Prehospital analgesia using nasal administration of S-ketamine--a case series

Esketamine: Less Drowsiness, More Analgesia

Racemic ketamine is a 1:1 mixture of 2 enantiomers that turn light in opposite direction: Dextrorotatory esketamine is approximately 4 times more affine for the N-methyl-D-aspartate (NMDA) receptor than levorotatory arketamine, which may explain why esketamine is about twice as potent as an analgesic and anesthetic as the racemate. Esketamine has attracted renewed interest in view of the opioid crisis, racemic ketamine's abuse, and esketamine's approval for expanded use. We evaluated the anesthesia literature concerning mental, cardiovascular, cerebral, and antinociceptive effects of esketamine published in English between 1980 and 2022. The review shows that esketamine and racemic ketamine are not "the same" at clinically equivalent analgesic and anesthetic dose: Psychomimetic effects seem to be essentially related to NMDA receptor blockade and esketamine is not devoid of unwanted mental impact. However, it probably involves less cholinergic inhibition. Cognitive disturbances during arousal, awakening, and recovery from the drug are less, and less pronounced with esketamine. The drug allows for an approximately 50% dose reduction in anesthesia and analgesia which goes along with a higher clearance and shorter recovery time as compared to racemic ketamine. In comparison of esketamine with placebo, esketamine shows cardiocirculatory stabilizing and neuroprotective effects which can be seen in anesthesia induction, cardiac surgery, and analgesia and sedation in brain injury. Evidence of esketamine's antinociceptive efficacy is inconsistent, although a recent meta-analysis reports improved pain relief after surgery in a study with short observation time. To better define esketamine's place, direct head-to-head comparison with the racemate at equi-analgesic/anesthetic dose is warranted.

What is the Evidence for Using Intranasal Medicine in the Prehospital Setting? A Systematic Review

OBJECTIVES

Intranasal (IN) medications offer a safe non-invasive way to rapidly deliver drugs in situations where intravenous (IV) access and intramuscular (IM) administration is challenging or not feasible. In the prehospital setting, this can be an essential alternative in time critical situations including trauma management, seizures, and agitated patients. However, there is a paucity of evidence summarizing its efficacy in this environment. This systematic review aims to assess the current evidence supporting the use of IN medicine (midazolam, ketamine, fentanyl, morphine, glucagon, and naloxone) in the prehospital setting alone.

METHODS

A systematic literature search (PROSPERO CRD42023440713) of PubMed, Web of Science, OVID Medline, "Cochrane Central Register of Controlled Trials," Cochrane reviews and Embase was performed from inception to June 2023 to identify studies where IN medications were administered to patients in the prehospital setting. All randomized controlled trials, observational cohort studies, case series, and case reports were included. Papers not written in English, review articles, abstracts, and non-published data (including letters to the editor) were excluded. The methodological quality of the included studies was interpreted using the Cochrane risk of bias tool and rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. No funding was received.

RESULTS

From 4818 studies, 39 were included (seven for midazolam, five for ketamine, twelve for fentanyl, one for diamorphine, two for glucagon, and twelve for naloxone). A total of 24,097 patients were treated with IN medications across all the studies. There were five moderate quality, four low quality, and thirty very low quality studies. The potential efficacy of IN fentanyl and ketamine was demonstrated consistently throughout the studies with less clear evidence for midazolam, morphine, glucagon, and naloxone. This review was severely limited by the study quality, with most studies demonstrating "high concerns" for bias.

CONCLUSIONS

Prehospital IN medication administration has wide-ranging potential, particularly for administering analgesia. There are likely to be certain populations, for example, pediatrics, that will benefit the most, although conclusions are limited by the quality of evidence currently available. We encourage additional research in this area, particularly with robust prospective double-blind RCTs.

Research advances in the clinical application of esketamine

Esketamine is dextrorotatory ketamine, which is an enantiomer of ketamine. Compared with ketamine, it has the advantages of a fast metabolism, fewer side effects, and strong pharmacological effects, so it is more suitable for clinical use. Esketamine has a powerful analgesic effect and has little effect on breathing. It has a wide range of applications in the fields of pediatric anesthesia, conscious sedation anesthesia, and emergency analgesia. In addition, it is also used for pain that is difficult to relieve with conventional drugs and to prevent postoperative pain. Various routes of administration are also suitable for patients who need short-term analgesia and sedation. As a drug, esketamine inevitably brings some side effects when it is used clinically. In this article, by introducing the mechanism of action and pharmacological characteristics of esketamine, its clinical application is reviewed, and it provides a reference for the more reasonable and safe clinical application of esketamine.

A Comparison of Intranasal Dexmedetomidine, Esketamine or a Dexmedetomidine-Esketamine Combination for Induction of Anaesthesia in Children: A Randomized Controlled Double-Blind Trial

Objective: To compare the efficacy of dexmedetomidine, esketamine or combined intranasal administration on the induction of inhalation anaesthesia in children.

