A randomized, double-blind, placebo-controlled study assessing the anti-inflammatory effects of ketamine in cardiac surgical patients

Effects of S-ketamine on Postoperative Recovery Quality and Inflammatory Response in Patients Undergoing Modified Radical Mastectomy

INTRODUCTION

S-ketamine plays an important role in reducing postoperative pain, but its impact on the quality of recovery in breast cancer has not been clarified. We designed this trial to explore the effects of s-ketamine on the quality of postoperative recovery and inflammatory response in modified radical mastectomy.

METHODS

A total of 138 patients were randomly assigned to group C (group control), group K1 (group of s-ketamine dose 1) and group K2 (group of s-ketamine dose 2). Groups K1 and K2 were given 0.1 mg/kg, 0.2 mg/kg s-ketamine intravenous (IV) after induction, followed by 0.1 mg/kg/h or 0.2 mg/kg/h continuous intravenous infusion, respectively. Group C received the same volume of saline. A 40-item Quality of Recovery Questionnaire (QoR-40) was used to assess the quality of recovery at 24 h postoperatively. Changes in inflammatory markers, nociceptive thresholds, and the occurrence of adverse events were recorded at 24 h postoperatively.

RESULTS

The QoR-40 scores at 24 h postoperatively were higher in group K2 [182.00 (179.00-185.00)] compared to group K1 [174.00 (169.50-180.50)] and group C [169.00 (163.75-174.25)] (group K2 vs. group K1, P < 0.001; group K2 vs. group C, P < 0.001). At 24 h postoperatively, the neutrophil count, NLR (neutrophil-lymphocyte ratio), and CRP (C-creative protein) were all significantly lower in group K2 than group C(P < 0.05), no differences were observed between group K1 and C(P > 0.05), group K1 and K2(P > 0.05), respectively. There was no significant difference in the incidence of adverse effects among the three groups (P > 0.05).

CONCLUSIONS

A high dose of s-ketamine improved the quality of recovery at 24 h after surgery, as well as alleviated the inflammatory response without increasing the incidence of adverse effects.

Administration of ketamine/xylazine increases severity of influenza (A/Puerto Rico/8/34) in mice

The use of ketamine/xylazine for its anesthetic, anti-inflammatory, and anti-depressant properties could alter other medications and immune functions of the body. Thus, the current study explored how ketamine/xylazine affects the severity of influenza infection in BALB/c and C57Bl/6 mice, monitored for weight loss after intranasal inoculation with A/Puerto Rico/8/34 influenza virus. Mice were inoculated by using a micropipettor to insert 18 μL of control or a suspension of virus into each nostril and allowing the mouse to inhale the material. Several experiments were performed where groups of mice were treated with various combinations of virus and anesthesia and the results compared. Mice were weighed daily and monitored for other signs of illness. The experiments continued until the mice either regained their original weight or died (were euthanized when signs indicated non-recoverable status), which ranged from nine to twenty-three days. Anesthetized mice experienced more weight loss. Additionally, in experiments where the virus suspension was potent enough to lead to death, only mice that were anesthetized died.

Exploration in the Therapeutic and Multi-Target Mechanism of Ketamine on Cerebral Ischemia Based on Network Pharmacology and Molecular Docking

Background

Ketamine is famous for its dissociative anesthetic properties. It is also analgesic, anti-inflammatory and anti-depressant, and even has a cerebral protective effect. We searched the evidence of the correlation between ketamine target and clinical efficacy and utilized network pharmacology to gather information about the multi-target mechanism of ketamine against cerebral ischemia (CI). We found that ketamine’s clinical significance may be more extensive than previously thought.

Methods

The drug target of ketamine and CI-related genes were predicted by SwissTargetPrediction, DrugBank, PubChem, GeneCards and DisGeNET databases. The intersection of ketamine’s drug-targets and CI-related genes was analyzed by using GO and KEGG. We predicted the molecular docking between the potential target and ketamine.

Results

The results indicated that the effect of ketamine on CI was primarily associated with the target of α-synuclein (SNCA), muscarinic acetylcholine receptor M1 (CHRM1) and nitric oxide synthase 1 (NOS1). It principally regulates the signal pathways of circadian transmission, calcium signaling pathway, dopaminergic synapse, cholinergic synapse and glutamatergic synapse. Molecular docking analysis exhibited that hydrogen bond and Pi-Pi interaction were the predominant modes of interaction.

