Ketamine Administration During Hospitalization Is Not Associated With Posttraumatic Stress Disorder Outcomes in Military Combat Casualties

Psychedelic Therapy: A Primer for Primary Care Clinicians-Ketamine

BACKGROUND

Ketamine, an arylcyclohexylamine dissociative anesthetic agent, has evolved into a versatile therapeutic. It has a rapid-onset, well-understood cardiovascular effects and a favorable safety profile in clinical use. Its enantiomeric compound, esketamine, was approved by the Food and Drug Administration in 2019 for both treatment-resistant depression and major depressive disorder with suicidal ideation.

AREAS OF UNCERTAINTY

Research indicates dose-dependent impacts on cognition, particularly affecting episodic and working memory following both acute administration and chronic use, albeit temporarily for the former and potentially persistent for the latter. Alongside acute risks to cardiovascular stability, ketamine use poses potential liver toxicity concerns, especially with prolonged or repeated exposure within short time frames. The drug's association with "ketamine cystitis," characterized by bladder inflammation, adds to its profile of physiological risks.

THERAPEUTIC ADVANCES

Data demonstrate a single intravenous infusion of ketamine exhibits antidepressant effects within hours (weighted effect size averages of depression scores (N = 518) following a single 0.5 mg/kg infusion of ketamine is d = 0.96 at 24 hours). Ketamine is also effective at reducing posttraumatic stress disorder (PTSD) symptom severity following repeated infusions (Clinician-Administered PTSD Scale scores: -11.88 points compared with midazolam control). Ketamine also decreased suicidal ideation in emergency settings (Scale for Suicidal Ideation scores: -4.96 compared with midazolam control). Through its opioid-sparing effect, ketamine has revolutionized postoperative pain management by reducing analgesic consumption and enhancing recovery.

LIMITATIONS

Many studies indicate that ketamine's therapeutic effects may subside within weeks. Repeated administrations, given multiple times per week, are often required to sustain decreases in suicidality and depressive symptoms.

CONCLUSIONS

Ketamine's comprehensive clinical profile, combined with its robust effects on depression, suicidal ideation, PTSD, chronic pain, and other psychiatric conditions, positions it as a substantial contender for transformative therapeutic application.

The Association Between Glasgow Coma Scale Scores and PTSD in Military Trauma Casualties: Does Mental Status Following Injury Play a Role in PTSD Development?

BACKGROUND

Posttraumatic stress disorder (PTSD) is prevalent among military personnel and may arise following a wide range of traumatic exposures. Consciousness level following traumatic injury may play a role in the development of PTSD, but its effects have been primarily investigated in the context of traumatic brain injury.

METHODS

Registry-based study surveying three databases documenting care from point of injury to long-term rehabilitation of traumatic injuries among military personnel. The study population was divided according to Glasgow Coma Scale (GCS) scores upon emergency department admission (GCS scores 15, 13 and 14, 9-12, and 3-8), with PTSD diagnoses being determined according to disability claim records. Multivariable logistic regression was utilized to determine the association between GCS score at admission and PTSD.

RESULTS

Overall, 3,376 military personnel hospitalized following traumatic injuries between 1997 and 2020 were included. The majority were male (92.3%), with a median age of 20 (interquartile range 19-22) at the injury time. Of these, 569 (16.9%) were diagnosed with PTSD according to disability claims, with a median follow-up time of 10.9 years. PTSD diagnosis was most prevalent (30.3% of patients), with a GCS score of 13 and 14. In the adjusted multivariable model, a GCS score of 13 and 14 was associated with significantly higher odds of PTSD diagnosis when compared to a GCS score of 15 (odds ratio 2.19, 95% CI, 1.21-3.88). The associations of other GCS groupings with PTSD diagnosis were nonsignificant.

CONCLUSIONS

Minimally impaired consciousness following traumatic injuries is associated with increased odds of PTSD. The role of patient awareness, analgesia, and sedation following an injury in developing PTSD warrants further investigation and could guide early diagnosis and preventive interventions.

