Inadvertent ketamine overdose in children: clinical manifestations and outcome

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

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

Dream of the Endless: Special Considerations in Procedural Sedation

Procedural sedation and analgesia (PSAA) is integral to facilitating painful and anxiety-inducing medical procedures in the emergency department (ED). Optimal PSAA enhances procedural success and improves both patient and provider satisfaction. The selection of appropriate sedative and analgesic agents, routes, and dosages, which depend on various patient- and procedure-specific factors is a complex process. Alternative routes of administration, such as intranasal, intramuscular, and oral, are all options, each with their own inherent benefits and limitations. It is important for providers to take into account patient-specific considerations, including age, medical history, body weight composition, and pregnancy, which can significantly impact PSAA effectiveness and safety. Implementation strategies targeted to minimize medication errors and optimize workflow are also important considerations in PSAA. By adopting a comprehensive and evidence-based approach, health care providers can navigate the intricacies of PSAA and ensure the best possible care for patients in the ED.

Randomised controlled trial of analgesia for the management of acute severe pain from traumatic injury: study protocol for the paramedic analgesia comparing ketamine and morphine in trauma (PACKMaN)

BACKGROUND

Prehospital analgesia is often required after traumatic injury, currently morphine is the strongest parenteral analgesia routinely available for use by paramedics in the United Kingdom (UK) when treating patients with severe pain. This protocol describes a multi-centre, randomised, double blinded trial comparing the clinical and cost-effectiveness of ketamine and morphine for severe pain following acute traumatic injury.

METHODS

A two arm pragmatic, phase III trial working with two large NHS ambulance services, with an internal pilot. Participants will be randomised in equal numbers to either (1) morphine or (2) ketamine by IV/IO injection. We aim to recruit 446 participants over the age of 16 years old, with a self-reported pain score of 7 or above out of 10. Randomised participants will receive a maximum of 20 mg of morphine, or a maximum of 30 mg of ketamine, to manage their pain. The primary outcome will be the sum of pain intensity difference. Secondary outcomes measure the effectiveness of pain relief and overall patient experience from randomisation to arrival at hospital as well as monitoring the adverse events, resource use and cost-effectiveness outcomes.

DISCUSSION

The PACKMAN study is the first UK clinical trial addressing the clinical and cost-effectiveness of ketamine and morphine in treating acute severe pain from traumatic injury treated by NHS paramedics. The findings will inform future clinical practice and provide insights into the effectiveness of ketamine as a prehospital analgesia.

TRIAL REGISTRATION

ISRCTN, ISRCTN14124474. Registered 22 October 2020, https://www.isrctn.com/ISRCTN14124474.

Prehospital Treatment of Benzodiazepine-Resistant Pediatric Status Epilepticus with Parenteral Ketamine: A Case Series

We report the initial six pediatric patients treated with ketamine for benzodiazepine-resistant status epilepticus in an urban, ground-based emergency medical services (EMS) system. Evidence for ketamine as a second-line agent for both adult and pediatric refractory seizure activity in the hospital setting has increased over the past decade. The availability of an inexpensive and familiar second-line prehospital anti-epileptic drug option is extremely desirable. We believe these initial data demonstrate promising seizure control effects without significant respiratory depression, indicating a potential role for ketamine in the EMS treatment of pediatric benzodiazepine-refractory seizures.

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.

Narrative Review: Low-Dose Ketamine for Pain Management

Pain is the leading cause of medical consultations and occurs in 50-70% of emergency department visits. To date, several drugs have been used to manage pain. The clinical use of ketamine began in the 1960s and it immediately emerged as a manageable and safe drug for sedation and anesthesia. The analgesic properties of this drug were first reported shortly after its use; however, its psychomimetic effects have limited its use in emergency departments. Owing to the misuse and abuse of opioids in some countries worldwide, ketamine has become a versatile tool for sedation and analgesia. In this narrative review, ketamine's role as an analgesic is discussed, with both known and new applications in various contexts (acute, chronic, and neuropathic pain), along with its strengths and weaknesses, especially in terms of psychomimetic, cardiovascular, and hepatic effects. Moreover, new scientific evidence has been reviewed on the use of additional drugs with ketamine, such as magnesium infusion for improving analgesia and clonidine for treating psychomimetic symptoms. Finally, this narrative review was refined by the experience of the Pain Group of the Italian Society of Emergency Medicine (SIMEU) in treating acute and chronic pain with acute manifestations in Italian Emergency Departments.