Conclusion

There are protein targets affected by ketamine in the treatment of CI. Three pivotal targets involving 298 proteins, SNCA, CHRM1 and NOS1, have emerged as multi-target mechanisms for ketamine in CI therapy. Similarly, this study also provides a new idea for introducing network pharmacology into the evaluation of multi-targeted drugs for CI and cerebral protection.

Ketamine and lidocaine infusions decrease opioid consumption during vaso-occlusive crisis in adolescents with sickle cell disease

PURPOSE OF REVIEW

Recurrent exposure to opioids can lead to development of opioid tolerance and opioid-induced hyperalgesia through activation of N-methyl-D-aspartate receptors. N-methyl-D-aspartate receptor antagonists ketamine and lidocaine can modulate development of opioid tolerance and OIH. This study evaluated the utility of ketamine and/or lidocaine in decreasing opioid consumption during acute pain episodes in adolescents with sickle cell disease. There has been an increased effort to promote opioid-sparing pain relieving methods given the ongoing opioid epidemic.

RECENT FINDINGS

There have been six studies published over the past decade that highlight the ability of ketamine to reduce opioid consumption in the management of sickle cell disease-related pain, primarily in adult patients. There has been one study (2015) that demonstrated a similar benefit with lidocaine, however this was also in adult patients.

SUMMARY

We retrospectively evaluated treatment with ketamine and/or lidocaine infusions in adolescents hospitalized for vaso-occlusive crisis (VOC). Patients served as self-controls using a comparison with a previous control admission for VOC. The use of ketamine and/or lidocaine as adjuncts to opioids resulted in lower daily opioid consumption in three of four patients. Our study suggests that ketamine and/or lidocaine infusions may be useful adjuncts in reducing opioid exposure during VOC pain.

Ketamine: The final frontier or another depressing end?

Two decades ago, the observation of a rapid and sustained antidepressant response after ketamine administration provided an exciting new avenue in the search for more effective therapeutics for the treatment of clinical depression. Research elucidating the mechanism(s) underlying ketamine's antidepressant properties has led to the development of several hypotheses, including that of disinhibition of excitatory glutamate neurons via blockade of N-methyl-d-aspartate (NMDA) receptors. Although the prominent understanding has been that ketamine's mode of action is mediated solely via the NMDA receptor, this view has been challenged by reports implicating other glutamate receptors such as AMPA, and other neurotransmitter systems such as serotonin and opioids in the antidepressant response. The recent approval of esketamine (Spravato™) for the treatment of depression has sparked a resurgence of interest for a deeper understanding of the mechanism(s) underlying ketamine's actions and safe therapeutic use. This review aims to present our current knowledge on both NMDA and non-NMDA mechanisms implicated in ketamine's response, and addresses the controversy surrounding the antidepressant role and potency of its stereoisomers and metabolites. There is much that remains to be known about our understanding of ketamine's antidepressant properties; and although the arrival of esketamine has been received with great enthusiasm, it is now more important than ever that its mechanisms of action be fully delineated, and both the short- and long-term neurobiological/functional consequences of its treatment be thoroughly characterized.

Ketamine applications beyond anesthesia - A literature review

Ketamine's clinical use began in the 1970s. Physicians benefited from its safety and ability to induce short-term anesthesia and analgesia. The psychodysleptic effects caused by the drug called its further clinical use into question. Despite these unpleasant effects, ketamine is still applied in veterinary medicine, field medicine, and specialist anesthesia. Recent intensive research brought into light new possible applications of this drug. It began to be used in acute, chronic and cancer pain management. Most interesting reports come from research on the antidepressive and antisuicidal properties of ketamine giving hope for the creation of an effective treatment for major depressive disorder. Other reports highlight the possible use of ketamine in treating addiction, asthma and preventing cancer growth. Besides clinical use, the drug is also applied to in animal model of schizophrenia. It seems that nowadays, with numerous possible applications, the use of ketamine has returned; to its former glory. Nevertheless, the drug must be used with caution because still the mechanisms by which it executes its functions and long-term effects of its use are not fully known. This review aims to discuss the well-known and new promising applications of ketamine.

