The impact of ketamine on emergency rapid sequence intubation: a systematic review and meta-analysis

BACKGROUND

Rapid sequence intubation (RSI) is a crucial step in the resuscitation process for critically ill patients, and the judicious use of sedative drugs during RSI significantly influences the clinical outcomes of patients. Ketamine is a commonly used anesthetic sedative; however, its impact on the mortality of patients undergoing RSI has yielded inconsistent findings. Therefore, we conducted a systematic review and meta-analysis investigating ketamine's role in RSI to provide insights into selecting appropriate sedatives for critically ill patients.

METHODS

In this systematic review and meta-analysis, we conducted a systematic search on MEDLINE (PubMed), Embase, and Cochrane Central Register of Controlled Trials, without restricting to randomized controlled trials (RCTs) or cohort studies. The search was performed from inception until Dec 12, 2023, with no language restrictions. All studies comparing the use of sedatives, including ketamine, and documenting in-hospital mortality were included in this study.

RESULTS

A total of 991 studies were identified, out of which 15 studies (5 RCTs and 10 cohort studies) involving 16,807 participants fulfilled the inclusion criteria. No significant impact on in-hospital mortality was observed with the use of ketamine compared to other drugs during RSI (OR 0.90, 95%CI 0.72 to 1.12). Low-quality evidence suggested that ketamine might reduce mortality within the first seven days of hospitalization (OR 0.42, 95%CI 0.19 to 0.93), but it may also have a potential effect on prolonging ICU-free days at day 28 (MD -0.71, 95%CI -1.38 to -0.05). There were no significant differences in the results of the other RSI-related outcomes, such as physiological function and adverse events.

CONCLUSIONS

Based on existing studies, ketamine showed no significant difference compared to other sedatives in terms of in-hospital mortality, physiological impact, and side effects following RSI. However, it may reduce mortality within 7 days while probably prolong the length of stay in the ICU.

TRIAL REGISTRATION

CRD42023478020.

KETAMINE: Neural- and network-level changes

Ketamine is a widely used clinical drug that has several functional and clinical applications, including its use as an anaesthetic, analgesic, anti-depressive, anti-suicidal agent, among others. Among its diverse behavioral effects, it influences short-term memory and induces psychedelic effects. At the neural level across different brain areas, it modulates neural firing rates, neural tuning, brain oscillations, and modularity, while promoting hypersynchrony and random connectivity between neurons. In our recent studies we demonstrated that topical application of ketamine on the visual cortex alters neural tuning and promotes vigorous connectivity between neurons by decreasing their firing variability. Here, we begin with a brief review of the literature, followed by results from our lab, where we synthesize a dendritic model of neural tuning and network changes following ketamine application. This model has potential implications for focused modulation of cortical networks in clinical settings. Finally, we identify current gaps in research and suggest directions for future studies, particularly emphasizing the need for more animal experiments to establish a platform for effective translation and synergistic therapies combining ketamine with other protocols such as training and adaptation. In summary, investigating ketamine's broader systemic effects, not only provides deeper insight into cognitive functions and consciousness but also paves the way to advance therapies for neuropsychiatric disorders.

Ketamine-based Sedation Use in Mechanically Ventilated Critically Ill Patients with COVID-19: A Multicenter Cohort Study

Backgrounds

Ketamine possesses analgesia, anti-inflammation, anticonvulsant, and neuroprotection properties. However, the evidence that supports its use in mechanically ventilated critically ill patients with COVID-19 is insufficient. The study's goal was to assess ketamine's effectiveness and safety in critically ill, mechanically ventilated (MV) patients with COVID-19.

Methods

Adult critically ill patients with COVID-19 were included in a multicenter retrospective-prospective cohort study. Patients admitted between March 1, 2020, and July 31, 2021, to five ICUs in Saudi Arabia were included. Eligible patients who required MV within 24 hours of ICU admission were divided into two sub-cohort groups based on their use of ketamine (Control vs. Ketamine). The primary outcome was the length of stay (LOS) in the hospital. P/F ratio differences, lactic acid normalization, MV duration, and mortality were considered secondary outcomes. Propensity score (PS) matching was used (1:2 ratio) based on the selected criteria.

Results

In total, 1,130 patients met the eligibility criteria. Among these, 1036 patients (91.7 %) were in the control group, whereas 94 patients (8.3 %) received ketamine. The total number of patients after PS matching, was 264 patients, including 88 patients (33.3 %) who received ketamine. The ketamine group's LOS was significantly lower (beta coefficient (95 % CI): -0.26 (-0.45, -0.07), P = 0.008). Furthermore, the PaO2/FiO2 ratio significantly improved 24 hours after the start of ketamine treatment compared to the pre-treatment period (6 hours) (124.9 (92.1, 184.5) vs. 106 (73.1, 129.3; P = 0.002). Additionally, the ketamine group had a substantially shorter mean time for lactic acid normalization (beta coefficient (95 % CI): -1.55 (-2.42, -0.69), P 0.01). However, there were no significant differences in the duration of MV or mortality.

Conclusions

Ketamine-based sedation was associated with lower hospital LOS and faster lactic acid normalization but no mortality benefits in critically ill patients with COVID-19. Thus, larger prospective studies are recommended to assess the safety and effectiveness of ketamine as a sedative in critically ill adult patients.

The Effect of Preprocedural Low-Dose Ketamine for Pain and Anxiety in Patients during Thoracic Epidural Catheterization

Background and Objectives: Thoracic epidural catheterization (TEC) can be both uncomfortable and fearful for patients when performed awake with the thought that the procedure may be painful. The aim of this study was to assess the effect of low-dose intravenous ketamine administration on pain and anxiety during the TEC procedure. Materials and Methods: Sixty patients were randomly divided into two groups to receive intravenous (IV) placebo (Group P) and IV low-dose (0.15 mg/kg) ketamine (LDK) (Group K) 3 min before the procedure in a double-blind manner. A visual analog scale (VAS) was used to measure anxiety (VAS-A) and pain (VAS-P) scores. Vital parameters were monitored before premedication (T1), 20 min after premedication (T2), during skin anesthesia (T3), during TEC (T4), and 5 min after TEC (T5). VAS-A values were recorded at T1, T3, T4, and T5 periods, and VAS-P levels were noted at T3, T4, and T5 periods. Results: During TEC (T4), both VAS-P and VAS-A were significantly lower in Group K (p < 0.001). The mean VAS-A value was 10.6 mm lower, and the mean VAS-P value was 9 mm lower in Group K than in Group P at the T4 time point. Additionally, the mean VAS-P value was 7.7 mm lower in Group K compared to Group P at the T3 time point (p < 0.001). Both groups showed a statistically significant difference in VAS-A measurements when compared at their respective time points (p < 0.001). However, only Group P demonstrated a statistically significant difference in VAS-P measurements (p < 0.001). VAS-P values remained stable in Group K. The number of patients who did not recall the procedure was significantly higher in Group K (p < 0.001). Furthermore, the number of patients who would consent to the same procedure in the future was significantly higher in Group K (p = 0.007). Conclusions: A preprocedural LDK (0.15 mg/kg) can effectively prevent anxiety and pain experienced by patients during the TEC procedure. Administration of LDK may provide a more comfortable procedure process without causing ketamine-induced side effects (hemodynamic, respiratory, and psychological).

Efficacy and safety of low-dose esketamine for painless gastrointestinal endoscopy in adults: a systematic evaluation and meta-analysis

Object: The benefits of low-dose esketamine for painless gastrointestinal endoscopy remain unclear. As such, the present study aimed to investigate the efficacy and safety of low-dose esketamine for this procedure. Methods: Seven common databases were searched for clinical studies investigating low-dose esketamine for painless gastrointestinal endoscopy. Subsequently, a meta-analysis was performed to synthesize and analyze the data extracted from studies fulfilling the inclusion criteria. Results: Meta-analysis revealed that, compared with propofol, low-dose esketamine in combination with propofol significantly reduced recovery time by 0.56 min (mean difference [MD] -0.56%, 95% confidence interval (CI) -1.08 to -0.05, p = 0.03), induction time by 9.84 s (MD -9.84, 95% CI -12.93 to -6.75, p < 0.00001), propofol dosage by 51.05 mg (MD -51.05, 95% CI -81.53 to -20.57, p = 0.01), and increased mean arterial pressure by 6.23 mmHg (MD 6.23, 95% CI 1.37 to 11.08, p = 0.01). Meanwhile, low-dose esketamine reduced injection pain by 63% (relative risk [RR] 0.37, 95% CI 0.28 to 0.49, p < 0.00001), involuntary movements by 40% (RR 0.60, 95% Cl 0.42 to 0.85, p < 0.005), choking by 42% (RR 0.58, 95% Cl 0.38 to 0.88, p = 0.01), bradycardia by 68% (RR 0.32, 95% Cl 0.18 to 0.58, p = 0.0002), hypotension by 71% (RR 0.29, 95% Cl 0.21 to 0.40, p < 0.00001), respiratory depression by 63% (RR 0.37, 95% 0.26 to 0.51, p < 0.00001), additional cases of propofol by 53% (RR 0.47, 95% Cl 0.29 to 0.77, p = 0.002), and increased hypertension by 1000% (RR 11.00, 95% Cl 1.45 to 83.28, p = 0.02). There were no significant differences in mean heart rate, mean oximetry saturation, delirium, dizziness, vomiting, tachycardia, and hypoxemia. Subgroup analyses revealed that, compared with other dose groups, 0.25 mg/kg esketamine afforded additional benefits in recovery and induction time, mean arterial pressure, involuntary movements, hypoxemia, and respiratory depression. Conclusion: Low-dose esketamine was found to be safe and effective for providing anesthesia during gastrointestinal endoscopy, with 0.25 mg/kg identified as the optimal dose within the dosage ranges examined. However, caution should be exercised when administering this drug to patients with inadequate preoperative blood pressure control.

