Ketamine Group Research Articles

Effectiveness of Intravenous Low-Dose Ketamine Versus Morphine for Procedural Burn Pain Management During Dressing Changes: A Randomized Clinical Trial

Background: There is limited literature on using low-dose intravenous ketamine as a single agent for procedural burn pain management during adult dressing changes. Aims & Objectives: To determine the effectiveness of low-dose ketamine compared to morphine as a single analgesic agent in procedural burn pain management during dressing changes. Materials & Methods: We performed an institutional review board-approved, randomized, prospective, double-blinded, controlled, non-inferiority trial. All adult patients 18 years and above scheduled for dressing change were screened. Patients who consented were randomized to receive low-dose ketamine infusion at 0.2mg/kg/hr. In the treatment group, morphine infusion at 0.1mg/kg/hr. In the control group. The primary endpoint was pain intensity, measured using a visual analog scale. Data were analyzed on an intention-to-treat (ITT) approach. Secondary endpoints included rescue analgesia requirements and the occurrence of adverse effects in both groups. Results: 82 patients were enrolled (ketamine 41 vs. morphine 41). We compared VAS scores at 5-minute intervals during the dressing changes. Overall, pain scores are similar in both groups (p-value=0.595). The pain control was homogenous. However, the morphine group required more rescue analgesia throughout the dressing changes than the low-dose ketamine group (p=0.013 at T15, p<0.001 at T20, and p<0.001 at T30). The occurrence of side effects was similar in both groups. Conclusion: This study suggests that low-dose ketamine provides as effective and more predictable procedural analgesia as morphine during dressing procedures for adult burn patients.

Comparison of Fentanyl, Ketamine, and Lidocaine Combined with Propofol Anesthesia in Patients with Crohn Disease Undergoing Colonoscopy.

BACKGROUND Colonoscopy is the predominant invasive procedure for Crohn disease (CD) patients. Opioids and propofol carry risks of respiratory and cardiovascular complications. This study aimed to evaluate whether substituting fentanyl with ketamine or lidocaine could diminish propofol usage and minimize adverse events. MATERIAL AND METHODS In total, 146 patients with CD scheduled for elective colonoscopy were assigned to anesthesia with fentanyl (n=47), ketamine (n=47), or lidocaine (n=55). Propofol was administered to achieve sufficient anesthesia. Measured outcomes in each group included propofol consumption, hypotension and desaturation incidents, adverse event types, consciousness recovery time, abdominal pain intensity, Aldrete scale, and Post Anaesthetic Discharge Scoring System (PADSS). RESULTS Patients administered fentanyl needed significantly more propofol (P=0.017) than those on ketamine, with lidocaine showing no notable difference (P=0.28). Desaturation was significantly less common in the ketamine and lidocaine groups than fentanyl group (P<0.001). The ketamine group experienced milder reductions in mean arterial (P=0.018) and systolic blood pressure (P<0.001). Recovery metrics (Aldrete and PADSS scores) were lower for fentanyl (P<0.001), although satisfaction and pain levels were consistent across all groups (P=0.797). Dizziness occurred less frequently with lidocaine than fentanyl (17.2%, P=0.018) and ketamine (15.1%, P=0.019), while metallic taste incidents were more prevalent in the lidocaine group (13.5%, P=0.04) than fentanyl group. CONCLUSIONS Using ketamine or lidocaine instead of fentanyl in anesthesia for colonoscopy in patients with CD significantly lowers propofol use, reduces desaturation events, maintains blood pressure more effectively, without increasing hypotension risk, and accelerates recovery, without negatively impacting adverse events or patient satisfaction.

Comparison of the effect of intraoperative dexmedetomidine versus ketamine on postoperative analgesia in fracture femur patients operated under subarachnoid block – A prospective randomized double-blind controlled trial

Abstract Background and Aims: Intravenous sedation during spinal anesthesia has the advantages of increased duration of spinal anesthesia and better postoperative pain control. The aim of this study was to compare the effect of intravenous bolus and infusion of dexmedetomidine versus ketamine given intraoperative on the postoperative analgesia in fracture femur patients operated under subarachnoid block. Material and Methods: In this prospective randomized double-blind controlled study, 75 patients aged 18–65 years posted for elective surgery were selected and randomly divided into three groups to receive ketamine (group K), dexmedetomidine (group D), and saline (control group C). Postoperative pain was evaluated using the numerical rating scale (NRS). The duration of analgesia and the amount of analgesic consumption were also recorded. Student’s t-test and Chi-square test were used to compare the two groups, and one-way ANOVA with posthoc analysis was performed for comparison of the three groups. Results: Patients in the ketamine group had better postoperative analgesia as assessed by decreased pain (on the NRS scale) and decreased need for postoperative rescue analgesics (P &lt; 0.001). The duration of sensory block and motor block was prolonged in group K as compared to the other two groups (P &lt; 0.001). Conclusion: Intraoperative use of intravenous ketamine was superior to dexmedetomidine for postoperative analgesia in fracture femur patients operated under subarachnoid block.