Low dose ketamine versus morphine for acute severe vaso occlusive pain in children: a randomized controlled trial

BACKGROUND AND AIMS

Acute pain episodes associated with sickle cell disease (SCD) are very difficult to manage effectively. Opioid tolerance and side effects have been major roadblocks in our ability to provide these patients with adequate pain relief. Ketamine is cheap, widely safe, readily available drug, with analgesic effects at sub-anesthetic doses and has been used in wide range of surgeries, pediatric burns dressing change and cancer related pain however, literature concerning its use in sickle cell crises is still limited in our setting. This study aimed to establish if 1 mg/kg of intravenous ketamine is non inferior to intravenous morphine 0.1 mg/kg in severe SCD-associated pain.

METHODS

We performed an institutional review board-approved randomized, prospective, double-blinded, active-control, non-inferiority trial at the national referral sickle cell center. Children between 7 and 18 years of age with severe painful sickle cell crisis, defined by numerical rating scale score of greater or equal to 7 were enrolled. Patients were consented and randomized to receive, either IV ketamine (LDK) 1 mg/kg or IV morphine (MOR) 0.1 mg/kg as an infusion over 10 min. The primary endpoint is maximal change in Numerical Rating Scale (NRS) pain score. Secondary outcomes were, incidence of adverse effects, optimal time to and duration of action of ketamine and incidence of treatment failures by treatment group. A clinically meaningful difference in validated pain scores was defined as 1.3 units. Assuming both treatments are on average equal, a sample size of 240 patients (120 per group) provided 95% power to demonstrate that IV LDK is non-inferior to IV morphine with a 0.05 level of significance and a 10% non-inferiority margin. All analyses were based on a modified intention to treat. This trial was registered with clinicaltrials.gov NCT02434939.

RESULTS

Two hundred and forty patients were enrolled (LDK120, MOR120). Demographic variables and baseline NRS scores (8.9 vs. 9.2) were similar. LDK was comparable to MOR in the maximum change in NRS scores, 66.4% vs. 61.3% (MD 5.5; 95% CI -2.2 to -13.2). Time to achieve maximum reduction in NRS pain scores was at 19.8 min for LDK and 34.1 min for MOR. The average duration of action for LDK was 60 min. MOR had more patients still at maximum effect at 120 min (45.8% vs. 37.5%; RR 1.2; 95% CI 0.9-1.7). LDK patients were 11.3 times more likely to develop side effects, though were transient, anticipated and non-life threatening (37.5% vs. 3.3%). MOR had significantly more treatment failures 40% vs. 28.3% (RR 0.7; 95% CI 0.5-1.03, p=0.07) Vital signs and sedation scores were similar in both groups.

CONCLUSIONS

Intravenous LDK at 1 mg/kg provides comparable analgesic effectiveness as IV MOR in the acute treatment of severe painful sickle cell crisis in children in the day care sickle cell center. However, it is associated with a high incidence of several transient, non-life threatening mild side effects.

IMPLICATIONS

Intravenous ketamine at 1 mg/kg can be a reliable alternative to morphine in the management of severe painful sickle cell crisis especially in a resource limited area where morphine is not readily available.

In Vogue: Ketamine for Neuroprotection in Acute Neurologic Injury

Neurologic deterioration following acute injury to the central nervous system may be amenable to pharmacologic intervention, although, to date, no such therapy exists. Ketamine is an anesthetic and analgesic emerging as a novel therapy for a number of clinical entities in recent years, including refractory pain, depression, and drug-induced hyperalgesia due to newly discovered mechanisms of action and new application of its known pharmacodynamics. In this focused review, the evidence for ketamine as a neuroprotective agent in stroke, neurotrauma, subarachnoid hemorrhage, and status epilepticus is highlighted, with a focus on its applications for excitotoxicity, neuroinflammation, and neuronal hyperexcitability. Preclinical modeling and clinical applications are discussed.

Effect of low-dose ketamine on post-operative serum IL-6 production among elective surgical patients: a randomized clinical trial

BACKGROUND

Surgery and Anesthesia cause an excessive pro-inflammatory response. Mulago Hospital is faced with staff shortage making post-operative pain management difficult.Interleukin-6 (IL-6) drives inflammatory pain, endothelial cell dysfunction and fibrogenesis. Ketamine is cheap and, readily available. We hypothesized that its attenuation of serum IL-6 was a surrogate for clinical benefit.

