Clinical experiences with intranasal esketamine for major depressive disorder resistant to treatment and with a psychiatric emergency: case presentations.

Recently, esketamine became availableas an intranasal formulation, proposed for treatment-resistant depression (TRD). Three cases of TRD are presented, two with features of a psychiatric emergency. The first case is a 35-year-old man with MDD onset at the age of 27 years, with five previous failed therapies. The second patient is a middle-aged man with a 21-year MDD onset and six previous antidepressant treatments discontinued for poor therapeutic effects and tolerability. He also presented suicidal ideation with intent and a history of a failed suicide attempt by self-cutting his forearms. The third case is a 28-year-old female with a first MDD episode in 2020, treated first with amitriptyline and then with intravenous clomipramine. She had a history of a previous suicide attempt by self-cutting and, by her admission, showed active suicidal ideation with intent. In all three cases, a rapid reduction of depressive symptoms was observed with a subsequent complete resolution of suicidal ideation and intent in the two patients with such risk. Intranasal esketamine treatment was carried out with concomitant oral antidepressant therapy. The third patient reported the only recorded side effect: dissociation 20 min after every esketamine administration. Our preliminary experience proved esketamine's effectiveness on TRD symptoms and successful outcomes in psychiatric emergencies such as suicide risk.

Stability of Drugs Stored in Helicopters for Use by Emergency Medical Services: A Prospective Observational Study.

STUDY OBJECTIVE: Drugs stored in rescue helicopters may be subject to extreme environmental conditions. The aim of this study was to measure whether drugs stored under the real-life conditions of a Swiss helicopter emergency medical service (HEMS) would retain their potency over the course of 1 year. METHODS: A prospective, longitudinal study measuring the temperature exposure and concentration of drugs stored on 2 rescue helicopters in Switzerland over 1 year. The study drugs included epinephrine, norepinephrine, amiodarone, midazolam, fentanyl, naloxone, rocuronium, etomidate, and ketamine. Temperatures were measured inside the medication storage bags and the crew cabins at 10-minute intervals. Drug stability was measured on a monthly basis over the course of 12 months using high-performance liquid chromatography. The medications were considered stable at a minimum remaining drug concentration of 90% of the label claim. RESULTS: Temperatures ranged from -1.2 °C to 38.1 °C (29.84 °F to 100.58 °F) inside the drug storage bags. Of all the temperature measurements inside the drug storage bags, 37% lay outside the recommended storage conditions. All drugs maintained a concentration above 90% of the label claim. The observation periods for rocuronium and etomidate were shortened to 7 months because of a supply shortage of reference samples. CONCLUSION: Drugs stored under the real-life conditions of Swiss HEMS are subjected to temperatures outside the manufacturer's approved storage requirements. Despite this, all drugs stored under these conditions remained stable throughout our study. Real-life stability testing could be a way to extend drug exchange intervals.

Microbiota-derived psychedelics: Lessons from COVID-19.

Emil Kraepelin believed that dementia praecox, the disorder we now call schizophrenia, was caused by the brain being poisoned with toxins generated in other parts of the body, especially the mouth, intestine or genitals. In this regard, Kraepelin hinted at the microbiome and conceptualized microbial molecules as drivers of severe psychiatric illness. However, it was not until the coronavirus disease (COVID-19) pandemic that Kraepelin's paradigm gained traction, particularly because this virus was associated with both gut barrier disruption and new-onset psychosis.Likewise, despite numerous studies linking severe psychiatric illness to genomic damage and dysfunctional DNA repair, this pathogenetic mechanism was underappreciated before the COVID-19 pandemic. The use of the psychotomimetic anesthetic, ketamine, for treatment-resistant depression has reawakened the interest in endogenous serotonergic hallucinogens, especially tryptamine and N,N-dimethyltryptamine (DMT), which are beneficial for depression but associated with psychosis.In this editorial, we take a closer look at the role of the microbiome in psychopathology, attempting to answer 2 questions:1. Why may psychosis-predisposing serotonergic hallucinogens alleviate depression?2. Are microbiota-derived psychedelics part of an inbuilt antidepressant system similar to endogenous opioids?

Profile of liver cholestatic biomarkers following prolonged ketamine administration in patients with COVID-19.