Benefit-Risk Balance of Ketamine versus Midazolam + Fentanyl for Sedation-Analgesia in Mechanically Ventilated Patients: Randomised Controlled Trial

Objective: Ketamine has interesting pharmacological properties for sedation-analgesia in intensive care. However, there are few studies on its benefit-risk balance. The aim of this study was to evaluate the efficacy and safety of ketamine compared with midazolam + fentanyl in mechanically ventilated patients. Methods: Randomised, non-inferiority, open-label, multicentre controlled trial. Patients aged 18 years or older requiring invasive mechanical ventilation for at least 24 hours were randomised to receive, after rapid sequence intubation, ketamine at a starting dose of 0.5 mg/kg/h (n = 191) or midazolam 0.2mg/kg/h + fentanyl 1μg/kg/h (n =191). Infusion rates were subsequently adjusted to achieve a RASS score between -2 and +1. The primary endpoint was the percentage of time spent in the RASS range -2 to +1 without the use of an alternative sedative; secondary endpoints included level of analgesia, adverse events (AEs), length of stay and mechanical ventilation, and cost of sedation. Results: In total, 73.5% of patients in the ketamine group vs. 71.3% in the midazolam group were within the target RASS range, a difference of 2.2% [95% CI: -3.2% to 7.5%]; p = 0.18. The most frequently observed AEs in the ketamine group were hypersalivation (21.2% vs. 2.3%; p&lt;0.001), psychodysleptic phenomena (19.8% vs. 2.6%;p&lt;0.001) and hallucinations (9.42% vs. 1.04%; p&lt;0.001). Delirium was the only AE more frequent in the Midazolam group than in the Ketamine group (23.5% vs 43.4%; p &lt; 0.0001). However, the risk of arterial hypertension (7.3% vs 4.2%; p = 0.188), diarrhoea (0% vs 5%; p = 0.05) and self-extubation (3.1% vs 4.2%; p = 0.452) did not differ between the 2 groups. The length of stay in intensive care between the 2 groups was 6.3 ± 1.6 days vs 7.3 ± 1.7 days (p &lt; 0.001) and that of mechanical ventilation 4.1 ± 0.94 days vs 4.84 ± 0.85 days (p &lt; 0.001). The daily cost of sedative treatment was lower with ketamine than with midazolam ($32.4 ± 0.8 vs $43 ± 6.3; p&lt;0.001). Conclusion: In this study, the efficacy of ketamine was not inferior to that of the midazolam + fentanyl combination, but its safety was poorer. Its low cost is a real advantage in our context.

Comparison of the effects of opioid-free anesthesia (OFA) and opioid-based anesthesia (OBA) on postoperative analgesia and intraoperative hemodynamics in patients undergoing spine surgery: A prospective randomized double-blind controlled trial.

Opioids form the basis of perioperative pain management but are associated with multiple side effects. In opioid-free anesthesia (OFA), several non-opioid drugs or neuraxial/regional blocks are used as substitutes for opioids. Ketamine, a N-methyl-d-aspartate antagonist, provides intense analgesia. However, there is a shortage of literature on the effects of ketamine-based OFA on hemodynamics (HD) and postoperative analgesia in patients undergoing thoracolumbar spine surgery. This prospective randomized controlled trial included 60 adult patients. The patients in Group OFA (n = 30) received OFA with ketamine and ketofol (1:5) infusion, and those in Group OBA (n = 30) received opioid-based anesthesia (OBA) with fentanyl and propofol infusion. The postoperative pain-free period, pain scores, rescue analgesia, intraoperative HDs, and postoperative complications were assessed. The mean pain-free period in Group OFA (9.86 ± 1.43 hr) was significantly higher than that in Group OBA (6.93 ± 1.93 hr) (P = 0.002). During the postoperative 48 hours, the total requirement of fentanyl was considerably lower in Group OFA (P < 0.05). There was a significantly higher incidence of hypertension in Group OFA (46%) and hypotension (43%) in Group OBA (43%), respectively. Postoperative nausea vomiting (PONV) was more common in Group OBA at the 2nd and 6th hr (P = 0.046 and P = 0.038). OFA with ketamine and ketofol provided adequate postoperative analgesia with a lower incidence of PONV after spine surgery. However, hypertension in the ketamine group and hypotension in the propofol group required fine titration of the infusion rate of drugs during the intraoperative period.