MATERIALS AND METHODS

Institutional Review Board's approval was sought and RCT was registered at clinical trials.gov (identifier number: NCT01339065). Consenting patients were randomized to receive pre-incision intravenous ketamine - 0.5mg/kg or 0.9% saline placebo in weighted dosing. Blood samples were collected and laboratory analyzed at baseline, post-operatively in PACU, 24 and 48 hours respectively.

RESULTS

We recruited 39 patients of whom 18 were randomized to the ketamine arm and 21 in the placebo arm with follow up at 24 and 48 hours. Serum IL-6 and IL-1β levels were analyzed using ELIZA assay of pre-coated micro wells. Ketamine suppressed serum IL-6 at PACU with reduced increase at 24 hours. There was no reaction in 98% of IL-1β assayed.

CONCLUSION

Low-dose ketamine attenuated early serum IL-6 levels due to surgical response with reduced 24 hour increase, but the difference was not statistically significant and we recommend more studies.

NMDA Receptor Antagonists, Gabapentinoids, α-2 Agonists, and Dexamethasone and Other Non-Opioid Adjuvants: Do They Have a Role in Plastic Surgery?

BACKGROUND

Inadequate pain control and opioid-related adverse effects result in delayed patient recovery and discharge times. Adjuvants help to improve the quality of analgesia and decrease opioid consumption, consequently decreasing opioid-related effects, such as nausea and vomiting, sedation, ileus, and respiratory depression. We review the mechanisms and clinical evidence for nonopioid adjuvants.

METHODS

MEDLINE, EMBASE, and the Cochrane Register were searched for meta-analyses, systematic reviews, and randomized, controlled trials that compared the adjuvants ketamine, gabapentin, pregabalin, dexmedetomidine, clonidine, and dexamethasone with placebo. Keywords used in the search included "plastic surgery," "reconstructive surgery," "opioid," "pain," "analgesia," and the names of each adjuvant. The references of included studies were searched for additional relevant studies.

RESULTS

Ketamine was found in 6 meta-analyses to have a significant reduction in opioid requirements and may reduce the hyperalgesia associated with opioids. This seems to be most beneficial in surgeries where high postoperative pain is expected. Multiple robust trials have demonstrated that the gabapentinoids and α-2 agonists significantly improve quality of analgesia and decrease opioid consumption. Two recent meta-analyses found that a single low-dose of dexamethasone used for postoperative nausea and vomiting prophylaxis may also improve postoperative analgesia. There is also emerging evidence for the use of low-dose naloxone, adenosine, and neuraxial neostigmine and acupuncture as part of a successful multimodal pain management regimen.

CONCLUSIONS

Although there is a lack of studies specifically focused in the plastic and reconstructive surgery patient population, the existing literature provides information about when the above adjuvants are likely to have the greatest impact.

Ketamine in adult cardiac surgery and the cardiac surgery Intensive Care Unit: an evidence-based clinical review

Ketamine is a unique anesthetic drug that provides analgesia, hypnosis, and amnesia with minimal respiratory and cardiovascular depression. Because of its sympathomimetic properties it would seem to be an excellent choice for patients with depressed ventricular function in cardiac surgery. However, its use has not gained widespread acceptance in adult cardiac surgery patients, perhaps due to its perceived negative psychotropic effects. Despite this limitation, it is receiving renewed interest in the United States as a sedative and analgesic drug for critically ill-patients. In this manuscript, the authors provide an evidence-based clinical review of ketamine use in cardiac surgery patients for intensive care physicians, cardio-thoracic anesthesiologists, and cardio-thoracic surgeons. All MEDLINE indexed clinical trials performed during the last 20 years in adult cardiac surgery patients were included in the review.

A comparison of the effects of ketamine and remifentanil on renal functions in coronary artery bypass graft surgery