BACKGROUND: To investigate the possible influence of prolonged ketamine (K) or esketamine (ESK) infusion on the profile of liver cholestatic biomarkers in patients with COVID-19 infection. METHODS: A retrospective analysis was performed on 135 patients with COVID-19 related ARDS who received prolonged K or ESK infusion. They were compared to 15 COVID-19 ICU patients who did not receive K/ESK while being mechanically ventilated and 108 COVID-19 patients who did not receive mechanical ventilation nor K/ESK. The profile of the liver function tests was analysed in the groups. RESULTS: Peak values of ALP, GGT and bilirubin were higher in the K/ESK group, but not for AST and ALT. Peak values of ALP were significantly higher among patients who underwent mechanical ventilation and who received K/ESK, compared with mechanically ventilated patients who did not receive K/ESK. There was a correlation between these peak values and the cumulative dose and duration of K/ESK therapy. CONCLUSIONS: Based on the observations of biliary anomalies in chronic ketamine abusers, prolonged exposure to ketamine sedation during mechanical ventilation may also be involved, in addition to viral infection causing secondary sclerosing cholangitis. The safety of prolonged ketamine sedation on the biliary tract requires further investigations.

The Use of Ketamine Sedation for the Treatment of Nail Bed Repairs in the Pediatric Emergency Department.

AIM: This study aimed to determine if sedation with ketamine is safe and effective for the treatment of nail bed injuries in the pediatric emergency department (PED). METHOD: A retrospective cohort study was carried out during a 9-month period in children aged between 18 months and 15 years, presenting to PED requiring nail bed repair. We documented complications of sedation, clinical outcome of the repair both immediate and at follow-up, and parental satisfaction at 4 months. A cost analysis was also undertaken. RESULTS: Ten repairs were performed. There were no serious adverse events. The average satisfaction score was 9.4/10. All patients were discharged from follow-up by 3 months. There was a cost saving of approximately £1500 per case. CONCLUSIONS: We have demonstrated nail bed injury repair facilitated by sedation with ketamine to be safe, effective, and cost efficient in the PED. This management strategy, brought to the fore during the COVID-19 pandemic, should be adopted widely in PEDs.

Occurrence of Z-drugs, benzodiazepines, and ketamine in wastewater in the United States and Mexico during the Covid-19 pandemic.

Z-drugs, benzodiazepines and ketamine are classes of psychotropic drugs prescribed for treating anxiety, sleep disorders and depression with known side effects including an elevated risk of addiction and substance misuse. These drugs have a strong potential for misuse, which has escalated over the years and was hypothesized here to have been exacerbated during the COVID-19 pandemic. Wastewater-based epidemiology (WBE) constitutes a fast, easy, and relatively inexpensive approach to epidemiological surveys for understanding the incidence and frequency of uses of these drugs. In this study, we analyzed wastewater (n = 376) from 50 cities across the United States and Mexico from July to October 2020 to estimate drug use rates during a pandemic event. Both time and flow proportional composite and grab samples of untreated municipal wastewater were analyzed using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry to determine loadings of alprazolam, clonazepam, diazepam, ketamine, lorazepam, nordiazepam, temazepam, zolpidem, and zaleplon in raw wastewater. Simultaneously, prescription data of the aforementioned drugs were extracted from the Medicaid database from 2019 to 2021. Results showed high detection frequencies of ketamine (90 %), lorazepam (87 %), clonazepam (76 %) and temazepam (73 %) across both Mexico and United States and comparatively lower detection frequencies for zaleplon (22 %), zolpidem (9 %), nordiazepam (<1 %), diazepam (<1 %), and alprazolam (<1 %) during the pandemic. Average mass consumption rates, estimated using WBE and reported in units of mg/day/1000 persons, ranged between 62 (temazepam) and 1100 (clonazepam) in the United States. Results obtained from the Medicaid database also showed a significant change (p < 0.05) in the prescription volume between the first quarter of 2019 (before the pandemic) and the first quarter of 2021 (pandemic event) for alprazolam, clonazepam and lorazepam. Study results include the first detections of zaleplon and zolpidem in wastewater from North America.

Antidepressant Effect of Ketamine on Inflammation-Mediated Cytokine Dysregulation in Adults with Treatment-Resistant Depression: Rapid Systematic Review.

