A prospective study of ketamine versus haloperidol for severe prehospital agitation

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.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

Bronchoscopist-Directed Continuous Flow Propofol Based Analgosedation during Flexible Interventional Bronchoscopy and EBUS

Sedation techniques in interventional flexible bronchoscopy and endobronchial ultrasound-guided transbronchial-needle aspiration (EBUS-TBNA) are inconsistent and the evidence for required general anesthesia under full anesthesiologic involvement is scarce. Moreover, we faced the challenge of providing bronchoscopic care with limited personnel. Hence, we retrospectively identified 513 patients that underwent flexible interventional bronchoscopy and/or EBUS-TBNA out of our institution between January 2020 and August 2022 to evaluate our deep analgosedation approach based on pethidine/meperidine bolus plus continuous flow adjusted propofol, the bronchoscopist-directed continuous flow propofol based analgosedation (BDcfP) in a two-personnel setting. Consequently, 502 out of 513 patients received BDcfP for analgosedation. We identified cardiovascular comorbidities, chronic obstructive pulmonary disease, and arterial hypertension as risk factors for periprocedural hypotension. Propofol flow rate did not correlate with hypotension. Theodrenaline and cafedrine might be used to treat periprocedural hypotension. Moreover, midazolam might be used to support the sedative effect. In conclusion, BDcfP is a safe and feasible sedative approach during interventional flexible bronchoscopy and EBUS-TBNA. In general, after the implementation of safety measures, EBUS-TBNA and interventional flexible bronchoscopy via BDcfP might safely be performed even with limited personnel.

The clinical toxicology of ketamine

INTRODUCTION

Ketamine is a pharmaceutical drug possessing both analgesic and anaesthetic properties. As an anaesthetic, it induces anaesthesia by producing analgesia with a state of altered consciousness while maintaining airway tone, respiratory drive, and hemodynamic stability. At lower doses, it has psychoactive properties and has gained popularity as a recreational drug.

OBJECTIVES

To review the epidemiology, mechanisms of toxicity, pharmacokinetics, clinical features, diagnosis and management of ketamine toxicity.

METHODS

Both OVID MEDLINE (January 1950-April 2023) and Web of Science (1900-April 2023) databases were searched using the term "ketamine" in combination with the keywords "pharmacokinetics", "kinetics", "poisoning", "poison", "toxicity", "ingestion", "adverse effects", "overdose", and "intoxication". Furthermore, bibliographies of identified articles were screened for additional relevant studies. These searches produced 5,268 non-duplicate citations; 185 articles (case reports, case series, pharmacokinetic studies, animal studies pertinent to pharmacology, and reviews) were considered relevant. Those excluded were other animal investigations, therapeutic human clinical investigations, commentaries, editorials, cases with no clinical relevance and post-mortem investigations.

EPIDEMIOLOGY

Following its introduction into medical practice in the early 1970s, ketamine has become a popular recreational drug. Its use has become associated with the dance culture, electronic and dubstep dance events.

MECHANISM OF ACTION

Ketamine acts primarily as a non-competitive antagonist on the glutamate N-methyl-D-aspartate receptor, causing the loss of responsiveness that is associated with clinical ketamine dissociative anaesthesia.

PHARMACOKINETICS

Absorption of ketamine is rapid though the rate of uptake and bioavailability is determined by the route of exposure. Ketamine is metabolized extensively in the liver. Initially, both isomers are metabolized to their major active metabolite, norketamine, by CYP2B6, CYP3A4 and CYP2C9 isoforms. The hydroxylation of the cyclohexan-1-one ring of norketamine to the three positional isomers of hydroxynorketamine occurs by CYP2B6 and CYP2A6. The dehydronorketamine metabolite occurs either by direct dehydrogenation from norketamine via CYP2B6 metabolism or non-enzymatic dehydration of hydroxynorketamine. Norketamine, the dehydronorketamine isomers, and hydroxynorketamine have pharmacological activity. The elimination of ketamine is primarily by the kidneys, though unchanged ketamine accounts for only a small percentage in the urine. The half-life of ketamine in humans is between 1.5 and 5 h.

CLINICAL FEATURES

Acute adverse effects following recreational use are diverse and can include impaired consciousness, dizziness, irrational behaviour, hallucinations, abdominal pain and vomiting. Chronic use can result in impaired verbal information processing, cystitis and cholangiopathy.

DIAGNOSIS

The diagnosis of acute ketamine intoxication is typically made on the basis of the patient's history, clinical features, such as vomiting, sialorrhea, or laryngospasm, along with neuropsychiatric features. Chronic effects of ketamine toxicity can result in cholangiopathy and cystitis, which can be confirmed by endoscopic retrograde cholangiopancreatography and cystoscopy, respectively.

MANAGEMENT

Treatment of acute clinical toxicity is predominantly supportive with empiric management of specific adverse effects. Benzodiazepines are recommended as initial treatment to reduce agitation, excess neuromuscular activity and blood pressure. Management of cystitis is multidisciplinary and multi-tiered, following a stepwise approach of pharmacotherapy and surgery. Management of cholangiopathy may require pain management and, where necessary, biliary stenting to alleviate obstructions. Chronic effects of ketamine toxicity are typically reversible, with management focusing on abstinence.

CONCLUSIONS

Ketamine is a dissociative drug employed predominantly in emergency medicine; it has also become popular as a recreational drug. Its recreational use can result in acute neuropsychiatric effects, whereas chronic use can result in cystitis and cholangiopathy.

Retrospective evaluation of ketamine versus droperidol on time to restraint removal in agitated emergency department patients

PURPOSE

Acute agitation and violent behavior in the emergency department (ED) can lead to significant patient morbidity and contribute to the growing problem of workplace violence against health care providers. To our knowledge, there is no available literature directly comparing intramuscular ketamine to intramuscular droperidol in ED patients presenting with undifferentiated agitation. The purpose of this investigation was to compare the effectiveness and safety of these agents for acute agitation in the ED.

METHODS

This was a retrospective observational study conducted at an urban, academic ED. The primary endpoint was time from the first dose of study medication to restraint removal. Safety endpoints included incidence of bradycardia (heart rate < 60 bpm), hypotension (systolic blood pressure < 90 mmHg), hypoxia (oxygen saturation < 90% or need for respiratory support), and incidence of intubation for ongoing agitation or respiratory failure.

RESULTS

An initial 189 patients were screened, of which, 92 met inclusion criteria. The median time from initial drug administration to restraint removal was 49 min (IQR 30, 168) in the ketamine group and 43 min (IQR 30, 80) in the droperidol group (Median difference 6 min; 95% CI [-7, 26]). There was no significant difference in rates of bradycardia (3% vs 3%, 95% CI [-7%, 8%]), hypotension (0% vs 2%, 95% CI [-5%, 2%]), or hypoxia (7% vs 10%, 95% CI [-15%, 9%]) in the ketamine versus droperidol groups respectively. One patient in the ketamine group was intubated for ongoing agitation, and one patient in the droperidol group was intubated for respiratory failure.

