To evaluate the efficacy and safety of intramuscular ketamine and haloperidol in sedation of severely agitated patients in emergency department (ED).

Methods

This randomized, double-blind clinical trial study was performed on agitated patients referring to two university educational hospitals. Patients were randomly assigned to receive intramuscular (IM) haloperidol (5 mg) or IM ketamine (4 mg/kg). The primary outcome was time to adequate sedation (AMSS ≤ +1). Secondary outcomes included the need for additional sedatives, required intubation, duration of hospitalization, and side effects.

Results

The 90 agitated patients were enrolled. The mean age was 30.37±7.36 years (range 18-56); 74% (67/90) were men. The mean time to adequate sedation in ketamine group (7.73 ± 4.71 minutes) was significantly lower than haloperidol group (11.42 ± 7.20 minutes) (p= 0.005). 15 minutes after intervention, the sedation score did not differ significantly in both groups (Ketamine:0.14 ± 0.59 vs. Haloperidol: 0.30 ± 0.60; p=0.167). The incidence of complications was not significantly different between groups. The physician's satisfaction from the patients' aggression control was significantly higher in ketamine group.

Conclusion

These data suggest ketamine may be used for short-term control of agitated patients, additional studies are needed to confirm if ketamine is safe in this patient population. Given rapid effective sedation and the higher physician satisfaction of ketamine in comparison to haloperidol, it may be considered as a safe and appropriate alternative to haloperidol.IRCT Code: IRCT20180129038549N5.

Ketamine for Rapid Sedation of Agitated Patients in the Prehospital and Emergency Department Settings: A Systematic Review and Proportional Meta-Analysis

BACKGROUND

Rapid tranquilization of agitated patients can prevent injuries and expedite care. Whereas antipsychotics and benzodiazepines are commonly used for this purpose, ketamine has been suggested as an alternative.

OBJECTIVE

The aim of this systematic review is to determine the safety and effectiveness of ketamine to sedate prehospital and emergency department (ED) patients with undifferentiated agitation.

METHODS

Studies and case series of patients receiving ketamine for agitation were included. Studies were excluded if ketamine was used for analgesia, procedural sedation, asthma, or induction. Information sources included traditional and gray literature.

RESULTS

The initial search yielded 1176 results from 14 databases. After review of titles and abstracts, 32 studies were reviewed and 18 were included in the analysis, representing 650 patient encounters. The mean dose of ketamine was 315 mg (SD 52) given intramuscularly, with adequate sedation achieved in 7.2 min (SD 6.2, range 2-500). Intubation occurred in 30.5% of patients (95% confidence interval [CI] 27.0-34.1%). In the majority of those patients, ketamine was administered by paramedics during ground transport and the patient was intubated on ED arrival. When ketamine was administered in the ED, the intubation rate was 1.8% (95% CI 0.0-4.4%); in air medical transport, the rate was 4.9% (95% CI 0.0-10.3%). Other reported side effects included: vomiting, 5.2% (2.3-8.1%); hypertension, 12.1% (5.7-18.6%); emergence reactions, 3.5% (1.4-5.6%); transient hypoxia, 1.8% (0.1-3.6%) and laryngospasm, 1.3% (0.3-2.3%).

CONCLUSIONS

Ketamine provides rapid sedation for undifferentiated agitated patients and is associated with higher intubation rates when used by ground Emergency Medical Services paramedics, compared with ED or air medical transport patients. Other side effects are common but usually self-limiting.

The Evolving Landscape of Acute Pain Management in the Era of the Opioid Crisis

PURPOSE OF REVIEW

The purpose of the study is to evaluate and analyze the role of both opioid and non-opioid analgesics in the emergency department (ED).

RECENT FINDINGS

Studies have shown that the implementation of opioid-prescribing policies in the ED has the potential to reduce the opioid addiction burden. Clinical studies point to inconsistencies in providers' approach to pain treatment. In this review, we discuss specific aspects of opioid utilization and explore alternative non-opioid approaches to pain management. Pain is the most common reason patients present to the ED. As such, emergency medicine (EM) providers must be well versed in treating pain. EM providers must be comfortable using a wide variety of analgesic medications. Opioid analgesics, while effective for some indications, are associated with significant adverse effects and abuse potential. EM providers should utilize opioid analgesics in a safe and rational manner in an effort to combat the opioid epidemic and to avoid therapeutic misadventures. EM providers should be aware of all of their therapeutic options, e.g., opioid and non-opioid, in order to provide effective analgesia for their patients, while avoiding adverse effects and minimizing the potential for misuse.