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

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

Ketamine-assisted psychotherapy in adolescents with multiple psychiatric diagnoses

Ketamine-assisted psychotherapy is a promising new treatment for a variety of mental disorders of adolescence. There is currently an adolescent mental health crisis, with a high prevalence of disorders, diagnostic complexity, and many adolescents failing to respond to conventional treatments. While there is strong evidence for the use of ketamine in adults for a variety of treatment-refractory mental illnesses, research in adolescents is in its early stages. Ketamine-assisted psychotherapy (KAP) has been described in adults with promising results and here we present the first published cases of the use of KAP in adolescents. The four cases include adolescents aged 14-19 at the initiation of treatment, each with a variety of comorbid diagnoses including treatment-resistant depression, bipolar disorder, eating disorders, anxiety, panic, and trauma-related symptoms. They each initially received sublingual ketamine, followed by sessions with intramuscular ketamine. Their courses varied, but each had symptomatic and functional improvements, and the treatment was well-tolerated. Subjective patient reports are included. Rapid resolution of symptomatology and suffering often occurs within months as the result of the application of KAP to adolescent psychiatric care but is not inevitable. Family involvement in the treatment process appears to be essential to success. The development of this modality may have a singularly positive impact that will expand the psychiatric toolbox and its healing potency.

Overdoses and deaths related to the use of ketamine and its analogues: a systematic review

Background: Although the misuse of ketamine constitutes a worldwide issue, ketamine is quickly taking its place as a therapeutic option in the management of several mental disorders. However, the use of ketamine and/or its analogues, as well as combinations with other drugs, can be fatal.Objective: To outline the cases of overdoses and deaths related to the use of ketamine and/or its analogues, as reported in the scientific literature. To investigate if ketamine is safe in a therapeutic context, particularly in its use as an antidepressant.Methods: Electronic searches were performed on three medical databases. Articles describing cases of overdose and/or death associated with ketamine and/or its analogues were included. After the removal of duplicates, title analysis and full-text analysis, 34 articles were included in this review.Results: Eighteen articles described fatal cases and sixteen described overdoses. Poly-substance use was mentioned in 53% of the selected articles. Most cases were males and the ages varied from two to 65 years old. A total of 312 overdose cases and 138 deaths were reported. In both death reports and overdose cases, ketamine was preponderant: 89.1% and 79%, respectively. No cases of overdose or death related to the use of ketamine as an antidepressant in a therapeutic setting were found; most of the deaths occurred in the circumstances of polydrug use and overdoses left no sequelae.Conclusion: There is legitimate concern about the risks involving the use of ketamine and its analogues, especially in recreational settings. On the other hand, ketamine as medicine is considered safe and it is listed as an essential medicine by the World Health Organization. Although clinicians must remain vigilant, this should not deter appropriate prescription.

Clinical Uses of Ketamine in Children: A Narrative Review

Ketamine is a phencyclidine derivative that acts as a noncompetitive N-methyl-D-aspartate as well as a glutamate receptor antagonist. It also has other minor mechanisms that contribute to its extensive drug profile. Ketamine is a bronchodilator and maintains normal airway reflexes and, thus, permits spontaneous respiration. This, coupled with the fact that it produces potent analgesia, makes it highly suitable for children.

Despite its many merits, the drug’s side effects, along with its cultural image of being a drug of abuse, a drug used in veterinary medicine, or a “date-rape drug” have sullied its reputation within the armamentarium of medicine. Even though it is widely used in developing countries, its use in Western nations has diminished. We have strived to explore the various clinical uses of ketamine in children through this article. In addition, the article also highlights how some of the fears associated with using the drug are unfounded and provides ways by which the drug’s side effects can be prevented and managed.

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.

An Analysis of Ketamine Doses Administrated to Nonintubated Casualties Prehospital

INTRODUCTION

Previous studies demonstrate that a significant proportion of casualties do not receive pain medication prehospital after traumatic injuries. To address possible reasons, the U.S. Military has sought to develop novel delivery methods to aid in administration of pain medications prehospital. We sought to describe the dose and route of ketamine administered prehospital to help inform materiel solutions.