Methods: Ninety children aged 1–6 years were randomly allocated into three equal groups to be premedicated with either intranasal dexmedetomidine 2 μg/kg (Group D), esketamine 1 mg/kg (Group S), or dexmedetomidine 1 μg/kg combined with esketamine 0.5 mg/kg (Group DS). The primary endpoint was the Induction Compliance Checklist (ICC) Scale. Secondary outcomes included the sedation success rate; the modified Yale Preoperative Anxiety Scale score; the time of reaching up to two points on the University of Michigan Sedation Scale (UMSS); Parental Separation Anxiety Scale; anaesthesiologist satisfaction with induction based on the visual analogue scale; emergence agitation scale score; and adverse effects.

Results: The children in the DS group showed a high degree of cooperation with inhalation anaesthesia induction, and their ICC score was significantly lower than that of the D and S groups (p = 0.001), but there was no difference between the D and S groups. The success rate of sedation was higher in Group DS (90%) than in Group D (70%) and Group S (53.3%) (p = 0.007). Anaesthesiologist satisfaction with induction was significantly higher in Group DS than in Groups D and S (p = 0.001). The incidence of emergence agitation and the Paediatric Anaesthesia Emergence Delirium (PAED) score in the DS group were lower than those in the D and S groups.

Conclusions: Preoperative intranasal administration of dexmedetomidine combined with esketamine can significantly improve the cooperation of children with inhalation anaesthesia masks. It is a sedation method that has a high success rate and reduces the incidence and degree of emergence agitation.

[Prehospital Pain Management: Overview and Potential Improvements]

Prehospital Pain Management: Overview and Potential Improvements Abstract. Pain is a frequent issue in the prehospital setting. Rapid and adequate analgesia has a positive effect on the physiological and psychological condition of patients. However, up to 43 % of patients still suffer insufficient analgesia. Several studies have identified some factors that contribute to this problem; these factors can be patient- and intervention-specific or dependent on the staff on duty. In order to improve prehospital analgesia in the future, structural and organizational changes as well as the implementation of new methods and therapies are essential.

The predictors, barriers and facilitators to effective management of acute pain in children by emergency medical services: A systematic mixed studies review

We aimed to identify predictors, barriers and facilitators to effective pre-hospital pain management in children. A segregated systematic mixed studies review was performed. We searched from inception to 30-June-2020: MEDLINE, CINAHL Complete, PsycINFO, EMBASE, Web of Science Core Collection and Scopus. Empirical quantitative, qualitative and multi-method studies of children under 18 years, their relatives or emergency medical service staff were eligible. Two authors independently performed screening and selection, quality assessment, data extraction and quantitative synthesis. Three authors performed thematic synthesis. Grading of Recommendations Assessment, Development and Evaluation and Confidence in the Evidence from Reviews of Qualitative Research were used to determine the confidence in cumulative evidence. From 4030 articles screened, 78 were selected for full text review, with eight quantitative and five qualitative studies included. Substantial heterogeneity precluded meta-analysis. Predictors of effective pain management included: 'child sex (male)', 'child age (younger)', 'type of pain (traumatic)' and 'analgesic administration'. Barriers and facilitators included internal (fear, clinical experience, education and training) and external (relatives and colleagues) influences on the clinician along with child factors (child's experience of event, pain assessment and management). Confidence in the cumulative evidence was deemed low. Efforts to facilitate analgesic administration should take priority, perhaps utilising the intranasal route. Further research is recommended to explore the experience of the child. Registration: PROSPERO CRD42017058960.

Intranasal Ketamine for Acute Pain

OBJECTIVES

The aim was to review current evidence regarding the off-label use of intranasal ketamine for acute pain presenting in the setting of the emergency department, and secondary to pediatric limb injuries, renal colic, digital nerve block, and migraines.

RESULTS

In all 5 indications reviewed, ketamine demonstrated efficacy in reducing pain. However, when compared with other agents, ketamine did not demonstrate superiority over opioids in pediatric limb injuries or renal colic and was not as efficacious as standard therapy for migraine relief. Ketamine was also associated with a greater incidence of transient adverse reactions, such as dizziness, bitter aftertaste, fatigue, and vomiting than opioid therapies.

DISCUSSION

The current body of evidence is insufficient to support the use of intranasal ketamine over other standard therapies for acute pain. However, current evidence can be used when developing dosing strategies, preparing for adverse reactions, and generating hypotheses for future, more robust research.

[Analgesia for trauma patients in emergency medicine]

Adequate analgesia is one of the most important measures of emergency care in addition to treatment of vital function disorders and, if indicated, should be promptly undertaken; however, a large proportion of emergency patients receive no or only inadequate pain therapy. The numeric rating scale (NRS) is recommended for pain assessment but is not applicable to every group of patients; therefore, vital signs and body language should be included in the assessment. Pain therapy should reduce the NPRS to <5 points. Ketamine and fentanyl, which have an especially rapid onset of action, and also morphine are suitable for analgesia in spontaneously breathing patients. Basic prerequisites for safe and effective analgesia by healthcare professionals are the use of adequate monitoring, the provision of well-defined emergency equipment, and the mastery of emergency procedures. In a structured competence system, paramedics and nursing personnel can perform safe and effective analgesia.