Association of ketamine use during procedural sedation with oxygen desaturation and healthcare utilisation: a multicentre retrospective hospital registry study

BACKGROUND

We investigated the effects of ketamine on desaturation and the risk of nursing home discharge in patients undergoing procedural sedation by anaesthetists.

METHODS

We included adult patients who underwent procedures under monitored anaesthetic care between 2005 and 2021 at two academic healthcare networks in the USA. The primary outcome was intraprocedural oxygen desaturation, defined as oxygen saturation <90% for ≥2 consecutive minutes. The co-primary outcome was a nursing home discharge.

RESULTS

Among 234,170 included patients undergoing procedural sedation, intraprocedural desaturation occurred in 5.6% of patients who received ketamine vs 5.2% of patients who did not receive ketamine (adjusted odds ratio [ORadj] 1.22, 95% confidence interval [CI] 1.15-1.29, P<0.001; adjusted absolute risk difference [ARDadj] 1%, 95% CI 0.7-1.3%, P<0.001). The effect was magnified by age >65 yr, smoking, or preprocedural ICU admission (P-for-interaction <0.001, ORadj 1.35, 95% CI 1.25-1.45, P<0.001; ARDadj 2%, 95% CI 1.56-2.49%, P<0.001), procedural risk factors (upper endoscopy of longer than 2 h; P-for-interaction <0.001, ORadj 2.91, 95% CI 1.85-4.58, P<0.001; ARDadj 16.2%, 95% CI 9.8-22.5%, P<0.001), and high ketamine dose (P-for-trend <0.001, ORadj 1.61, 95% CI, 1.43-1.81 for ketamine >0.5 mg kg-1). Concomitant opioid administration mitigated the risk (P-for-interaction <0.001). Ketamine was associated with higher odds of nursing home discharge (ORadj 1.11, 95% CI 1.02-1.21, P=0.012; ARDadj 0.25%, 95% CI 0.05-0.46%, P=0.014).

CONCLUSIONS

Ketamine use for procedural sedation was associated with an increased risk of oxygen desaturation and discharge to a nursing home. The effect was dose-dependent and magnified in subgroups of vulnerable patients.

Observational study of the effect of ketamine infusions on sedation depth, inflammation, and clinical outcomes in mechanically ventilated patients with SARS-CoV-2

Severely ill patients with COVID-19 are challenging to sedate and often require high-dose sedation and analgesic regimens. Ketamine can be an effective adjunct to facilitate sedation of critically ill patients but its effects on sedation level and inflammation in COVID-19 patients have not been studied. This retrospective, observational cohort study evaluated the effect of ketamine infusions on inflammatory biomarkers and clinical outcomes in mechanically ventilated patients with SARS-CoV-2 infection. A total of 186 patients were identified (47 received ketamine, 139 did not). Patients who received ketamine were significantly younger than those who did not (mean (standard deviation) 59.2 (14.2) years versus 66.3 (14.4) years; P = 0.004), but there was no statistically significant difference in body mass index (P = 0.25) or sex distribution (P = 0.91) between groups. Mechanically ventilated patients who received ketamine infusions had a statistically significant reduction in Richmond Agitation-Sedation Scale score (-3.0 versus -2.0, P < 0.001). Regarding inflammatory biomarkers, ketamine was associated with a reduction in ferritin (P = 0.02) and lactate (P = 0.01), but no such association was observed for C-reactive protein (P = 0.27), lactate dehydrogenase (P = 0.64) or interleukin-6 (P = 0.87). No significant association was observed between ketamine administration and mortality (odds ratio 0.971; 95% confidence interval 0.501 to 1.882; P = 0.93). Ketamine infusion was associated with improved sedation depth in mechanically ventilated COVID-19 patients and provided a modest anti-inflammatory benefit but did not confer benefit with respect to mortality or intensive care unit length of stay.

Ketamine-Induced Sclerosing Cholangitis Associated With Early Inflammatory Bowel Disease During Chronic Topical Ketamine Use

Ketamine-induced sclerosing cholangitis has been described with chronic intranasal and intravenous use. Our case follows chronic topical use for peripheral neuropathy. It is also uniquely associated with early inflammatory bowel disease, a known complication of primary sclerosing cholangitis.

Assessing the safety of deep sedation in outpatient pediatric oral health care

BACKGROUND

Children are the patient subgroup with the lowest error tolerance regarding deep sedation (DS)-supported care. This study assessed the safety of DS-supported pediatric dental treatment carried out in an outpatient setting through retrospective review of patient charts.

METHODS

An automated script was developed to identify charts of pediatric patients who underwent DS-supported dental procedures from 2017 through 2019 at a dental clinic. Charts were assessed for the presence of sedation-related adverse events (AEs). A panel of experts performed a second review and confirmed or refuted the designation of AE (by the first reviewer). AEs were classified with the Tracking and Reporting Outcomes of Procedural Sedation system.

RESULTS

Of the 175 DS cases, 19 AEs were identified in 15 cases (8.60%). Using the Tracking and Reporting Outcomes of Procedural Sedation classification system, 7 (36.84%) events were related to the airway and breathing category, 9 (47.37%) were related to sedation quality (including a dizzy patient who fell at the checkout desk and sustained a head laceration), and 3 (15.79%) were classified as an allergy.

CONCLUSION

This study suggests an AE (whether relatively minor or of potentially major consequence) occurs in 1 of every 12 DS cases involving pediatric patients, performed at an outpatient dental clinic. Larger studies are needed, in addition to root cause analyses.

PRACTICAL IMPLICATIONS

As dentists increasingly pivot in the use of DS services from in-hospital to outpatient settings, patients expect comparable levels of safety. This work helps generate evidence to drive targeted efforts to improve the safety and reliability of pediatric outpatient sedation.

Outpatient Ketamine Infusions for the Treatment of Fibromyalgia and Chronic Pain Syndrome: A Case Report

Intravenous (IV) ketamine has demonstrable efficacy for chronic pain management. Its use in an outpatient setting has provided relief from myriad pain syndromes and additionally may reduce dependence on opioids. Nevertheless, its long-term ability to provide these benefits is understudied. Here, we present the case of a 68-year-old female who presented to our clinic with persistent fibromyalgia, accompanied by other pain symptoms that had been recalcitrant to traditional pain management therapy including nerve blocks, ablations, spinal cord stimulation, and morphine medication. We administered seven increasing IV ketamine doses over two weeks. The patient reported significant, widespread pain relief. The patient continued to receive IV ketamine twice weekly for over a year and remains on this schedule. Pain relief has persisted under this regimen, along with a demonstrable improvement in quality of life, a reduced use of morphine, and the cessation of anti-depressant medication. This case indicates that long-term ketamine infusions show promise for chronic pain management and that more longitudinal studies on this treatment are warranted.

Efficacy and safety of ketamine for neonatal refractory status epilepticus: case report and systematic review

Background

Evidence-based data on treatment of neonatal status epilepticus (SE) are scarce. We aimed to collect data on the efficacy and safety of ketamine for the treatment of neonatal SE and to assess its possible role in the treatment of neonatal SE.

Methods

We described a novel case and conducted a systematic literature review on neonatal SE treated with ketamine. The search was carried out in Pubmed, Cochrane, Clinical Trial Gov, Scopus and Web of Science.

Results

Seven published cases of neonatal SE treated with ketamine were identified and analyzed together with our novel case. Seizures typically presented during the first 24 h of life (6/8). Seizures were resistant to a mean of five antiseizure medications. Ketamine, a NMDA receptor antagonist, appeared to be safe and effective in all neonates treated. Neurologic sequelae including hypotonia and spasticity were reported for 4/5 of the surviving children (5/8). 3/5 of them were seizure free at 1-17 months of life.

Discussion

Neonatal brain is more susceptible to seizures due to a shift towards increased excitation because of a paradoxical excitatory effect of GABA, a greater density of NMDA receptors and higher extracellular concentrations of glutamate. Status epilepticus and neonatal encephalopathy could further enhance these mechanisms, providing a rationale for the use of ketamine in this setting.

Conclusions

Ketamine in the treatment of neonatal SE showed a promising efficacy and safety profile. However, further in-depth studies and clinical trials on larger populations are needed.