MATERIALS AND METHODS

This is a secondary analysis of a previously described dataset focused on prehospital data within the Department of Defense Trauma Registry from 2007 to 2020. We isolated encounters in which ketamine was administered along with the amount dosed and the route of administration in nonintubated patients.

RESULTS

Within our dataset, 862 casualties met inclusion for this analysis. The median age was 28 and nearly all (98%) were male. Most were battle injuries (88%) caused by explosives (54%). The median injury severity score was 10 with the extremities accounting to the most frequent seriously injured body region (38%). The mean dose via intravenous route was 50.4 mg (n = 743, 95% CI 46.5-54.3), intramuscular was 66.7 mg (n = 234, 95% CI 60.3-73.1), intranasal was 56.5 mg (n = 10, 39.1-73.8), and intraosseous was 83.3 mg (n = 34, 66.3-100.4). Most had a medic or CLS in their chain of care (87%) with air evacuation as the primary mechanism of evacuation (86%).

CONCLUSIONS

The average doses administered were generally larger than the doses recommended by Tactical Combat Casualty Care guidelines. Currently, guidelines may underdose analgesia. Our data will help inform materiel solutions based on end-user requirements.

An Analysis of Prolonged, Continuous Ketamine Infusions

INTRODUCTION

Opioids carry high risk of dependence, and patients can rapidly build tolerance after repetitive dosing. Low-dose ketamine is an analgesic agent alternative that provides more hemodynamic stability. We sought to describe the effects of prolonged ketamine use in non-burn patients.

MATERIALS AND METHODS

We queried the electronic health system at the Brooke Army Medical Center for patient encounters with ketamine infusions lasting >72 hours. We abstracted data describing demographics, vital signs, ketamine infusion dose and duration, and discharge diagnoses potentially relevant to ketamine side effects.

RESULTS

We identified 194 subjects who met the study inclusion criteria. The median age was 39 years, most were male (67.0%), and most were primarily admitted for a non-trauma reason (59.2%). The mean ketamine drip strength was 43.9 mg/h (95% CI, 36.7-51.1; range 0.1-341.6) and the mean drip length was 130.8 hours (95% CI, 120.3-141.2; range 71-493). Most subjects underwent mechanical ventilation (56.1%) at some point during the infusion and most survived to hospital discharge (83.5%). On a per-day basis, the average heart rate was 93 beats per minute, systolic blood pressure was 128 mmHg, diastolic blood pressure was 71 mmHg, oxygen saturation was 96%, and respiratory rate was 22 respirations per minute.

CONCLUSIONS

We demonstrate that continuous ketamine infusions provide a useful adjunct for analgesia and/or sedation. Further development of this adjunct modality may serve as an alternative agent to opioids.

Ketamine: Is the current 200 mg product fit for purpose in the emergency department?

OBJECTIVE

To describe the magnitude of ketamine doses administered in the ED, to identify an appropriate product to minimise risk of administration errors and diversion.

METHODS

Retrospective audit of patients prescribed ketamine in two mixed adult/paediatric EDs over 12 months.

RESULTS

Ketamine was administered to 386 patients (722 doses). The most common dose was ≤20 mg (52.1%), followed by 21-50 mg (30.5%). Overall, 215 patients required one dose only (71 received a dose ≤20 mg), while 299 required no more than two doses.

CONCLUSION

Over three-quarters of ketamine doses were ≤50 mg; therefore, 50 mg in 1 mL may be an appropriate product.

Ketamine Versus Etomidate and Peri-intubation Hypotension: A National Emergency Airway Registry Study

BACKGROUND

The hemodynamic impact of induction agents is a critically important consideration in emergency intubations. We assessed the relationship between peri-intubation hypotension and the use of ketamine versus etomidate as an induction agent for emergency department (ED) intubation.

METHODS

We analyzed ED intubation data for patients aged >14 years from the National Emergency Airway Registry performed in 25 EDs during 2016 through 2018. We excluded patients with preintubation hypotension (systolic blood pressure <100 mm Hg) or cardiac arrest prior to intubation. The primary outcome was peri-intubation hypotension. Secondary outcomes included interventions for hypotension (e.g., intravenous fluids or vasopressors). We report adjusted odds ratios (aOR) from multivariable logistic regression models controlling for patient demographics, difficult airway characteristics, and intubation modality.