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.

Is intravenously administered, subdissociative-dose KETAmine non-inferior to MORPHine for prehospital analgesia (the KETAMORPH study): study protocol for a randomized controlled trial

Background

Acute pain is a common condition among prehospital patients and prompt management is pivotal. Opioids are the most frequently analgesics used in the prehospital setting. However, opioids are highly addictive, and some patients may develop opioid dependence, even when they are exposed to brief opioid treatments. Therefore, alternative non-opioid analgesia should be developed to manage pain in the prehospital setting. Used at subdissociative doses, ketamine, a noncompetitive N-methyl-D-aspartate and glutamate receptor antagonist, provides analgesic effects accompanied by preservation of protective airway reflexes. In this context, we will carry out a randomized controlled, open-label, multicenter trial to compare a subdissociative dose of ketamine to morphine to provide pain relief in the prehospital setting, in patients with traumatic and non-traumatic pain.

Methods/design

This will be a multicenter, single-blind, randomized controlled trial. Consecutive adults will be enrolled in the prehospital setting if they experience moderate to severe, acute, non-traumatic and traumatic pain, defined as a numeric rating scale score greater or equal to 5. Patients will be randomized to receive ketamine or morphine by intravenous push. The primary outcome will be the between-group difference in mean change in numeric rating scale pain scores measured from the time before administration of the study medication to 30 min later.

Discussion

This upcoming randomized clinical trial was design to assess the efficacy and safety of ketamine, an alternative non-opiate analgesia, to manage non-traumatic and traumatic pain in the prehospital setting. We aim to provide evidence to change prescribing practices to reduce exposition to opioids and the subsequent risk of addiction.

Trial registration

ClinicalTrials.gov, ID: NCT03236805. Registered on 2 August 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2634-3) contains supplementary material, which is available to authorized users.

A retrospective analysis of ketamine administration by critical care paramedics in a pre-hospital care setting

Objective:

This project aims to describe pre-hospital use of ketamine in trauma by South East Coast Ambulance Service critical care paramedics and evaluate the occurrence of any side effects or adverse events.

Methods:

A retrospective analysis of patients receiving pre-hospital ketamine for trauma between 16 March 2013 and 30 April 2017. Administrations were identified from Advanced Life Saving Interventions and Procedures reports submitted by the clinician and, later, from an electronic database. Each was scrutinised for patient demographics, doses and reports of side effects or adverse events.

Results:

A total of 510 unique administrations were identified. Following the exclusion of 61 records, 449 (88.0%) administrations remained. The most common indication for administration of ketamine was lower limb injury, with 228 (50.8%) administrations. Ketamine was only administered intravenously, and the median dose of ketamine for all administrations was 30 mg (interquartile range 20–40 mg). The gender split was dominated by males who accounted for 302 (67.3%) administrations compared to 147 (32.7%) females. The median age of patients was 44 years (interquartile range 28–58 years), with women on average being older than men. Telephone calls to a consultant were made for 243/449 (54.1%) of the administrations, reflecting a need for sanctioning of the drug, advice on dosages or indications, for example.

Conclusions:

Critical care paramedics within a well governed system are able to safely administer ketamine within an approved dosing regimen under a Patient Group Direction. Median doses are in keeping with nationally approved guidelines. Reported side effects were within the described frequencies in the British National Formulary. Prospective studies are now needed in order to confirm the safety and efficacy of ketamine administration among the advanced paramedic population.

Ketamine in the Prehospital Environment: A National Survey of Paramedics in the United States

BACKGROUND

Use of ketamine in the prehospital setting may be advantageous due to its potent analgesic and sedative properties and favorable risk profile. Use in the military setting has demonstrated both efficacy and safety for pain relief. The purpose of this study was to assess ketamine training, use, and perceptions in the civilian setting among nationally certified paramedics (NRPs) in the United States.