Ketamine-propofol (ketofol) in procedural sedation: a narrative review

Sedation methods for dental treatment are increasingly explored. Recently, ketofol, which is a combination of ketamine and propofol, has been increasingly used because the advantages and disadvantages of propofol and ketamine complement each other and increase their effectiveness. In this review, we discuss the pharmacology of ketamine and propofol, use of ketofol in various clinical situations, and differences in efficacy between ketofol and other sedatives.

A Comparison of the Anti-Anxiety Effects of Oral Ketamine and Fluvoxamine in Children with Separation Anxiety Disorder Manifesting as School Refusal

Background

Children suffer from a high prevalence of anxiety problems that require prompt treatment. It has been demonstrated that ketamine offers rapid anti-anxiety effects. This study aimed to evaluate ketamine's anti-anxiety impact in the treatment of children with school-refusal separation anxiety disorder.

Materials and Methods

In this open-labeled randomized clinical trial, 71 children (6-10 years) diagnosed with school refusal separation anxiety disorder were randomly assigned to two groups; a case group, who received ketamine at a weekly rising dose of 0.1 to 1 mg/kg; the control group treated with Fluvoxamine (25 mg/day), which could increase to 200 mg/day if necessary. The SCARED and CATS questionnaires were used to assess anxiety before treatment, at the 8^th and 16^th weeks of intervention. The data were analyzed using repeated-measures analysis of covariance.

Results

The mean anxiety scores in the eighth week (19.7 ± 16.1) were significantly lower in the ketamine group than before (31.5 ± 10.8). Until the sixteenth week (19.4 ± 14.6), there was no further decrease in scores in the ketamine group, in the fluvoxamine group, pre-treatment scores (36.3 ± 16.5) and eighth week (36.9 ± 16.6) were not significantly different, but scores decreased significantly in a sixteenth week (26.2 ± 12.5).

Conclusion

In first eight weeks of treatment, ketamine was more successful than fluvoxamine at reducing anxiety disorder, considering the emergence of this disorder and the lack of major adverse effects of ketamine, it seems to be beneficial in early phases of treatment. Due to the quick onset of ketamine in future trials, their combination therapy is recommended during the initial weeks of treatment.

Pharmacological Mechanism of Ketamine in Suicidal Behavior Based on Animal Models of Aggressiveness and Impulsivity: A Narrative Review

Around 700,000 people die from suicide each year in the world. Approximately 90% of suicides have a history of mental illness, and more than two-thirds occur during a major depressive episode. Specific therapeutic options to manage the suicidal crisis are limited and measures to prevent acting out also remain limited. Drugs shown to reduce the risk of suicide (antidepressants, lithium, or clozapine) necessitate a long delay of onset. To date, no treatment is indicated for the treatment of suicidality. Ketamine, a glutamate NMDA receptor antagonist, is a fast-acting antidepressant with significant effects on suicidal ideation in the short term, while its effects on suicidal acts still need to be demonstrated. In the present article, we reviewed the literature on preclinical studies in order to identify the potential anti-suicidal pharmacological targets of ketamine. Impulsive-aggressive traits are one of the vulnerability factors common to suicide in patients with unipolar and bipolar depression. Preclinical studies in rodent models with impulsivity, aggressiveness, and anhedonia may help to analyze, at least in part, suicide neurobiology, as well as the beneficial effects of ketamine/esketamine on reducing suicidal ideations and preventing suicidal acts. The present review focuses on disruptions in the serotonergic system (5-HT_B receptor, MAO-A enzyme), neuroinflammation, and/or the HPA axis in rodent models with an impulsive/aggressive phenotype, because these traits are critical risk factors for suicide in humans. Ketamine can modulate these endophenotypes of suicide in human as well as in animal models. The main pharmacological properties of ketamine are then summarized. Finally, numerous questions arose regarding the mechanisms by which ketamine may prevent an impulsive-aggressive phenotype in rodents and suicidal ideations in humans. Animal models of anxiety/depression are important tools to better understand the pathophysiology of depressed patients, and in helping develop novel and fast antidepressant drugs with anti-suicidal properties and clinical utility.

Effects of ketamine-induced H3K9 hypoacetylation during pregnancy on cardiogenesis of mouse offspring

BACKGROUND

Prenatal exposure to adverse factors can cause congenital heart defects. Ketamine, a widely used anesthetic drug, produces several adverse reactions such as tachycardia, hypertension, and laryngospasm, especially in pediatric patients. This study aimed to detect the effects of ketamine exposure during pregnancy on the cardiogenesis of mouse offspring and the potential mechanisms.

METHODS

In this study, ketamine at an addictive dose (5 mg/kg) was administered to mice during early gestation to explore the epigenetic mechanism of its causing cardiac dysplasia. The cardiac morphology of the mouse offspring was observed through hematoxylin-eosin staining and transmission electron microscopy. The heart function of one-month-old neonates was detected by echocardiography. The expression of cardiomyogenesis-related genes was detected by western blot and RT-qPCR. The acetylation level of histone H3K9 at the Mlc2 promoter and its deacetylase level and activity were detected by CHIP-qPCR, RT-qPCR, and ELISA, respectively.

RESULTS

Our data revealed that ketamine exposure during pregnancy could cause cardiac enlargement, myocardial sarcomere disorganization, and decreased cardiac contractile function in mouse offspring. Moreover, ketamine reduced the expression of Myh6, Myh7, Mlc2, Mef2c, and cTnI. The histone H3K9 acetylation level at the Mlc2 promoter was down-regulated by increasing the histone deacetylase activity and HDAC3 level upon ketamine administration.

CONCLUSIONS

Our work indicates that H3K9 acetylation is a vital player in cardiac dysplasia in offspring caused by prenatal ketamine exposure and HDAC3 is a key regulatory factor.

Comparison of the cardiovascular effects of immobilization with three different drug combinations in free-ranging African lions

Thirty-six free-ranging lions (12 per group) were immobilized with tiletamine-zolazepam (Zoletil 0.6 mg/kg i.m.) plus medetomidine (0.036 mg/kg i.m.) (TZM), ketamine (3.0 mg/kg i.m.) plus medetomidine (0.036 mg/kg i.m.) (KM) or ketamine (1.2 mg/kg i.m.) plus butorphanol (0.24 mg/kg i.m.) plus medetomidine (0.036 mg/kg i.m.) (KBM). During immobilization cardiovascular variables were monitored at 5-minute intervals for a period of 30 minutes. Lions immobilized with all three drug combinations were severely hypertensive. Systolic arterial pressure was higher at initial sampling in lions immobilized with KM (237.3 ± 24.8 mmHg) than in those immobilized with TZM (221.0 ± 18.1 mmHg) or KBM (226.0 ± 20.6 mmHg) and decreased to 205.8 ± 19.4, 197.7 ± 23.7 and 196.3 ± 17.7 mmHg, respectively. Heart rates were within normal ranges for healthy, awake lions and decreased throughout the immobilization regardless of drug combination used. Lions immobilized with TZM had a higher occurrence (66%) of skipped heart beats than those immobilized with KBM (25%). The three drug combinations all caused negative cardiovascular effects, which were less when KBM was used, but adverse enough to warrant further investigations to determine if these effects can be reversed or prevented when these three combinations are used to immobilize free-living lions.

Post-Partum Depression Lactating Rat Model for Evaluating Ketamine's Safety as a Pharmacotherapeutic Treatment: Roles in Cardiac and Urinary Function

Depression is one of the world's most common and mentally disabling illnesses. Post-partum depression is a subtype of depression that affects one in seven women worldwide. Successful pharmacological treatment must consider the consequences for both, since the mother-child bond is fundamental for the well-being of both mother and infant as well as the general development of the newborn. Changes in maternal physiology and/or behavior can significantly influence the development of breastfed infants. Ketamine has been extensively studied for use as an antidepressant due to its mixed mechanisms of action. Safety and efficacy studies in the cardiovascular and urinary systems of a lactating postpartum depression animal model are essential for contributing toward ketamine's clinical use in the respective patient population. Thus, this project aimed to study the implications of postpartum maternal exposure to ketamine during lactation on the cardiovascular system of female rats submitted to the depression induction model by maternal separation. This model promotes depressive effects through stress caused by the interruption of mother-infant bond early in the offspring's life. To achieve depression, each dam was separated from her offspring for 3 h per day, from post-natal day 2 (PND2) to PND12. Experimental groups received daily treatment with either 5, 10, or 20 mg/kg of ketamine intraperitoneally during the lactation period, from PND2 to PND21. Behavioral tests consisted of the maternal and aggressive maternal behavior tests, the olfactory preference test, and the forced swim test. A technique for the detection of catecholamines and indoleamines in the heart muscle was developed for the experimental model groups. The histopathological evaluation was performed on these animals' cardiac muscles and urinary bladders. Our findings suggest that ketamine is safe for use in postpartum depression and does not induce cardiovascular and/or urinary systems toxicity.