IMPORTANCE trial: a provisional study-design of a single-center, phase II, double-blinded, placebo-controlled, randomized, 4-week study to compare the efficacy and safety of intranasal esketamine in chronic opioid refractory pain

Background:  Cancer is the second leading cause of death globally. Up to 86% of advanced cancer patients experience significant pain, while 10-20% live in chronic pain. Besides, increasing prescription of opioids resulted in 33,000 deaths in the US in 2015. Both reduce patients’ functional status and quality of life. While cancer survival rates are increasing, therapeutic options for chronic opioid refractory pain are still limited. Esketamine is the s-enantiomer of ketamine, with superior analgesic effect and less psychotomimetic side effects. Intranasal esketamine was approved by the FDA for treatment-resistant depression. However, its use in chronic cancer pain has never been tested. Therefore, we propose a phase II, randomized, placebo-controlled trial to evaluate the efficacy and safety of intranasal esketamine in chronic opioid refractory cancer pain.

Methods and analysis: We will recruit 120 subjects with chronic opioid refractory pain, defined as pain lasting more than 3 months despite optimal therapy with high dose opioids (>60 mg morphine equivalent dose/day) and optimal adjuvant therapy. Subjects will be randomized into two groups: intranasal esketamine (56mg) and placebo. Treatment will be administered twice a week for four consecutive weeks. The primary outcome is defined as reduction in the Numeric Pain Rating Scale (NPRS) after first application. Secondary outcomes include NPRS reduction after four weeks, the number of daily morphine rescue doses, functional status and satisfaction, and depression.

Conclusion: This study may extend therapeutic options in patients with chronic pain, thus improving their quality of life and reducing opioid use.

Trial registration: Clinical Trials.gov, NCT04666623. Registered on 14 December 2020

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

BACKGROUND

Few publications have addressed prehospital use of ketamine in analgesic doses. We aimed to assess the effect and safety profile of ketamine compared with other analgesic drugs (or no drug) in adult prehospital patients with acute pain.

METHODS

A systematic review of clinical trials assessing prehospital administration of ketamine in analgesic doses compared with other analgesic drugs or no analgesic treatment in adults. We searched PubMed, EMBASE, Cochrane Library and Epistemonikos from inception until 15 February 2020, including relevant articles in English and Nordic languages. We used the Cochrane and Grading of Recommendations Assessment, Development and Evaluation methodologies and exclusively assessed patient-centred outcomes. Two independent authors screened trials for eligibility, extracted data and assessed risk of bias.

RESULTS

We included eight studies (2760 patients). Ketamine was compared with various opioids given alone, and intranasal ketamine given with nitrous oxide was compared with nitrous oxide given alone. Four randomised controlled trials (RCTs) and one cluster randomised trial included 699 patients. One prospective cohort included 27 patients and two retrospective cohorts included 2034 patients. Five of the eight studies had high risks of bias. Pain score with ketamine is probably lower than after opioids as demonstrated in a cluster-RCT (308 patients) and a retrospective cohort (158 patients) study, Δvisual analogue scale -0.4 (-0.8 to 0.0) and Δnumeric pain rating scale -3.0 (-3.86 to -2.14), respectively. Ketamine probably leads to less nausea and vomiting (risk ratio (RR) 0.24 (0.11 to 0.52)) but more agitation (RR 7.81 (1.85 to 33)) than opioids.

CONCLUSIONS

This systematic literature review finds that ketamine probably reduces pain more than opioids and with less nausea and vomiting but higher risk of agitation. Risk of bias in included studies is high.

OTHER

Scandinavian society of anaesthesiology and intensive care medicine funded meetings and software. The Norwegian Air Ambulance Foundation funded publication. Otherwise this research received no grant from any agency in the public, commercial or not-for-profit sectors.

PROSPERO REGISTRATION NUMBER

CRD42018114399.

Intranasal Ketamine for Treatment of Acute Pain in Pediatrics: A Systematic Review

OBJECTIVES

Intranasal ketamine has not been well studied in acute pain treatment and does not have a recognized place in therapy in current practice guidelines for pediatric patients. Ketamine has a unique mechanism of action with a favorable side effect profile that may provide benefit to the pediatric population for acute pain. The purpose of this review is to summarize the evidence evaluating intranasal ketamine versus any other comparator for children who require acute pain treatment.

METHODS

A systematic review was performed to include clinical studies of intranasal ketamine for acute pain that reported any pain-related outcome and adverse events in children 0 to 17 years old. Trials were identified through PubMed, Google Scholar, clinical trial registries, research registries, and key journals through April 2018. The Jadad scoring system was used to assess the methodological quality of the included randomized controlled trials.