METHODS

A cross-sectional survey of NRPs was performed. The electronic questionnaire assessed paramedic training, authorization, use, and perceptions of ketamine. Included in the analysis were completed surveys of paramedics who held one or more state paramedic credentials, indicated "patient care provider" as their primary role, and worked in non-military settings. Descriptive statistics were calculated.

RESULTS

A total of 14,739 responses were obtained (response rate=23%), of which 10,737 (73%) met inclusion criteria and constituted the study cohort. Over one-half (53%) of paramedics reported learning about ketamine during their initial paramedic training. Meanwhile, 42% reported seeking ketamine-related education on their own. Of all respondents, only 33% (3,421/10,737) were authorized by protocol to use ketamine. Most commonly authorized uses included pain management (55%), rapid sequence intubation (RSI; 72%), and chemical restraint/sedation (72%). One-third of authorized providers (1,107/3,350) had never administered ketamine, with another 32% (1,070/3,350) having administered ketamine less than five times in their career. Ketamine was perceived to be safe and effective as the vast majority reported that they were comfortable with the use of ketamine (94%) and would, in similar situations (95%), use it again.

CONCLUSION

This was the first large, national survey to assess ketamine training, use, and perceptions among paramedics in the civilian prehospital setting. While training related to ketamine use was commonly reported among paramedics, few were authorized to administer the drug by their agency's protocols. Of those authorized to use ketamine, most paramedics had limited experience administering the drug. Future research is needed to determine why the prevalence of ketamine use is low and to assess the safety and efficacy of ketamine use in the prehospital setting. Buckland DM , Crowe RP , Cash RE , Gondek S , Maluso P , Sirajuddin S , Smith ER , Dangerfield P , Shapiro G , Wanka C , Panchal AR , Sarani B . Ketamine in the prehospital environment: a national survey of paramedics in the United States. Prehosp Disaster Med. 2018;33(1):23-28.

Student paramedic rapid sequence intubation in Johannesburg, South Africa: A case series

Introduction

Pre-hospital rapid sequence intubation was introduced within paramedic scope of practice in South Africa seven years ago. Since then, little data has been published on this high-risk intervention as practiced operationally or by students learning rapid sequence intubation in the pre-hospital environment. The objective of this study was to describe a series of pre-hospital rapid sequence intubation cases, including those that South African University paramedic students had participated in.

Methods

A University clinical learning database was searched for all endotracheal intubation cases involving the use of neuromuscular blockers between 1 January 2011 and 31 December 2015. Data from selected cases were extracted and analysed descriptively.

Results

Data indicated that most patients were young adult trauma victims with a dominant injury mechanism of vehicle-related accidents. The majority of cases utilised ketamine and suxamethonium, with a low rate of additional paralytic medication administration. 63% and 72% of patients received post-intubation sedation and analgesia, respectively. The overall intubation success rate from complete records was 99.6%, with a first pass success rate of 87.9%. Students were successful in 92.4% of attempts with a first-pass success rate of 85.2%. Five percent of patients experienced cardiac arrest between rapid sequence intubation and hospital arrival.

Discussion

Students demonstrated a good intubation success and first pass-success rate. However, newly qualified paramedics require strict protocols, clinical governance, and support to gain experience and perform pre-hospital rapid sequence intubation at an acceptable level in operational practice. More research is needed to understand the low rate of post-intubation paralysis, along with non-uniform administration of post-intubation sedation and analgesia, and the 5% prevalence of cardiac arrest.

Paradoxical Emergence: Administration of Subanesthetic Ketamine during Isoflurane Anesthesia Induces Burst Suppression but Accelerates Recovery

BACKGROUND

Promoting arousal by manipulating certain brain regions and/or neurotransmitters has been a recent research focus, with the goal of trying to improve recovery from general anesthesia. The current study tested the hypothesis that a single subanesthetic dose of ketamine during isoflurane anesthesia would increase cholinergic tone in the prefrontal cortex and accelerate recovery.