Ketamine for Treatment of Posttraumatic Stress Disorder: State of the Field

Posttraumatic stress disorder (PTSD) is a chronic and debilitating condition. Although several psychotherapeutic and pharmacological treatments are recommended for PTSD, many individuals do not respond to treatment or respond only partially, highlighting a critical need for additional treatments. Ketamine has the potential to address this therapeutic need. This review discusses how ketamine emerged as a rapid-acting antidepressant and has become a potential treatment for PTSD. A single dose of intravenous (IV) ketamine has been shown to facilitate rapid reduction of PTSD symptoms. Repeated IV ketamine administration significantly improved PTSD symptoms, compared with midazolam, in a predominantly civilian sample of individuals with PTSD. However, in a veteran and military population, repeated IV ketamine did not significantly reduce PTSD symptoms. Further study of ketamine as a treatment for PTSD is necessary, including which populations benefit most from this therapy and the potential benefits of combining psychotherapy and ketamine.

Ketamine as a therapeutic agent in major depressive disorder and posttraumatic stress disorder: Potential medicinal and deleterious effects

Major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) are the most common causes of emotional distress that impair an individual's quality of life. MDD is a chronic mental illness that affects 300 million people across the world. Clinical manifestations of MDD include fatigue, loss of interest in routine tasks, psychomotor agitation, impaired ability to focus, suicidal ideation, hypersomnolence, altered psychosocial functioning, and appetite loss. Individuals with depression also demonstrate a reduced behavioral response while experiencing pleasure, a symptom known as anhedonia. Like MDD, PTSD is a prevalent and debilitating psychiatric disorder resulting from a traumatic incident such as sexual assault, war, severe accident, or natural disaster. Symptoms such as recalling event phases, hypervigilance, irritability, and anhedonia are common in PTSD. Both MDD and PTSD pose enormous socioeconomic burdens across the globe. The search for effective treatment with minimal side effects is still ongoing. Ketamine is known for its anesthetic and analgesic properties. Psychedelic and psychotropic effects of ketamine have been found on the nervous system, which highlights its toxicity. In this article, the effectiveness of ketamine as a potential therapeutic for PTSD and MDD along with its mechanisms of action, clinical trials, and possible side effects have been discussed.

Patterns of Palliation: A Review of Casualties That Received Pain Management Before Reaching Role 2 in Afghanistan

INTRODUCTION

Battlefield pain management changed markedly during the first 20 years of the Global War on Terror. Morphine, long the mainstay of combat analgesia, diminished in favor of fentanyl and ketamine for military pain control, but the options are not hemodynamically or psychologically equivalent. Understanding patterns of prehospital analgesia may reveal further opportunities for combat casualty care improvement.

MATERIALS AND METHODS

Using Department of Defense Trauma Registry data for the Afghanistan conflict from 2005 to 2018, we examined 2,402 records of prehospital analgesia administration to assess temporal trends in medication choice and proportions receiving analgesia, including subanalysis of a cohort screened for an indication with minimal contraindication for analgesia. We further employed frequency matching to explore the presence of disparities in analgesia by casualty affiliation.

RESULTS

Proportions of documented analgesia increased throughout the study period, from 0% in 2005 to 70.6% in 2018. Afghan casualties had the highest proportion of documented analgesia (53.0%), versus U.S. military (31.9%), civilian/other (23.3%), and non-U.S. military (19.3%). Fentanyl surpassed morphine in the frequency of administration in 2012. The median age of those receiving ketamine was higher (30 years) than those receiving fentanyl (26 years) or nonsteroidal anti-inflammatory drugs (23 years). Among the frequency-matched subanalysis, the odds ratio for ketamine administration with Afghan casualties was 1.84 (95% CI, 1.30-2.61).

CONCLUSIONS

We observed heterogeneity of prehospital patient care across patient affiliation groups, suggesting possible opportunities for improvement toward an overall best practice system. General increase in documented prehospital pain management likely reflects efforts toward complete documentation, as well as improved options for analgesia. Current combat casualty care documentation does not include any standardized pain scale.

The potential of ketamine for posttraumatic stress disorder: a review of clinical evidence

Posttraumatic stress disorder (PTSD) is a devastating condition, for which there are few pharmacological agents, often with a delayed onset of action and poor efficacy. Trauma-focused psychotherapies are further limited by few trained providers and low patient engagement. This frequently results in disease chronicity as well as psychiatric and medical comorbidity, with considerable negative impact on quality of life. As such, off-label interventions are commonly used for PTSD, particularly in chronic refractory cases. Ketamine, an N-methyl-D-aspartate (NDMA) receptor antagonist, has recently been indicated for major depression, exhibiting rapid and robust antidepressant effects. It also shows transdiagnostic potential for an array of psychiatric disorders. Here, we synthesize clinical evidence on ketamine in PTSD, spanning case reports, chart reviews, open-label studies, and randomized trials. Overall, there is high heterogeneity in clinical presentation and pharmacological approach, yet encouraging signals of therapeutic safety, efficacy, and durability. Avenues for future research are discussed.