HIGH DOSES OF KETAMINE INFLICT MYOCARDIAL INJURY AND CAUSE CHANGES IN THE RELATIVE BODY WEIGHT TO HEART OF ADULT ALBINO WISTAR RATS

Objective: Ketamine is widely used as an anesthetic agent in surgery and emergency medicine. It is also used for procedural sedation, treatment of depression, pain management, and sometimes as a recreational drug. These uses, however, have recommended doses to prevent myocardial injury. This study, therefore, was designed to investigate the level of injury on the myocardium following the administration of high doses of ketamine and to determine the relative body weight to heart weight of the experimental animals. Method: A total of 12 male albino Wistar rats were used and grouped into four including the control group. They were weighed daily and administered 100 mg, 150 mg, and 200 mg/kg/body weight of ketamine intraperitoneally for 2 weeks and weighed again. Experiment was terminated after 14 days and animals were sacrificed and the heart harvested for analysis. Results: Ketamine caused a significant myocardial injury with increase in the doses in different groups by causing inflammation, hypertrophy, vacuolar degenerative changes, atrophy, and extensive hemorrhage around the myocytes. Weight differentiation was noticed in all experimental groups with heart weight contributing to the total body weight by 1.63%, 1.7%, and 1.2% for the 100 mg, 150 mg, and 200 mg/kg/body weight of ketamine groups, respectively. Conclusion: Higher doses of ketamine cause significant myocardial injury as well as differential changes in body weight and heart weight in experimental animals.

A Randomised Controlled Trial Comparing Ketamine versus Fentanyl for Procedural Sedation in the Emergency Department for Adults with Isolated Extremity Injury.

Alleviating pain and anxiety of patients during procedures is an essential skill for an Emergency Physician (EP). Several sedatives and dissociative agents are used for PSA (Procedural Sedation and Analgesia). In this study, we aimed to compare two drugs that is, ketamine and fentanyl for procedural sedation in adults with isolated limb injuries in the Emergency Department (ED). In this prospective, randomised controlled interventional trial, patients aged between 18 to 65 years with isolated extremity injury requiring PSA in the ED were recruited. A total of 200 subjects were included in the study and randomly allocated to either the fentanyl (n=100) or the ketamine (n=100) group. Patients were blinded to the intervention and subsequently premedicated with Midazolam. Following this, they received either ketamine or fentanyl based on the group they were allocated to. Vital signs, including but not limited to the level of sedation, were measured at predetermined time intervals. A Modified Aldrete Score of >8 was used as a criterion for disposition from the ED. Data were collected in a pre-designed proforma. We aimed to compare the effectiveness as well as ascertain the safety profile of the two drugs for PSA in the ED. There was no significant difference between the two groups when age, gender, mechanism of injury and comorbidities were compared. We found that there was no statistically significant difference between the two groups when blood pressure, respiratory rate and depth of sedation were compared. In both groups, there was a significant decrease in pain on the Numerical Rating Scale (NRS) following drug administration from 8 to 3 (p<0.001). Patients in the fentanyl group had an increased incidence of transient oxygen desaturation (p<0.001). Vomiting was more common in the ketamine group (p<0.001). PSA is a safe and efficacious procedure for patients undergoing painful procedures in ED. Patients in both the groups maintained hemodynamic stability throughout the procedure. From our study, we were able to conclude that both ketamine and fentanyl are similar in efficacy for PSA in the ED for adults with isolated limb injuries. In addition, no significant cardiovascular adverse events were noted in either group in our study.