CONCLUSIONS

Intramuscular droperidol and intramuscular ketamine were associated with similar times from drug administration to restraint removal in patients presenting to the ED with undifferentiated agitation. Prospective studies are warranted to evaluate IM droperidol and IM ketamine head-to-head as first line agents for acute agitation in the ED.

A retrospective cohort study of pre-hospital agitation management by advanced paramedic practitioners in critical care

Introduction: Pre-hospital clinicians can expect to encounter patients with agitation, including acute behavioural disturbance (ABD). These situations carry significant risk for patients and emergency medical services. Advanced paramedics within the London Ambulance Service (LAS) are frequently tasked to these incidents. At present, little evidence exists regarding clinical decision-making and management of this patient group. We sought to explore the demographics of patients presenting with potential ABD and quantify the degree of agitation, physical restraint, effectiveness of chemical sedation and any associated complications.Methods: A retrospective analysis of pre-hospital clinical records for patients coded with ABD and attended by LAS advanced paramedics between 1 October 2019 and 30 September 2020. Sedation assessment tool (SAT) scores were used as the primary outcome measure.Results: A total of 237 patient records were identified. Of the patients, 147 (62%) were physically restrained and 104 (44%) were chemically sedated. Sedation was more commonly administered where patients were exposed to physical restraint. High SAT scores were associated with the administration of sedative agents and at higher doses. Of patients undergoing sedation, 89 (85%) had a SAT score reduction of 2 points or a final score ≤ 0. The mean SAT score reduction was 2.72. Three cases of minor injury were reported following physical restraint.Conclusion: Advanced paramedics undertook sedation in less than half the cohort, suggesting that other strategies such as communication and positioning were utilised. Most patients were managed into a state between being restless and rousable, largely negating the need for ongoing physical restraint during hospital transfer. Appropriately trained advanced paramedics can utilise sedation safely and effectively in selected cases.

Intubation Rates following Prehospital Administration of Ketamine for Acute Agitation: A Systematic Review and Meta-Analysis

BACKGROUND

Ketamine is a fast-acting, dissociative anesthetic with a favorable adverse effect profile that is effective for managing acute agitation as a chemical restraint in the prehospital and emergency department (ED) settings. However, some previously published individual studies have reported high intubation rates when ketamine was administered prehospitally.

OBJECTIVE

This systematic review aims to determine the rate and settings in which intubation following prehospital administration of ketamine for agitation is occurring, as well as associated indications and adverse events.

METHODS

We searched PubMed, Scopus, Ovid MEDLINE, Embase, CINAHL Plus, PsycINFO, the Cochrane Library, ClinicalTrials.gov, OpenGrey, Open Access Theses and Dissertation, and Google Scholar from the earliest possible date until 13/February/2022. Inclusion criteria required studies to describe agitated patients who received ketamine in the prehospital setting as a first-line drug to control acute agitation. Reference lists of appraised studies were screened for additional relevant articles. Study quality was assessed using the Newcastle-Ottawa quality assessment scale. Synthesis of results was completed via meta-analysis, and the GRADE tool was used for certainty assessment.

RESULTS

The search yielded 1466 unique records and abstracts, of which 50 full texts were reviewed, resulting in 18 being included in the analysis. All studies were observational in nature and 15 were from USA. There were 3476 patients in total, and the overall rate of intubation was 16% (95% confidence interval [CI] = 8%-26%). Most intubations occurred in the ED. Within the studies, the prehospital intubation rate ranged from 0% to 7.9% and the ED intubation rate ranged from 0 to 60%. The overall pooled prehospital intubation rate was 1% (95% CI = 0%-2%). The overall pooled ED intubation rate was 19% (95% CI = 11%-30%). The most common indications for intubation were for airway protection and respiratory depression/failure.

CONCLUSIONS

There is wide variation in intubation rates between and within studies. The majority of intubations performed following prehospital administration of ketamine for agitation took place in the ED.

Novel uses of ketamine in the emergency department

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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.

Promises and Pitfalls of NMDA Receptor Antagonists in Treating Violent Aggression

Treatment options for chronically aggressive individuals remain limited despite recent medical advances. Traditional pharmacological agents used to treat aggression, such as atypical antipsychotics, have limited efficacy and are often replete with dangerous side effects. The non-competitive NMDAR antagonists ketamine and memantine are promising alternatives, but their effects appear to be highly dependent on dosage, context, and personal experience. Importantly, these drugs can increase aggression when combined with substances of abuse or during periods of heightened stress. This is likely due to mechanistic differences operating at specific synapses under different contexts. Previous findings from our lab and others have shown that early life stress, substance abuse, and attack experience promote aggression through NMDAR-dependent synaptic plasticity within aggression-related brain circuits. Ketamine and memantine affect these types of aggression in opposite ways. This has led us to propose that ketamine and memantine oppositely affect aggression brought on by early life stress, substance abuse, or attack experience through opposite effects on NMDAR-dependent synaptic plasticity. This would account for the persistent effects of these drugs on aggression and suggest they could be leveraged as a more long-lasting treatment option. However, a more thorough examination of the effects of ketamine and memantine on cellular and synaptic function will be necessary for responsible administration. Additionally, because the effects of ketamine and memantine are highly dependent on prior drug use, traumatic stress, or a history of aggressive behavior, we propose a more thorough medical evaluation and psychiatric assessment will be necessary to avoid possible adverse interactions with these drugs.

A Comparative Analysis Between Ketamine Versus Combination of Midazolam and Haloperidol for Rapid Safe Control of Agitated Patients in Emergency Department: A Systematic Review

We aim to discuss the efficacy and adverse effects of using ketamine in agitated patients in the emergency department (ED) compared with the combination therapy of haloperidol with benzodiazepine.

This systematic review followed Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) guidelines. An electronic search from PubMed/Medline, Cochrane library, and Google Scholar was conducted from their inception to 30^th April 2022. We included agitated patients in ED who were given infusion with ketamine only. Our comparative group was patients infused with combined therapy of haloperidol and benzodiazepine. We did not include letters, case reports, abstracts, conference papers, appraisals, reviews, and studies where full text was unavailable. We did not put any language restrictions.

Three studies were selected in our manuscript (one cohort and two randomized controlled trials). All three studies showed that ketamine was used to achieve sedation in less time than the other group. However, two studies reported significantly more adverse effects in ketamine-infused groups.

We concluded that ketamine use is superior when its primary focus is to sedate the patient as quickly as possible, but it carries some side effects that should be considered. However, we still need more studies assessing the efficacy of ketamine in agitated patients presenting in the ED.

Adverse events following emergent prehospital sedation of patients with behavioral emergencies: A retrospective cohort study

BACKGROUND

Patients presenting to emergency medical services (EMS) with behavioral emergencies may require emergent sedation to facilitate care, but concerns about sedation-related adverse events (AEs) exist. This study aimed to describe the frequency of AEs following emergent prehospital sedation with three types of sedative agents: ketamine, benzodiazepines and antipsychotics.