Risk Factors for the Development of Neuropsychiatric Adverse Effects in Ketamine-Treated Pain

Ketamine use has increased recently for the management of acute and chronic pain. Ketamine can cause a variety of neuropsychiatric adverse effects, such as hallucinations, dysphoria, and nightmares. The objective of this study was to explore risk factors for the development of neuropsychiatric adverse effects in ketamine-treated pain. This was a retrospective, single-center cohort study of hospitalized patients who received low dose intravenous (IV) ketamine or oral ketamine for pain. Patients who had a neuropsychiatric adverse effect were compared to those who did not. One hundred and seventy-one patients were included, with 155 receiving IV ketamine and 16 receiving oral ketamine. Overall, 50 (29.2%) had a neuropsychiatric adverse effect and 26 (15.2%) required treatment discontinuation. No significant differences were found between patients who tolerated ketamine and those who did not. Patients who had an adverse effect were numerically less likely to receive benzodiazepines (28% vs 39.7%, p = 0.153), as were patients who required discontinuation of ketamine (23.1% vs. 41.4%, p = 0.08). In patients receiving ketamine for pain, predicting who may be more likely to experience neuropsychiatric adverse effects remains difficult. Further research is warranted to determine whether benzodiazepines are safe and effective for mitigating these adverse effects in this setting.

Anesthesia and surgery in very precarious conditions. Clinical cases

We performed herniorrhaphy on 21 children (4 of them infants) and 3 adults, in very precarious conditions, in a hospital in a economically depressed area of the Democratic Republic of Congo. Anesthesia technique used in adults was subarachnoid and intravenous and intramuscular ketamine in children. Ketamine is an irreplaceable anesthetic in many parts of the world without resources, where the minimum safety means are not available. Knowing the simple anesthetic techniques, but with less risk, can also be useful in resourceful places, in unexpected situations. Greater solidarity is needed, both from anesthesia societies and from anesthesiologists, to alleviate the great deficiencies in well-trained professionals and means in places without resources.

Comparative study of haemodynamic effects of intravenous ketamine-fentanyl and propofol-fentanyl for laryngeal mask airway insertions in children undergoing herniotomy under general anaesthesia in a nigerian tertiary hospital

BACKGROUND

Insertion of laryngeal mask airway (LMA) with propofol in children may cause hypotension, laryngospasm and apnoea. Ketamine and fentanyl have been combined separately with propofol to prevent depression of cardiovascular system during LMA insertion, especially in paediatric patients. Ketamine-fentanyl and propofol-fentanyl combinations have analgesic effect, prevent coughing and apnoea and regarded as agents of choice for LMA insertions. However, the cardiovascular effects of the two admixtures for LMA insertions have not been fully assessed in children. We compared the haemodynamic effects of ketamine-fentanyl and propofol-fentanyl combinations for LMA insertion in paediatric patients who underwent herniotomy in our facility.

PATIENTS AND METHODS

This comparative study was conducted on 80 children aged 1-15 years, ASA physical Statuses I and II, who had herniotomy under general anaesthesia. The patients were randomised into two groups (A and B) of 40 patients each and LMA was inserted following administrations of the two different drug combinations. Patients in Group A received pre-mixed ketamine 2 mg/kg and fentanyl 2 μg/kg while the patients in Group B received pre-mixed propofol 2.5 mg/kg and fentanyl 2 μg/kg. The blood pressure and incidence of apnoea were determined in the two groups during and after the LMA insertion.

RESULTS

The haemodynamic states of the patients were not comparable statistically as the heart rate, systolic, diastolic and mean arterial blood pressure were significantly higher and stable in the ketamine-fentanyl group than the propofol-fentanyl group (P < 0.05). The incidence of apnoea was significantly lower in the ketamine-fentanyl group compared with propofol-fentanyl group (P = 0.045), but post-anaesthesia discharge scores were similar, with no significant difference in both groups (P = 0.241).

CONCLUSION

The use of ketamine-fentanyl combination for LMA insertion in paediatric patients was associated with better haemodynamic changes and lower incidence of apnoea when compared with propofol-fentanyl combination.

Postoperative Outcomes Associated With Procedural Sedation Conducted by Physician and Nonphysician Anesthesia Providers: Findings From the Prospective, Observational African Surgical Outcomes Study

BACKGROUND

There is an unmet need for essential surgical services in Africa. Limited anesthesia services are a contributing factor. Nonphysician anesthesia providers are utilized to assist with providing anesthesia and procedural sedation to make essential surgeries available. There is a paucity of data on outcomes following procedural sedation for surgery in Africa. We investigated the postoperative outcomes following procedural sedation by nonphysicians and physicians in Africa. We hypothesized that the level of training of the sedation provider may be associated with the incidence of severe postoperative complications and death.

METHODS

A secondary analysis of a prospective cohort of inhospital adult surgical patients representing 25 African countries was performed. The primary outcome was a collapsed composite of inhospital severe postoperative complications and death. We assessed the association between receiving procedural sedation conducted by a nonphysician (versus physician) and the composite outcome using logistic regression. We used the inverse probability of treatment weighting propensity score method to adjust for potential confounding variables including patient age, hemoglobin level, American Society of Anesthesiologists (ASA) physiological status, diabetes mellitus, urgency of surgery, severity of surgery, indication for surgery, surgical discipline, seniority of the surgical team, hospital level of specialization, and hospital funding system using public or private funding. All patients who only received procedural sedation for surgery were included.

RESULTS

Three hundred thirty-six patients met the inclusion criteria, of which 98 (29.2%) received sedation from a nonphysician provider. The incidence of severe postoperative complications and death was 10 of 98 (10.2%) in the nonphysician group and 5 of 238 (2.1%) in the physician group. The estimated association between procedural sedation conducted by a nonphysician provider and inhospital outcomes was an 8-fold increase in the odds of severe complications and/or death, with an odds ratio (95% confidence interval [CI]) of 8.3 (2.7-25.6).

CONCLUSIONS

The modest number of observations in this secondary data analysis suggests that shifting the task of procedural sedation from physicians to nonphysicians to increase access to care may be associated with severe postoperative complications and death in Africa. Research focusing on identifying factors contributing to adverse outcomes associated with procedural sedation is necessary to make this practice safer.

CYP 450 enzymes influence (R,S)-ketamine brain delivery and its antidepressant activity

Esketamine, the S-stereoisomer of (R,S)-ketamine was recently approved by drug agencies (FDA, EMA), as an antidepressant drug with a new mechanism of action. (R,S)-ketamine is a N-methyl-d-aspartate receptor (NMDA-R) antagonist putatively acting on GABAergic inhibitory synapses to increase excitatory synaptic glutamatergic neurotransmission. Unlike monoamine-based antidepressants, (R,S)-ketamine exhibits rapid and persistent antidepressant activity at subanesthetic doses in preclinical rodent models and in treatment-resistant depressed patients. Its major brain metabolite, (2R,6R)-hydroxynorketamine (HNK) is formed following (R,S)-ketamine metabolism by various cytochrome P450 enzymes (CYP) mainly activated in the liver depending on routes of administration [e.g., intravenous (largely used for a better bioavailability), intranasal spray, intracerebral, subcutaneous, intramuscular or oral]. Experimental or clinical studies suggest that (2R,6R)-HNK could be an antidepressant drug candidate. However, questions still remain regarding its molecular and cellular targets in the brain and its role in (R,S)-ketamine's fast-acting antidepressant effects. The purpose of the present review is: 1) to review (R,S)-ketamine pharmacokinetic properties in humans and rodents and its metabolism by CYP enzymes to form norketamine and HNK metabolites; 2) to provide a summary of preclinical strategies challenging the role of these metabolites by modifying (R,S)-ketamine metabolism, e.g., by administering a pre-treatment CYP inducers or inhibitors; 3) to analyze the influence of sex and age on CYP expression and (R,S)-ketamine metabolism. Importantly, this review describes (R,S)-ketamine pharmacodynamics and pharmacokinetics to alert clinicians about possible drug-drug interactions during a concomitant administration of (R,S)-ketamine and CYP inducers/inhibitors that could enhance or blunt, respectively, (R,S)-ketamine's therapeutic antidepressant efficacy in patients.

Efficacy of ketamine in the treatment of migraines and other unspecified primary headache disorders compared to placebo and other interventions: a systematic review

BACKGROUND

Migraine headaches are the second leading cause of disability worldwide and are responsible for significant morbidity, reduction in the quality of life, and loss of productivity on a global scale. The purpose of this systematic review and meta-analysis was to evaluate the efficacy of ketamine on migraines and other primary headache disorders compared to placebo and other active interventions, such as midazolam, metoclopramide/diphenhydramine, and prochlorperazine/diphenhydramine.

METHODS

An electronic search of databases published up to February 2021, including Medline via PubMed, EMBASE, Web of Science, and Cochrane Library, a hand search of the bibliographies of the included studies, as well as literature and systematic reviews found through the search was conducted to identify randomized controlled trials (RCTs) investigating ketamine in the treatment of migraine/headache disorders compared to the placebo. The authors assessed the risk of bias according to the Cochrane Handbook guidelines.