Determination of Ketamine and Palmatine in Rat Plasma by UHPLC-MS/MS and their Pharmacokinetic Interaction

Objective:: Ketamine, commonly known as “K-powder,” is increasingly being abused as a “prom drug.” Palmatine, a typical isoquinoline alkaloid, is mainly found in the roots and stems of natural Chinese herbal medicine plants such as Phellodendron chinense, Coptis chinensis, Sankezhen and Nantianzhu. Herein, we aim to establish a UHPLC-MS/MS method to determine ketamine and palmatine concentrations in rat plasma and investigate the pharmacokinetic interaction of ketamine and palmatine. Methods:: Three groups of eighteen rats each were assigned to ketamine, palmatine, ketamine and palmatine. The pharmacokinetic interaction between ketamine and palmatine was demonstrated using UHPLC-MS/MS. Results:: When ketamine was combined with palmatine, the mean residence time (MRT) was significantly different from that of the ketamine group. MRT decreased after combined use. The interaction showed that palmatine can influence the mean residence time of ketamine; no significant differences were observed for other pharmacokinetic parameters between the ketamine or palmatine group and the ketamine-palmatine group. Conclusion:: Palmatine may influence the mean residence time of ketamine.

The impact of ketamine on outcomes in critically ill patients: a systematic review with meta-analysis and trial sequential analysis of randomized controlled trials.

This meta-analysis aims to evaluate the effects of ketamine in critically ill intensive care unit (ICU) patients. We searched for randomized controlled trials (RCTs) in PubMed, Scopus, and the Cochrane Library; the search was performed initially in January but was repeated in December of 2023. We focused on ICU patients of any age. We included studies that compared ketamine with other traditional agents used in the ICU. We synthesized evidence using RevMan v5.4 and presented the results as forest plots. We also used trial sequential analysis (TSA) software v. 0.9.5.10 Beta and presented results as TSA plots. For synthesizing results, we used a random-effects model and reported differences in outcomes of two groups in terms of mean difference (MD), standardized MD, and risk ratio with 95% confidence interval. We assessed the risk of bias using the Cochrane RoB tool for RCTs. Our outcomes were mortality, pain, opioid and midazolam requirements, delirium rates, and ICU length of stay. Twelve RCTs involving 805 ICU patients (ketamine group, n=398; control group, n=407) were included in the meta-analysis. The ketamine group was not superior to the control group in terms of mortality (in five studies with 318 patients), pain (two studies with 129 patients), mean and cumulative opioid consumption (six studies with 494 patients), midazolam consumption (six studies with 304 patients), and ICU length of stay (three studies with 270 patients). However, the model favored the ketamine group over the control group in delirium rate (four studies with 358 patients). This result is significant in terms of conventional boundaries (alpha=5%) but is not robust in sequential analysis. The applicability of the findings is limited by the small number of patients pooled for each outcome. Our meta-analysis did not demonstrate differences between ketamine and control groups regarding any outcome except delirium rate, where the model favored the ketamine group over the control group. However, this result is not robust as sensitivity analysis and trial sequential analysis suggest that more RCTs should be conducted in the future.

Interleaved Propofol-Ketamine Maintains DBS Physiology and Hemodynamic Stability: A Double-Blind Randomized Controlled Trial.

The gold standard anesthesia for deep brain stimulation (DBS) surgery is the "awake" approach, using local anesthesia alone. Although it offers high-quality microelectrode recordings and therapeutic-window assessment, it potentially causes patients extreme stress and might result in suboptimal surgical outcomes. General anesthesia or deep sedation is an alternative, but may reduce physiological testing reliability and lead localization accuracy. The aim is to investigate a novel anesthesia regimen of ketamine-induced conscious sedation for the physiological testing phase of DBS surgery. Parkinson's patients undergoing subthalamic DBS surgery were randomly divided into experimental and control groups. During physiological testing, the groups received 0.25 mg/kg/h ketamine infusion and normal saline, respectively. Both groups had moderate propofol sedation before and after physiological testing. The primary outcome was recording quality. Secondary outcomes included hemodynamic stability, lead accuracy, motor and cognitive outcome, patient satisfaction, and adverse events. Thirty patients, 15 from each group, were included. Intraoperatively, the electrophysiological signature and lead localization were similar under ketamine and saline. Tremor amplitude was slightly lower under ketamine. Postoperatively, patients in the ketamine group reported significantly higher satisfaction with anesthesia. The improvement in Unified Parkinson's disease rating scale part-III was similar between the groups. No negative effects of ketamine on hemodynamic stability or cognition were reported perioperatively. Ketamine-induced conscious sedation provided high quality microelectrode recordings comparable with awake conditions. Additionally, it seems to allow superior patient satisfaction and hemodynamic stability, while maintaining similar post-operative outcomes. Therefore, it holds promise as a novel alternative anesthetic regimen for DBS. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Comparison of Dexmedetomidine and Ketamine in Serratus Anterior Plane Block for Postoperative Pain Control in Thoracotomy Patients: A Randomized Clinical Trial.