Background: Major depressive disorder (MDD) and treatment-resistant depression (TRD) represent a global source of societal and health burden. To advise proper management of inflammation-related depression among TRD patients, it is important to identify therapeutic clinical treatments. A key factor is related to proinflammatory cytokines such as interleukin- (IL-) 1ß, IL-6, and tumor necrosis factor- (TNF-) α which have been implicated in the pathogenesis of depressive symptoms in MDD patients. Ketamine may provide an anti-inflammatory therapeutic strategy by targeting proinflammatory pathways associated with depressive disorders, which may be exacerbated in the ageing population with TRD. Objective: Despite a burgeoning body of literature demonstrating that inflammation is linked to TRD, there is still a lack of comprehensive research on the relationship between proinflammatory biomarkers and ketamine's antidepressant effect on TRD patients. Method: The Cochrane Library and PubMed/MEDLINE databases were systematically searched from inception up to February 1, 2022, adopting broad inclusion criteria to assess clinical topics related to the impact of ketamine on inflammatory cytokines in TRD patients. The present work is in compliance with the World Health Organization Rapid Review Guide. Results: Five out of the seven studies examined in this review show that ketamine infusion may reduce depressive symptoms with a quick start of effect on TRD patients. Based on the Montgomery-Åsberg Depression Rating Scale (MADRS) and Hamilton Depression Rating Scale (HAM-D) scores, the overall response rate for ketamine was 56%; that is, 56% of those treated with ketamine had MADRS/HAM-D scores decreased by at least 50%. Conclusions: While the anti-inflammatory effects of ketamine modulate specific proinflammatory cytokines, its rapid antidepressant effect on TRD patients remains inconsistent. However, our study findings can provide a reliable basis for future research on how to improve systemic inflammatory immune disorders and mental health. We suggest that ketamine infusion may be part of a comprehensive treatment approach in TRD patients with elevated levels of depression-specific inflammatory biomarkers.

Association of intranasal esketamine, a novel 'standard of care' treatment and outcomes in the management of patients with treatment-resistant depression: protocol of a prospective cohort observational study of naturalistic clinical practice.

INTRODUCTION: Esketamine is the S-enantiomer of racemic ketamine and has been approved by the Food and Drug Administration for the management of treatment resistant depression, demonstrating effective and long-lasting benefits. The objective of this observational study is to elucidate the association of intranasal (IN) esketamine with beneficial and negative outcomes in the management of treatment resistant major depressive disorder. METHODS AND ANALYSIS: This is a multicentre prospective cohort observational study of naturalistic clinical practice. We expect to recruit 10 patients per research centre (6 centres, total 60 subjects). After approval to receive IN esketamine as part of their standard of care management of moderate to severe treatment resistant depression, patients will be invited to participate in this study. Association of esketamine treatment with outcomes in the management of depression will be assessed by measuring the severity of depression symptoms using the Montgomery-Åsberg Depression Rating Scale (MADRS), and tolerability by systematically tracking common side effects of ketamine treatment, dissociation using the simplified 6-Item Clinician Administered Dissociative Symptom Scale and potential for abuse using the Likeability and Craving Questionnaire (LCQ). Change in depressive symptoms (MADRS total scores) over time will be evaluated by within-subject repeated measures analysis of variance. We will calculate the relative risk associated with the beneficial (reduction in total scores for depression) outcomes, and the side effect and dropout rates (tolerability) of adding IN esketamine to patients' current pharmacological treatments. Covariate analysis will assess the impact of site and demographic variables on treatment outcomes. ETHICS AND DISSEMINATION: Approval to perform this study was obtained through the Health Sciences Research Ethics Board at Queen's University. Findings will be shared among collaborators, through departmental meetings, presented on different academic venues and publishing our manuscript.

Allergic reaction induced by subcutaneous administration of ketamine: a case report.

Ketamine can be used for depression and suicidal ideation due to its effectiveness and low complication rates; moreover, allergic reactions are rare. Immediately after subcutaneous (SC) ketamine administration, a 22-year-old man rapidly developed hives on the trunk and face without oxygen desaturation. Symptoms disappeared after treatment with prednisolone. This case presents an allergic reaction to ketamine compatible with mast cell activation and release of preformed mediators, without being able to prove whether the event was mediated by immunoglobulin E. This is the only case reported to date of an allergic reaction to SC ketamine for psychiatric treatment.

Interactions of the protease inhibitor, ritonavir, with common anesthesia drugs.

