The association between ketamine given for prehospital chemical restraint with intubation and hospital admission

Recent trends and risk factors for chemical and physical restraint use in the emergency department evaluation and treatment of trauma patients

BACKGROUND

Despite research linking chemical and physical restraints to negative outcomes including unplanned intubations and psychological distress, there is little guidance for their use in the care of trauma patients. We used institutional data to describe recent trends in chemical and physical restraint in the emergency department evaluation and treatment of trauma patients and to identify characteristics associated with their use.

METHODS

This study includes adult trauma activations at a United States urban level I trauma center from January 2016 to July 2022. Data were collected from the trauma registry and medical record. We assessed the use of chemical restraints and physical restraints during care provided in the trauma resuscitation bay and emergency department. We assessed trends over time graphically and with logistic regression. We used multivariable regression models to evaluate associations between restraint use and patient and clinical characteristics and the outcomes of ICU admission, hospitalization duration, and mortality.

RESULTS

Of the 8,112 patients, most were male (74.8 %), White (55.8 %), and privately insured (35.2 %). Overall, 8.1 % were restrained with 7.1 % chemically restrained and 2.7 % physically restrained. Overall restraint use increased 254 % (p < 0.001) from 2016 to 2022 driven primarily by a 460 % (p < 0.001) increase in chemical restraint use including a 630 % increase in ketamine administrations (p < 0.001). Use of restraints was associated with pre-existing psychotic disorders, intoxication, altered mental status, increasing injury severity, and Medicaid insurance (p < 0.001). Chemical restraint administration was associated with a 3.5 percentage point (95 %CI 1.1-5.9; p = 0.004) increase in the probability of ICU admission and a 1.0 day (95 %CI 0.6-1.4; p < 0.001) increase in hospitalization duration.

CONCLUSIONS

In this institutional study, nearly one-in-twelve trauma patients were restrained during emergency department evaluation and treatment. Restraint utilization increased during the study driven primarily by increases in ketamine and restraints utilized during trauma bay evaluation and resuscitation. Future research should assess the generalizability of these findings. It is important that rigorous guidelines are established to ensure the safe and effective use of restraints in trauma.

Fixed dose ketamine for prehospital management of hyperactive delirium with severe agitation

INTRODUCTION

Patients exhibiting signs of hyperactive delirium with severe agitation (HDSA) may require sedating medications for stabilization and safe transport to the hospital. Determining the patient's weight and calculating the correct weight-based dose may be challenging in an emergency. A fixed dose ketamine protocol is an alternative to the traditional weight-based administration, which may also reduce dosing errors. The objective of this study was to evaluate the frequency and characteristics of adverse events following pre-hospital ketamine administration for HDSA.

METHODS

Emergency Medical Services (EMS) records from four agencies were searched for prehospital ketamine administration. Cases were included if a 250 mg dose of ketamine was administered on standing order to an adult patient for clinical signs consistent with HDSA. Protocols allowed for a second 250 mg dose of ketamine if the first dose was not effective. Both the 250 mg initial dose and the total prehospital dose were analyzed for weight based dosing and adverse events.

RESULTS

Review of 132 cases revealed 60 cases that met inclusion criteria. Patients' median weight was 80 kg (range: 50-176 kg). No patients were intubated by EMS, one only requiring suction, three required respiratory support via bag valve mask (BVM). Six (10%) patients were intubated in the emergency department (ED) including the three (5%) supported by EMS via BVM, three (5%) others who were sedated further in the ED prior to requiring intubation. All six patients who were intubated were discharged from the hospital with a Cerebral Performance Category (CPC) 1 score. The weight-based dosing equivalent for the 250 mg initial dose (OR: 2.62, CI: 0.67-10.22) and the total prehospital dose, inclusive of the 12 patients that were administered a second dose, (OR: 0.74, CI: 0.27, 2.03), were not associated with the need for intubation.

CONCLUSION

The 250 mg fixed dose of ketamine was not >5 mg/kg weight-based dose equivalent for all patients in this study. Although a second 250 mg dose of ketamine was permitted under standing orders, only 12 (20%) of the patients were administered a second dose, none experienced an adverse event. This indicates that the 250 mg initial dose was effective for 80% of the patients. Four patients with prehospital adverse events likely related to the administration of ketamine were found. One required suction, three (5%) requiring BVM respiratory support by EMS were subsequently intubated upon arrival in the ED. All 60 patients were discharged from the hospital alive. Further research is needed to determine an optimal single administration dose for ketamine in patients exhibiting signs of HDSA, if employing a standardized fixed dose medication protocol streamlines administration, and if the fixed dose medication reduces the occurrence of dosage errors.