RESULTS

The initial search strategy yielded 398 unduplicated references, which were independently assessed by three review authors. After evaluation, this number was reduced to five RCTs (two unclear risk of bias and three high risk of bias). The total number of patients in all the studies was 193. Due to the high risk of bias, small sample size, heterogeneity of the outcomes reported, and heterogeneity of the comparison groups, the quality of the evidence was very low. One RCT reported that intranasal ketamine was superior to intranasal midazolam in improving the aura attack severity, but not duration, while another reported that intranasal ketamine was not superior to metoclopramide and diphenhydramine in reducing the headache severity. In one trial, subcutaneous ketamine was superior to saline in migraine severity reduction; however, intravenous (I.V.) ketamine was inferior to I.V. prochlorperazine and diphenhydramine in another study.

CONCLUSION

Further double-blind controlled studies are needed to assess the efficacy of ketamine in treating acute and chronic refractory migraines and other primary headaches using intranasal and subcutaneous routes. These studies should include a long-term follow-up and different ketamine dosages in diagnosed patients following international standards for diagnosing headache/migraine.

Ketamine versus propofol for rapid sequence induction in trauma patients: a retrospective study

BACKGROUND

Rapid Sequence Induction (RSI) is used for emergency tracheal intubation to minimise the risk of pulmonary aspiration of stomach contents. Ketamine and propofol are two commonly used induction agents for RSI in trauma patients. Yet, no consensus exists on the optimal induction agent for RSI in the trauma population. The aim of this study was to compare 30-day mortality in trauma patients after emergency intubation prehospitally or within 30 min after arrival in the trauma centre using either ketamine or propofol for RSI.

METHODS

In this investigator-initiated, retrospective study we included adult trauma patients emergently intubated with ketamine or propofol registered in the local trauma registry at Rigshospitalet, a tertiary university hospital that hosts a level-1 trauma centre. The primary outcome was 30-day mortality. Secondary outcomes included hospital and Intensive Care Unit length of stay as well as duration of mechanical ventilation. We analysed outcomes using multivariable logistic regression models adjusting for age, sex, injury severity score, shock (systolic blood pressure < 90 mmHg) and Glasgow Coma Scale score before intubation and present results as odds ratios (ORs) with 95% confidence intervals.

RESULTS

From January 1st, 2015 through December 31st, 2019 we identified a total of 548 eligible patients. A total of 228 and 320 patients received ketamine and propofol, respectively. The 30-day mortality for patients receiving ketamine and propofol was 20.2% and 22.8% (P = 0.46), respectively. Adjusted OR for 30-day mortality was 0.98 [0.58-1.66], P = 0.93. We found no significant association between type of induction agent and hospital length of stay, Intensive Care Unit length of stay or duration of mechanical ventilation.

CONCLUSIONS

In this study, trauma patients intubated with ketamine did not have a lower 30-day mortality as compared with propofol.

Effect on Opioids Requirement of Early Administration of Intranasal Ketamine for Acute Traumatic Pain

OBJECTIVES

To evaluate the efficacy and safety of early administration of low-dose intranasal ketamine on reducing the need for opioid and nonopioid analgesic agents in emergency department (ED) patients with acute moderate to severe acute limbs' trauma pain.

PATIENTS AND METHODS

This is a double-blind, randomized, prospective, controlled study conducted in the ED. The included patients were randomly assigned to intranasal pulverization of ketamine or placebo. Protocol treatment was given at the triage. The primary outcome is the need for opioids during ED stay. Secondary outcome included the requirement of nonopioid analgesic agents and the percentage of patients discharged from the ED with a visual analog scale (VAS) <30. A combined outcome score including the 3 outcome items was constructed.

RESULTS

The authors included 1102 patients, 550 patients in the placebo group, and 552 in the intranasal ketamine group. The groups were similar regarding demographics, clinical characteristics, and baseline VAS. The need for opioids was decreased in the intranasal ketamine group compared with the placebo group (17.2% vs. 26.5%; P<0.001). The need for nonopioid analgesics was significantly lower in the intranasal ketamine group compared with the placebo group (31.1% vs. 39.6%; P=0.003). The percentage of patients discharged with a VAS score <30 was significantly higher in the intranasal ketamine group (P<0.001). The mean combined outcome score was 0.97 in the placebo group and 0.67 in the intranasal ketamine group (P<0.001).

CONCLUSION

Intranasal ketamine administered early in the triage was associated with a decrease in opioids and nonopioid analgesics need in patients with acute limb trauma-related pain.

The Effects of Ketamine on the Gut Microbiome on CD1 Mice

The intestinal microbiota of an organism can significantly alter outcome data in otherwise identical experiments. Occasionally, animals may require sedation or anesthesia for scientific or health-related purposes, and certain anesthetics, such as ketamine, can profoundly affect the gastrointestinal system. While many factors can alter the gut microbiome (GM), the effects of anesthetics on the composition or diversity of the GM have not been established. The goal of the current study was to determine whether daily administration of ketamine would significantly alter the microbiome of CD1 mice. To achieve this goal, female CD1 mice received daily injections of ketamine HCl (100 mg/kg) or the equivalent volume of 0.9% saline for 10 consecutive days. Fecal samples were collected before the first administration and 24 h after the final dose of either ketamine or saline. Samples were analyzed by 16S rRNA sequencing to identify changes between groups in diversity or composition of GM. The study found no significant changes to the GM after serial ketamine administration when treated mice were housed with controls. Therefore, ketamine administration is unlikely to alter the GM of a CD1 mouse and should not serve be a confounding factor in reproducibility of research.

Low-Dose Ketamine Infusion for Perioperative Pain Management in Patients Undergoing Laparoscopic Gastric Bypass: A Prospective Randomized Controlled Trial

Introduction

Obesity is a common comorbidity seen in the perioperative setting and is associated with many diseases including cardiovascular disease and obstructive sleep apnea. Laparoscopic Roux-en-Y gastric bypass is the gold standard surgical treatment for patients whose weight is refractory to diet and exercise. Caring for these patients perioperatively presents unique challenges to anesthesiologists and is associated with an increased risk of adverse respiratory events. In our study, we hypothesize that a low-dose perioperative ketamine infusion will reduce opioid consumption and improve analgesia when compared to standard therapy.

Methods

This is a single-center, prospective randomized controlled study enrolling 35 patients in total. Patients were randomized equally into the ketamine and control group. Preop, intraop, and postop management regimens were standardized. The ketamine group received a 0.3 mg/kg ideal body weight ketamine bolus after induction followed by a 0.2 mg/kg/hr ketamine infusion continued into the postop setting for up to 24 hours. Data collected included total perioperative opioids used converted to oral morphine equivalents (ME), pain scores, side effects, hospital length of stay, and patient satisfaction captured via postoperative questionnaires.

Results

The use of perioperative opioid consumption was significantly lower in the ketamine group when compared with the control group (179.9 ME versus 248.7 ME, P=0.03). There was no statistically significant difference in pain scores or hospital length of stay postoperatively between the two groups. There were also no reported adverse respiratory events, prolonged sedation, agitation, or other side effects reported in either group. The patient satisfaction questionnaires showed a significant difference with the ketamine group reporting lower maximum pain scores, a decrease in how pain limited activities of daily living once discharged, and increased hospital pain management satisfaction scores.

Conclusions

Perioperative low-dose ketamine infusions significantly reduced opioid consumption in morbidly obese patients undergoing laparoscopic gastric bypass surgery.

Ketamine Use in Operation Enduring Freedom

INTRODUCTION

Ketamine is a dissociative anesthetic increasingly used in the prehospital and battlefield environment. As an analgesic, it has been shown to have comparable effects to opioids. In 2012, the Defense Health Board advised the Joint Trauma System to update the Tactical Combat Casualty Care Guidelines to include ketamine as an acceptable first line agent for pain control on the battlefield. The goal of this study was to investigate trends in the use of ketamine during Operation Enduring Freedom (OEF) and Operation Freedom's Sentinel (OFS) during the years 2011-2016.

MATERIALS AND METHODS

A retrospective review of Department of Defense Trauma Registry (DoDTR) data was performed for all patients receiving ketamine during OEF/OFS in 2011-2016. Prevalence of ketamine use, absolute use, mechanism of injury, demographics, injury severity score, provider type, and co-administration rates of various medications and blood products were evaluated.

RESULTS

Total number of administrations during the study period was 866. Ketamine administration during OEF/OFS increased during the years 2011-2013 (28 patient administrations in 2011, 264 administrations in 2012, and 389 administrations in 2013). A decline in absolute use was noted from 2014 to 2016 (98 administrations in 2014, 41 administrations in 2015, and 46 administrations in 2016). The frequency of battlefield ketamine use increased from 0.4% to 11.3% for combat injuries sustained in OEF/OFS from 2011 to 2016. Explosives (51%) and penetrating trauma (39%) were the most common pattern of injury in which ketamine was administered. Ketamine was co-administered with fentanyl (34.4%), morphine (26.2%), midazolam (23.1%), tranexamic acid (12.3%), plasma (10.3%), and packed red blood cells (18.5%).