The protease inhibitor, ritonavir, is a strong inhibitor of CYP 3A. The drug is used for management of the human immunovirus and is currently part of an oral antiviral drug combination (nirmatrelvir-ritonavir) for the early treatment of SARS-2 COVID-19-positive patients aged 12 years and over who have recognized comorbidities. The CYP 3A enzyme system is responsible for clearance of numerous drugs used in anesthesia (e.g., alfentanil, fentanyl, methadone, rocuronium, bupivacaine, midazolam, ketamine). Ritonavir will have an impact on drug clearances that are dependent on ritonavir concentration, anesthesia drug intrinsic hepatic clearance, metabolic pathways, concentration-response relationship, and route of administration. Drugs with a steep concentration-response relationship (ketamine, midazolam, rocuronium) are mostly affected because small changes in concentration have major changes in effect response. An increase in midazolam concentration is observed after oral administration because CYP 3A in the gastrointestinal wall is inhibited, causing a large increase in relative bioavailability. Fentanyl infusion may be associated with a modest increase in plasma concentration and effect, but the large between subject variability of pharmacokinetic and pharmacodynamic concentration changes suggests it will have little impact on an individual patient, especially when used with adverse effect monitoring. It has been proposed that drugs that have no or only a small metabolic pathway involving the CYP 3A enzyme be used during anesthesia, for example, propofol, atracurium, remifentanil, and the volatile agents. That anesthesia approach denies children of drugs with considerable value. It is better that the inhibitory changes in clearance of these drugs are understood so that rational drug choices can be made to tailor drug use to the individual patient. Altered drug dose, anticipation of duration of effect, timing of administration, use of reversal agents and perioperative monitoring would better behoove children undergoing anesthesia.

At-home, sublingual ketamine telehealth is a safe and effective treatment for moderate to severe anxiety and depression: Findings from a large, prospective, open-label effectiveness trial.

BACKGROUND: At-home Ketamine-assisted therapy (KAT) with psychosocial support and remote monitoring through telehealth platforms addresses access barriers, including the COVID-19 pandemic. Large-scale evaluation of this approach is needed for questions regarding safety and effectiveness for depression and anxiety. METHODS: In this prospective study, a large outpatient sample received KAT over four weeks through a telehealth provider. Symptoms were assessed using the Patient Health Questionnaire (PHQ-9) for depression, and the Generalized Anxiety Disorder scale (GAD-7) for anxiety. Demographics, adverse events, and patient-reported dissociation were also analyzed. Symptom trajectories were identified using Growth Mixture Modeling, along with outcome predictors. RESULTS: A sample of 1247 completed treatment with sufficient data, 62.8 % reported a 50 % or greater improvement on the PHQ-9, d = 1.61, and 62.9 % on the GAD-7, d = 1.56. Remission rates were 32.6 % for PHQ-9 and 31.3 % for GAD-7, with 0.9 % deteriorating on the PHQ-9, and 0.6 % on the GAD-7. Four patients left treatment early due to side effects or clinician disqualification, and two more due to adverse events. Three patient subpopulations emerged, characterized by Improvement (79.3 %), Chronic (11.4 %), and Delayed Improvement (9.3 %) for PHQ-9 and GAD-7. Endorsing side effects at Session 2 was associated with delayed symptom improvement, and Chronic patients were more likely than the other two groups to report dissociation at Session 4. CONCLUSION: At-home KAT response and remission rates indicated rapid and significant antidepressant and anxiolytic effects. Rates were consistent with laboratory- and clinic-administered ketamine treatment. Patient screening and remote monitoring maintained low levels of adverse events. Future research should assess durability of effects.

Long-term ketamine infusion-induced cholestatic liver injury in COVID-19-associated acute respiratory distress syndrome.