RESULTS

There were 738 encounters with ketamine and 6,068 with etomidate. Patients receiving ketamine were more likely to have difficult airway characteristics (effect size difference = 8.8%, 95% confidence interval [CI] = 5.3% to 12.4%) and to undergo intubation with video laryngoscopy (8.1%, 95% CI = 4.4% to 12.0%). Peri-intubation hypotension incidence was 18.3% among patients receiving ketamine and 12.4% among patients receiving etomidate (effect size difference = 5.9%, 95% CI = 2.9% to 8.8%). Patients receiving ketamine were more likely to receive treatment for peri-intubation hypotension (effect size difference = 6.5%, 95% CI = 3.9% to 9.3%). In logistic regression analyses, patients receiving ketamine remained at higher risk for peri-intubation hypotension (aOR = 1.4, 95% CI = 1.2 to 1.7) and treatment for hypotension (aOR = 1.8, 95% CI = 1.4 to 2.0). There was no difference in the aOR of hypotension between patients receiving ketamine at doses ≤1.0 mg/kg versus >1.0 mg/kg or patients receiving etomidate at doses ≤0.3 mg/kg versus >0.3 mg/kg.

CONCLUSIONS

Pending additional data, our results suggest that clinicians should not necessarily prioritize ketamine over etomidate based on concern for hemodynamic compromise among ED patients undergoing intubation.

Iatrogenic Oral Ketamine Overdose in Palliative Care

Background: Optimal pain management in the palliative care setting often requires multiple pharmacological interventions including novel and off-label therapies. Ketamine is an anesthetic agent with increasing evidence supporting its use for pain. Through N-methyl-d-aspartate antagonism and activity at opioid receptors, it is an adjuvant to traditional analgesics with the benefit of being opioid sparing. Ketamine has a wide safety profile with limited reports of overdose. Little is published on supratherpeutic dosing in the pain setting. Objective: We report a case of a 41-year-old male with refractory nociceptive and neuropathic cancer-related pain. Conventional therapies were ineffective. Ketamine was initiated to reduce opioid burden and attenuate pain with good response. The patient received an iatrogenic overdose (10 times ordered dose) of the drug. Several self-limited physiologic and psychologic reactions were observed during subsequent monitoring. Design: This is a study and analysis of a patient with refractory nociceptive and neuropathic pain syndrome treated with ketamine who sustained an iatrogenic overdose of ketamine. Conclusions: Ketamine's use to treat pain is increasing along with its evidence of efficacy. Despite ketamine's wide safety profile, the medication is not without risk, especially in palliative care wherein patients are on multiple drugs with potentially severe interactions. Careful examination of the risks of overdose, especially of the various formulations of the drug, is needed.

Iatrogenic emergency medicine procedure complications and associated trouble-shooting strategies

PURPOSE

The purpose of this paper is to provide a consolidated reference for the acute management of selected iatrogenic procedural injuries occurring in the emergency department (ED).

DESIGN/METHODOLOGY/APPROACH

A literature search was performed utilizing PubMed, Scopus, Web of Science and Google Scholar for studies through March of 2017 investigating search terms "iatrogenic procedure complications," "error management" and "procedure complications," in addition to the search terms reflecting case reports involving the eight below listed procedure complications.

FINDINGS

This may be particularly helpful to academic faculty who supervise physicians in training who present a higher risk to cause such injuries.

ORIGINALITY/VALUE

Emergent procedures performed in the ED present a higher risk for iatrogenic injury than in more controlled settings. Many physicians are taught error-avoidance rather than how to handle errors when learning procedures. There is currently very limited literature on the error management of iatrogenic procedure complications in the ED.

Ketamine for military prehospital analgesia and sedation in combat casualties

Ketamine is an effective drug for battlefield analgesia. Recent evidence suggests that it can be safely and effectively used by Level 6 Pre-Hospital Emergency Care (PHEC) practitioners. This article presents a review of the evidence, and outlines the future use of ketamine for provision of analgesia and sedation in combat casualties.