Postoperative pain control after thoracotomy is very important, and if not controlled, it can cause severe complications. This study aimed to compare dexmedetomidine and ketamine in serratus anterior plane block (SAPB) in pain control after thoracotomy. This randomized clinical trial was conducted on 74 patients aged 18 to 60 years old with American Society of Anesthesiologists (ASA) class I or II who were referred to Imam Khomeini hospital in Ahvaz, Iran, for thoracotomy and randomly divided into two groups. After surgery, the SAPB with ultrasound-guided was performed. In the ropivacaine-ketamine (RK) group, ketamine 0.5 mg/kg and 0.4 cc/kg ropivacaine solution 0.25% and in the ropivacaine-dexmedetomidine (RD) group, in addition to 0.4 cc/kg ropivacaine 0.25%, dexmedetomidine 0.5 µg/kg was added. Verbal Numeric Scale (VNS), systolic blood pressure (SBP), diastolic blood pressure (DBP), respiratory rate (RR), heart rate (HR), and mean arterial blood pressure (MAP) were recorded. There was no significant difference in both groups in terms of demographic information (P < 0.05). The average VNS was lower in the ketamine group than in the dexmedetomidine group; however, there was a significant difference only at 1, 12, and 24 hours after surgery (P < 0.05). There was no statistically significant difference between the two groups in terms of SBP and DBP, HR, and MAP. There was a significant difference in the RR in the two groups at 12 and 24 hours after the operation (P < 0.05). Dexmedetomidine and ketamine, which were used as supplements to ropivacaine for SAPB in patients undergoing elective thoracotomy, reduced the pain intensity after thoracotomy; nevertheless, the intensity of pain reduction was more and more effective in the group receiving ketamine.

The impact of ketamine on delayed neurocognitive recovery in elderly patients undergoing spinal anaesthesia for orthopaedic procedures, a pilot study.

Delayed neurocognitive recovery is an objectively measurable decline in the cognitive status at varying intervals after surgery under both general and spinal anaesthesia. In this study, we used the Short Portable Mental Status Questionnaire to evaluate the protective effect of ketamine infusion on cognitive function of elderly patients undergoing spinal anaesthesia for orthopaedic procedures. A randomised, double-blinded placebo-controlled trial. Forty-two geriatric patients listed for elective orthopaedic surgery under spinal anaesthesia were randomly assigned to receive an intravenous infusion of either ketamine (0.3mg/kg) or isotonic saline (control group) after receiving spinal anaesthesia, which continued throughout the procedure. Cognitive performance was evaluated, as a primary outcome, with Short Portable Mental Status Questionnaire. Baseline cognitive performance was comparable in both groups. Patients in the ketamine group showed statistically significant fewer errors in the postoperative Short Portable Mental Status Questionnaire compared with the baseline evaluations (p = 0.038). Patients in the ketamine group showed significantly lower verbal numerical scale scores than the control group (p = 0.04) at six hours after surgery. Elderly patients undergoing spinal anaesthesia showed a better cognitive status after receiving an intravenous infusion of 0.3mg/kg ketamine. However, further research with a larger sample size and different assessment tools might be required to verify our results.

Ketamine Compared With Morphine for Out-of-Hospital Analgesia for Patients With Traumatic Pain

Pain is a common out-of-hospital symptom among patients, and opioids are often prescribed. Research suggests that overprescribing for acute traumatic pain is still prevalent, even when limits restricting opioid prescriptions have been implemented. Ketamine hydrochloride is an alternative to opioids in adults with out-of-hospital traumatic pain. To assess the noninferiority of intravenous ketamine compared with intravenous morphine sulfate to provide pain relief in adults with out-of-hospital traumatic pain. The Intravenous Subdissociative-Dose Ketamine Versus Morphine for Prehospital Analgesia (KETAMORPH) study was a multicenter, single-blind, noninferiority randomized clinical trial comparing ketamine hydrochloride (20 mg, followed by 10 mg every 5 minutes) with morphine sulfate (2 or 3 mg every 5 minutes) in adult patients with out-of-hospital trauma and a verbal pain score equal to or greater than 5. Enrollment occurred from November 23, 2017, to November 26, 2022, in 11 French out-of-hospital emergency medical units. Patients were randomly assigned to ketamine (n = 128) or morphine (n = 123). The primary outcome was the between-group difference in mean change in verbal rating scale pain scores measured from the time before administration of the study drug to 30 minutes later. A noninferiority margin of 1.3 was chosen. A total of 251 patients were randomized (median age, 51 [IQR, 34-69] years; 111 women [44.9%] and 140 men [55.1%] among the 247 with data available) and were included in the intention-to-treat population. The mean pain score change was -3.7 (95% CI, -4.2 to -3.2) in the ketamine group compared with -3.8 (95% CI, -4.2 to -3.4) in the morphine group. The difference in mean pain score change was 0.1 (95% CI, -0.7 to 0.9) points. There were no clinically meaningful differences for vital signs between the 2 groups. The intravenous morphine group had 19 of 113 (16.8% [95% CI, 10.4%-25.0%]) adverse effects reported (most commonly nausea [12 of 113 (10.6%)]) compared with 49 of 120 (40.8% [95% CI, 32.0%-49.6%]) in the ketamine group (most commonly emergence phenomenon [24 of 120 (20.0%)]). No adverse events required intervention. In the KETAMORPH study of patients with out-of-hospital traumatic pain, the use of intravenous ketamine compared with morphine showed noninferiority for pain reduction. In the ongoing opioid crisis, ketamine administered alone is an alternative to opioids in adults with out-of-hospital traumatic pain. ClinicalTrials.gov Identifier: NCT03236805.