BACKGROUND: A higher-than-usual resistance to standard sedation regimens in COVID-19 patients suffering from acute respiratory distress syndrome (ARDS) has led to the frequent use of the second-line anaesthetic agent ketamine. Simultaneously, an increased incidence of cholangiopathies in mechanically ventilated patients receiving prolonged infusion of high-dose ketamine has been noted. Therefore, the objective of this study was to investigate a potential dose-response relationship between ketamine and bilirubin levels. METHODS: Post hoc analysis of a prospective observational cohort of patients suffering from COVID-19-associated ARDS between March 2020 and August 2021. A time-varying, multivariable adjusted, cumulative weighted exposure mixed-effects model was employed to analyse the exposure-effect relationship between ketamine infusion and total bilirubin levels. RESULTS: Two-hundred forty-three critically ill patients were included into the analysis. Ketamine was infused to 170 (70%) patients at a rate of 1.4 [0.9-2.0] mg/kg/h for 9 [4-18] days. The mixed-effects model revealed a positively correlated infusion duration-effect as well as dose-effect relationship between ketamine infusion and rising bilirubin levels (p < 0.0001). In comparison, long-term infusion of propofol and sufentanil, even at high doses, was not associated with increasing bilirubin levels (p = 0.421, p = 0.258). Patients having received ketamine infusion had a multivariable adjusted competing risk hazard of developing a cholestatic liver injury during their ICU stay of 3.2 [95% confidence interval, 1.3-7.8] (p = 0.01). CONCLUSIONS: A causally plausible, dose-effect relationship between long-term infusion of ketamine and rising total bilirubin levels, as well as an augmented, ketamine-associated, hazard of cholestatic liver injury in critically ill COVID-19 patients could be shown. High-dose ketamine should be refrained from whenever possible for the long-term analgosedation of mechanically ventilated COVID-19 patients.

Sevoflurane in combination with esketamine is an effective sedation regimen in COVID-19 patients enabling assisted spontaneous breathing even during prone positioning.

BACKGROUND: Effective analgosedation for control of dyspnoea and for toleration of prone positioning (PP) in severe coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS) is difficult to adjust. This study was designed to evaluate the feasibility and safety of sedation with inhaled sevoflurane in combination with intravenous esketamine during PP in patients with COVID-19-ARDS (CARDS). METHODS: All mechanically ventilated COVID-19 patients admitted to the departmental intensive care unit from March to June 2020 were included in this epidemiological cohort study. Patients were sedated with inhaled sevoflurane in combination with eske-tamine during PP and not or only lightly sedated during the supine position. Assisted spontaneous breathing was applied in both prone and supine position. RESULTS: Adverse events were documented prospectively, and routine ventilation parameters, hemodynamic parameters, Richmond Agitation and Sedation Scale (RASS) and sevoflurane consumption were monitored. Altogether, 146 episodes of PP in 15 patients were observed. No severe sedation-related event was observed during 2610 hours of PP. In 2498 hours (96%) patients were successfully converted to a pressure-supported spontaneous breathing mode. CONCLUSIONS: Inhaled sedation with the AnaConDa-S-System (Sedana Medical AB, Danderyd, Sweden) alone is insufficient as soon as minute volume exceeds 7-8 L min-1, most likely due to technical reasons. Inhaled sedation with sevoflurane in combination with esketamine, however, safely enables prolonged prone positioning in patients with CARDS. Moreover, sedation depth was light enough to enable assisted spontaneous breathing during prone positioning.

Non-parenteral Ketamine for Depression: A Practical Discussion on Addiction Potential and Recommendations for Judicious Prescribing.

Intravenous (IV) ketamine is increasingly used off-label at subanesthetic doses for its rapid antidepressant effect, and intranasal (IN) esketamine has been recently approved in several countries for treating depression. The clinical utility of these treatments is limited by a paucity of publicly funded IV ketamine and IN esketamine programs and cost barriers to private treatment programs, as well as the drug cost for IN esketamine itself, which makes generic ketamine alternatives an attractive option. Though evidence is limited, use of non-parenteral racemic ketamine formulations (oral, sublingual, and IN) may offer more realistic access in less rigidly supervised settings, both for acute and maintenance treatment in select cases. However, the psychiatric literature has repeatedly cautioned on the addictive potential of ketamine and raised caution for both less supervised and longer-term use of ketamine. To date, these concerns have not been discussed in view of available evidence, nor have they been discussed within a broader clinical context. This paper examines the available relevant literature and suggests that ketamine misuse risks appear not dissimilar to those of other well-established and commonly prescribed agents with abuse potential, such as stimulants or benzodiazepines. As such, ketamine prescribing should be considered in a similar risk/benefit context to balance patient access and need for treatment with concern for potential substance misuse. Our consortium of mood disorder specialists with significant ketamine prescribing experience considers prescribing of non-parenteral ketamine a reasonable clinical treatment option in select cases of treatment-resistant depression. This paper outlines where this may be appropriate and makes practical recommendations for clinicians in judicious prescribing of non-parenteral ketamine.

Efficacy comparison of intraperitoneal anaesthesia and post-operative analgesia regimens in laboratory rats.