RESULTS

Six studies consisting of 261 patients were reviewed. Intranasal ketamine demonstrated pain relief in all included clinical studies; however, there was inconsistency in dosing, comparators, scales, and indications. Two of the randomized controlled trials were rated as high quality, and 1 randomized controlled trial was rated as poor quality on the Jadad scale.

CONCLUSIONS

Intranasal ketamine was safe and effective in the 6 clinical studies included in this systematic review.

Out-of-hospital ketamine: review of a growing trend in patient care

Ketamine is a unique medication with a long history of use in the emergency department. Out-of-hospital indications for ketamine have been explored and are currently expanding in some systems. This article provides background on ketamine history and pharmacology, its use in the hospital environment and possible applications for emergency medical services usage of this medication. Contraindications and adverse reactions are discussed to provide education on the nuances of ketamine administration and mitigation strategies. Out-of-hospital indications for ketamine are discussed including airway management, rapid sequence induction, analgesia, sedation, and treatment of excited delirium.

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.

Pre-hospital intranasal analgesia for children suffering pain: a rapid evidence review

Introduction:

Pre-hospital analgesic treatment of injured children is suboptimal, with very few children in pain receiving analgesia. Studies have identified a number of barriers to pre-hospital pain management in children which include the route of analgesia administration. The aim of this review is to critically evaluate the pre-hospital literature, exploring the safety and efficacy of intranasal (IN) analgesics for children suffering pain.

Methods:

We performed a rapid evidence review, searching from inception to 17 December 2018, CINAHL, MEDLINE and Google Scholar. We included studies of children < 18 years suffering pain who were administered any IN analgesic in the pre-hospital setting. Our outcomes were effective pain management, defined as a pain score reduction of ≥ 2 out of 10, safety and rates of analgesia administration. Screening and risk of bias assessments were performed in duplicate. We performed a narrative synthesis.

Results:

From 310 articles screened, 23 received a full-text review resulting in 10 articles included. No interventional studies were found. Most papers reported on the use of intranasal fentanyl (INF) (n = 8) with one reporting IN ketamine and the other IN S-ketamine. Narrative synthesis showed that INF appeared safe and effective at reducing pain; however, its ability to increase analgesia administration rates was unclear. The effectiveness, safety and ability of IN ketamine and S-ketamine to increase analgesia administration rates were unclear. There was no evidence for IN diamorphine for children in this setting.

Conclusion:

Interventional studies are needed to determine with a higher confidence the effectiveness and safety of IN analgesics (fentanyl, ketamine, S-ketamine, diamorphine) for children in the pre-hospital setting.

Randomized clinical trial on the efficacy of intranasal or oral ketamine-midazolam combinations compared to oral midazolam for outpatient pediatric sedation

Purpose

The optimal sedative regime that provides the greatest comfort and the lowest risk for procedural sedation in young children remains to be determined. The aim of this randomized, blinded, controlled, parallel-design trial was to evaluate the efficacy of intranasal ketamine and midazolam as the main component of the behavioral guidance approach for preschoolers during dental treatment.

Materials and methods

Children under seven years of age, with caries and non-cooperative behavior, were randomized into three groups: (KMIN) intranasal ketamine and midazolam; (KMO) oral ketamine and midazolam; or (MO) oral midazolam. The dental sedation appointments were videotaped, and the videos were analyzed using the Ohio State University Behavioral Rating Scale (OSUBRS) to determine the success of the sedation in each group. Intra- and postoperative adverse events were recorded. Data analysis involved descriptive statistics and non-parametric tests (P < 0.05, IBM SPSS).

Results

Participants were 84 children (28 per group; 43 boys), with a mean age of 3.1 years (SD 1.2). Children’s baseline and the dental sedation session characteristics were balanced among groups. The success of the treatment as assessed by the dichotomous variable ‘quiet behavior for at least 60% of the session length’ was: KMIN 50.0% (n = 14; OR 2.10, 95% CI 0.71 to 6.30), KMO 46.4% (n = 13; OR 1.80, 95% CI 0.62 to 5.40), MO 32.1% (n = 9) (P = 0.360). Adverse events were minor, occurred in 37 of 84 children (44.0%), and did not differ among groups (P = 0.462).

Conclusion

All three regimens provided moderate dental sedation with minor adverse events, with marked variability in the behavior of children during dental treatment. The potential benefit of the ketamine–midazolam combination should be further investigated in studies with larger samples.

Trial registration

ClinicalTrials.gov, identifier: NCT02447289. Registered on 11 May 2015, named “Midazolam and Ketamine Effect Administered Through the Nose for Sedation of Children for Dental Treatment (NASO).”