CONCLUSIONS

This study demonstrates increasing use of ketamine by the U.S. Military on the battlefield and effectiveness of clinical practice guidelines in influencing practice patterns.

Harm related to recreational ketamine use and its relevance for the clinical use of ketamine. A systematic review and comparison study

BACKGROUNDS

Ketamine is a dissociative anesthetic that is currently considered for several new indications.

AIM

To deduce the safety of long-term ketamine treatment using the harm of heavy recreational (non-medical) ketamine use as a proxy for maximal possible harm of ketamine treatment.

METHODS

Systematic literature review according to PRISMA guidelines to identify controlled studies on ketamine-related harm in heavy recreational ketamine users. Results were compared with serious adverse events (SAEs) in patients treated with ketamine according to three systematic reviews considering dosing regimen and cumulative dose.

RESULTS

The systematic search yielded 25 studies. Heavy recreational ketamine use can escalate to ketamine dependency and was often dose-dependently associated with other SAEs, including cognitive and mental disorders, and gastrointestinal and urinary tract symptoms, which disappeared upon marked reduction of ketamine use. Heavy ketamine users have a much higher cumulative exposure to ketamine than ketamine treated patients (>90 times), which may explain why SAEs in the clinical context are mostly mild and reversible and why ketamine dependence was not reported in these patients.

CONCLUSION

Treatment of patients with ketamine is not associated with ketamine dependency or SAEs. However, caution is needed since data on long-term clinical ketamine use with a long-term follow-up is lacking.

The multiple faces of ketamine in anaesthesia and analgesia

Objective

Ketamine is an anaesthetic agent with a unique dissociative profile and pharmacological effects ranging from the induction and maintenance of anaesthesia to analgesia and sedation, depending on the dose. This article provides information for the clinical use of ketamine in anaesthesia, in both conventional and special circumstances.

Methods

This is a non-systematic review of the literature, through a PubMed search up to February 2021.

Results

With a favourable pharmacokinetic profile, ketamine is used in hospital and prehospital settings for emergency situations. It is suitable for patients with many heart conditions and, unlike other anaesthetics, its potential for cardiorespiratory depression is low. Furthermore, it may be used when venous access is difficult as it may be administered through various routes. Ketamine is the anaesthetic of choice for patients with bronchospasm thanks to its bronchodilatory and anti-inflammatory properties.

Conclusion

With a favourable pharmacokinetic profile, ketamine is used in hospital and prehospital settings for emergency situations and is suitable for patients with many cardiac and respiratory conditions.

Challenges in Sedation Management in Critically Ill Patients with COVID-19: a Brief Review

Purpose of Review

To highlight the challenges associated with providing sedation and analgesia to critically ill patients with coronavirus disease 2019 (COVID-19) and also understand the pathophysiological alterations induced by the disease process as well as the logistical difficulties encountered by providers caring for these patients. We also discuss the rationale and risks associated with the use of common sedative agents specifically within the context of COVID-19 and provide evidence-based management strategies to help manage sedation and analgesia in such patients.

Recent Findings

A significant proportion of patients with COVID-19 require intensive care and mechanical ventilation, thus requiring sedation and analgesia. These patients tend to require higher doses of sedative medications and often for long periods of time. Most of the commonly used sedative and analgesic agents carry unique risks that should be considered within the context of the unique pathophysiology of COVID-19, the logistical issues the disease poses, and the ongoing drug shortages.

Summary

With little attention being paid to sedation practices specific to patients with COVID-19 in critical care literature and minimal mention in national guidelines, there is a significant gap in knowledge. We review the existing literature to discuss the unique challenges that providers face while providing sedation and analgesia to critically ill patients with COVID-19 and propose evidence-based management strategies.

Intravenous Ketamine Bolus(es) for the Treatment of Status Epilepticus, Refractory Status Epilepticus, and Cluster Seizures: A Retrospective Study of 15 Dogs

Status epilepticus (SE) and cluster seizures (CS) are common occurrences in veterinary neurology and frequent reasons of admission to veterinary hospitals. With prolonged seizure activity, gamma amino-butyric acid (GABA) receptors (GABAa receptors) become inactive, leading to a state of pharmacoresistance to benzodiazepines and other GABAergic medications, which is called refractory status epilepticus (RSE). Prolonged seizure activity is also associated with overexpression of N-methyl-D-aspartic (NMDA) receptors. Rodent models have shown the efficacy of ketamine (KET) in treating RSE, and its use has been reported in one canine case of RSE. Boluses of KET 5 mg/kg IV have become the preferred treatment for RSE in our hospital. A retrospective study was performed to evaluate and report our experience with KET IV bolus to treat prolonged and/or repeated seizure activity in cases of canine CS, SE, and RSE. A total of 15 dogs were retrieved, for 20 hospitalizations and 28 KET IV injections over 3 years. KET IV boluses were used 12 times for RSE (9 generalized seizures, 3 focal seizures) and KET terminated the episode of RSE 12/12 times (100%); however, seizures recurred 4/12 times (33%) within ≤6 h of KET IV bolus. When used for CS apart from episodes of RSE, KET IV bolus was associated with termination of the CS episode only 4/14 times (29%). Only 4/28 (14%) KET IV boluses were associated with adverse effects imputable only to the use of KET. One dog experienced a short, self-limited seizure activity during administration of KET IV, which was most likely related to a pre-mature use of KET IV (i.e., before GABAergic resistance and NMDA receptor overexpression had taken place). This study indicates that KET 5 mg/kg IV bolus may be successful for the treatment of RSE in dogs.

Outcomes for 298 breastfed neonates whose mothers received ketamine and diazepam for postpartum tubal ligation in a resource-limited setting

Background

Anesthesia in lactating women is frequently indicated for time-sensitive procedures such as postpartum tubal ligation. Ketamine and diazepam are two of the most commonly used anesthetic agents in low resource settings, but their safety profile in lactating women has not been established.

Methods

Medical records of post-partum tubal ligations between 2013 and 2018 at clinics of the Shoklo Malaria Research Unit were reviewed for completeness of key outcome variables. Logistic regression identified presence or absence of associations between drug doses and adverse neonatal outcomes: clinically significant weight loss (≥95th percentile) and neonatal hyperbilirubinemia requiring phototherapy.

Results

Of 358 records reviewed, 298 were lactating women with singleton, term neonates. There were no severe outcomes in mothers or neonates. On the first postoperative day 98.0% (290/296) of neonates were reported to be breastfeeding well and 6.4% (19/298) had clinically significant weight loss. Phototherapy was required for 13.8% (41/298) of neonates. There was no association between either of the outcomes and increasing ketamine doses (up to 3.8 mg/kg), preoperative oral diazepam (5 mg), or increasing lidocaine doses (up to 200 mg). Preoperative oral diazepam resulted in lower doses of intraoperative anesthetics. Doses of intravenous diazepam above 0.1 mg/kg were associated with increased risk (adjusted odds ratio per 0.1 mg/kg increase, 95%CI) of weight loss (1.95, 95%CI 1.13–3.35, p = 0.016) and jaundice requiring phototherapy (1.87, 95%CI 1.11–3.13, p = 0.017).

Conclusions

In resource-limited settings ketamine use appears safe in lactating women and uninterrupted breastfeeding should be encouraged and supported. Preoperative oral diazepam may help reduce intraoperative anesthetic doses, but intravenous diazepam should be used with caution and avoided in high doses in lactating women.

Prehospital Ketamine Use for Rapid Sequence Intubation: Are Higher Doses Associated With Adverse Events?

OBJECTIVE

Ketamine for rapid sequence intubation (RSI) is typically dosed at 1 to 2 mg/kg intravenously. The need to ensure dissociation during RSI led some to administer ketamine at doses greater than 2 mg/kg. This study assessed associations between ketamine dose and adverse events.

METHODS

This multisite, retrospective study included adult subjects undergoing RSI with intravenous ketamine. Subjects were categorized into 2 groups: a standard ketamine dose (≤ 2 mg/kg intravenously) or a high dose (> 2 mg/kg intravenously). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for adverse events.

RESULTS

Eighty subjects received standard-dose ketamine, and 50 received high-dose ketamine. The high-dose group had a significantly (P < .05) higher proportion of trauma patients, were younger, and had higher predose blood pressure compared with the standard-dose group. High-dose ketamine was associated with greater odds of adverse events including hypotension (OR = 7.0; 95% CI, 3.0-16.6), laryngospasm (OR = 10.8; 95% CI, 1.3-93.4), bradycardia (OR = 7.5; 95% CI, 1.5-36.6), repeat medications (OR = 12.9; 95% CI, 1.5-107.9), oxygen desaturation (OR = 6.0; 95% CI, 1.8-19.9), multiple attempts (OR = 3.2; 95% CI, 1.5-6.8%), and failed airway (OR = 3.6; 95% CI, 1.0-12.7).