Accidental Ketamine Overdose on Induction of General Anesthesia

BACKGROUND Ketamine is used as an induction and sedation agent in emergency departments and operating rooms throughout the country. Despite its widespread clinical use, there are few cases of significant morbidity and mortality attributed to ketamine overdose in the clinical setting. CASE REPORT The anesthesia provider in the room was an oral maxillofacial surgeon who inadvertently took out a more highly concentrated bottle of ketamine that is typically used for pediatric patients. The patient received 950 mg (100 mg/ml concentration) of intravenous ketamine instead of the intended 95 mg (10 mg/ml concentration). After the ketamine was given, there were no signs to any involved provider that a mistake had occurred until the wake-up appeared to be unusually prolonged. CONCLUSIONS Despite this, the patient did not demonstrate any systemic effects such as hemodynamic or CNS perturbations other than prolonged awakening. This case highlights one (drug overdose) of many causes of delayed emergence from anesthesia and reminds the provider caring for the patient to be mindful of drug concentrations used when preparing to sedate a patient, as relying on effects of the parent drug is not always adequate.

Design of a Precision Medication Dispenser: Preventing Overdose by Increasing Accuracy and Precision of Dosage

Liquid medication overdose in pediatric patients results in over 70000 visits to the emergency room yearly in the USA. Various studies have demonstrated that the root cause of this high incidence is due to user and device error in dose measurement. The standard measuring cup and syringe suffer from the challenge of accurately measuring and dispensing viscous liquids, which comprise the majority of children’s medication formulations. Here, we describe the development of a precision medication dispenser that overcomes challenges associated with viscous fluid flow at low volumes and flow rates, while incorporating various ergonomic and user-friendly features. The device performs with >95% accuracy and 94% precision across the 1–5-mL range of volume, a significant improvement when compared to current commercially available dispensers.

Considerations for physicians using ketamine for sedation of children in emergency departments

OBJECTIVE

Ketamine use in emergency departments (EDs) for procedural sedation and analgesia is becoming increasingly common. However, few studies have examined patient factors related to adverse events associated with ketamine. This study investigated factors for consideration when using ketamine to sedate pediatric ED patients.

METHODS

The study included pediatric patients receiving ketamine for laceration repair in the ED. Before sedation, information was collected about upper respiratory tract infection symptoms, allergy history, and fasting time. Patients received 2 mg/kg ketamine intravenously or 4 mg/kg ketamine intramuscularly. The primary outcomes were adverse events due to ketamine.

RESULTS

We studied 116 patients aged 8 months to 7 years (2.8±1.5 years). The group with adverse events was significantly younger on average than the group without adverse events (2.5±1.5 vs. 3.1±1.5, P=0.028). Upper respiratory tract infection symptoms were not significant variables affecting ketamine sedation (48.9% vs. 43.7%, P=0.719). There was no significant association between duration of fasting and adverse events (P=0.073 and P=0.897, respectively), or between food type and adverse events (P=0.734). However, the number of attempts to sedate and ketamine dose correlated with adverse events (P<0.001 and P=0.022, respectively). In multiple logistic regression analysis, intravenous injection and ketamine dose were significant factors (odds ratio, 16.77; 95% confidence interval, 1.78 to 498.54; odds ratio, 4.37; 95% confidence interval, 1.59 to 22.9, respectively).

CONCLUSION

Emergency medicine physicians should consider injection type and ketamine dose when using ketamine sedation while suturing lacerations.

Severe bilateral cerebellar edema from ingestion of ketamine: case report

The use of ketamine as a drug of abuse has increased and so too has the risk of accidental overdose. Here, the authors report the case of a 10-month-old infant who inadvertently ingested ketamine. The child demonstrated severe cerebellar swelling that required emergency surgical intervention. The authors describe the clinical course of this child and present the radiographic characteristics of the brain. The imaging characteristics were not consistent with purely anoxic injury, thus suggesting a specific effect of this drug. To the authors' knowledge, similar imaging characteristics in this context have not been described.

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.

Ketamine Abuse Syndrome: Hepatobiliary and Urinary Pathology Among Adolescents in Flushing, NY

OBJECTIVES

Ketamine is a recreational drug widely abused in East Asia and also in certain subpopulations of the United States. Many US clinicians are unaware of abuse symptoms, leading to misdiagnosis and missed opportunities for intervention. We will discuss clinical patterns that should alert a clinician to the possibility of ketamine abuse.