Ketamine and Ketamine Metabolite Pharmacology: Insights into Therapeutic Mechanisms

Ketamine, a racemic mixture consisting of (S)- and (R)-ketamine, has been in clinical use since 1970. Although best characterized for its dissociative anesthetic properties, ketamine also exerts analgesic, anti-inflammatory, and antidepressant actions. We provide a comprehensive review of these therapeutic uses, emphasizing drug dose, route of administration, and the time course of these effects. Dissociative, psychotomimetic, cognitive, and peripheral side effects associated with short-term or prolonged exposure, as well as recreational ketamine use, are also discussed. We further describe ketamine's pharmacokinetics, including its rapid and extensive metabolism to norketamine, dehydronorketamine, hydroxyketamine, and hydroxynorketamine (HNK) metabolites. Whereas the anesthetic and analgesic properties of ketamine are generally attributed to direct ketamine-induced inhibition of N-methyl-D-aspartate receptors, other putative lower-affinity pharmacological targets of ketamine include, but are not limited to, γ-amynobutyric acid (GABA), dopamine, serotonin, sigma, opioid, and cholinergic receptors, as well as voltage-gated sodium and hyperpolarization-activated cyclic nucleotide-gated channels. We examine the evidence supporting the relevance of these targets of ketamine and its metabolites to the clinical effects of the drug. Ketamine metabolites may have broader clinical relevance than was previously considered, given that HNK metabolites have antidepressant efficacy in preclinical studies. Overall, pharmacological target deconvolution of ketamine and its metabolites will provide insight critical to the development of new pharmacotherapies that possess the desirable clinical effects of ketamine, but limit undesirable side effects.

Intranasal Ketamine and Its Potential Role in Cancer-Related Pain

Cancer-related pain continues to be a significant therapeutic challenge, made more difficult by contemporary opioid use and diversion concerns. Conventional treatment using a tiered approach of nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and adjuvant agents is limited; and alternatives are needed for patients with rapidly progressing pain and those who develop hyperalgesia and tolerance to opioids. Ketamine, an N-methyl-d-aspartate (NMDA) selective antagonist, has historically been used for anesthesia in adult and pediatric populations but has also been investigated for depression, bipolar disorder, and general and postoperative pain management. As an analgesic, low-dose ketamine decreases morphine requirements and rates of nausea and vomiting, suggesting a potentially beneficial role in cancer-related pain. Ketamine is typically administered intravenously and has a rapid onset of action with a relatively short half-life (2-3 hours) but is inconvenient for use in an ambulatory setting. Oral bioavailability is low and erratic, limiting application of this route for chronic use. Intranasal administration has a number of potential advantages, including avoidance of first-pass hepatic metabolism, no need for venous access, ability to repeat doses quickly, and rapid absorption. Although early studies of intranasal ketamine are promising in a number of indications, information is more limited in its use as an adjunct in cancer-related pain. We review the background, rationale, pharmacokinetics, and clinical and safety data using intranasal ketamine as an adjunctive agent and its potential in cancer-related pain.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Böttiger B, Bouillon B, Fischer M, Gaier G, Gliwitzky B, Helm M, Hilbert-Carius P, Hossfeld B, Meisner C, Schempf B, Wafaisade A, Bernhard M. Analgesia in Patients with Trauma in Emergency Medicine

BACKGROUND

Suitable analgesic drugs and techniques are needed for the acute care of the approximately 18 200-18 400 seriously injured patients in Germany each year.

METHODS

This systematic review and meta-analysis of analgesia in trauma patients was carried out on the basis of randomized, controlled trials and observational studies. A systematic search of the literature over the 10-year period ending in February 2016 was carried out in the PubMed, Google Scholar, and Springer Link Library databases. Some of the considered trials and studies were included in a meta-analysis. Mean differences (MD) of pain reduction or pain outcome as measured on the Numeric Rating Scale were taken as a summarizing measure of treatment efficacy.

RESULTS

Out of 685 studies, 41 studies were considered and 10 studies were included in the meta-analysis. Among the drugs and drug combinations studied, none was clearly superior to another with respect to pain relief. Neither fentanyl versus morphine (MD -0.10 with a 95% confidence interval of [-0.58; 0.39], p = 0.70) nor ketamine versus morphine (MD -1.27 [-3.71; 1.16], p = 0.31), or the combination of ketamine and morphine versus morphine alone (MD -1.23 [-2.29; -0.18], p = 0.02) showed clear superiority regarding analgesia.

CONCLUSION

Ketamine, fentanyl, and morphine are suitable for analgesia in spontaneously breathing trauma patients. Fentanyl and ketamine have a rapid onset of action and a strong analgesic effect. Our quantitative meta-analysis revealed no evidence for the superiority of any of the three substances over the others. Suitable monitoring equipment, and expertise in emergency procedures are prerequisites for safe and effective analgesia by healthcare professionals..