CONCLUSION

Ketamine at higher doses was associated with increased odds of adverse events. Studies assessing adverse events of ketamine at lower than standard doses in shock patients are needed.

The effect of changes in cardiovascular activity on corneal biomechanics and pulsation in rabbits

The aim was to assess the relationships between cardiovascular activity, corneal pulse characteristics, and corneal biomechanics in rabbits. Seventeen rabbits were randomly assigned to one of two anesthetic regimens to induce differences in arterial blood pressure and heart rate. Experimental protocol included measuring blood flow parameters in the ophthalmic artery by color Doppler imaging, corneal biomechanical parameters using a non-contact tonometer Corvis ST, and the corneal pulse (CP) signal using a non-contact ultrasonic technique. Statistically significantly lower mean values of normalized amplitudes of higher CP harmonics and changes in eight of the twelve corneal biomechanical parameters were observed in the rabbit group with lower arterial blood pressure and higher heart rate, intraocular pressure, and resistive index. The results of partial correlations showed that the CP signal energy and amplitude of its first harmonic correlate with the resistive index, diastolic and mean arterial pressures, whereas no statistically significant correlation was found between any of the CP parameters and intraocular pressure. Our pilot study indicates, for the first time, that non-contact and continuous measuring of corneal pulse allows indirectly assessing changes in cardiovascular activity when the confounding effect of intraocular pressure is eliminated.

Ketamine for the treatment of prehospital acute pain: a systematic review of benefit and harm

BACKGROUND

Few publications have addressed prehospital use of ketamine in analgesic doses. We aimed to assess the effect and safety profile of ketamine compared with other analgesic drugs (or no drug) in adult prehospital patients with acute pain.

METHODS

A systematic review of clinical trials assessing prehospital administration of ketamine in analgesic doses compared with other analgesic drugs or no analgesic treatment in adults. We searched PubMed, EMBASE, Cochrane Library and Epistemonikos from inception until 15 February 2020, including relevant articles in English and Nordic languages. We used the Cochrane and Grading of Recommendations Assessment, Development and Evaluation methodologies and exclusively assessed patient-centred outcomes. Two independent authors screened trials for eligibility, extracted data and assessed risk of bias.

RESULTS

We included eight studies (2760 patients). Ketamine was compared with various opioids given alone, and intranasal ketamine given with nitrous oxide was compared with nitrous oxide given alone. Four randomised controlled trials (RCTs) and one cluster randomised trial included 699 patients. One prospective cohort included 27 patients and two retrospective cohorts included 2034 patients. Five of the eight studies had high risks of bias. Pain score with ketamine is probably lower than after opioids as demonstrated in a cluster-RCT (308 patients) and a retrospective cohort (158 patients) study, Δvisual analogue scale -0.4 (-0.8 to 0.0) and Δnumeric pain rating scale -3.0 (-3.86 to -2.14), respectively. Ketamine probably leads to less nausea and vomiting (risk ratio (RR) 0.24 (0.11 to 0.52)) but more agitation (RR 7.81 (1.85 to 33)) than opioids.

CONCLUSIONS

This systematic literature review finds that ketamine probably reduces pain more than opioids and with less nausea and vomiting but higher risk of agitation. Risk of bias in included studies is high.

OTHER

Scandinavian society of anaesthesiology and intensive care medicine funded meetings and software. The Norwegian Air Ambulance Foundation funded publication. Otherwise this research received no grant from any agency in the public, commercial or not-for-profit sectors.

PROSPERO REGISTRATION NUMBER

CRD42018114399.

Ketamine for rapid sequence intubation in adult trauma patients: A retrospective observational study

BACKGROUND

In the trauma population, ketamine is commonly used during rapid sequence induction. However, as ketamine has been associated with important side effects, this study sought to compare in-hospital mortality in trauma patients after induction with ketamine versus other induction agents.

METHODS

We retrospectively identified adult trauma patients intubated in the pre-hospital phase or initially in the trauma bay at two urban level-1 trauma centers during a 2-year period using local trauma registries and medical records. In-hospital mortality was compared for patients intubated with ketamine versus other agents using logistic regression with adjustment for age, gender, Injury Severity Score (ISS), systolic blood pressure (SBP) < 90 mm Hg, and pre-hospital Glasgow Coma Scale (GCS) score.

RESULTS

A total of 343 trauma patients were included with a median ISS of 25 [17-34]. The most frequently used induction agents were ketamine (36%) and propofol (36%) followed by etomidate (9%) and midazolam (5%). There was no difference in ISS or the presence of SBP <90 mm Hg according to the agent of choice, but the pre-hospital GCS score was higher for patients intubated with ketamine (median 8 vs 5, P = .001). The mortality for patients intubated with ketamine was 18% vs 27% for patients intubated with other agents (P = .14). This remained statistically insignificant in the multivariable logistic regression analysis (odds ratio 0.68 [0.33-1.41], P = .30).

CONCLUSIONS

We found no statistically significant difference in mortality among patients intubated in the initial phase post-trauma with the use of ketamine compared with other agents (propofol, etomidate, or midazolam).

Sedation, Analgesia, and Paralysis in COVID-19 Patients in the Setting of Drug Shortages

The rapid spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to a global pandemic. The 2019 coronavirus disease (COVID-19) presents with a spectrum of symptoms ranging from mild to critical illness requiring intensive care unit (ICU) admission. Acute respiratory distress syndrome is a major complication in patients with severe COVID-19 disease. Currently, there are no recognized pharmacological therapies for COVID-19. However, a large number of COVID-19 patients require respiratory support, with a high percentage requiring invasive ventilation. The rapid spread of the infection has led to a surge in the rate of hospitalizations and ICU admissions, which created a challenge to public health, research, and medical communities. The high demand for several therapies, including sedatives, analgesics, and paralytics, that are often utilized in the care of COVID-19 patients requiring mechanical ventilation, has created pressure on the supply chain resulting in shortages in these critical medications. This has led clinicians to develop conservation strategies and explore alternative therapies for sedation, analgesia, and paralysis in COVID-19 patients. Several of these alternative approaches have demonstrated acceptable levels of sedation, analgesia, and paralysis in different settings but they are not commonly used in the ICU. Additionally, they have unique pharmaceutical properties, limitations, and adverse effects. This narrative review summarizes the literature on alternative drug therapies for the management of sedation, analgesia, and paralysis in COVID-19 patients. Also, this document serves as a resource for clinicians in current and future respiratory illness pandemics in the setting of drug shortages.

Pharmacodynamic elucidation of glutamate & dopamine in ketamine-induced anaesthesia

General anaesthetics are some of the most widely used and essential therapeutic agents. However, despite over a century of research, the molecular mechanisms of general anaesthesia in the central nervous system remain elusive. Ketamine (ketamine hydrochloride) has been approved for use in general anaesthesia either alone or in combination with other medications. It is a superb drug for use in short-term medical procedures that do not require skeletal muscle relaxation, and it has approval for the induction of general anaesthesia as a pre-anaesthetic to other general anaesthetic agents. However, Several questions remain unsolved, including the exact identification of the neural substrate of consciousness and its components, the pharmacodynamic interactions between anaesthetic agents, the mechanisms of cognitive alterations that follow an anaesthetic procedure, the identification of an eventual unitary mechanism of anaesthesia-induced alteration of consciousness, the relationship between network effects and the biochemical targets of anaesthetic agents, leading to difficulties in between-studies comparisons. Thus, the glutamate and dopamine systems play distinct roles in terms of neuronal signalling, yet both have proposed to contribute significantly to the pathophysiology of neuropsychiatric diseases. Imaging of the glutamate system and other aspects of research on the dopamine system have produced less consistent findings, potentially due to methodological limitations and the heterogeneity of the disorder. In this review, we discuss the neural circuits through which the two systems interact and how their disruption may cause psychotic symptoms. We also summarize from a molecular perspective of mechanisms of action of ketamine as general anaesthetics on ligand-gated ion channels mediated modulation of dopamine in the brain region.

Efficacy of cystectasia in the treatment of ketamine-induced bladder contracture

Background

The treatment of ketamine-induced bladder contractures remains poorly studied. We therefore evaluated the efficacy of cystectasia with a sodium hyaluronate balanced solution in this kind of bladder contracture.

Methods

Eighteen patients presenting with ketamine-induced bladder contracture between July 2010 and February 2018 were selected and analysed. Ketamine was discontinued in all patients, who were then treated with weekly cystectasia (0.09% sodium hyaluronate balanced solution) 3 times. The volume of the first perfusion was twice the preoperatively measured bladder capacity, and the volume of the subsequent two perfusions was increased by 100 mL each time. The Pelvic Pain and Urgency/Frequency (PUF) symptom score, O'Leary-Sant Interstitial Cystitis (IC) Symptom Index (ICSI), IC Problem Index (ICPI), Quality of Life (QOL) score, and bladder capacity were recorded before surgery and 3 and 12 months after the 3^rd expansion.