We have investigated the effects of ketamine-based and remifentanil-based anesthetic protocol on perioperative serum cystatin-C levels, and creatinine and/or cystatin-C-based eGFR equations in terms of acute kidney injury in coronary artery bypass graft (CABG) surgery. Using a simple randomization method (coin tossing), patients were divided into the two groups and not-blinded to the anesthetist. Remifentanil-midazolam-propofol or ketamine-midazolam-propofol-based anesthetic regimen was chosen. Different eGFR formulas using creatinine (MDRD, CKD-EPI, Cockrauft Gault); cystatin-C (eGFR1, eGFR2) or a combination of creatinine and cystatin-C (eGFR 3) were used to calculate estimated glomerular filtration rates (eGFRs). High-sensitive troponin T was used to determine if ketamine use in coronary surgery contributed to myocardial cell damage. Thirty-seven patients were included in the study (remifentanil group = 19, ketamine Group = 18). Urea, creatinine, cystatin-C levels were comparable between the groups in all the measurement times and also postoperative day 2 samples showed statistically higher results compared to baseline (p < 0.001). Effects of ketamine and remifentanil on renal functions were found similar. Creatinine and cystatin-C-based eGFR equations resulted similar in our study. Reversible stage 1 acute kidney injury (AKI) was observed on postoperative day 2 in seven patients from the remifentanil group and six patients from the ketamine group. Hs-troponin T was found to be higher in postoperative day 1 samples; there were no significant difference between the groups. Our results indicated that patients who have normal renal functions undergoing on-pump coronary bypass surgery, effects of ketamine and remifentanil on renal functions in terms of AKI were found to be similar.

The Prevention of Delirium and Complications Associated with Surgical Treatments (PODCAST) study: protocol for an international multicentre randomised controlled trial

INTRODUCTION

Postoperative delirium is one of the most common complications of major surgery, affecting 10-70% of surgical patients 60 years and older. Delirium is an acute change in cognition that manifests as poor attention and illogical thinking and is associated with longer intensive care unit (ICU) and hospital stay, long-lasting cognitive deterioration and increased mortality. Ketamine has been used as an anaesthetic drug for over 50 years and has an established safety record. Recent research suggests that, in addition to preventing acute postoperative pain, a subanaesthetic dose of intraoperative ketamine could decrease the incidence of postoperative delirium as well as other neurological and psychiatric outcomes. However, these proposed benefits of ketamine have not been tested in a large clinical trial.

METHODS

The Prevention of Delirium and Complications Associated with Surgical Treatments (PODCAST) study is an international, multicentre, randomised controlled trial. 600 cardiac and major non-cardiac surgery patients will be randomised to receive ketamine (0.5 or 1 mg/kg) or placebo following anaesthetic induction and prior to surgical incision. For the primary outcome, blinded observers will assess delirium on the day of surgery (postoperative day 0) and twice daily from postoperative days 1-3 using the Confusion Assessment Method or the Confusion Assessment Method for the ICU. For the secondary outcomes, blinded observers will estimate pain using the Behavioral Pain Scale or the Behavioral Pain Scale for Non-Intubated Patients and patient self-report.

ETHICS AND DISSEMINATION

The PODCAST trial has been approved by the ethics boards of five participating institutions; approval is ongoing at other sites. Recruitment began in February 2014 and will continue until the end of 2016. Dissemination plans include presentations at scientific conferences, scientific publications, stakeholder engagement and popular media.

REGISTRATION DETAILS

The study is registered at clinicaltrials.gov, NCT01690988 (last updated March 2014). The PODCAST trial is being conducted under the auspices of the Neurological Outcomes Network for Surgery (NEURONS).

TRIAL REGISTRATION NUMBER

NCT01690988 (last updated December 2013).

Decreased postoperative C-reactive protein production in dogs with pyometra through the use of low-dose ketamine

OBJECTIVE

To determine the effects of subanesthetic ketamine in dogs with pyometra on C-reactive protein (CRP) concentrations following surgery.

DESIGN

Prospective, nonconcealed, alternating allocation controlled trial.

SETTING

Veterinary teaching hospital.

ANIMALS

Sixteen dogs diagnosed with pyometra.

INTERVENTIONS

The tentative diagnosis of canine pyometra was based on compatible history, physical examination findings, ultrasonographic findings, and hematological evaluation. Two different anesthesia and analgesic protocols with and without low-dose ketamine were used during and following ovariohysterectomy in 16 female dogs (n = 8 per group) that were diagnosed with naturally occurring pyometra. Dogs were sequentially allocated to treatment groups in an alternating fashion without concealment. Serum was collected before, 24, and 48 hours after surgery for CRP measurement.

MEASUREMENTS AND MAIN RESULTS

Perioperative physical parameters in the 2 groups of dogs were similar. The serum concentrations of CRP in both groups were essentially the same before surgery, but significantly increased in the control group and decreased in ketamine group at 48 hours after surgery.

CONCLUSIONS

Low-dose ketamine attenuated the postoperative concentration of serum CRP in dogs with pyometra compared with dogs that did not receive ketamine in the perioperative period. Further studies are warranted to determine the clinical implications of these findings.