METHODS

This retrospective cohort study included patients ≥ 15 years who presented to 1031U.S. EMS agencies in calendar year 2019 with behavioral emergencies necessitating emergent prehospital sedation. Serious AEs (SAE) included cardiac arrest, invasive airway placement, and severe oxygen desaturation (<75%). Less-serious AEs included positive pressure ventilation, any oxygen desaturation (<90%), oropharyngeal or nasopharyngeal airway placement, and suctioning. The need for additional sedation was also assessed.

FINDINGS

Of 7973 patients, 1996 received ketamine; 4137 received a benzodiazepine; 1532 received an antipsychotic agent; and 308 received an indeterminant agent. Cardiac arrest occurred in 11 patients (0·1%) and any SAE occurred in 165 patients (2·1%). Invasive airway placement was more frequent with ketamine (40, 2·0%) compared with benzodiazepines (17, 0·4%) or antipsychotics (3, 0·2%). Oxygen desaturation below 75% also occurred more frequently with ketamine (51, 2·6%) than with benzodiazepines (52, 1·3%) or antipsychotics (14, 0·9%). Patients sedated with ketamine were less likely to require additional sedation. Propensity-matching to minimize potential confounding between patient condition, sedative choice and AEs did not meaningfully alter the results.

INTERPRETATION

Although SAEs were rare among patients receiving emergent prehospital sedation, prehospital clinicians should remain mindful of the potential risks and monitor patients closely.

FUNDING

None.

Ketamine use in critically ill patients: a narrative review

Ketamine is unique among anesthetics and analgesics. The drug is a rapid-acting general anesthetic that produces an anesthetic state characterized by profound analgesia, preserved pharyngeal-laryngeal reflexes, normal or slightly enhanced skeletal muscle tone, cardiovascular and respiratory stimulation, and occasionally a transient and minimal respiratory depression. Research has demonstrated the efficacy of its use on anesthesia, pain, palliative care, and intensive care. Recently, it has been used for postoperative and chronic pain, as an adjunct in psychotherapy, as a treatment for depression and posttraumatic stress disorder, as a procedural sedative, and as a treatment for respiratory and/or neurologic clinical conditions. Despite being a safe and widely used drug, many physicians, such as intensivists and those practicing in emergency care, are not aware of the current clinical applications of ketamine. The objective of this narrative literature review is to present the theoretical and practical aspects of clinical applications of ketamine in intensive care unit and emergency department settings.

Efficacy and safety of ketamine in mechanically ventilated intensive care unit patients: a scoping review

Objectives: Mechanically ventilated patients account for about one-third of all admissions to the intensive care unit (ICU). Ketamine has been conditionally recommended to aid with analgesia in such patients, with low quality of evidence available to support this recommendation. We aimed to perform a narrative scoping review of the current knowledge of the use of ketamine, with a specific focus on mechanically ventilated ICU patients. Methods: We searched MEDLINE and EMBASE for relevant articles. Bibliographies of retrieved articles were examined for references of potential relevance. We included studies that described the use of ketamine for postoperative and emergency department management of pain and in the critically unwell, mechanically ventilated population. Results: There are few randomised controlled trials evaluating ketamine's utility in the ICU. The evidence is predominantly retrospective and observational in nature and the results are heterogeneous. Available evidence is summarised in a descriptive manner, with a division made between high dose and low dose ketamine. Ketamine's pharmacology and use as an analgesic agent outside of the ICU is briefly discussed, followed by evidence for use in the ICU setting, with particular emphasis on analgesia, sedation and intubation. Finally, data on adverse effects including delirium, coma, haemodynamic adverse effects, raised intracranial pressure, hypersalivation and laryngospasm are presented. Conclusions: Ketamine is used in mechanically ventilated ICU patients with several potentially positive clinical effects. However, it has a significant side effect profile, which may limit its use in these patients. The role of low dose ketamine infusion in mechanically ventilated ICU patients is not well studied and requires investigation in high quality, prospective randomised trials.

Managing acute agitation and aggression in the world of drug shortages

Acute agitation and aggression create safety risks for both patients and staff, often leading to psychiatric emergencies. Quick and appropriate treatment is necessary to achieve safe and effective outcomes. Unfortunately, there are several factors that hinder timely interventions, such as medication shortages and delay in staff preparedness. Ultimately, the goal of managing acute agitation and aggression in the clinical setting is to de-escalate the situation and prevent harm to patients and staff. This article will explore useful interventions in realizing treatment goals for the management of agitation and aggression in adults while navigating limitations faced in practice.

Rapid tranquilization of the agitated patient in the emergency department: A systematic review and network meta-analysis

BACKGROUND

Safe and effective tranquilization of the acutely agitated patient is challenging, and head-to-head comparisons of medications are limited. We aimed to identify the most optimal agent(s) for rapid tranquilization of the severely agitated patient in the emergency department (ED).

METHODS

The protocol for systematic review was registered (PROSPERO; CRD42020212534). We searched MEDLINE, Embase, PsycINFO, and Cochrane Database/CENTRAL from inception to June 2, 2021. We limited studies to randomized controlled trials that enrolled adult ED patients with severe agitation and compared drugs for rapid tranquilization. Predetermined outcomes were: 1) Adequate sedation within 30 min (effectiveness), 2) Immediate, serious adverse event - cardiac arrest, ventricular tachydysrhythmia, endotracheal intubation, laryngospasm, hypoxemia, hypotension (safety), and 3) Time to adequate sedation (effect onset). We extracted data according to PRISMA-NMA and appraised trials using Cochrane RoB 2 tool. We performed Bayesian network meta-analysis (NMA) using a Markov Chain Monte Carlo method with random-effects model and vague prior distribution to calculate odds ratios with 95% credible intervals for dichotomous outcomes and frequentist NMA to calculate mean differences with 95% confidence intervals for continuous outcomes. We assessed confidence in results using CINeMA. We used surface under the cumulative ranking (SUCRA) curves to rank agent(s) for each outcome.

RESULTS

Eleven studies provided data for effectiveness (1142 patients) and safety (1147 patients). Data was insufficient for effect onset. The NMA found that ketamine (SUCRA = 93.0%) is most likely to have superior effectiveness; droperidol-midazolam (SUCRA = 78.8%) is most likely to be safest. There are concerns with study quality and imprecision. Quality of the point estimates varied for effectiveness but mostly rated "very low" for safety.

CONCLUSIONS

Available evidence suggests that ketamine and droperidol have intermediate effectiveness for rapid tranquilization of the severely agitated patient in the ED. There is insufficient evidence to definitively determine which agent(s) may be safest or fastest-acting. Further, direct-comparison study of ketamine and droperidol is recommended.

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.