Factors Influencing Quality of Pain Management in a Physician Staffed Helicopter Emergency Medical Service

BACKGROUND

Pain is frequently encountered in the prehospital setting and needs to be treated quickly and sufficiently. However, incidences of insufficient analgesia after prehospital treatment by emergency medical services are reported to be as high as 43%. The purpose of this analysis was to identify modifiable factors in a specific emergency patient cohort that influence the pain suffered by patients when admitted to the hospital.

METHODS

For that purpose, this retrospective observational study included all patients with significant pain treated by a Swiss physician-staffed helicopter emergency service between April and October 2011 with the following characteristics to limit selection bias: Age > 15 years, numerical rating scale (NRS) for pain documented at the scene and at hospital admission, NRS > 3 at the scene, initial Glasgow coma scale > 12, and National Advisory Committee for Aeronautics score < VI. Univariate and multivariable logistic regression analyses were performed to evaluate patient and mission characteristics of helicopter emergency service associated with insufficient pain management.

RESULTS

A total of 778 patients were included in the analysis. Insufficient pain management (NRS > 3 at hospital admission) was identified in 298 patients (38%). Factors associated with insufficient pain management were higher National Advisory Committee for Aeronautics scores, high NRS at the scene, nontrauma patients, no analgesic administration, and treatment by a female physician. In 16% (128 patients), despite ongoing pain, no analgesics were administered. Factors associated with this untreated persisting pain were short time at the scene (below 10 minutes), secondary missions of helicopter emergency service, moderate pain at the scene, and nontrauma patients. Sufficient management of severe pain is significantly better if ketamine is combined with an opioid (65%), compared to a ketamine or opioid monotherapy (46%, P = .007).

CONCLUSIONS

In the studied specific Swiss cohort, nontrauma patients, patients on secondary missions, patients treated only for a short time at the scene before transport, patients who receive no analgesic, and treatment by a female physician may be risk factors for insufficient pain management. Patients suffering pain at the scene (NRS > 3) should receive an analgesic whenever possible. Patients with severe pain at the scene (NRS ≥ 8) may benefit from the combination of ketamine with an opioid. The finding about sex differences concerning analgesic administration is intriguing and possibly worthy of further study.

Subdissociative intranasal ketamine plus standard pain therapy versus standard pain therapy in the treatment of paediatric sickle cell disease vaso-occlusive crises in resource-limited settings: study protocol for a randomised controlled trial

INTRODUCTION

Pediatric sickle cell disease, highly prevalent in sub-Saharan Africa, carries great morbidity and mortality risk. Limited resources and monitoring make management of acute vaso-occlusive crises challenging. This study aims to evaluate the efficacy and safety of subdissociative intranasal ketamine as a cheap, readily available and easily administered adjunct to standard pain therapy. We hypothesise that subdissociative, intranasal ketamine may significantly augment current approaches to pain management in resource-limited settings in a safe and cost-effective manner.

METHODS AND ANALYSIS

This is a multicentred, randomised, double-blind, placebo-controlled trial enrolling children 4-16 years of age with sickle cell disease and painful vaso-occlusive pain crises. Study sites include two sub-Saharan teaching and referral hospitals with acute intake areas. All patients receive standard analgesic therapy during evaluation. Patients randomised to the treatment arm receive 1 mg/kg intranasal ketamine at onset of therapy, while placebo arm participants receive volume-matched intranasal normal saline. All participants and clinical staff are blinded to the treatment allocation. Data will be analysed on an intention-to-treat basis. Primary endpoints are changes in self-report pain scales (Faces Pain Scale-Revised) at 30, 60 and 120 minutes and rates of adverse events. Secondary endpoints include hospital length of stay, total analgesia use and quality of life assessment 2-3 weeks postintervention.

ETHICS AND DISSEMINATION

The research methods for this study have been approved by the Cameroon Baptist Convention Health Board Institutional Review Board (IRB2015-07), the Tanzanian National Institute for Medical Research (NIMR/HQ/R.8a/Vol. IX/2299), Muhimbili National Hospital IRB (MNH/IRB/I/2015/14) and the Tanzanian Food and Drugs Authority (TFDA0015/CTR/0015/9). Data reports will be provided to the Data and Safety Monitoring Board (DSMB) periodically throughout the study as well as all reports of adverse events. All protocol amendments will also be reviewed by the DSMB. Study results, regardless of direction or amplitude, will be submitted for publication in relevant peer-reviewed journals.

TRIAL REGISTRATION

ClinicalTrials.Gov, NCT02573714. Date of registration: 8 October 2015. Pre-results.

Comparing the analgesic effect of intranasal with intravenous ketamine in isolated orthopedic trauma: A randomized clinical trial

Objectives

Ketamine is commonly used in anesthetic and sedation before surgical procedures and acts as an analgesic in smaller doses. The aim of this study was to assess the effects of intranasal (IN) ketamine in patients with moderate to severe limb trauma (visual analog scale (VAS) > 60 mm).