METHODS

Adult male rats were implanted with electroencephalography electrodes (frontal, parietal, and occipital cortex) and a microdialysis guide cannula targeted for the prefrontal cortex. After establishing general anesthesia with isoflurane, animals were randomly assigned to receive a saline control or ketamine injection. When isoflurane was discontinued nearly 90 min after drug or saline administration, recovery from anesthesia was measured by experimenters and blinded observers. During the entire experiment, electrophysiologic signals were recorded and acetylcholine was quantified by high-performance liquid chromatography with electrochemical detection.

RESULTS

A single dose of subanesthetic ketamine caused an initial 125% increase in burst suppression ratio (last isoflurane sample: 37.48 ± 24.11% vs. isoflurane after ketamine injection: 84.36 ± 8.95%; P < 0.0001), but also a significant 44% reduction in emergence time (saline: 877 ± 335 s vs. ketamine: 494 ± 108 s; P = 0.0005; n = 10 per treatment). Furthermore, ketamine caused a significant 317% increase in cortical acetylcholine release (mean after ketamine injection: 0.18 ± 0.16 pmol vs. ketamine recovery: 0.75 ± 0.41 pmol; P = 0.0002) after isoflurane anesthesia was discontinued.

CONCLUSIONS

Administration of subanesthetic doses of ketamine during isoflurane anesthesia increases anesthetic depth but-paradoxically-accelerates the recovery of consciousness, possibly through cholinergic mechanisms.

Anesthesia Provision in Disasters and Armed Conflicts

PURPOSE OF REVIEW

Disasters and armed conflicts are characterized by high numbers of trauma cases, and occur mainly in developing countries where the healthcare response is already impaired, resulting in an inadequate response. Aside of the trauma cases, other surgical health conditions are also still present and require urgent care. Surgical care needs are different from context to context and depend on local means and capabilities.

RECENT FINDINGS

Doctors without Borders (MSF) has proven that even in precarious situations, safe administration of anesthesia is possible, and the "do no harm" principle can and must be upheld. Anesthesia providers need to recognize the difficulties linked to these contexts.

SUMMARY

Local, spinal and general intravenous (mainly with Ketamine) anesthetics seem to be the most widely accepted. Inhalation anesthesia has constraints; regional is underused and epidural is not recommended. Standard operative procedures should be in place, and an informed consent from the patient must be granted.

Intranasal ketamine for acute traumatic pain in the Emergency Department: a prospective, randomized clinical trial of efficacy and safety

BACKGROUND

Ketamine has been well studied for its efficacy as an analgesic agent. However, intranasal (IN) administration of ketamine has only recently been studied in the emergency setting. The objective of this study was to elucidate the efficacy and adverse effects of a sub-dissociative dose of IN Ketamine compared to IV and IM morphine.

METHODS

A single-center, randomized, prospective, parallel clinical trial of efficacy and safety of IN ketamine compared to IV and IM morphine for analgesia in the emergency department (ED). A convenience sample of 90 patients aged 18-70 experiencing moderate-severe acute traumatic pain (≥80 mm on 100 mm Visual Analog Scale [VAS]) were randomized to receive either 1.0 mg/kg IN ketamine, 0.1 mg/kg IV MO or 0.15 mg/kg IM MO. Pain relief and adverse effects were recorded for 1 h post-administration. The primary outcome was efficacy of IN ketamine compared to IV and IM MO, measured by "time-to-onset" (defined as a ≥15 mm pain decrease on VAS), as well as time to and degree of maximal pain reduction.

RESULTS

The 3 study groups showed a highly significant, similar maximal pain reduction of 56 ± 26 mm for IN Ketamine, and 59 ± 22 and 48 ± 30 for IV MO and IM MO, respectively. IN Ketamine provided clinically-comparable results to those of IV MO with regards to time to onset (14.3 ± 11.2 v. 8.9 ± 5.6 min, respectively) as well as in time to maximal pain reduction (40.4 ± 16.3) versus (33.4 ± 18), respectively.

CONCLUSIONS

IN ketamine shows efficacy and safety comparable to IV and IM MO. Given the benefits of this mode of analgesia in emergencies, it should be further studied for potential clinical applications.