METHODS

We present 6 adolescent patients who presented to the pediatric emergency department and inpatient wards with urinary and hepatobiliary symptoms in the setting of ketamine abuse.

RESULTS

We identified 6 patients with confirmed ketamine abuse who presented with epigastric pain or urinary pain. All had laboratory and radiographic evidence of disease.

CONCLUSIONS

Ketamine abuse is associated with a distinctive pattern of symptoms involving the urinary and hepatobiliary systems.

Ketamine-A Narrative Review of Its Uses in Medicine

One of the most fascinating drugs in the anesthesiologist's armament is ketamine, an N-methyl-D-aspartate receptor antagonist with a myriad of uses. The drug is a dissociative anesthetic and has been used more often as an analgesic in numerous hospital units, outpatient pain clinics, and in the prehospital realm. It has been used to treat postoperative pain, chronic pain, complex regional pain syndrome, phantom limb pain, and other neuropathic conditions requiring analgesia. Research has also demonstrated its efficacy as an adjunct in psychotherapy, as a treatment for both depression and posttraumatic stress disorder, as a procedural sedative, and as a treatment for respiratory and neurologic conditions. Ketamine is not without its adverse effects, some of which can be mitigated with certain efforts. Such effects make it necessary for the clinician to use the drug only in situations where it will provide the greatest benefit with the fewest adverse effects. To the best of our knowledge, none of the reviews regarding ketamine have taken a comprehensive look at the drug's uses in all territories of medicine. This review will serve to touch on its chemical data, pharmacokinetics and pharmacodynamics, medical uses, and adverse effects while focusing specifically on the drugs usage in anesthesia and analgesia.

Role of ketamine for analgesia in adults and children

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

Alternative sedation for the higher risk endoscopy: a randomized controlled trial of ketamine use in endoscopic retrograde cholangiopancreatography

OBJECTIVE

Sedation for endoscopy carries an element of cardiorespiratory risk, more significant for certain procedures and in certain patient groups. Ketamine has features which make it an attractive agent for sedation during the higher risk endoscopy; the objectives of this pilot trial were to assess the effectiveness and tolerability of ketamine as a primary agent for sedation during endoscopy.

METHODS

The study was a prospective randomized controlled trial, in which American Society of Anesthesiologists' (ASA) class 1-3 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) received either conventional sedation with midazolam and pethidine or a combination of midazolam and ketamine. Patients were monitored physiologically and in respect to depth of sedation (Modified Observer's Assessment of Alertness/Sedation score) and were observed post procedure for evidence of emergence reactions or other complications. After full recovery, patients completed a questionnaire on their experiences, with particular emphasis on vivid dreaming or other complications attributable to ketamine.

RESULTS

Demographically, control (n = 18) and study (n = 19) groups were similar in makeup. Median midazolam dose was 2 mg (interquartile range [IQR] = 1-3) and 2 mg (IQR = 2-3), respectively (p = 0.98); median procedure duration was 25.5 min (IQR = 17-30) and 21.0 min (IQR = 15-34) (p = 0.92). Median satisfaction with sedation (scored from 0 to 4) was 3.5 (range 1-4) and 4 (range 2-4) respectively (p = 0.88). No patient in either group experienced emergence reactions, dysphoria, or vivid dreaming.

CONCLUSION

In this pilot study, sedation for endoscopy with ketamine and midazolam was as effective as conventional sedation, as acceptable to patients, and was not associated with dysphoric events. Ketamine may have potential as an agent for sedation in higher risk patients.