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.

Association of Ketamine Dosing with Intubation and Other Adverse Events in Patients with Behavioral Emergencies

OBJECTIVE

Varying rates of complications have been reported for prehospital sedation with ketamine, and the relationship to dosing has not been studied on a large scale. We evaluated the association between prehospital ketamine dosing and rates of intubations and other adverse events in patients with behavioral emergencies.

METHODS

Using the 2018/2019 ESO public-use research datasets, we included all non-traumatic, adult behavioral and drug-related EMS encounters with ketamine administration. Based on consensus guidelines, we stratified patients into "above" and "at/below" the maximum dosing for sedation (2 mg/kg IV/IO or 5 mg/kg IM) using the highest single dose of ketamine given. We created propensity scores for matched subjects using 1:1 propensity score matching. Using logistic regression, we compared rates of intubation and other airway interventions, antipsychotic coadministration, improvement reported by EMS, hypoxia, hypotension, and cardiac arrest between the two groups.

RESULTS

We included 2383 patients: 478 in the above and 1905 in the at/below dose group. Above-dose ketamine was associated with a higher rate of intubation or supraglottic airway placement (6.4% v 3.3%, OR 2.0, 95% CI 1.00-3.90). Other airway interventions were similar (40.0% v 40.0%, OR 1, 95% CI 0.80-1.30). The above-dose group also showed a higher rate of improvement noted by EMS clinicians (92.5% v 88.7%, OR 1.6, 95% CI 1.01-2.40). The rates of antipsychotic coadministration, hypoxia, hypotension, and cardiac arrest were similar between the cohorts.

CONCLUSIONS

Patients given ketamine doses above consensus recommendations for sedation appeared more likely to receive prehospital intubation but not more likely to experience other adverse events.

A Comparison of Prehospital Pediatric Analgesic Use of Ketamine and Opioids

OBJECTIVE/INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

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.

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.

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.

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.

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.

The Expanding Role of Ketamine in the Emergency Department

Patients frequently come to the emergency department for pain. For decades, ketamine has been used in the emergency department for procedural sedation but is now receiving attention as a potential alternative to opioids because of its unique analgesic effects. Additionally, ketamine's dissociative properties have made it a popular choice for sedating profoundly agitated patients. In this narrative review, these new roles for ketamine in the emergency department are discussed.

Psychiatric Considerations Regarding Prehospital Administration of Ketamine for Agitation

Recently, ketamine has seen increased use among emergency medical services in the prehospital setting as a first-line means of chemical restraint for agitated patients. In this case report, we explore an instance in which ketamine administration for nonpsychotic agitation before emergency department (ED) evaluation may have caused unexpected psychotic symptoms leading to a complicated ED course necessitating admission. As ketamine gains widespread use in the prehospital setting, the safety profile deserves reevaluation. In the following report, we review relevant literature and discuss important factors to consider regarding the use of prehospital ketamine, including psychiatric and substance abuse history.

A Prospective Study of the Safety and Effectiveness of Droperidol in Children for Prehospital Acute Behavioral Disturbance

Study objective: Although uncommon, children (<16 years) with acute behavioral disturbance are a significant issue for emergency medical service providers. In this study, we aimed to investigate the safety and effectiveness of droperidol in children with prehospital acute behavioral disturbance. Methods: This was a prospective observational study over 1 year investigating the use of droperidol (0.1-0.2 mg/kg) for children (< 16 years) with acute behavioral disturbance. Inclusion criteria for acute behavioral disturbance were defined by a sedation assessment tool score of ≥2 determined by the attending paramedic. The primary outcome was the proportion of adverse effects (need for airway intervention, oxygen saturation <90% and/or respiratory rate <12, systolic blood pressure <90 mmHg, sedation assessment tool score of -3 and dystonic reactions). Secondary outcomes included time to sedation (sedation assessment tool score decreased by 2 or more, or a score of zero), requirement for additional sedation, failure to sedate and proportion of sedation success defined as the number of patients successfully sedated who did not suffer any adverse events or receive additional sedation. Results: There were 96 patients (males 51 [53%], median age 14 years [range 7-15 years]) who presented on 102 occasions over the one year study period. Self-harm and/or harm to others was the commonest (74/105 [70%]) cause of acute behavioral disturbance followed by alcohol (16/105 [15%]). There were 9 adverse events in 8 patients (8/102 [8%]; 95% confidence intervals [CI]: 3-13%) Five patients had hypotension, all asymptomatic and only one required treatment; 2 dystonic reactions managed with benztropine and one patient with respiratory depression. Median time to sedation was 14 min (interquartile range (IQR): 10-20 min; range: 3-85 min). There was no requirement for prehospital additional sedation (0/102 [0%]; 95% CI: 0-4%) and additional sedation in the first hour of arrival to hospital was required by 4 patients (4/102 [4%]; 95% CI: 1-10%). Overall successful sedation was achieved in 89 (87%) patients. Conclusions: The use of droperidol in children for acute behavioral disturbance in the prehospital setting is both safe and effective.