Outcomes Associated with Lower Doses of Ketamine by Emergency Medical Services for Profound Agitation

Introduction

Ketamine is commonly used to treat profound agitation in the prehospital setting. Early in ketamine’s prehospital use, intubation after arrival in the emergency department (ED) was frequent. We sought to measure the frequency of ED intubation at a Midwest academic medical center after prehospital ketamine use for profound agitation, hypothesizing that intubation has become less frequent as prehospital ketamine has become more common and prehospital dosing has improved.

Methods

We conducted a retrospective cohort study of adult patients receiving ketamine in the prehospital setting for profound agitation and transported to a midwestern, 60,000-visit, Level 1 trauma center between January 1, 2017–March 1, 2021. We report descriptive analyses of patient-level prehospital clinical data and ED outcomes. The primary outcome was proportion of patients intubated in the ED.

Results

A total of 78 patients received ketamine in the prehospital setting (69% male, mean age 36 years). Of the 42 (54%) admitted patients, 15 (36% of admissions) were admissions to the intensive care unit. Overall, 12% (95% confidence interval [CI]), 4.5–18.6%)] of patients were intubated, and indications included agitation (n = 4), airway protection not otherwise specified (n = 4), and respiratory failure (n = 1).

Conclusion

Endotracheal intubation in the ED after prehospital ketamine use for profound agitation in our study sample was found to be less than previously reported.

Rapid Agitation Control With Ketamine in the Emergency Department: A Blinded, Randomized Controlled Trial

STUDY OBJECTIVE

We hypothesized that the use of intramuscular ketamine would result in a clinically relevant shorter time to target sedation.

METHODS

We conducted a randomized clinical trial comparing the rapidity of onset, level of sedation, and adverse effect profile of ketamine compared to a combination of midazolam and haloperidol for behavioral control of emergency department patients with severe psychomotor agitation. We included patients with severe psychomotor agitation measured by a Richmond Agitation Score (RASS) ≥+3. Patients in the ketamine group were treated with a 5 mg/kg intramuscular injection. Patients in the midazolam and haloperidol group were treated with a single intramuscular injection of 5 mg midazolam and 5 mg haloperidol. The primary outcome was the time, in minutes, from study medication administration to adequate sedation, defined as RASS ≤-1. Secondary outcomes included the need for rescue medications and serious adverse events.

RESULTS

Between June 30, 2018, and March 13, 2020, we screened 308 patients and enrolled 80. The median time to sedation was 14.7 minutes for midazolam and haloperidol versus 5.8 minutes for ketamine (difference 8.8 minutes [95% confidence interval (CI) 3.0 to 14.5]). Adjusted Cox proportional model analysis favored the ketamine arm (hazard ratio 2.43, 95% CI 1.43 to 4.12). Five (12.5%) patients in the ketamine arm and 2 (5.0%) patients in the midazolam and haloperidol arm experienced serious adverse events (difference 7.5% [95% CI -4.8% to 19.8%]).

CONCLUSION

In ED patients with severe agitation, intramuscular ketamine provided significantly shorter time to adequate sedation than a combination of intramuscular midazolam and haloperidol.

Recommandations de pratique clinique sur la prise en charge du patient adulte à présentation psychiatrique dans les structures d’urgences

De nombreux patients consultant aux urgences souffrent de pathologies psychiatriques préexistantes ou ont une symptomatologie évocatrice d’une pathologie psychiatrique. En effet, les troubles psychiatriques touchent un adulte sur quatre, et 75%des affections psychiatriques débutent avant l’âge de 25 ans. Le parcours de soins d’un patient adulte à présentation psychiatrique dans les structures d’urgences concerne de multiples intervenants. La complexité inhérente à ces patients complexes ainsi qu’à l’interdisciplinarité induite dans la prise en charge impose un cadre de prise en charge clair et consensuel. Des experts de la psychiatrie, de la gérontopsychiatrie et de la médecine d’urgence se sont réunis pour émettre ces recommandations de bonnes pratiques. Le choix de présenter des recommandations de bonnes pratiques et non des recommandations formalisées d’experts a été fait devant l’insuffisance de littérature de fort niveau de preuve dans certaines thématiques et de l’existence de controverses. À travers ces recommandations de bonnes pratiques cliniques, ils se sont attachés à décrire la prise en charge de ses patients aussi bien en préqu’en intrahospitalier. Les objectifs de ces recommandations sont de présenter les éléments indispensables à l’organisation du parcours de soins de ces patients, la gestion de l’agitation ainsi que la prise en charge pharmacologique ou non. Une partie spécifique est consacrée aux aspects réglementaires.

Out-of-Hospital Ketamine: Indications for Use, Patient Outcomes, and Associated Mortality

STUDY OBJECTIVE

To describe out-of-hospital ketamine use, patient outcomes, and the potential contribution of ketamine to patient death.

METHODS

We retrospectively evaluated consecutive occurrences of out-of-hospital ketamine administration from January 1, 2019 to December 31, 2019 reported to the national ESO Data Collaborative (Austin, TX), a consortium of 1,322 emergency medical service agencies distributed throughout the United States. We descriptively assessed indications for ketamine administration, dosing, route, transport disposition, hypoxia, hypercapnia, and mortality. We reviewed cases involving patient death to determine whether ketamine could be excluded as a potential contributing factor.

RESULTS

Indications for out-of-hospital ketamine administrations in our 11,291 patients were trauma/pain (49%; n=5,575), altered mental status/behavioral indications (34%; n=3,795), cardiovascular/pulmonary indications (13%; n=1,454), seizure (2%; n=248), and other (2%; n=219). The highest median dose was for altered mental status/behavioral indications at 3.7 mg/kg (interquartile range, 2.2 to 4.4 mg/kg). Over 99% of patients (n=11,274) were transported to a hospital. Following ketamine administration, hypoxia and hypercapnia were documented in 8.4% (n=897) and 17.2% (n=1,311) of patients, respectively. Eight on-scene and 120 in-hospital deaths were reviewed. Ketamine could not be excluded as a contributing factor in 2 on-scene deaths, representing 0.02% (95% confidence interval 0.00% to 0.07%) of those who received out-of-hospital ketamine. Among those with in-hospital data, ketamine could not be excluded as a contributing factor in 6 deaths (0.3%; 95% confidence interval 0.1% to 0.7%).

CONCLUSION

In this large sample, out-of-hospital ketamine was administered for a variety of indications. Patient mortality was rare. Ketamine could not be ruled out as a contributing factor in 8 deaths, representing 0.07% of those who received ketamine.

The Reemergence of Ketamine for Treatment in Critically Ill Adults

OBJECTIVES

To assess the evidence and discuss the risks and clinical relevance of ketamine for the treatment of various disease states impacting the adult critically ill population.

DATA SOURCES

A literature review was performed using PubMed evaluating primary literature published until August 2018.