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

Background

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

Methods

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

Results

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

Conclusion

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

Legal highs: staying on top of the flood of novel psychoactive substances

There has been growing clinical, public, and media awareness and concern about the availability and potential harmfulness of so-called 'legal highs', which are more appropriately called new or novel psychoactive substances (NPS). A cat-and-mouse process has emerged wherein unknown chemists and laboratories are producing new, and as yet nonproscribed, compounds for human consumption; and as soon as they are banned, which they inevitably are, slightly modified analogues are produced to circumvent new laws. This rapidly changing environment, 81 new substances were identified in 2013 alone, has led to confusion for clinicians, psychopharmacologists, and the public at large. Our difficulties in keeping up with the process has had a two-fold negative effect: the danger of ignoring what is confusing; and the problem that some of the newer synthesized compounds appear ever more potent. This review aims to circumscribe a quick moving and growing field, and to categorize NPS into five major groups based upon their 'parent' compounds: stimulants similar to cocaine, amphetamines and ecstasy; cannabinoids; benzodiazepine based drugs; dissociatives similar to ketamine and phencyclidine (PCP); and those modelled after classic hallucinogens such as LSD and psilocybin. Pharmacodynamic actions, subjective and physical effects, harmfulness, risk of dependency and, where appropriate, putative clinical potentials are described for each class. Clinicians might encounter NPS in various ways: anecdotal reportage; acute intoxication; as part of a substance misuse profile; and as a precipitant or perpetuating factor for longer-term physical and psychological ill health. Current data are overall limited, and much of our knowledge and treatment strategies are based upon those of the 'parent' compound. There is a critical need for more research in this field, and for professionals to make themselves more aware of this growing issue and how it might affect those we see clinically and try to help: a brave new world of so-called 'psychonauts' consuming NPS will also need informed 'psychotherapeutonauts'. The paper should serve as a primer for clinicians and interested readers, as well as provide a framework into which to place the new substances that will inevitably be synthesized in the future.

Total Intravenous Anesthesia Using N-Methyl-D-Aspartate (NMDA) Receptor-Sparing Drugs in a Patient with Anti-NMDA Receptor Encephalitis

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a recently identified syndrome characterized by psychosis and dysautonomia. Treatment includes resection of the underlying tumor. While the pathologic mechanism involves disruption of NMDA function by anti-NMDA receptor autoantibodies, there are few descriptions of the perioperative management or anesthetic approach for such patients. We report a classic presentation of anti-NMDA receptor encephalitis and describe the use of total IV anesthesia with NMDA receptor-sparing drugs. Modest postoperative analgesic requirements, not reported in prior cases, are also described in our report.

Ketamine use: a review

AIMS

Ketamine remains an important medicine in both specialist anaesthesia and aspects of pain management. At the same time, its use as a recreational drug has spread in many parts of the world during the past few years. There are now increasing concerns about the harmful physical and psychological consequences of repeated misuse of this drug. The aim of this review was to survey and integrate the research literature on physical, psychological and social harms of both acute and chronic ketamine use.

METHOD

The literature on ketamine was systematically searched and findings were classified into the matrix of Nutt et al.'s (2007) rational scale for assessing the harms of psychoactive substances.

RESULTS

A major physical harm is ketamine induced ulcerative cystitis which, although its aetiology is unclear, seems particularly associated with chronic, frequent use of the drug. Frequent, daily use is also associated with neurocognitive impairment and, most robustly, deficits in working and episodic memory. Recent studies suggest certain neurological abnormalities which may underpin these cognitive effects. Many frequent users are concerned about addiction and report trying but failing to stop using ketamine.

CONCLUSIONS

The implications of these findings are drawn out for treatment of ketamine-induced ulcerative cystitis in which interventions from urologists and from addiction specialists should be coordinated. Neurocognitive impairment in frequent users can impact negatively upon achievement in education and at work, and also compound addiction problems. Prevention and harm minimization campaigns are needed to alert young people to these harmful and potentially chronic effects of ketamine.

Ketamine and midazolam sedation for pediatric gastrointestinal endoscopy in the Arab world

AIM: To evaluate the safety and effectiveness of intravenous ketamine-midazolam sedation during pediatric endoscopy in the Arab world.

METHODS: A retrospective cohort study of all pediatric endoscopic procedures performed between 2002-2008 at the shared endoscopy suite of King Abdullah University Hospital, Jordan University of Science & Technology, Jordan was conducted. All children were > 1 year old and weighed > 10 kg with American Society of Anesthesiologists class 1 or 2. Analysis was performed in terms of sedation-related complications (desaturation, respiratory distress, apnea, bradycardia, cardiac arrest, emergence reactions), adequacy of sedation, need for sedation reversal, or failure to complete the procedure.