Anesthesia and the neurobiology of fear and posttraumatic stress disorder

PURPOSE OF REVIEW

Dysfunction of fear memory systems underlie a cluster of clinically important and highly prevalent psychological morbidities seen in perioperative and critical care patients, most archetypally posttraumatic stress disorder (PTSD). Several sedative-hypnotics and analgesics are known to modulate fear systems, and it is theoretically plausible that clinical decisions of the anesthesiologist could impact psychological outcomes. This review aims to provide a focused synthesis of relevant literature from multiple fields of research.

RECENT FINDINGS

There is evidence in some contexts that unconscious fear memory systems are less sensitive to anesthetics than are conscious memory systems. Opiates may suppress the activation of fear systems and have benefit in the prevention of PTSD following trauma. There is inconsistent evidence that the use of propofol and benzodiazepines for sedation following trauma may potentiate the development of PTSD relative to other drugs. The benefits of ketamine seen in the treatment of major depression are not clearly replicated in PTSD-cluster psychopathologies, and its effects on fear processes are complex.

SUMMARY

There are multiple theoretical mechanisms by which anesthetic drugs can modulate fear systems and clinically important fear-based psychopathologies. The current state of research provides some evidence to support further hypothesis investigation. However, the absence of effectiveness studies and the inconsistent signals from smaller studies provide insufficient evidence to currently offer firm clinical guidance.

Is Prehospital Ketamine Associated With a Change in the Prognosis of PTSD?

INTRODUCTION

Ketamine is an alternative to opioids for prehospital analgesia following serious combat injury. Limited research has examined prehospital ketamine use, associated injuries including traumatic brain injury (TBI) and PTSD outcomes following serious combat injury.

MATERIALS AND METHODS

We randomly selected 398 U.S. service members from the Expeditionary Medical Encounter Database who sustained serious combat injuries in Iraq and Afghanistan, 2010-2013. Of these 398 patients, 213 individuals had charted prehospital medications. Clinicians reviewed casualty records to identify injuries and all medications administered. Outcomes were PTSD diagnoses during the first year and during the first 2 years postinjury extracted from military health databases. We compared PTSD outcomes for patients treated with either (a) prehospital ketamine (with or without opioids) or (b) prehospital opioids (without ketamine).

RESULTS

Fewer patients received prehospital ketamine (26%, 56 of 213) than only prehospital opioids (69%, 146 of 213) (5%, 11 of 213 received neither ketamine nor opioids). The ketamine group averaged significantly more moderate-to-serious injuries, particularly lower limb amputations and open wounds, compared with the opioid group (Ps < .05). Multivariable regressions showed a significant interaction between prehospital ketamine (versus opioids) and TBI on first-year PTSD (P = .027). In subsequent comparisons, the prehospital ketamine group had significantly lower odds of first-year PTSD (OR = 0.08, 95% CI [0.01, 0.71], P = .023) versus prehospital opioids only among patients who did not sustain TBI. We also report results from separate analyses of PTSD outcomes among patients treated with different prehospital opioids only (without ketamine), either morphine or fentanyl.

CONCLUSIONS

The present results showed that patients treated with prehospital ketamine had significantly lower odds of PTSD during the first year postinjury only among patients who did not sustain TBI. These findings can inform combat casualty care guidelines for use of prehospital ketamine and opioid analgesics following serious combat injury.

Long-term increase in sensitivity to ketamine's behavioral effects in mice exposed to mild blast induced traumatic brain injury