Rapid agitation control with ketamine in the emergency department (RACKED): a randomized controlled trial protocol

Background

The rapid control of patients presenting to the emergency department (ED) with psychomotor agitation and violent behavior is paramount for the safety of patients and ED staff. The use of intramuscular (IM) ketamine in the pre-hospital and ED settings has demonstrated promising preliminary results to provide rapid and safe behavioral control. A prospective, randomized controlled trial is required to measure the potential superiority of IM ketamine compared to current standard care (IM benzodiazepines plus antipsychotics).

Methods

This will be a parallel, prospective, randomized, controlled trial of 5 mg/kg IM ketamine compared to a combination of 5 mg IM midazolam and 5 mg IM haloperidol. The study will enroll approximately 184 patients, randomized equally to two study arms. There will be one study visit during which study medication will be administered and assessments will be completed. A follow-up safety visit will occur on day 3. The primary objective of this study is to compare IM ketamine to a combination of IM midazolam and haloperidol with regards to the time required for adequate behavioral control, in minutes, in patients presenting to the ED with psychomotor agitation and violent behavior, as measured by the Richmond Agitation-Sedation Scale (RASS).

Discussion

We present a novel study to determine whether ketamine is a rapid and safe option, compared to a combination of midazolam and haloperidol for the sedation of patients presenting to the ED with psychomotor agitation and violent behavior. To our knowledge, this study is the first randomized controlled trial to compare ketamine to current standard care for this indication. We have attempted to address numerous logistical issues with the design of this study including a waiver of consent, ensuring adequate blinding of outcome assessors, patient enrolment, and data monitoring.

Trial registration

Clinicaltrials.gov, NCT03375671. Registered on 18 December 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2992-x) contains supplementary material, which is available to authorized users.

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.

Outcomes of Prehospital Chemical Sedation With Ketamine Versus Haloperidol and Benzodiazepine or Physical Restraint Only

OBJECTIVE

The goal of this study is to describe complications and outcomes of prehospital ketamine use for agitation as compared to other methods of physical or chemical restraint such as haloperidol plus benzodiazepine or physical restraint only.

METHODS

We conducted a single-center retrospective review of patient encounters in which restraint was administered in the prehospital setting. At the beginning of our study window, only physical restraint was available to paramedics managing agitated patients but subsequently, haloperidol and benzodiazepines were introduced, followed by ketamine 2 years later. By comparing patients before and after each transition, we divided subjects into 3 cohorts based on restraint type: physical restraint, haloperidol plus benzodiazepine, and ketamine. Demographic data were collected, and outcome measures included intubation rate, need for additional physical or chemical restraint, emergency department (ED) length of stay, need for hospital admission, and employee injury.

RESULTS

Of 214 subjects included in the study, 95 patients were administered ketamine, 68 received haloperidol and benzodiazepine, and 51 were physically restrained. Eleven of the patients (11.6%) who received ketamine were intubated. Compared to patients who received haloperidol plus benzodiazepine, patients who received ketamine were more likely to be intubated (odds ratio [OR] = 8.77, 95% confidence interval [CI], 1.10-69.68) and were more likely to require additional chemical restraint when compared to haloperidol/benzodiazepine or physical restraint only (OR =2.94, 95% CI, 1.49-5.80, and OR =2.15, 95% CI, 1.07-4.31, respectively). There were no differences between the 2 chemical sedation groups in terms of ED length of stay or hospital admission rate.

CONCLUSIONS

This study demonstrates a lower intubation rate in patients administered ketamine than prior literature in association with a lower weight-based dosing regimen. Ketamine use was correlated with a higher frequency of intubation and a greater need for additional chemical restraint when compared with other restraint modalities, though exogenous factors such as provider preference may have impacted this result. There was no difference in ED length of stay or admission rate between the ketamine and haloperidol plus benzodiazepine groups. Further prospective study is needed to determine whether there is a subset of patients for whom ketamine would be beneficial compared to other therapies.