Pre-adolescence repeat exposure to sub-anesthetic doses of ketamine induces long-lasting behaviors and cognition impairment in male and female rat adults

In pre-adolescence, repeated anesthesia may be required for therapeutic interventions. Adult cognitive and neurobehavioral problems may result from preadolescent exposure to anesthetics. This study examined the long-term morphological and functional effects of repeated sub-anesthetic doses of ketamine exposure on male and female rat adults during pre-adolescence. Weaned 48 pre-adolescent rats from eight mothers and were randomly divided into four equal groups: control group and the ketamine group of males and females (20 mg/kg daily for 14 days); then animals received care for 20–30 days. Repeated exposure to sub-anesthetic doses of ketamine on cognitive functions was assayed using Social discrimination and novel object tests. Besides, an elevated plus maze and fear conditioning apparatus were utilized to determine exploratory and anxiety-like behavior in adults. Toluidine blue stain was used to evaluate the number of dead neurons in the hippocampus, and the effects of ketamine on synaptic plasticity were compared in the perforant pathway of the CA1 of the hippocampus. Our study indicates that repeated exposure to sub-anesthetic doses of ketamine during pre-adolescence can result in neurobehavioral impairment in male and female rat adulthood but does not affect anxiety-like behavior. We found a significant quantifiable increase in dark neurons. Recorded electrophysiologically, repeat sub-anesthetic doses of ketamine resulted in hampering long-term potentiation and pair pulse in male adult animals. Our results showed that repeated exposure to sub-anesthetic doses of ketamine during pre-adolescence can induce hippocampus and neuroplasticity changes later in adulthood. This study opens up a new line of inquiry into potential adverse outcomes of repeated anesthesia exposure in pre-adolescent rats.

Prevalence of Delirium After Abdominal Surgery and Association With Ketamine: A Retrospective, Propensity-Matched Cohort Study.

Delirium is a common postoperative complication for older patients in the ICU. Ketamine, used primarily as an analgesic, has been thought to prevent delirium. Determine the prevalence and association of delirium with low-dose ketamine use in ICU patients after abdominal surgery. Single-center, retrospective, propensity-matched cohort study. Eight hospital academic medical center. Cohort comprising 1836 patients admitted to the ICU after abdominal surgery between June 23, 2018 and September 1, 2022. Propensity score matching (PSM) with a 3:1 ratio between no-ketamine use and ketamine use was performed through a greedy algorithm (caliper of 0.005). Outcomes of interest included: delirium (assessed by Confusion Assessment Method-ICU), mean pain score (Numeric Pain Scale or Critical Care Pain Observation Tool score as available), mean opioid consumption (morphine milligram equivalents), length of stay (d), and mortality. Prevalence of delirium was 47.71% (95% CI, 45.41-50.03%) in the cohort. Of 1836 patients, 120 (6.54%) used low-dose ketamine infusion. After PSM, the prevalence of delirium was 56.02% (95% CI, 51.05-60.91%) in all abdominal surgery patients. The ketamine group had 41% less odds of delirium (odds ratio [OR] = 0.59; 95% CI, 0.37-0.94; p = 0.026) than patients with no-ketamine use. Patients with ketamine use had higher mean pain scores (3.57 ± 2.86 vs. 2.21 ± 2.09, p < 0.001). In the subgroup analysis, patients in the ketamine-use group 60 years old or younger had 64% less odds of delirium (OR = 0.36; 95% CI, 0.13-0.95; p = 0.039). The mean pain scores were higher in the ketamine group for patients 60 years old or older. There was no significant difference in mortality and opioid consumption. Low-dose ketamine infusion was associated with lower prevalence of delirium in ICU patients following abdominal surgery. Prospective studies should further evaluate ketamine use and delirium.