Glutamate and its receptors in the pathophysiology and treatment of major depressive disorder

Monoaminergic neurotransmitter (serotonin, norepinephrine and dopamine) mechanisms of disease dominated the research landscape in the pathophysiology and treatment of major depressive disorder (MDD) for more than 50 years and still dominate available treatment options. However, the sum of all brain neurons that use monoamines as their primary neurotransmitter is <20%. In addition, most patients treated with monoaminergic antidepressants are left with significant residual symptoms and psychosocial disability not to mention side effects, e.g., sexual dysfunction. In the past several decades, there has been greater focus on the major excitatory neurotransmitter in the human brain, glutamate, in the pathophysiology and treatment of MDD. Although several preclinical and human magnetic resonance spectroscopy studies had already implicated glutamatergic abnormalities in the human brain, it was rocketed by the discovery that the N-methyl-D-aspartate receptor antagonist ketamine has rapid and potent antidepressant effects in even the most treatment-resistant MDD patients, including those who failed to respond to electroconvulsive therapy and who have active suicidal ideation. In this review, we will first provide a brief introduction to glutamate and its receptors in the mammalian brain. We will then review the clinical evidence for glutamatergic dysfunction in MDD, the discovery and progress-to-date with ketamine as a rapidly acting antidepressant, and other glutamate receptor modulators (including proprietary medications) for treatment-resistant depression. We will finally conclude by offering potential future directions necessary to realize the enormous therapeutic promise of glutamatergic antidepressants.

Ketamine and peripheral inflammation

The old anesthetic ketamine has demonstrated interactions with the inflammatory response. This review intends to qualify the nature and the mechanism underlying this interaction. For this purpose, preclinical data will be presented starting with the initial works, and then, the probable mechanisms will be discussed. A summary of the most relevant clinical data will be presented. In conclusion, ketamine appears as a unique "homeostatic regulator" of the acute inflammatory reaction and the stress-induced immune disturbances. This is of some interest at a moment when the short- and long-term deleterious consequences of inadequate inflammatory reactions are increasingly reported. Large-scale studies showing improved patient's outcome are, however, required before to definitively assert the clinical reality of this positive effect.

Ketamine: use in anesthesia

The role of ketamine anesthesia in the prehospital, emergency department and operating theater settings is not well defined. A nonsystematic review of ketamine was performed by authors from Australia, Europe, and North America. Results were discussed among authors and the final manuscript accepted. Ketamine is a useful agent for induction of anesthesia, procedural sedation, and analgesia. Its properties are appealing in many awkward clinical scenarios. Practitioners need to be cognizant of its side effects and limitations.

Targeting the glutamatergic system to treat major depressive disorder: rationale and progress to date

Major depressive disorder (MDD) is a severe, debilitating medical illness that affects millions of individuals worldwide. The young age of onset and chronicity of the disorder has a significant impact on the long-term disability that affected individuals face. Most existing treatments have focused on the 'monoamine hypothesis' for rational design of compounds. However, patients continue to experience low remission rates, residual subsyndromal symptoms, relapses and overall functional impairment. In this context, growing evidence suggests that the glutamatergic system is uniquely central to the neurobiology and treatment of MDD. Here, we review data supporting the involvement of the glutamatergic system in the pathophysiology of MDD, and discuss the efficacy of glutamatergic agents as novel therapeutics. Preliminary clinical evidence has been promising, particularly with regard to the N-methyl-D-aspartate (NMDA) antagonist ketamine as a 'proof-of-concept' agent. The review also highlights potential molecular and inflammatory mechanisms that may contribute to the rapid antidepressant response seen with ketamine. Because existing pharmacological treatments for MDD are often insufficient for many patients, the next generation of treatments needs to be more effective, rapid acting and better tolerated than currently available medications. There is extant evidence that the glutamatergic system holds considerable promise for developing the next generation of novel and mechanistically distinct agents for the treatment of MDD.

The effect of perioperative intravenous lidocaine and ketamine on recovery after abdominal hysterectomy

BACKGROUND

Perioperative ketamine infusion reduces postoperative pain; perioperative lidocaine infusion reduces postoperative narcotic consumption, speeds recovery of intestinal function, improves postoperative fatigue, and shortens hospital stay. However, it is unknown whether perioperative IV lidocaine and/or ketamine enhances acute functional recovery. We therefore tested the primary hypothesis that perioperative IV lidocaine and/or ketamine in patients undergoing open abdominal hysterectomy improves rehabilitation as measured by a 6-minute walk distance (6-MWD) on the second postoperative morning.