TRIAL REGISTRATION

Retrospectively registered on 27 June 2016. ClinicalTrials.gov ID: NCT02817477.

Intubation of Profoundly Agitated Patients Treated with Prehospital Ketamine

Background

Profound agitation in the prehospital setting confers substantial risk to patients and providers. Optimal chemical sedation in this setting remains unclear.

Objective

The goal of this study was to describe intubation rates among profoundly agitated patients treated with prehospital ketamine and to characterize clinically significant outcomes of a prehospital ketamine protocol.

Methods

This was a retrospective cohort study of all patients who received prehospital ketamine, per a predefined protocol, for control of profound agitation and who subsequently were transported to an urban Level 1 trauma center from May 1, 2010 through August 31, 2013. Identified records were reviewed for basic ambulance run information, subject characteristics, ketamine dosing, and rate of intubation. Emergency Medical Services (EMS) ambulance run data were matched to hospital-based electronic medical records. Clinically significant outcomes are characterized, including unadjusted and adjusted rates of intubation.

Results

Overall, ketamine was administered 227 times in the prehospital setting with 135 cases meeting study criteria of use of ketamine for treatment of agitation. Endotracheal intubation was undertaken for 63% (85/135) of patients, including attempted prehospital intubation in four cases. Male gender and late night arrival were associated with intubation in univariate analyses (χ2=12.02; P=.001 and χ2=5.34; P=.021, respectively). Neither ketamine dose, co-administration of additional sedating medications, nor evidence of ethanol (ETOH) or sympathomimetic ingestion was associated with intubation. The association between intubation and both male gender and late night emergency department (ED) arrival persisted in multivariate analysis. Neither higher dose (>5mg/kg) ketamine nor co-administration of midazolam or haloperidol was associated with intubation in logistic regression modeling of the 120 subjects with weights recorded. Two deaths were observed. Post-hoc analysis of intubation rates suggested a high degree of provider-dependent variability.

Conclusions

Prehospital ketamine is associated with a high rate of endotracheal intubation in profoundly agitated patients; however, ketamine dosing is not associated with intubation rate when adjusted for potential confounders. It is likely that factors not included in this analysis, including both provider comfort with post-ketamine patients and anticipated clinical course, play a role in the decision to intubate patients who receive prehospital ketamine.

OlivesTD, NystromPC, ColeJB, DoddKW, HoJD. Intubation of profoundly agitated patients treated with prehospital ketamine. Prehosp Disaster Med. 2016;31(6):593–602.

Role of ketamine for analgesia in adults and children

Ketamine an N-methyl-D-aspartate (NMDA) receptor blocking agent and a dissociative anesthetic with neurostimulatory side effects. In recent years, multiple research trials as well as systematic reviews and meta-analyses suggest the usefulness of ketamine as a strong analgesic used in subanesthetic intravenous doses, and also as a sedative. In addition, ketamine was noted to possess properties of anti-tolerance, anti-hyperalgesia and anti-allodynia most likely secondary to inhibition of the NMDA receptors. Tolerance, hyperalgesia and allodynia phenomena are the main components of opioid resistance, and pathological pain is often seen in the clinical conditions involving neuropathic pain, opioid-induced hyperalgesia, and central sensitization with allodynia or hyperalgesia. All these conditions are challenging to treat. In low doses, ketamine does not have major adverse dysphoric effects and also has the favorable effects of reduced incidence of opioid-induced nausea and vomiting. Therefore, ketamine can be a useful adjunct for pain control after surgery. Additional studies are required to determine the role of ketamine in the immediate postoperative period after surgical interventions known to produce severe pain and in the prevention and treatment of chronic pain.

Ketamine for prehospital trauma analgesia in a low-resource rural trauma system: a retrospective comparative study of ketamine and opioid analgesia in a ten-year cohort in Iraq

Background

Opioid analgesics are used in most trauma systems, and only a few studies report on the use of ketamine for prehospital analgesia. In a low-cost rural trauma system in Iraq paramedics have been using prehospital ketamine analgesia for ten years. This study aims to evaluate the effects of prehospital analgesia on physiologic trauma severity indicators and compare the effect of ketamine and pentazocine on those indicators.