The Electrographic Effects of Ketamine on Patients With Refractory Status Epilepticus After Cardiac Arrest: A Single-Center Retrospective Cohort.

To investigate the effects of ketamine on patients with refractory status epilepticus after cardiac arrest. In this retrospective cohort, selected EEG segments from patients after cardiac arrest were classified into different EEG patterns (based on background continuity and burden of epileptiform discharges) and spectral profiles (based on the presence of frequency components). For patients who received ketamine, EEG data were compared before, during, and after ketamine infusion; for the no-ketamine group, EEG data were compared at three separated time points during recording. Ketamine usage was determined by clinical providers. Electrographic improvement in epileptiform activity was scored, and the odds ratio was calculated using the Fisher exact test. Functional outcome measures at time of discharge were also examined. Of a total of 38 patients with postcardiac arrest refractory status epilepticus, 13 received ketamine and 25 did not. All patients were on ≥2 antiseizure medications including at least one sedative infusion (midazolam). For the ketamine group, eight patients had electrographic improvement, compared with only two patients in the no-ketamine group, with an odds ratio of 7.19 (95% confidence interval 1.16-44.65, P value of 0.0341) for ketamine versus no ketamine. Most of the patients who received ketamine had myoclonic status epilepticus, and overall neurologic outcomes were poor with no patients having a favorable outcome. For postarrest refractory status epilepticus, ketamine use was associated with electrographic improvement, but with the available data, it is unclear whether ketamine use or EEG improvement can be linked to better functional recovery.

Antipsychotic effect of diosgenin in ketamine-induced murine model of schizophrenia: Involvement of oxidative stress and cholinergic transmission

A decrease in the levels of antioxidant arsenals exacerbate generation of reactive oxygen/nitrogen species, leading to neurochemical dysfunction, with significant impact on the pathogenesis of psychotic disorders such as schizophrenia. This study examined the preventive and reversal effects of diosgenin, a phyto-steroidal saponin with antioxidant functions in mice treated with ketamine which closely replicates schizophrenia-like symptoms in human and laboratory animals. In the preventive phase, adult mice cohorts were clustered into 5 groups (n = 9). Groups 1 and 2 received saline (10 mL/kg, i.p.), groups 3 and 4 were pretreated with diosgenin (25 and 50 mg/kg), and group 5 received risperidone (0.5 mg/kg) orally for 14 days. Mice in groups 2–5 additionally received a daily dose of ketamine (20 mg/kg, i.p.) or saline (10 mL/kg/day, i.p.). In the reversal phase, mice received intraperitoneal injection of ketamine or saline for 14 consecutive days prior to diosgenin (25 and 50 mg/kg/p.o./day) and risperidone (0.5 mg/kg/p.o./day) treatment from days 8–14. Mice were assessed for behavioral changes. Oxidative, nitrergic markers, and cholinergic (acetylcholinesterase activity) transmission were examined in the striatum, prefrontal-cortex and hippocampus. Diosgenin prevented and reversed hyperlocomotion, cognitive and social deficits in mice treated with ketamine relative to ketamine groups. The increased acetylcholinesterase, malondialdehyde and nitrite levels produced by ketamine were reduced by diosgenin in the striatum, prefrontal-cortex and hippocampus, but did not reverse striatal nitrite level. Diosgenin increased glutathione, and catalase levels, except for hippocampal catalase activity when compared with ketamine controls. Conclusively, these biochemical changes might be related to the behavioral deficits in ketamine-treated mice, which were prevented and reversed by diosgenin.

Subhypnotic Intravenous Ketamine Improves Patient Satisfaction With Burn Wound Care: A Quality Improvement Project.