STUDY SELECTION

Case reports, observational studies (cohort, case-control), and randomized controlled trials involving patients 18 years and older in a nonperioperative setting using either IV or intramuscular ketamine were included for analysis. Uses of ketamine discussed focused on critically ill patients in the ICU and emergency department settings.

DATA EXTRACTION

Included studies were evaluated for dosing, outcomes, and adverse effects of ketamine. For each study, the design, population, intervention, investigated outcomes, and results were assessed.

DATA SYNTHESIS

The evidence was organized according to use of ketamine, which included pain, sedation, status asthmaticus, alcohol withdrawal syndrome, status epilepticus, and acute behavioral psychologic disturbances. Evaluation of the evidence was based on the included primary literature along with any related guideline recommendations.

CONCLUSIONS

Ketamine has suggested potential benefit in several disease states impacting critically ill patients including pain, alcohol withdrawal syndrome, status epilepticus, and acute agitation. Further supporting evidence is needed to validate its use in the setting of critical illness.

A Prospective Study of Intramuscular Droperidol or Olanzapine for Acute Agitation in the Emergency Department: A Natural Experiment Owing to Drug Shortages

STUDY OBJECTIVE

Intramuscular medications are commonly used to treat agitation in the emergency department (ED). The purpose of this study is to compare intramuscular droperidol and olanzapine for treating agitation.

METHODS

This was a prospective observational study of ED patients receiving intramuscular droperidol or olanzapine for acute agitation. The treating physician determined the medication and dose; however, over time drug shortages made either olanzapine (July to September 2019) or droperidol (November 2019 to March 2020) unavailable, creating a natural experiment. The primary outcome was time to adequate sedation, assessed by the Altered Mental Status Scale (AMSS), defined as time to AMSS score less than or equal to 0.

RESULTS

We analyzed 1,257 patients (median age 42 years; 73% men); 538 received droperidol (median dose 5 mg) and 719 received olanzapine (median dose 10 mg). The majority of patients (1,086; 86%) had agitation owing to alcohol intoxication. Time to adequate sedation was 16 minutes (interquartile range 10 to 30 minutes) for droperidol and 17.5 minutes (interquartile range 10 to 30 minutes) for olanzapine (absolute difference -0.7 minutes; 95% confidence interval -2.1 to 0.5 minutes). Adjusted Cox proportional hazard model analysis revealed no difference between groups in time to sedation (hazard ratio for adequate sedation for droperidol compared with olanzapine 1.12; 95% confidence interval 1.00 to 1.25). Patients receiving olanzapine were more likely to receive additional medications for sedation (droperidol 17%; olanzapine 24%; absolute difference -8% [95% confidence interval -12% to -3%]). We observed no difference between drugs regarding adverse effects except for extrapyramidal adverse effects, which were more common with droperidol (n=6; 1%) than olanzapine (n=1; 0.1%).

CONCLUSION

We found no difference in time to adequate sedation between intramuscular droperidol and olanzapine.

Randomized Double-blind Trial of Intramuscular Droperidol, Ziprasidone, and Lorazepam for Acute Undifferentiated Agitation in the Emergency Department

BACKGROUND

The optimal agent to treat acute agitation in the emergency department (ED) has not been determined. The objective of this study was to compare the effectiveness and safety of intramuscular droperidol, ziprasidone, and lorazepam for acute agitation in the ED.

METHODS

This was a randomized, double-blind trial of ED patients with acute agitation requiring parenteral sedation. The study was conducted under exception from informed consent (21 CFR 50.24) from July 2004 to March 2005. Patients were randomized to receive 5 mg of droperidol, 10 mg of ziprasidone, 20 mg of ziprasidone, or 2 mg of lorazepam intramuscularly. We recorded Altered Mental Status Scale (AMSS) scores, nasal end-tidal carbon dioxide (ETCO₂ ), and pulse oximetry (SpO₂ ) at 0, 15, 30, 45, 60, 90, and 120 minutes as well as QTc durations and dysrhythmias. Respiratory depression was defined as a change in ETCO₂ consistent with respiratory depression or SpO₂  < 90%. The primary outcome was the proportion of patients adequately sedated (AMSS ≤ 0) at 15 minutes.

RESULTS

We enrolled 115 patients. Baseline AMSS scores were similar between groups. For the primary outcome, adequate sedation at 15 minutes, droperidol administration was effective in 16 of 25 (64%) patients, compared to seven of 28 (25%) for 10 mg of ziprasidone, 11 of 31 (35%) for 20 mg of ziprasidone, and nine of 31 (29%) for lorazepam. Pairwise comparisons revealed that droperidol was more effective that the other medications, with 39% (95% confidence interval [CI] = 3% to 54%) more compared to 20 mg of ziprasidone and 33% (95% CI = 8% to 58%) more compared to lorazepam. There was no significant difference between groups in need of additional rescue sedation. Numerically, respiratory depression was lower with droperidol (3/25 [12%]) compared to 10 mg of ziprasidone (10/28 [36%]), 20 mg of ziprasidone (12/31 [39%]), or lorazepam (15/31 [48%]). One patient receiving 20 mg of ziprasidone required intubation to manage an acute subdural hematoma. No patients had ventricular dysrhythmias. QTc durations were similar in all groups.

CONCLUSIONS

Droperidol was more effective than lorazepam or either dose of ziprasidone for the treatment of acute agitation in the ED and caused fewer episodes of respiratory depression.

Use of intramuscular ketamine by paramedics in the management of severely agitated patients

OBJECTIVE

Administration of a sedative agent is required for safe transport of prehospital patients with severe agitation to EDs. Ambulance services in Australasia use ketamine, droperidol or midazolam as first line agent but the optimal agent is uncertain. In Victoria, intramuscular (IM) ketamine is used. The present study aimed to examine the prehospital characteristics and ED outcomes of patients with severe agitation after IM ketamine administration.

METHODS

A retrospective review was conducted for patients who received IM ketamine for severe agitation over a 2-year period. Data were sourced from Ambulance Victoria and linked to hospital data. The primary outcome was time to sedation. Data collected included baseline characteristics, adverse events and ED outcomes.

RESULTS

Three hundred and fifty-eight prehospital cases transported to 32 hospitals were included. Outcome data were available for 305 patients (21 hospitals). Median age was 31 years (IQR 23-40). 71.2% were male. Adequate sedation was achieved in 96.9% of cases in a median time of 5.0 min (IQR 3.0-7.0; range 1-31 min). Adverse events were transient hypoxia (5.0%), hyper-salivation (4.2%) and emergence reactions (0.8%). A total of 45 (14.8%) patients were intubated; two prehospital.

CONCLUSION

Intramuscular ketamine is effective with a low rate of prehospital complications in severely agitated patients in the prehospital setting. Given the variation in ambulance practice in Australasia, prospective, randomised trials in the prehospital setting comparing ketamine to other sedating agents such as droperidol in patients with severe agitation are required.