INTRODUCTION: Effective and safe anesthesia for rodents has long been a leading concern among biomedical researchers. Intraperitoneal injection constitutes an alternative to inhalant anesthesia. PURPOSE: The aim of this study was to identify a safe, reliable, and effective anesthesia and postoperative analgesia protocol for laboratory rats exposed to painful procedures. MATERIAL AND METHODS: Twenty-seven female Wistar rats in an ongoing study that required surgery were randomized into groups for three different intraperitoneal anesthesia protocols and three different analgesia regimens. The anesthesia groups were (1) medetomidine + ketamine (MK), (2) ketamine + xylacine (KX), and (3) fentanyl + medetomidine (FM). Three analgesia groups were equally distributed among the anesthesia groups: (1) local mepivacaine + oral ibuprofen (MI), (2) oral tramadol + oral ibuprofen (TI), and (3) local tramadol + oral tramadol + + oral ibuprofen (TTI). A core was assigned to measure anesthesia (0-3) and analgesia (0-2) effectiveness; the lower the score, the more effective the treatment. RESULTS: The mean MK score was 0.44 versus 2.00 for FM and 2.33 for KX. Mean score for analgesia on the first postoperative day was TTI (4.66) TI (9.13), and MI (10.14). Mean score 48 hours after surgery was TTI (3.4), TI (6.71), and MI (9.5). These differences were statistically significant. CONCLUSION: MK was shown to be a reliable, safe, and effective method of anesthesia. The TTI analgesia regimen is strongly recommended in light of these results.

Resolution of status epilepticus after ketamine administration.

BACKGROUND: Status Epilepticus is the most common non-traumatic neurologic emergency in childhood. Current algorithms prioritize the use of benzodiazepines as first line treatment followed by Levetiracetam or Valproic Acid, possibly Fosphenytoin and eventually high dose Propofol and intubation. CASE REPORT: A 9-month old girl was brought to the emergency department with a continuous seizure involving the right upper and lower extremity for 45 min prior to arrival. Patient received a dose of rectal Diazepam, intramuscular Midazolam, 2 doses of Lorazepam, Levetiracetam, Fosphenytoin and 2 additional doses of Lorazepam. The seizure remained refractory and generalized. In anticipation of intubation, and because of its action on the NMDA receptor, Ketamine (1 mg/kg IV) was administered. The clonic movements and eye deviations stopped. Patient was intubated for airway protection, sedated with Propofol, then admitted to the PICU. EEG showed no evidence of a seizure pattern. Labs (CBC, CMP, COVID) were unremarkable except for WBC 24.5, blood glucose of 346 and CO2 of 17 with normal anion gap. Urinalysis showed a urinary tract infection. Patient was at her baseline on 1 week post-discharge re-evaluation. Ketamine theoretically may abort seizures through blockade of NMDA receptors which are unregulated in status epilepticus. To date, no randomized controlled trials have been reported. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Ketamine may have a role in treating status epilepticus. It may be considered for induction for rapid sequence intubation and possibly as a third or fourth line agent in refractory cases.

Impact of ketamine as an adjunct sedative in acute respiratory distress syndrome due to COVID-19 Pneumonia.

PURPOSE: Deep sedation is sometimes needed in acute respiratory distress syndrome. Ketamine is a sedative that has been shown to have analgesic and sedating properties without having a detrimental impact on hemodynamics. This pharmacological profile makes ketamine an attractive sedative, potentially reducing the necessity for other sedatives and vasopressors, but there are no studies evaluating its effect on these medications in patients requiring deep sedation for acute respiratory distress syndrome. MATERIALS AND METHODS: This is a retrospective, observational study in a single center, quaternary care hospital in southeast Texas. We looked at adults with COVID-19 requiring mechanical ventilation from March 2020 to September 2020. RESULTS: We found that patients had less propofol requirements at 72 h after ketamine initiation when compared to 24 h (median 34.2 vs 54.7 mg/kg, p = 0.003). Norepinephrine equivalents were also significantly lower at 48 h than 24 h after ketamine initiation (median 38 vs 62.8 mcg/kg, p = 0.028). There was an increase in hydromorphone infusion rates at all three time points after ketamine was introduced. CONCLUSIONS: In this cohort of patients with COVID-19 ARDS who required mechanical ventilation receiving ketamine we found propofol sparing effects and vasopressor requirements were reduced, while opioid infusions were not.