Joint BAP NAPICU evidence-based consensus guidelines for the clinical management of acute disturbance: De-escalation and rapid tranquillisation

The British Association for Psychopharmacology and the National Association of Psychiatric Intensive Care and Low Secure Units developed this joint evidence-based consensus guideline for the clinical management of acute disturbance. It includes recommendations for clinical practice and an algorithm to guide treatment by healthcare professionals with various options outlined according to their route of administration and category of evidence. Fundamental overarching principles are included and highlight the importance of treating the underlying disorder. There is a focus on three key interventions: de-escalation, pharmacological interventions pre-rapid tranquillisation and rapid tranquillisation (intramuscular and intravenous). Most of the evidence reviewed relates to emergency psychiatric care or acute psychiatric adult inpatient care, although we also sought evidence relevant to other common clinical settings including the general acute hospital and forensic psychiatry. We conclude that the variety of options available for the management of acute disturbance goes beyond the standard choices of lorazepam, haloperidol and promethazine and includes oral-inhaled loxapine, buccal midazolam, as well as a number of oral antipsychotics in addition to parenteral options of intramuscular aripiprazole, intramuscular droperidol and intramuscular olanzapine. Intravenous options, for settings where resuscitation equipment and trained staff are available to manage medical emergencies, are also included.

Excited Delirium: A Systematic Review

OBJECTIVE

We aimed to clarify the definition, epidemiology, and pathophysiology of excited delirium syndrome (ExDS) and to summarize evidence-based treatment recommendations.

METHODS

We conducted a systematic literature search of MEDLINE, Ovid, Web of Knowledge, and Cochrane Library for articles published to March 18, 2017. We also searched the gray literature (Google Scholar) and official police or medical expert reports to complete specific epidemiologic data. Search results and full-text articles were independently assessed by two investigators and agreements between reviewers assessed with K statistics. We classified articles by study type, setting, and evidence level.

RESULTS

After reviewing the title and abstract of 3,604 references, we fully reviewed 284 potentially relevant references, from which 66 were selected for final review. Six contributed to the definition of ExDS, 24 to its epidemiology, 38 to its pathophysiology, and 27 to its management. The incidence of ExDS varies widely with medical or medicolegal context. Mortality is estimated to be as much as 8.3% to 16.5%. Patients are predominantly male. Male sex, young age, African-American race, and being overweight are independent risk factors. Pathophysiology hypotheses mostly implicate dopaminergic pathways. Most cases occur with psychostimulant use or among psychiatric patients or both. Proposed treatments are symptomatic, often with rapid sedation with benzodiazepines or antipsychotic agents. Ketamine is suggested as an alternative.

CONCLUSION

The overall quality of studies was poor. A universally recognized definition is lacking, remaining mostly syndromic and based on clinical subjective criteria. High mortality rate may be due to definition inconsistency and reporting bias. Our results suggest that ExDS is a real clinical entity that still kills people and that has probably specific mechanisms and risk factors. No comparative study has been performed to conclude whether one treatment approach is preferable to another in the case of ExDS.

Ketamine reduces the need for intubation in patients with acute severe mental illness and agitation requiring transport to definitive care: An observational study

OBJECTIVES

The aim of this study was to review mental health patients transported by a dedicated statewide critical care retrieval team before and after the implementation of a ketamine sedation guideline.

METHODS

This is a a retrospective cohort study of mental health patients with acute behavioural disturbance, transported between January 2010 and December 2015.

RESULTS

A total of 78 patients were transported in the study period, 50 before and 28 after implementation of the ketamine guideline in June 2013. The introduction of the ketamine guideline was associated with a significant reduction in intubation for transport (36.00 vs 7.14%) (odds ratio 0.14, 95% confidence interval 0.02-0.71, P < 0.01). The likelihood of utilising ketamine for non-intubated patients (n = 58) was higher in the period after implementation (37.50 vs 84.62%, odds ratio 9.17, 95% confidence interval 2.54-33.08, P < 0.005). The incidence of complications in our series was low.

CONCLUSIONS

The implementation of a ketamine clinical practice guideline for agitated mental health patients was associated with an increase in the number of patients receiving ketamine as part of their sedation regime and a reduction in the number of patients requiring intubation for transport. Appropriately trained critical care retrieval teams should consider ketamine as part of the sedation regime for agitated mental health patients.

Intubation of Profoundly Agitated Patients Treated with Prehospital Ketamine

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

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