Patient Outcomes Following Ketamine Administration for Acute Agitation with a Decreased Dosing Protocol in the Prehospital Setting

BACKGROUND

Agitated behaviors are frequently encountered in the prehospital setting and require emergent treatment to prevent harm to patients and prehospital personnel. Chemical sedation with ketamine works faster than traditional pharmacologic agents, though it has a higher incidence of adverse events, including intubation. Outcomes following varying initial doses of prehospital intramuscular (IM) ketamine use have been incompletely described.

OBJECTIVE

To determine whether using a lower dose IM ketamine protocol for agitation is associated with more favorable outcomes.

METHODS

This study was a pre-/post-intervention retrospective chart review of prehospital care reports (PCRs). Adult patients who received chemical sedation in the form of IM ketamine for agitated behaviors were included. Patients were divided into two cohorts based on the standard IM ketamine dose of 4mg/kg and the lower IM dose of 3mg/kg with the option for an additional 1mg/kg if required. Primary outcomes included intubation and hospital admission. Secondary outcomes included emergency department (ED) length of stay, additional chemical or physical restraints, assaults on prehospital or ED employees, and documented adverse events.

RESULTS

The standard dose cohort consisted of 211 patients. The lower dose cohort consisted of 81 patients, 17 of whom received supplemental ketamine administration. Demographics did not significantly differ between the cohorts (mean age 35.14 versus 35.65 years; P = .484; and 67.8% versus 65.4% male; P = .89). Lower dose subjects were administered a lower ketamine dose (mean 3.24mg/kg) compared to the standard dose cohort (mean 3.51mg/kg). There was no statistically significant difference between the cohorts in intubation rate (14.2% versus 18.5%; P = .455), ED length of stay (14.31 versus 14.88 hours; P = .118), need for additional restraint and sedation (P = .787), or admission rate (26.1% versus 25.9%; P = .677). In the lower dose cohort, 41.2% (7/17) of patients who received supplemental ketamine doses were intubated, a higher rate than the patients in this cohort who did not receive supplemental ketamine (8/64, 12.5%; P <.01).

CONCLUSION

Access to effective, fast-acting chemical sedation is paramount for prehospital providers. No significant outcomes differences existed when a lower dose IM ketamine protocol was implemented for prehospital chemical sedation. Patients who received a second dose of ketamine had a significant increase in intubation rate. A lower dose protocol may be considered for an agitation protocol to limit the amount of medication administered to a population of high-risk patients.

Paramedic occupational violence mitigation: a comprehensive systematic review of emergency service worker prevention strategies and experiences for use in prehospital care

Occupational violence is a significant issue within the context of prehospital healthcare with the majority of paramedics reporting some form of abuse, intimidation, physical or sexual assault during their career. Though the paramedic literature acknowledges the severity of this issue, there is limited literature examining occupational violence mitigation strategies. Despite this, the operational and environmental similarities that exist between paramedics and other emergency service workers such as the police and firefighters, provide an opportunity to review relatable occupational violence mitigation strategies and experiences.This review used Joanna Briggs Institute guidance for systematic reviews of both qualitative evidence and effectiveness. Studies included in this review incorporated those published in English from 1990 to January 2020.Two qualitative studies met the criteria for review. From these, a total of 22 findings were extracted and combined to form four categories from which two syntheses were developed. Twenty-four quantitative studies, encompassing six unique fields, met the criteria for review.Mitigation strategies for emergency service worker occupational violence are not easily defined. They are dynamic, multilayered and encompass a variety of complex social, medical and psychological influences. In spite of this, there are clear benefits to their application in regard to the approaches and training of violence mitigation. The paramedic environment would benefit from strategies that are flexible to the ongoing needs of the workers and the specific cultural, environmental and social factors that encompass the paramedic organisation.

Safety and efficacy of pharmacologic agents used for rapid tranquilization of emergency department patients with acute agitation or excited delirium

Introduction: Management of patients with acute agitation or aggressive behavior can pose a significant challenge to health-care providers in emergency departments. Areas covered: This article provides a comprehensive review of the pharmacologic properties, efficacy, and safety profiles of select intramuscular (IM) sedative agents (i.e., antipsychotics, benzodiazepines, and ketamine) for rapid tranquilization. Expert opinion: Using antipsychotics and benzodiazepines - whether a single agent or combined - will have similar efficacy in producing sedation. But there are differences in the time to sedation depending on which agent is used. Based upon the available studies, droperidol (5-10 mg IM) and midazolam (5-10 mg IM) have the fastest onset of sedation when either is used as a single agent. When combination therapy is used, using midazolam with an antipsychotic agent, instead of lorazepam, may result in faster sedative effect. QT prolongation and torsades de pointes are uncommon adverse drug effects of antipsychotic administration. Ketamine is often reserved as a second-line agent when antipsychotics and benzodiazepines fail to produce the desired tranquilization. However, ketamine (5 mg/kg IM) is more frequently associated with airway compromise requiring endotracheal intubation. A low-dose of ketamine (2 mg/kg IM) may reduce the risk of airway compromise while providing adequate sedation.

Considerations for Acute and Emergent Deployed Mental Health Patient Management and Theater Transports: A Scoping Review

Background

Although combat stress and psychiatric casualties of war have consistently contributed to the need for deployed patient transport to higher echelons of care, little is known regarding specific evidence-based strategies for providing psychological support and optimal transport interventions for warriors.

Study Objective

The purpose of this scoping review is to map existing literature related to considerations for deployed mental health patient transport. The review’s primary aims are to identify the existing scientific research evidence, determine research and training gaps, and recommend critical areas for future military research.

Methods

We used Arksey and O’Malley’s six-stage scoping review methodological framework (identify the research question, identify relevant studies, select studies, chart data, report results, and consultation). Using a systematic search strategy, we evaluated peer-reviewed literature from five databases (PubMed, CINAHL, PsycINFO, Web of Science, and Embase) and gray literature from the Defense Technical Information Center. All publications were independently screened for eligibility by two researchers during three review rounds (title, abstract, and full text).

Results

We identified 1,384 publications, 61 of which met our inclusion criteria. Most publications and technical reports were level IV evidence and below, primarily retrospective cohort studies and epidemiologic surveillance reports. Few rigorously designed studies were identified. Eight research themes and a variety of research and critical training gaps were derived from the reviewed literature. Themes included (1) characterizing mental health patients aeromedically evacuated from theater; (2) in-flight sedation medications; (3) need for aeromedical evacuation (AE) in-theater education, training, and guidelines for staff; (4) epidemiological surveillance of AE from theater; (5) mental health management in deployed settings; (6) suicide-related event management; (7) transport issues for mental health patients; and (8) psychological stressors of AE. Research is needed to establish clinical practice guidelines for mental health condition management in theater and throughout the continuum of en route care.

Intramuscular medication for treatment of agitation in the emergency department: A systematic review of controlled trials

BACKGROUND

Severely agitated patients in the emergency department (ED) are often sedated with intramuscularly-administered medications. The evidence base underlying particular medication choices is surprisingly sparse, as existing reviews either have methodological limitations or have included data collected outside of emergent settings.