Results

No significant complications were observed during the 3 expansions. Fourteen patients completed the full follow-up schedule. Preoperatively and at the 3- and 12-month follow-up evaluations performed after the 3^rd expansion, the PUF symptom scores were 20.4±3.6, 11.5±3.1, and 13.2±3.3, respectively; the mean ICSI was 13.6±2.8, 7.7±2.3, and 8.2±2.5, respectively; the mean ICPI was 10.6±2.6, 7.3±2.1, and 7.7±2.5, respectively; and the mean QOL scores were 6.0±0, 2.1±0.5, and 2.7±0.8, respectively; and the mean bladder catheter volume was 83±27, 234±56, and 228±52 mL, respectively. There were significant differences between all preoperative and postoperative values.

Conclusions

Cystectasia with a sodium hyaluronate balanced solution is an effective treatment modality for ketamine-induced bladder contracture.

Upper-airway collapsibility and compensatory responses under moderate sedation with ketamine, dexmedetomidine, and propofol in healthy volunteers

BACKGROUND

Ketamine is a potent sedative drug that helps to maintain upper-airway patency, due to its higher upper-airway dilator muscular activity and higher level of duty cycle, as seen in rats. However, no clinical trials have tested passive upper-airway collapsibility and changes in the inspiratory duty cycle against partial upper-airway obstruction in humans. The present study evaluated both the passive mechanical upper-airway collapsibility and compensatory response against acute partial upper-airway obstruction using three different sedative drugs in a crossover trial.

METHODS

Eight male volunteers entered this nonblinded, randomized crossover study. Upper-airway collapsibility (passive critical closing pressure) and inspiratory duty cycle were measured under moderate sedation with ketamine, propofol, and dexmedetomidine. Propofol, dexmedetomidine, and ketamine anesthesia were induced to obtain adequate, same-level sedation, with a BIS value of 50-70 and the OAA/S score of 2-3 and RASS score of -3.

RESULTS

The median passive critical closing pressure of 0.08 [-5.51 to 1.20] cm H2 O was not significantly different compared to that of propofol sedation (-0.32 [-1.41 to -0.19] cm H2 O) and of dexmedetomidine sedation (-0.28 [-0.95 to -0.03] cm H2 O) (p = .045). The median passive RUS for ketamine 54.35 [32.00 to 117.50] cm H2 O/L/s was significantly higher than that for propofol 5.50 [2.475 to 19.60] cm H2 O/L/s; (mean difference, 27.50; 95% CI 9.17 to 45.83) (p = .009) and for dexmedetomidine 19.25 [4.125 to 22.05] cm H2 O/L/s; (mean difference, 22.88; 95% CI 4.67 to 41.09) (p = .021). The inspiratory duty cycle increased significantly as the inspiratory airflow decreased in passive conditions for each sedative drug, but behavior differed among the three sedative drugs.

CONCLUSION

Our findings demonstrate that ketamine sedation may have an advantage of both maintained passive upper-airway collapsibility and a compensatory respiratory response, due to both increase in neuromuscular activity and the increased duty cycle, to acute partial upper-airway obstruction.

GluN2A-selective positive allosteric modulator-nalmefene-flumazenil reverses ketamine-fentanyl-dexmedetomidine-induced anesthesia and analgesia in rats

Anesthetics are used to produce hypnosis and analgesic effects during surgery, but anesthesia for a long time after the operation is not conducive to the recovery of animals or patients. Therefore, finding appropriate treatments to counter the effects of anesthetics could enhance postoperative recovery. In the current study, we discovered the novel role of a GluN2A-selective positive allosteric modulator (PAM) in ketamine-induced anesthesia and investigated the effects of the PAM combined with nalmefene and flumazenil (PNF) in reversing the actions of an anesthetic combination (ketamine-fentanyl-dexmedetomidine, KFD). PAM treatment dose-dependently decreased the duration of the ketamine-induced loss of righting reflex (LORR). Compared with those in the KFD group, the duration of LORR and the analgesic effect of the KFD + PNF group were obviously decreased. Meanwhile, successive administration of PNF and KFD had no adverse effects on the cardiovascular and respiratory systems. Both the KFD group and the KFD + PNF group showed no changes in hepatic and renal function or cognitive function in rats. Moreover, the recovery of motor coordination of the KFD + PNF group was faster than that of the KFD group. In summary, our results suggest the potential application of the PNF combination as an antagonistic treatment strategy for anesthesia.

Sedation Strategies for Procedures Outside the Operating Room

With the rapid development of diagnostic and therapeutic procedures performed outside the operating room (OR), the need for appropriate sedation care has emerged in importance to ensure the safety and comfort of patients and clinicians. The preparation and administration of sedatives and sedation care outside the OR require careful attention, proper monitoring systems, and clinically useful sedation guidelines. This literature review addresses proper monitoring and selection of sedatives for diagnostic and interventional procedures outside the OR. As the depth of sedation increases, respiratory depression and cardiovascular suppression become serious, necessitating careful surveillance using appropriate monitoring equipment.

Subdissociative Ketamine Use in the Emergency Department

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

Safety and Efficacy of Ketamine Versus Ketamine-Fentanyl-Dexmedetomidine Combination for Anesthesia and Analgesia in Rats

Ketamine (KET), a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, is most frequently used as an anesthetic, analgesic, and sedative drug in pediatric clinical practices. However, the adverse effects of KET administration such as psychotic episodes limited the use of KET. The aim of the present study was to evaluate whether the addition of small doses of fentanyl (FENT) and dexmedetomidine would reduce the overall KET consumption without concession on the safety and efficacy of anesthesia and analgesia in rats. We compared the effects of KET (50 mg/kg) administration alone and KET (25 mg/kg) combined with FENT (0.005 mg/kg) and dexmedetomidine (0.05 mg/kg) (KFD) on the times of onset and duration of anesthesia and analgesia. Compared with the KET group, the KFD group provides similar onset time of anesthesia, but longer duration of anesthesia, and better analgesic effect. Unlike the KET group, the KFD group had a lower heart rate and higher respiratory rate. Meanwhile, KFD induced markedly changes in the electroencephalography (EEG) spectral power when compared with control and KET. Furthermore, combination of FENT and dexmedetomidine alleviated the liver toxicity of KET. These results indicated that, when compared with KET alone, the administration of KFD combination offered safer and more efficient anesthesia.

Effect of Intranasal Ketamine vs Fentanyl on Pain Reduction for Extremity Injuries in Children: The PRIME Randomized Clinical Trial

IMPORTANCE

Timely analgesia is critical for children with injuries presenting to the emergency department, yet pain control efforts are often inadequate. Intranasal administration of pain medications provides rapid analgesia with minimal discomfort. Opioids are historically used for significant pain from traumatic injuries but have concerning adverse effects. Intranasal ketamine may provide an effective alternative.

OBJECTIVE

To determine whether intranasal ketamine is noninferior to intranasal fentanyl for pain reduction in children presenting with acute extremity injuries.

DESIGN, SETTING, AND PARTICIPANTS

The Pain Reduction With Intranasal Medications for Extremity Injuries (PRIME) trial was a double-blind, randomized, active-control, noninferiority trial in a pediatric, tertiary, level 1 trauma center. Participants were children aged 8 to 17 years presenting to the emergency department with moderate to severe pain due to traumatic limb injuries between March 2016 and February 2017. Analyses were intention to treat and began in May 2017.

INTERVENTIONS

Intranasal ketamine (1.5 mg/kg) or intranasal fentanyl (2 µg/kg).

MAIN OUTCOMES AND MEASURES

The primary outcome was reduction in visual analog scale pain score 30 minutes after intervention. The noninferiority margin for this outcome was 10.

RESULTS

Of 90 children enrolled, 45 (50%) were allocated to ketamine (mean [SD] age, 11.8 [2.6] years; 26 boys [59%]) and 45 (50%) to fentanyl (mean [SD] age, 12.2 [2.3] years; 31 boys [74%]). Thirty minutes after medication, the mean visual analog scale reduction was 30.6 mm (95% CI, 25.4-35.8) for ketamine and 31.9 mm (95% CI, 26.6-37.2) for fentanyl. Ketamine was noninferior to fentanyl for pain reduction based on a 1-sided test of group difference less than the noninferiority margin, as the CIs crossed 0 but did not cross the prespecified noninferiority margin (difference in mean pain reduction between groups, 1.3; 90% CI, -6.2 to 8.7). The risk of adverse events was higher in the ketamine group (relative risk, 2.5; 95% CI, 1.5-4.0), but all events were minor and transient. Rescue analgesia was similar between groups (relative risk, 0.89; 95% CI, 0.5-1.6).

CONCLUSIONS AND RELEVANCE

Ketamine provides effective analgesia that is noninferior to fentanyl, although participants who received ketamine had an increase in adverse events that were minor and transient. Intranasal ketamine may be an appropriate alternative to intranasal fentanyl for pain associated with acute extremity injuries. Ketamine should be considered for pediatric pain management in the emergency setting, especially when opioids are associated with increased risk.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02778880.