RESULTS: A total of 301 patients (including 160 males) with a mean age of 9.26 years (range, 1-18 years) were included. All were premedicated with atropine; and 79.4% (239/301) had effective and uneventful sedation. And 248 (82.4%) of the 301 patients received a mean dose of 0.16 mg/kg (range, 0.07-0.39) midazolam and 1.06 mg/kg (range, 0.31-2.67) ketamine, respectively within the recommended dosage guidelines. Recommended maximum midazolam dose was exceeded in 17.6% patients [34 female (F):19 male (M), P = 0.003] and ketamine in 2.7% (3 M:5 F). Maximum midazolam dose was more likely to be exceeded than ketamine (P < 0.001). Desaturation occurred in 37 (12.3%) patients, and was reversible by supplemental oxygen in all except 4 who continue to have desaturation despite supplemental oxygen. Four (1.3%) patients had respiratory distress and 6 (2%) were difficult to sedate and required a 3rd sedative; 12 (4%) required reversal and 7 (2.3%) failed to complete the procedure. None developed apnea, bradycardia, arrest, or emergence reactions.

CONCLUSION: Ketamine-midazolam sedation appears safe and effective for diagnostic pediatric gastrointestinal endoscopy in the Arab world for children aged > 1 year and weighing > 10 kg without co-morbidities.

Is anesthesia bad for the newborn brain?

Although certain data suggest that common general anesthetics may be neurotoxic to immature animals, there are also data suggesting that these same anesthetics may be neuroprotective against hypoxicischemic injury, and that inadequate analgesia during painful procedures may lead to increased neuronal cell death in animals and long-term behavioral changes in humans. The challenge for the pediatric anesthesia community is to design and implement studies in human infants to ascertain the safety of general anesthesia. In this article, the authors review the relevant preclinical and clinical data that are currently available on this topic.

Adverse events associated with ketamine for procedural sedation in adults

STUDY OBJECTIVES

Ketamine is widely used as a procedural sedation agent in pediatrics, where its safety and efficacy are supported by numerous studies. Emergency physicians use ketamine infrequently in adults, as it is believed to have a more significant side effect profile in this population. However, adult data on ketamine use in the emergency medicine literature are sparse. Our objective was to determine ketamine's adverse effect profile in adults when used for procedural sedation.

METHODS

We performed a literature review based on adverse effect research methodology recommendations. PubMed, EMBASE, TOXNET, and a variety of specialized databases were queried without regard to publication date or language. Experts were contacted to locate additional data. Inclusion criteria included adult study; ketamine used to facilitate the performance of painful procedures; dose of at least 1 mg/kg intravenous or at least 2 mg/kg intramuscular; original data and adverse events reported; spontaneously breathing patient, and no continuous cotherapies. Studies that met inclusion criteria were abstracted onto structured forms and their results qualitatively summarized.

RESULTS

Of the 5512 unique citations that were evaluated, 87 met criteria for inclusion. Most studies were performed in the 1970s and published in the anesthesia literature. Contexts, end points, and methodological quality varied widely across studies. Ketamine reliably produces conditions that facilitate the performance of painful procedures. Pharyngeal reflexes are generally preserved and cardiovascular tone stimulated, including a rise in blood pressure and myocardial oxygen demand. Laryngospasm and airway obstruction are reported, and though ketamine is a respiratory stimulant, a brief period of apnea around the time of injection is common. Reports of significant cardiorespiratory adverse events are rare, despite ketamine's frequent use in austere, poorly monitored settings. Dysphoric emergence phenomena occur in 10% to 20% of cases; sedating medications are effective in preventing and managing these reactions.

CONCLUSION

When ketamine is used for procedural sedation in adults, emergence phenomena occur in 10% to 20% of patients. Although providers must be prepared to recognize and manage airway obstruction, cardiorespiratory adverse events are rare and typically do not affect outcomes.

The difficult-to-sedate patient in the endoscopy suite

More than 20 million endoscopic procedures are performed in the United States annually. More than 98% of these endoscopies are performed with sedation. This includes both diagnostic and therapeutic procedures. Sedation reduces a patient's anxiety and discomfort, often improving their satisfaction with the procedure. Sedation creates a relaxed patient and a relaxed procedure environment allowing for a successful endoscopic examination.