The combative multitrauma patient: a protocol for prehospital management

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.

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.

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.

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.

Acute behavioural disturbance: a physical emergency psychiatrists need to understand

The phenomenon of acute behavioural disturbance (ABD) (also known as acute behavioural disorder or excited delirium) is an underrecognised and potentially life-threatening syndrome, and an emergency in psychiatric settings. Causes are discussed and the pathophysiology explained. The challenges faced by practitioners are highlighted, including how ‘standard’ control and restraint can exacerbate symptoms. Initial treatment strategies are suggested.

Subdissociative Ketamine Use in the Emergency Department

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Novel Agent for Management of Agitated Delirium: A Case Series of Ketamine Utilization in the Pediatric Emergency Department

Control of the agitated patient in the emergency department is challenging. Many options exist for chemical sedation, but most have suboptimal pharmacodynamic action, and many have undesirable adverse effects. There are reports of ketamine administration for control of agitation prehospital and in traumatically injured patients. Ketamine is a noncompetitive N-methyl-D-aspartic acid receptor antagonist, making it an effective dissociative agent. We present 5 cases of ketamine administration to manage agitated adolescent patients with underlying psychiatric disease and/or drug intoxication. Ketamine, as a dissociative agent, may be an alternative pharmacological consideration for the control of agitation in patients with undifferentiated agitated delirium.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Use of Prehospital Ketamine for Control of Agitation in a Metropolitan Firefighter-based EMS System

Abstract Introduction. Prehospital personnel frequently encounter agitated, combative, and intoxicated patients in the field. In recent years, ketamine has been described as an effective sedative agent to treat such patients; however, a paucity of research exists describing the use of prehospital ketamine. The objective of this study was to provide a descriptive analysis of the Columbus Division of Fire's experience with utilizing ketamine in the prehospital setting. We hypothesized that ketamine administration improves patient condition, is effective at sedating patients, and does not result in endotracheal intubation in the prehospital setting or in the emergency department (ED). Methods. We conducted a retrospective cohort chart review of Columbus Division of Fire patient care reports and hospital records from destination hospitals in the central Ohio region between October 2010 and October 2012. All patients receiving ketamine administered by Columbus Division of Fire personnel for sedation were included. Patients 17 years and younger were excluded. The primary outcome was the percentage of patients noted to have an "improved" condition recorded in the data field of the patient care report. The secondary outcomes were the effectiveness of sedation and the performance of endotracheal intubation. Results. A total of 36 patients met inclusion criteria over the study period. Data were available on 35 patients for analysis. The mean IV dose of ketamine was 138 mg (SD = 59.5, 100-200). The mean IM dose of ketamine was 324 mg (SD = 120, 100-500). Prehospital records noted an improvement in patient condition after ketamine administration in 32 cases (91%, 95% CI 77-98%). Six patients required sedation post-ketamine administration either by EMS (2) or in the ED (4) (17%, 95% CI 6.5-34%). Endotracheal intubation was performed in eight (23%, 95% CI 10-40%) patients post-ketamine administration. Conclusion. We found that in a cohort of patients administered ketamine, paramedics reported a subjective improvement in patient condition. Endotracheal intubation was performed in 8 patients.

Comparison of droperidol and haloperidol for use by paramedics: assessment of safety and effectiveness

BACKGROUND

Since the 2001 "black box" warning on droperidol, its use in the prehospital setting has decreased substantially in favor of haloperidol. There are no studies comparing the prehospital use of either drug. The goal of this study was to compare QTc prolongation, adverse events, and effectiveness of droperidol and haloperidol among a cohort of agitated patients in the prehospital setting.

METHODS

In this institutional review board-approved before and after study, we collected data on 532 patients receiving haloperidol (n = 314) or droperidol (n = 218) between 2007 and 2010. We reviewed emergency department (ED) electrocardiograms when available (haloperidol, n = 78, 25%; droperidol, n = 178, 76%) for QTc length (in milliseconds), medical records for clinically relevant adverse events (defined a priori as systolic blood pressure (SBP) <90 mmHg, seizure, administration of anti-dysrhythmic medications, cardioversion or defibrillation, bag-valve-mask ventilation, intubation, cardiopulmonary arrest, and prehospital or in-hospital death). We also compared effectiveness of the medications, using administration of additional sedating medications within 30 minutes of ED arrival as a proxy for effectiveness.

RESULTS

The mean haloperidol dose was 7.9 mg (median 10 mg, range 4-20 mg). The mean droperidol dose was 2.9 mg (median 2.5 mg, range 1.25-10 mg.) Haloperidol was given i.m. in 289 cases (92%), and droperidol was given i.m. in 132 cases (61%); in all other cases, the medication was given i.v.. There was no statistically significant difference in median QTc after medication administration (haloperidol 447 ms, 95% CI: 440-454 ms; droperidol 454 ms, 95% CI: 450-457). There were no statistically significant differences in adverse events in the droperidol group as compared to the haloperidol group. One patient in the droperidol group with a history of congenital heart disease suffered a cardiopulmonary arrest and was resuscitated with neurologically intact survival. There was no significant difference in the use of additional sedating medications within 30 minutes of ED arrival after receiving droperidol (2.9%, 95% CI: -2.5-8.4%).

CONCLUSIONS

In this cohort of agitated patients treated with haloperidol or droperidol in the prehospital setting, there was no significant difference found in QTc prolongation, adverse events, or need for repeat sedation between haloperidol and droperidol.

Ketamine: use in anesthesia

The role of ketamine anesthesia in the prehospital, emergency department and operating theater settings is not well defined. A nonsystematic review of ketamine was performed by authors from Australia, Europe, and North America. Results were discussed among authors and the final manuscript accepted. Ketamine is a useful agent for induction of anesthesia, procedural sedation, and analgesia. Its properties are appealing in many awkward clinical scenarios. Practitioners need to be cognizant of its side effects and limitations.

Propofol infusion for the retrieval of the acutely psychotic patient

Transporting acutely psychotic patients is hazardous because of the risks they present to themselves, escorting staff, and aircraft. Various strategies have been proposed, usually involving combinations of sedating drugs and physical restraint. Thus far, none guarantees safe retrieval while completely mitigating risks. This case proposes the use of propofol as an alternative to more traditionally used agents. An infusion facilitated the uneventful and safe retrieval of a patient who had demonstrated resistance and tolerance to other drugs. Discussion is also presented on the potential utility of propofol for the retrieval of acutely psychotic patients.