Neurobehavioral deficits emerge in nearly 50% of patients following a mild traumatic brain injury (TBI) and may persist for months. Ketamine is used frequently as an anesthetic, analgesic and for management of persistent psychiatric complications. Although ketamine may produce beneficial effects in patients with a history of TBI, differential sensitivity to its impairing effects could make the therapeutic use of ketamine in TBI patients unsafe. This series of studies examined male C57BL/6 J mice exposed to a mild single blast overpressure (mbTBI) for indications of altered sensitivity to ketamine at varying times after injury. Dystaxia (altered gait), diminished sensorimotor gating (reduced prepulse inhibition) impaired working memory (step-down inhibitory avoidance) were examined in mbTBI and sham animals 15 min following intraperitoneal injections of saline or R,S-ketamine hydrochloride, from day 7-16 post injury and again from day 35-43 post injury. Behavioral performance in the forced swim test and sucrose preference test were evaluated on day 28 and day 74 post injury respectively, 24 h following drug administration. Dynamic gait stability was compromised in mbTBI mice on day 7 and 35 post injury and further exacerbated following ketamine administration. On day 14 and 42 post injury, prepulse inhibition was robustly decreased by mbTBI, which ketamine further reduced. Ketamine-associated memory impairment was apparent selectively in mbTBI animals 1 h, 24 h and day 28 post shock (tested on day 15/16/43 post injury). Ketamine selectively reduced immobility scores in the FST in mbTBI animals (day 28) and reversed mbTBI induced decreases in sucrose consumption (Day 74). These results demonstrate increased sensitivity to ketamine in mice when tested for extended periods after TBI. The results suggest that ketamine may be effective for treating neuropsychiatric complications that emerge after TBI but urge caution when used in clinical practice for enhanced sensitivity to its side effects in this patient population.

Ketamine for the treatment of mental health and substance use disorders: comprehensive systematic review

BACKGROUND

In the past two decades, subanaesthetic doses of ketamine have been demonstrated to have rapid and sustained antidepressant effects, and accumulating research has demonstrated ketamine's therapeutic effects for a range of psychiatric conditions.

AIMS

In light of these findings surrounding ketamine's psychotherapeutic potential, we systematically review the extant evidence on ketamine's effects in treating mental health disorders.

METHOD

The systematic review protocol was registered in PROSPERO (identifier CRD42019130636). Human studies investigating the therapeutic effects of ketamine in the treatment of mental health disorders were included. Because of the extensive research in depression, bipolar disorder and suicidal ideation, only systematic reviews and meta-analyses were included. We searched Medline and PsycINFO on 21 October 2020. Risk-of-bias analysis was assessed with the Cochrane Risk of Bias tools and A Measurement Tool to Assess Systematic Reviews (AMSTAR) Checklist.

RESULTS

We included 83 published reports in the final review: 33 systematic reviews, 29 randomised controlled trials, two randomised trials without placebo, three non-randomised trials with controls, six open-label trials and ten retrospective reviews. The results were presented via narrative synthesis.

CONCLUSIONS

Systematic reviews and meta-analyses provide support for robust, rapid and transient antidepressant and anti-suicidal effects of ketamine. Evidence for other indications is less robust, but suggests similarly positive and short-lived effects. The conclusions should be interpreted with caution because of the high risk of bias of included studies. Optimal dosing, modes of administration and the most effective forms of adjunctive psychotherapeutic support should be examined further.

Ketamine for post-traumatic stress disorders and it's possible therapeutic mechanism

Posttraumatic stress disorder (PTSD) is a devastating medical illness, for which currently available pharmacotherapies have poor efficacy. Accumulating evidence from clinical and preclinical animal investigations supports that ketamine exhibits a rapid and persistent effect against PTSD, though the underlying molecular mechanism remains to be clarified. In this literature review, we recapitulate the achievements from early ketamine studies to the most up-to-date discoveries, with an effort to discuss an inclusive therapeutic role of ketamine for PTSD treatment and its possible therapeutic mechanism. Ketamine seems to have an inimitable mechanism of action entailing glutamate modulation via actions at the N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors, as well as downstream activation of brain-derived neurotrophic factor (BDNF) and mechanistic target of rapamycin (mTOR) signaling pathways to potentiate synaptic plasticity.

Ketamine-50 years in use: from anesthesia to rapid antidepressant effects and neurobiological mechanisms

Over the past 50 years, ketamine has solidified its position in both human and veterinary medicine as an important anesthetic with many uses. More recently, ketamine has been studied and used for several new indications, ranging from chronic pain to drug addiction and post-traumatic stress disorder. The discovery of the rapid-acting antidepressant effects of ketamine has resulted in a surge of interest towards understanding the precise mechanisms driving its effects. Indeed, ketamine may have had the largest impact for advancements in the research and treatment of psychiatric disorders in the past few decades. While intense research efforts have been aimed towards uncovering the molecular targets underlying ketamine's effects in treating depression, the underlying neurobiological mechanisms remain elusive. These efforts are made more difficult by ketamine's complex dose-dependent effects on molecular mechanisms, multiple pharmacologically active metabolites, and a mechanism of action associated with the facilitation of synaptic plasticity. This review aims to provide a brief overview of the different uses of ketamine, with an emphasis on examining ketamine's rapid antidepressant effects spanning molecular, cellular, and network levels. Another focus of the review is to offer a perspective on studies related to the different doses of ketamine used in antidepressant research. Finally, the review discusses some of the latest hypotheses concerning ketamine's action.