Methods

In a triple-blind randomized controlled clinical trial; 154 patients with isolated orthopedic trauma and visual analog scale (VAS) ≥60 mm were included on the basis of inclusion and exclusion criteria. Patients were divided into two groups of ketamine-IN (0.4 mg/kg IN ketamine and an equal volume of placebo saline intravenously (IV)) and ketamine-IV (0.2 mg/kg ketamine IV with 0.5 ml saline IN) on the basis of balanced block randomization method. At 5, 10, 20, and 30 min, patients were assessed for VAS measurement and adverse events. Repeated measure ANOVA, independent t-test and chi square test were employed. The level of statistical significance was considered to be less than 0.05.

Results

Mean VAS in IN ketamine and IV group at minute 30 was 31.50 ± 13.40 and 29.35 ± 11.73, respectively. At minute 30, 31 patients (20.39%) required a low-dose of morphine as rescue analgesia (P = 0.427). The results showed that mean change score of VAS (difference of time 0 and time 30) in IN ketamine and IV ketamine VAS were 43.8 (95% confidence interval: 41.1–46.5) and 46.4 (95% confidence interval: 42.8–50.1) and there is no difference between two groups in case of score change of VAS (P = 0.245). Adverse events in nasal and intravenous ketamine in both groups were mild and transient.

Conclusion

IN ketamine is associated with few side effects and appropriate analgesic effects in isolated orthopedic trauma patients, and it may be used in cases where there is no need for venipuncture of peripheral vessels, especially in crowded EDs.

Intranasal sedation using ketamine and midazolam for pediatric dental treatment (NASO): study protocol for a randomized controlled trial

BACKGROUND

Uncooperative children may need to receive dental treatment under sedation, which is indicated when nonpharmacological behavior guidance is unsuccessful. There are randomized controlled trials (RCTs) comparing different sedative protocols for dental procedures; however, the evidence for superiority of one form over another is weak. The primary aim of this study is to investigate the efficacy of intranasally administered ketamine plus midazolam for the dental treatment of children.

METHODS

We have designed a three-armed, parallel RCT to assess intranasal sedation using ketamine/midazolam in terms of the following measures: efficacy, safety, and cost-effectiveness. Two- to 6-year-old healthy children, referred for dental treatment in a dental sedation center in Brazil due to uncooperative behavior and requiring restorative dental procedures, will be recruited. Each child will be randomly assigned to one of the three groups: A - Intranasal administration of ketamine (4.0 mg/kg, maximum 100 mg) and midazolam (0.2 mg/kg, maximum 5.0 mg); B - Oral administration of ketamine (4.0 mg/kg, maximum 100 mg) and midazolam (0.5 mg/kg, maximum 20 mg); and C - Oral administration of midazolam (1.0 mg/kg, maximum 20 mg). The primary outcome is the child's behavior assessed through an observational scale using digital videos of the restorative dental treatment under sedation. The secondary outcomes are as follows: acceptance of sedative administration; memory of intraoperative events; the child's stress; adverse events; the child's pain during the procedure; the parent's, dentists', and child's perceptions of sedation; and economic analysis. Measures will be taken at baseline and drug administration and during and after the dental procedure. The necessary sample size was estimated to be 84 children after a blinded interim analysis of the first 30 cases.

DISCUSSION

This study will provide data that can substantially add to science and pediatric dentistry as it examines the effect of sedative regimes from different perspectives (outcomes).

TRIAL REGISTRATION

ClinicalTrials.gov, identifier: NCT02447289 . Registered on 11 May 2015, named "Midazolam and Ketamine Effect Administered Through the Nose for Sedation of Children for Dental Treatment (NASO)."

Clinical evaluation of intranasal medetomidine-ketamine and medetomidine-S(+)-ketamine for induction of anaesthesia in rabbits in two centres with two different administration techniques

OBJECTIVE

The aim was to compare efficacy and side effects of induction with medetomidine-ketamine or medetomidine-S(+)-ketamine by intranasal (IN) instillation in rabbits and to evaluate both protocols during subsequent isoflurane anaesthesia.

STUDY DESIGN

Prospective, blinded, randomized experimental study in two centres.

ANIMALS

Eighty-three healthy New Zealand White rabbits undergoing tibial or ulnar osteotomy.

METHODS

Medetomidine (0.2 mg kg^-1) with 10 mg kg^-1 ketamine (MK) or 5 mg kg^-1 S(+)-ketamine (MS) was administered IN to each rabbit in a randomized fashion. In Centre 1 (n = 42) rabbits were held in sternal recumbency, and in Centre 2 (n = 41) in dorsal recumbency, during drug instillation. Adverse reactions were recorded. If a rabbit swallowed during endotracheal intubation, half of the initial IN dose was repeated and intubation was re-attempted after 5 minutes. Anaesthesia was maintained with isoflurane. Heart rate, blood pressure, endtidal carbon dioxide concentration and blood gases were recorded. Data were analysed using Student's t-test, Mann-Whitney test and Fisher's exact test.