Methods

The investigation was conducted as a retrospective cohort study with parallel group design. Three subsamples of trauma patients were compared: no analgesia (n = 275), pentazocine analgesia (n = 888), and ketamine analgesia (n = 713). Physiologic severity scores were calculated based on rated values for respiratory rate, blood pressure, and consciousness. The associations between outcomes and explanatory variables were assessed using a generalized linear model.

Results

Paramedic administration of analgesia was associated with a better physiologic severity score (PSS) outcome (p = 0.01). In the two subsamples receiving analgesia significantly better outcomes were observed for respiration (p < 0.0001) and systolic blood pressure (p < 0.0001). In patients with Injury Severity Score >8 ketamine was associated with a significantly better effect on the systolic blood pressure compared to opioid analgesia (p = 0.03).

Conclusion

Prehospital analgesia for trauma victims improves physiologic severity indicators in a low-resource trauma system. Compared to pentazocine, ketamine was associated with improved blood pressure for patients with serious injuries. In a low-resource setting, ketamine seems to be a good choice for prehospital analgesia in trauma patients.

The analgesic effect of combined treatment with intranasal S-ketamine and intranasal midazolam compared with morphine patient-controlled analgesia in spinal surgery patients: a pilot study

Objectives

Ketamine is a well-known analgesic and dose-dependent anesthetic used in emergency and disaster medicine. Recently, a new formulation of S-ketamine, as an intranasal spray, was developed and tested in our institution in healthy volunteers. The authors investigated the effect of intranasal S-ketamine spray combined with midazolam intranasal spray in postoperative spinal surgery patients.

Materials and methods

In this prospective, computer-randomized, double-blinded noninferiority study in spinal surgery patients, the effects of intranasal S-ketamine and midazolam were compared with standard morphine patient-controlled analgesia (PCA). The primary end point was the numeric rating scale pain score 24 hours after surgery.

Results

Twenty-two patients finished this study, eleven in each group. There were similar numeric rating scale scores in the morphine PCA and the S-ketamine-PCA groups at 1, 2, 4, 24, 48, and 72 hours after surgery during rest as well as in motion. There were no differences in the satisfaction scores at any time between the groups. The number of bolus demands and deliveries was not significantly different.

Discussion

In our study, we found that an S-ketamine intranasal spray combined with intra-nasal midazolam was similar in effectiveness, satisfaction, number of demands/deliveries of S-ketamine and morphine, and number/severity of adverse events compared with standard intravenous PCA with morphine. S-ketamine can be regarded as an effective alternative for a traditional intravenous morphine PCA in the postoperative setting.

Prehospital use of i.m. ketamine for sedation of violent and agitated patients

INTRODUCTION

Violent and agitated patients pose a serious challenge for emergency medical services (EMS) personnel. Rapid control of these patients is paramount to successful prehospital evaluation and also for the safety of both the patient and crew. Sedation is often required for these patients, but the ideal choice of medication is not clear. The objective is to demonstrate that ketamine, given as a single intramuscular injection for violent and agitated patients, including those with suspected excited delirium syndrome (ExDS), is both safe and effective during the prehospital phase of care, and allows for the rapid sedation and control of this difficult patient population.

METHODS

We reviewed paramedic run sheets from five different catchment areas in suburban Florida communities. We identified 52 patients as having been given intramuscular ketamine 4 mg/kg i.m., following a specific protocol devised by the EMS medical director of these jurisdictions, to treat agitated and violent patients, including a subset of which would be expected to suffer from ExDS. Twenty-six of 52 patients were also given parenteral midazolam after medical control was obtained to prevent emergence reactions associated with ketamine.

RESULTS

Review of records demonstrated that almost all patients (50/52) were rapidly sedated and in all but three patients no negative side effects were noted during the prehospital care. All patients were subsequently transported to the hospital before ketamine effects wore off.

CONCLUSION

Ketamine may be safely and effectively used by trained paramedics following a specific protocol. The drug provides excellent efficacy and few clinically significant side effects in the prehospital phase of care, making it an attractive choice in those situations requiring rapid and safe sedation especially without intravenous access.