Can Intraoperative Low-Dose R,S-Ketamine Prevent Depressive Symptoms After Surgery? The First Meta-Analysis of Clinical Trials

Background: Postoperative depression is a common complication after surgery that profoundly affects recovery and prognosis. New research indicates that (R,S)-ketamine is a potent antidepressant that exerts a rapid and sustained antidepressive effect. However, there is no consensus on whether intraoperative low-dose (R,S)-ketamine prevents postoperative depression. Objectives: This study aimed to investigate the safety, feasibility, and short-term complications of intraoperative low-dose (R,S)-ketamine in preventing postoperative depressive symptoms. Methods: The Web of Science, Cochrane, PubMed, and CNKI databases were systematically searched (last search February 28, 2020) to identify studies involving ketamine. Sensitivity and metaregression analyses were performed to identify potential confounders. The meta-analysis was performed using Review Manager 5.3. Results: A total of 13 studies (seven in Chinese and six in English) representing 1,148 cases of patients who were treated with (R,S)-ketamine and 874 cases of patients who received other treatments were included in the meta-analysis. Anesthesia duration and blood loss did not significantly differ between the two groups, demonstrating that (R,S)-ketamine was safe (odds ratio,OR: 0.27; 95% CI: -1.14 to 1.68; P = 0.71) for prophylactic treatment of postoperative depression. Blood loss (OR: -1.83; 95% CI: -8.34 to 4.68; P = 0.58), the number of postoperative depressive patients (95% CI: 0.8-1.07; P = 0.08; (R,S)-ketamine: control = 12.9%:15.8%), and postoperative complications (OR: 0.83, 95% CI: 0.44-1.58; P = 0.57; (R,S)-ketamine: control = 19.3%:19.3%) were all similar across groups. Intra-operative low-dose (R,S)-ketamine reduced extubation time (OR: -2.84; 95% CI: -5.48 to -0.21; P = 0.03). Conclusions: The prophylactic anti-depressant effect of (R,S)-ketamine did not significantly differ between the (R,S)-ketamine and control groups in patients undergoing general or spinal anesthesia. However, (R,S)-ketamine use led to a higher incidence of adverse reactions in patients under 40 years of age who underwent a Cesarean section under spinal anesthesia.

A Narrative Review of Methods for Causal Inference and Associated Educational Resources

BACKGROUND AND OBJECTIVES

Root cause analysis involves evaluation of causal relationships between exposures (or interventions) and adverse outcomes, such as identification of direct (eg, medication orders missed) and root causes (eg, clinician's fatigue and workload) of adverse rare events. To assess causality requires either randomization or sophisticated methods applied to carefully designed observational studies. In most cases, randomized trials are not feasible in the context of root cause analysis. Using observational data for causal inference, however, presents many challenges in both the design and analysis stages. Methods for observational causal inference often fall outside the toolbox of even well-trained statisticians, thus necessitating workforce training.

METHODS

This article synthesizes the key concepts and statistical perspectives for causal inference, and describes available educational resources, with a focus on observational clinical data. The target audience for this review is clinical researchers with training in fundamental statistics or epidemiology, and statisticians collaborating with those researchers.

RESULTS

The available literature includes a number of textbooks and thousands of review articles. However, using this literature for independent study or clinical training programs is extremely challenging for numerous reasons. First, the published articles often assume an advanced technical background with different notations and terminology. Second, they may be written from any number of perspectives across statistics, epidemiology, computer science, or philosophy. Third, the methods are rapidly expanding and thus difficult to capture within traditional publications. Fourth, even the most fundamental aspects of causal inference (eg, framing the causal question as a target trial) often receive little or no coverage. This review presents an overview of (1) key concepts and frameworks for causal inference and (2) online documents that are publicly available for better assisting researchers to gain the necessary perspectives for functioning effectively within a multidisciplinary team.

CONCLUSION

A familiarity with causal inference methods can help risk managers empirically verify, from observed events, the true causes of adverse sentinel events.