OBJECTIVES

The objective of this review was to examine all controlled trials in emergent settings that have used standardized scales to measure the effectiveness of intramuscular medication for the treatment of acute agitation.

METHODS

This review was registered in Prospero as CRD42018105745. PubMed, International Pharmaceutical Abstracts, Web of Science, PsycINFO, and clinicaltrials.gov were searched for prospective controlled trials investigating intramuscular antipsychotics for agitation. Articles were assessed for bias across five domains using the revised Cochrane Risk of Bias Tool.

RESULTS

Eight studies were eligible for inclusion in the systematic review, none of which had a low risk of bias. Five studies had a moderate risk of bias with heterogenous designs, populations, and treatments. These studies seemed to suggest that second generation antipsychotics (SGAs) likely reduce agitation as effectively as first generation antipsychotics (FGAs) plus an adjunctive medication with similar or lower risk of side effects.

CONCLUSIONS

Existing trials on the use of intramuscular antipsychotics in the ED/psychiatric ED setting were small, heterogenous, and at a moderate or high risk of bias. Given the clinical importance of this topic, further prospective investigations are desperately needed but are currently unfeasible under Food and Drug Administration Exception From Informed Consent regulations.

Rescue Intubation in the Emergency Department After Prehospital Ketamine Administration for Agitation

Objective:

Prehospital intramuscular (IM) ketamine is increasingly used for chemical restraint of agitated patients. However, few studies have assessed emergency department (ED) follow-up of patients receiving prehospital ketamine for this indication, with previous reports suggesting a high rate of post-administration intubation. This study examines the rate of and reasons for intubation and other airway interventions in agitated patients who received ketamine by Emergency Medical Services (EMS).

Methods:

This retrospective cohort study included patients who received prehospital ketamine for agitation and were transported to two community hospital EDs. Charts were reviewed for demographics, ketamine dose, and airway intervention by EMS or in the ED. Characteristics of patients who were intubated versus those who did not receive airway intervention were analyzed.

Results:

Over 28 months, 86 patients received ketamine for agitation. Fourteen (16.3%) underwent endotracheal intubation. Patients with a higher temperature and a lower Glasgow Coma Score (GCS) were more likely to require intubation. There was no age or dose-dependent association on intubation rate. Intubated patients averaged 39 years old versus 44 for patients not intubated (negative five-year difference; 95% CI, -16 to 6). The mean ketamine dose was 339.3mg in patients intubated versus 350.7mg in patients not (-11.4mg difference; 95% CI, -72.4 to 49.6). The mean weight-based ketamine dose was 4.44mg/kg in patients intubated versus 4.96mg/kg in patients not (-0.53mg/kg difference; 95% CI, -1.49 to 0.43).

Conclusions:

The observed rate of intubation in patients receiving prehospital ketamine for agitation was 16.3%. Study data did not reveal an age or dose-dependent rate of intubation. Further research should be conducted to compare the airway intervention rate of agitated patients receiving ketamine versus other sedatives in a controlled fashion.

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.

Retrospective Study of Midazolam Protocol for Prehospital Behavioral Emergencies

Introduction

Agitated patients in the prehospital setting pose challenges for both patient care and emergency medical services (EMS) provider safety. Midazolam is frequently used to control agitation in the emergency department setting; however, limited data exist in the prehospital setting. We describe our experience treating patients with midazolam for behavioral emergencies in a large urban EMS system. We hypothesized that using midazolam for acute agitation leads to improved clinical conditions without causing significant clinical deterioration.

Methods

We performed a retrospective review of EMS patient care reports following implementation of a behavioral emergencies protocol in a large urban EMS system from February 2014–June 2016. For acute agitation, paramedics administered midazolam 1 milligram (mg) intravenous (IV), 5 mg intramuscular (IM), or 5 mg intranasal (IN). Results were analyzed using descriptive statistics, Levene’s test for assessing variance among study groups, and t-test to evaluate effectiveness based on route.

Results

In total, midazolam was administered 294 times to 257 patients. Median age was 30 (interquartile range 24–42) years, and 66.5% were male. Doses administered were 1 mg (7.1%) and 5 mg (92.9%). Routes were IM (52.0%), IN (40.8%), and IV (7.1%). A second dose was administered to 37 patients. In the majority of administrations, midazolam improved the patient’s condition (73.5%) with infrequent adverse events (3.4%). There was no significant difference between the effectiveness of IM and IN midazolam (71.0% vs 75.4%; p = 0.24).

Conclusion

A midazolam protocol for prehospital agitation was associated with reduced agitation and a low rate of adverse events.

The Hennepin Ketamine Study Investigators' Reply

We read with interest the recent editorial, "The Hennepin Ketamine Study," by Dr. Samuel Stratton commenting on the research ethics, methodology, and the current public controversy surrounding this study.1 As researchers and investigators of this study, we strongly agree that prospective clinical research in the prehospital environment is necessary to advance the science of Emergency Medical Services (EMS) and emergency medicine. We also agree that accomplishing this is challenging as the prehospital environment often encounters patient populations who cannot provide meaningful informed consent due to their emergent conditions. To ensure that fellow emergency medicine researchers understand the facts of our work so they may plan future studies, and to address some of the questions and concerns in Dr. Stratton's editorial, the lay press, and in social media,2 we would like to call attention to some inaccuracies in Dr. Stratton's editorial, and to the lay media stories on which it appears to be based.Ho JD, Cole JB, Klein LR, Olives TD, Driver BE, Moore JC, Nystrom PC, Arens AM, Simpson NS, Hick JL, Chavez RA, Lynch WL, Miner JR. The Hennepin Ketamine Study investigators' reply. Prehosp Disaster Med. 2019;34(2):111-113.

Ketamine Safety and Use in the Emergency Department for Pain and Agitation/Delirium: A Health System Experience

INTRODUCTION

Two protocols were developed to guide the use of subdissociative dose ketamine (SDDK) for analgesia and dissociative sedation ketamine for severe agitation/excited delirium in the emergency department (ED). We sought to evaluate the safety of these protocols implemented in 18 EDs within a large health system.

METHODS

We conducted a retrospective chart review to evaluate all adult patients who received intravenous (IV) SDDK for analgesia and intramuscular (IM) dissociative sedation ketamine for severe agitation/excited delirium in 12 hospital-based and six freestanding EDs over a one-year period from the protocol implementation. We developed a standardized data collection form and used it to record patient information regarding ketamine use, concomitant medication use, and any comorbidities that could have impacted the incidence of adverse events.

RESULTS

Approximately 570,000 ED visits occurred during the study period. SDDK was used in 210 ED encounters, while dissociative sedation ketamine for severe agitation/excited delirium was used in 37 ED encounters. SDDK was used in 83% (15/18) of sites while dissociative sedation ketamine was used in 50% (9/18) of sites. Endotracheal intubation, non-rebreather mask, and nasal cannula ≥ four liters per minute were identified in one, five, and three patients, respectively. Neuropsychiatric adverse events were identified in 4% (9/210) of patients who received SDDK.