Despite advancements in pain management for burn injuries, analgesia often fails to meet our patients' needs. We hypothesized that low doses of intravenous (IV) ketamine as an adjunct to our current protocol would be safe, improving both nurse and patient satisfaction with analgesia during hydrotherapy. Burn patients admitted who underwent hydrotherapy from June 1, 2021, to June 30, 2023 were surveyed. Ketamine was administered with the standard opioid-midazolam regimen. Demographics, oral morphine equivalents, midazolam, ketamine doses and time of administration, and adverse events were collected. Patient and nurse satisfaction scores were collected. The ketamine and no-ketamine groups were compared. P < .05 was considered significant. Eighty-five hydrotherapies were surveyed, 47 without ketamine, and 38 with ketamine. Demographics, comorbidities, %TBSA, and hospital length of stay were not different. The median amount of ketamine given was 0.79 mg/kg [0.59-1.06]. Patients who received ketamine were more likely to receive midazolam (100% vs 61.7%; P < .001), and both oral and IV opioids (94.7% vs 68.1%; P = .002) prior to hydrotherapy and less likely to receive rescue opioids or midazolam during hydrotherapy. Two patients in the ketamine group had hypertension (defined as SBP > 180) that did not require treatment. Nurses tended to be more satisfied with patient pain control when ketamine was used (10 [8-10] vs 9 [7-10], P = .072). Patient satisfaction was higher in the ketamine group (10 [8.8-10] vs 9 [7-10], P = .006). Utilizing subhypnotic dose of IV ketamine for hydrotherapy is safe and associated with increased patient satisfaction.

Intraoperative low-dose ketamine infusion for postoperative pain relief in laparoscopic surgeries – A randomised, double blind controlled clinical trial

Abstract Background: Patients undergoing laparoscopic surgery often experience moderate-to-severe postoperative pain. The use of opioids for postoperative pain relief often results in respiratory depression and other adverse effects. Hence, we studied the effect of ketamine infusion administered at a low dose intraoperatively on postoperative pain relief. Materials and Methods: Fifty-two patients belonging to American Society of Anesthesia (ASA) I/ASA II, scheduled for laparoscopic surgery were randomized into two groups (n = 26). Group A received 0.2 mg/kg bolus of ketamine before the skin incision followed by an infusion of 0.1 mg/kg/h throughout the period of surgery. Group B received an equal volume of saline bolus and infusion. Postoperative pain was assessed (Numerical Rating Scale [NRS] scale) every 30 min till 6 h. The time taken for first rescue analgesia, the total amount of opioid used, and degree of sedation postoperatively were also compared. Pain scores between the groups were compared using the Chi-square test. Results: Pain scores (NRS scores) over various time intervals postoperatively were significantly reduced in the ketamine group (P &lt; 0.001). The overall cumulative opioid consumption was significantly lower in the ketamine group compared to the placebo (69.29 ± 23.35 mg vs. 107.88 ± 35.21 mg, respectively, P = 0.008). There was also a significant difference in time to first rescue analgesia between the ketamine and placebo groups (2.60 ± 1.87 h vs. 0.43 ± 0.85 h, respectively, P = 0.001). Conclusion: Intraoperative low-dose ketamine infusion as an adjuvant significantly decreased postoperative pain with a reduced total dose of opioid consumption and a delayed time to first rescue analgesic.

An analysis of oxidative stress indices and clinical parameters in budgerigars (Melopsittacus undulatus) treated with medetomidine-ketamine and midazolam-ketamine.

Various companion birds, including budgerigars, are anesthetized with injectable anesthesia.The current study aimed to evaluate oxidative stress indices including malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) along with clinical parameters such as the time required to induce, maintain and recover from medetomidine-ketamine anesthesia and midazolam-ketamine anesthesia in budgerigars.Among 20 mature and healthy budgerigars, three groups were assigned as follows: Control (n = 4) to determine baseline oxidative stress indices medetomidine + ketamine (n = 8) anesthetized by intramuscular injections of medetomidine (0.04 mg kg-1) and ketamine (30.00 mg kg-1) in the pectoral muscles, midazolam + ketamine (n = 8) anesthetized by intramuscular injections of midazolam (1.00 mg kg-1) and ketamine (50.00 mg kg-1). Half of birds (n = 4) in the second and third groups were euthanized by cervical dislocation 1 hr after anesthesia induction, blood samples were collected directly from the heart, and sera were extracted. Additionally, the remaining birds were euthanized 24 hr later, and their serum was analyzed for oxidative stress indices. Clinical parameters were recorded during the study.Compared to the medetomidine + ketamine group, the midazolam + ketamine group experienced shorter induction, anesthetic, and recovery times. Administering medetomidine and ketamine elevated TOS levels compared with midazolam + ketamine. No significant difference was found between the test groups for TAC, MDA, or OSI.Therefore, the midazolam + ketamine regimen appears superior to medetomidine + ketamine when performing minor surgeries on budgerigars.