METHODS

Women having open hysterectomy were anesthetized with sevoflurane, followed by patient-controlled morphine. Patients were factorially randomized to one of the following groups: (1) lidocaine and placebo, (2) placebo and ketamine, (3) placebo and placebo, or (4) lidocaine and ketamine. Lidocaine was given as a bolus (1.5 mg/kg), followed by lidocaine infusion of 2 mg/kg/h for the first 2 hours, and then 1.2 mg/kg/h for 24 postoperative hours. Ketamine was given as a bolus (0.35 mg/kg), followed by ketamine infusion of 0.2 mg/kg/h for the first 2 hours, and then 0.12 mg/kg/h for 24 postoperative hours. The primary double-blind outcome was 6-MWD on the second postoperative morning; secondary outcomes included pain scores, opioid consumption, postoperative nausea and vomiting, and fatigue score.

RESULTS

The study was stopped after a planned interim analysis of 64 patients showed that lidocaine crossed the preplanned futility boundary, with mean ± SD of 202 ± 66 m versus 202 ± 73 m for lidocaine versus placebo, respectively, and mean difference (interim adjusted 97.5% confidence interval) of 0.93 m (-52, 54) (P = 0.96); the ketamine effect also crossed the futility boundary, with mean ± SD of 193 ± 77 m versus 210 ± 61 m for ketamine versus placebo, respectively, and mean difference (interim adjusted 97.5% confidence interval) of -11 m (-65, 44) (P = 0.54). No interaction between the 2 intervention effects was observed (P = 0.96). Neither intervention significantly influenced any of the secondary outcomes.

CONCLUSION

Our results do not support use of lidocaine or ketamine for improving 6-MWD on the second postoperative day after open hysterectomy.

Effect of ketamine hydrochloride on the analgesic effects of tramadol hydrochloride in horses with signs of chronic laminitis-associated pain

OBJECTIVE

To investigate the effects of ketamine hydrochloride on the analgesic effects of tramadol hydrochloride in horses with signs of pain associated with naturally occurring chronic laminitis.

ANIMALS

15 client-owned adult horses with chronic laminitis.

PROCEDURES

Each horse received tramadol alone or tramadol and ketamine in a randomized, crossover study (≥ 2 months between treatments). Tramadol (5 mg/kg) was administered orally every 12 hours for 1 week. When appropriate, ketamine (0.6 mg/kg/h) was administered IV for 6 hours on each of the first 3 days of tramadol administration. Noninvasive systemic blood pressure values, heart and respiratory rates, intestinal sounds, forelimb load and off-loading frequency (determined via force plate system), and plasma tumor necrosis factor-α and thromboxane B(2) concentrations were assessed before (baseline) during (7 days) and after (3 days) each treatment.

RESULTS

Compared with baseline data, arterial blood pressure decreased significantly both during and after tramadol-ketamine treatment but not with tramadol alone. Forelimb off-loading frequency significantly decreased during the first 3 days of treatment with tramadol only, returning to baseline frequency thereafter. The addition of ketamine to tramadol treatment reduced off-loading frequency both during and after treatment. Forelimb load did not change with tramadol alone but increased with tramadol-ketamine treatment. Plasma concentrations of tumor necrosis factor-α and thromboxane B(2) were significantly reduced with tramadol-ketamine treatment but not with tramadol alone.

CONCLUSIONS AND CLINICAL RELEVANCE

In horses with chronic laminitis, tramadol administration induced limited analgesia, but this effect was significantly enhanced by administration of subanesthetic doses of ketamine.