CONCLUSION

Patients experienced limited neuropsychiatric adverse events from SDDK. Additionally, dissociative sedation ketamine for severe agitation/excited delirium led to less endotracheal intubation than reported in the prehospital literature. The favorable safety profile of ketamine use in the ED may prompt further increases in usage.

Castration of Dogs Using Local Anesthesia After Sedating With Xylazine and Subanesthetic Doses of Ketamine

Orchiectomy is performed in some species using only sedation and local anesthesia to decrease the expense of performing the procedure using general anesthesia. The objective of this study was to determine if dogs can be castrated safely and painlessly by using only sedation and local anesthesia. After dogs were sedated with intramuscularly administered xylazine (1 mg/kg) and subanesthetic ketamine (1 mg/kg), testes and skin were anesthetized with 2% lidocaine (6 mg/kg, total dose) buffered with sodium bicarbonate. Systolic, diastolic, and mean blood pressures; heart and respiratory rates; and movement scores were determined before and during surgery when manipulations were most likely to cause pain. No dog reacted substantially to injection of the combination of sedatives, and no dog reacted noticeably to injection of lidocaine. During surgery, the average heart rate was reduced from baseline by 40–60 beats per minute, and the average respiratory rate was reduced by ~10 breaths per minute. An overall reduction of arterial blood pressures was observed. All but one dog moved purposely in response to a toe pinch at the end of surgery. We found that sedating dogs intramuscularly with xylazine and a sub-anesthetic dose of ketamine and administering lidocaine at the incision site and intratesticularly allowed dogs to be castrated humanely and avoided the expense of general anesthesia and the need for hospitalization.

Managing Acute Agitation and Psychotic Symptoms in the Emergency Department

Background and goals:

It is fairly common for adolescents with a presenting problem of acute agitation to present to the Emergency Department. These patients present challenges with respect to both differential diagnosis and management. Furthermore, with many adolescents having extended stays in emergency departments, it is important for ED physicians to have a basic familiarity with diagnosis and treatment.

Method:

In this paper, we present a primer on the conditions underlying acute agitation and review approaches to management in the emergency department.

Discussion:

Psychotic disorders, such as schizophrenia, are distinct from other conditions presenting with psychotic symptoms, which can range from depression to substance use to non-psychiatric medical conditions. Agitation, a state of excessive verbal and physical activity, can accompany any of these conditions. Unlike the case for adults, practice guidelines do not exist, and there is no fully agreed upon expert consensus yet. Emergency physicians should have a working knowledge of antipsychotic medications and need to consider pharmacological as well as non-pharmacological treatments for optimal management.

Evaluation of Ketamine for Excited Delirium Syndrome in the Adult Emergency Department

BACKGROUND

Excited delirium syndrome (ExDS) is characterized by delirium, agitation, and hyperadrenergic autonomic dysfunction. A guideline for ExDS management, which recommends the use of ketamine as a second-line agent, was implemented in our hospital's adult emergency department (ED).

OBJECTIVE

The primary objective was to determine whether ketamine, 1 mg/kg intravenous (i.v.) or 2 mg/kg intramuscular (i.m.), is being used according to the ExDS guideline. Secondary objectives included evaluating the specific agents, routes, and dosages used to manage ExDS and the safety and efficacy of ketamine.

METHODS

Single-center, retrospective chart review of patients who received ketamine for the management of ExDS in the ED. Efficacy was measured by documented Richmond Agitation Sedation Scale (RASS) scores. Safety was assessed through evaluation of vital signs and adverse effects.

RESULTS

Thirty-one patients met inclusion criteria. Eight (25.8%) of them received ketamine for ExDS in adherence with all aspects of the guideline. Administration of ketamine led to a statistically significant decrease in median RASS score of 4 (interquartile range [IQR] 3 to 4) vs. 0 (IQR 2 to -1) (p = 0.001). There were no statistically significant differences in vital signs or RASS scores in our subgroup analyses of patients treated according to protocol and of those treated with ketamine, 2 mg/kg i.m.

CONCLUSIONS

We found discordance between current practice and our department's ExDS guideline for patients managed with ketamine. Despite the lack of adherence to departmental guidelines and allowing for limitations of this analysis due to small sample size, the use of low-dose, 1 mg/kg i.v. or 2 mg/kg i.m., ketamine was effective and appears to be a reasonable option as second-line therapy for ExDS.

Psychiatric Outcomes of Patients With Severe Agitation Following Administration of Prehospital Ketamine

BACKGROUND

Ketamine is an emerging drug used in the management of undifferentiated, severe agitation in the prehospital setting. However, prior work has indicated that ketamine may exacerbate psychotic symptoms in patients with schizophrenia. The objective of this study was to describe psychiatric outcomes in patients who receive prehospital ketamine for severe agitation.

METHODS

This is a retrospective cohort study, conducted at two tertiary academic medical centers, utilizing chart review of patients requiring prehospital sedation for severe agitation from January 1, 2014, to June 30, 2016. Patients received either intramuscular (IM) versus intravenous (IV) ketamine or IM versus IV benzodiazepine. The primary outcome was psychiatric inpatient admission with secondary outcomes including ED psychiatric evaluation and nonpsychiatric inpatient admission. Generalized estimating equations and Fisher's exact tests were used to compare cohorts.

RESULTS

During the study period, 141 patient encounters met inclusion with 59 (42%) receiving prehospital ketamine. There were no statistically significant differences between the ketamine and benzodiazepine cohorts for psychiatric inpatient admission (6.8% vs. 2.4%, difference = 4.3%, 95% CI = -2% to 12%, p = 0.23) or ED psychiatric evaluation (8.6% vs. 15%, difference = -6.8%, 95% CI = -18% to 5%, p = 0.23). Patients with schizophrenia who received ketamine did not require psychiatric inpatient admission (17% vs. 10%, difference = 6.7%, 95% CI = -46% to 79%, p = 0.63) or ED psychiatric evaluation (17% vs. 50%, difference = -33%, 95% CI = -100% to 33%, p = 0.55) significantly more than those who received benzodiazepines, although the subgroup was small (n = 16). While there was no significant difference in the nonpsychiatric admission rate between the ketamine and benzodiazepine cohorts (35% vs. 51%, p = 0.082), nonpsychiatric admissions in the benzodiazepine cohort were largely driven by intubation (63% vs. 3.8%, difference = 59%, 95% CI = 38% to 79%, p < 0.001).

CONCLUSIONS

Administration of prehospital ketamine for severe agitation was not associated with an increase in the rate of psychiatric evaluation in the emergency department or psychiatric inpatient admission when compared with benzodiazepine treatment, regardless of the patient's psychiatric history.