RESULTS

In all, 39 animals were assigned to the MK group and 44 to the MS group. Two rabbits in the MS group held in dorsal recumbency died after instillation of the drug. Eight (MK) and 11 rabbits (MS) were insufficiently anaesthetized and received a second IN dose. One rabbit in MK and three in MS required an isoflurane mask induction after the second IN dose. There were no significant differences between treatments for induction, intraoperative data, blood gas values and recovery data.

CONCLUSION AND CLINICAL RELEVANCE

This study indicated that medetomidine-ketamine and medetomidine-S(+)-ketamine were effective shortly after IN delivery, but in dorsal recumbency IN administration of S(+)-ketamine led to two fatalities. Nasal haemorrhage was noted in both cases; however, the factors leading to death have not been fully elucidated.

Safety and efficacy of intranasally administered medications in the emergency department and prehospital settings

PURPOSE

The safety and efficacy of medications that may be administered via the intranasal route in adult patients in the prehospital and emergency department (ED) settings are reviewed.

SUMMARY

When medications of appropriate molecular character and concentration are delivered intranasally, they are quickly transported across this capillary network and delivered to the systemic circulation, thereby avoiding the absorption-limiting effects of first-pass metabolism. Therapeutic drug concentrations are rapidly attained in the cerebrospinal fluid, making intranasal administration a very effective mode of delivery. To optimize the bioavailability of intranasally administered drugs, providers must minimize the barriers to absorption, minimize the volume by maximizing the concentration, maximize the absorptive surface of the nasal mucosa, and use a delivery system that maximizes drug dispersion and minimizes drug runoff. Medications can be instilled into the nasal cavity with syringes or droppers by applying a few drops at a time or via atomization. The intranasal route of administration may be advantageous for patients who require analgesia, sedation, anxiolysis, termination of seizures, hypoglycemia management, narcotic reversal, and benzodiazepine reversal in the ED or prehospital settings. Medications that have been studied in the adult population include fentanyl, sufentanil, hydromorphone, ketamine, midazolam, haloperidol, naloxone, flumazenil, and glucagon. The available data do indicate, however, that intranasal administration may be a safe, effective, and well tolerated route of administration.

CONCLUSION

Based on the published literature, intranasal administration of fentanyl, sufentanil, ketamine, hydromorphone, midazolam, haloperidol, naloxone, glucagon, and, in limited cases, flumazenil may be a safe, effective, and well-tolerated alternative to intramuscular or intravenous administration in the prehospital and ED settings.

Intranasal ketamine for the treatment of patients with acute pain in the emergency department

BACKGROUND

Pain in the emergency department (ED) is common but undertreated. The objective of this study was to examine the efficacy and safety of intranasal (IN) ketamine used as an analgesic for patients with acute injury with moderate to severe pain.

METHODS

This study was a cross sectional, observational study of patients more than 8 years old experiencing moderate to severe pain [visual analog score (VAS) >50 mm]. The initial dose of IN ketamine was 0.7 mg/kg with an additional dose of 0.3 mg/kg if VAS was more than 50 mm after 15 minutes. Pain scores and vital signs were recorded at 0, 15, 30 and 60 minutes. Side-effects, sedation level and patient's satisfaction were also recorded. The primary outcome was the number of patients achieving ≥ 20 mm reductions in VAS at 15 minutes. Other secondary outcome measures were median reduction in VAS at 15, 30 and 60 minutes, changes of vital signs, adverse events, satisfaction of patients, and need for additional ketamine.

RESULTS

Thirty-four patients with a median age of 29.5 years (IQR 17.5-38) were enrolled, and they had an initial median VAS of 80 mm (IQR 67-90). The VAS decreased more than 20 mm at 15 minutes in 27 (80%) patients. The reduction of VAS from baseline to 40 mm (IQR 20-40), 20 mm (IQR 14-20) and 20 mm (IQR 10-20) respectively at 15, 30 and 60 minutes (P<0.001). No critical changes of vital signs were noted and adverse effects were mild and transient.

CONCLUSION

This study showed that IN ketamine is an analgesic choice for patients with acute injury in moderate to severe pain in an overcrowded and resource limited ED.

Ketamine: repurposing and redefining a multifaceted drug

This short review will highlight recent clinical and basic research that supports the therapeutic utility of ketamine as a rapid-acting, life-saving antidepressant and a versatile analgesic. After 50 years of use as a dissociative anesthetic and misuse as a street drug, ketamine has re-emerged as a useful off-label agent for ameliorating various types of pain and resistant depression. In addition to its ability to inhibit N-methyl-D-aspartate (NMDA) receptors, the diverse actions of ketamine might involve epigenetic mechanisms such as microRNA regulation. Thus, ketamine is transitioning from being the pharmacologist's nightmare to one of the most interesting developments in the pharmacology of depression and pain.