Targeting the glutamatergic system to treat major depressive disorder: rationale and progress to date

Major depressive disorder (MDD) is a severe, debilitating medical illness that affects millions of individuals worldwide. The young age of onset and chronicity of the disorder has a significant impact on the long-term disability that affected individuals face. Most existing treatments have focused on the 'monoamine hypothesis' for rational design of compounds. However, patients continue to experience low remission rates, residual subsyndromal symptoms, relapses and overall functional impairment. In this context, growing evidence suggests that the glutamatergic system is uniquely central to the neurobiology and treatment of MDD. Here, we review data supporting the involvement of the glutamatergic system in the pathophysiology of MDD, and discuss the efficacy of glutamatergic agents as novel therapeutics. Preliminary clinical evidence has been promising, particularly with regard to the N-methyl-D-aspartate (NMDA) antagonist ketamine as a 'proof-of-concept' agent. The review also highlights potential molecular and inflammatory mechanisms that may contribute to the rapid antidepressant response seen with ketamine. Because existing pharmacological treatments for MDD are often insufficient for many patients, the next generation of treatments needs to be more effective, rapid acting and better tolerated than currently available medications. There is extant evidence that the glutamatergic system holds considerable promise for developing the next generation of novel and mechanistically distinct agents for the treatment of MDD.

Ketamine as a neuroprotective and anti-inflammatory agent in children undergoing surgery on cardiopulmonary bypass: a pilot randomized, double-blind, placebo-controlled trial

OBJECTIVE

Infants are potentially more susceptible to cell death mediated via glutamate excitotoxicity attributed to cardiopulmonary bypass. We hypothesized that ketamine, via N-methyl D-aspartate receptor blockade and anti-inflammatory effects, would reduce central nervous system injury during cardiopulmonary bypass.

METHODS

We randomized 24 infants, without chromosomal abnormalities, to receive ketamine (2 mg/kg, n = 13) or placebo (saline, n = 11) before cardiopulmonary bypass for repair of ventricular septal defects. Plasma markers of inflammation and central nervous system injury were compared at the end of surgery, and 6, 24, and 48 hrs after surgery. Magnetic resonance imaging and spectroscopy before cardiopulmonary bypass and at the time of hospital discharge were performed in a subset of cases and controls (n = 5 in each group). Cerebral hemodynamics were monitored postoperatively using near-infrared spectroscopy, and neurodevelopmental outcomes were assessed using Bayley Scales of Infant Development-II before and 2-3 wks after surgery.

RESULTS

Statistically significant differences were noted in preoperative inspired oxygen levels, intraoperative cooling and postoperative temperature, respiratory rate, platelet count, and bicarbonate levels. The peak concentration of C-reactive protein was lower in cases compared to controls at 24 hrs (p = .048) and 48 hrs (p = .001). No significant differences were noted in the expression of various cytokines, chemokines, S100, and neuron-specific enolase between the cases and controls. Magnetic resonance imaging with spectroscopy studies showed that ketamine administration led to a significant decrease in choline and glutamate plus glutamine/creatine in frontal white matter. No statistically significant differences occurred between pre- and postoperative Bayley Scales of Infant Development-II scores.

CONCLUSIONS

We did not find any evidence for neuroprotection or neurotoxicity in our pilot study. A large, adequately powered randomized control trial is needed to discern the central nervous system effect of ketamine on the developing brain. brain.

TRIAL REGISTRATION

The trial is registered at www.ClinicalTrials.gov, NCT00556361.

Advances in translational neuropathic research: example of enantioselective pharmacokinetic-pharmacodynamic modeling of ketamine-induced pain relief in complex regional pain syndrome

Historically, complex regional pain syndrome (CRPS) was poorly defined, which meant that scientists and clinicians faced much uncertainty in the study, diagnosis, and treatment of the syndrome. The problem could be attributed to a nonspecific diagnostic criteria, unknown pathophysiologic causes, and limited treatment options. The two forms of CRPS still are painful, debilitating disorders whose sufferers carry heavy emotional burdens. Current research has shown that CRPS I and CRPS II are distinctive processes, and the presence or absence of a partial nerve lesion distinguishes them apart. Ketamine has been the focus of various studies involving the treatment of CRPS; however, currently, there is incomplete data from evidence-based studies. The question as to why ketamine is effective in controlling the symptoms of a subset of patients with CRPS and not others remains to be answered. A possible explanation to this phenomenon is pharmacogenetic differences that may exist in different patient populations. This review summarizes important translational work recently published on the treatment of CRPS using ketamine.

Effects of ketamine on endotoxin and traumatic brain injury induced cytokine production in the rat

BACKGROUND

Endotoxemia from lipopolysaccharide (LPS) induces systemic cytokine production, whereas traumatic brain injury (TBI) increases intracerebral cytokine production. In anesthetic doses, ketamine has potent anti-inflammatory properties. However, its anti-inflammatory effects at subanesthetic doses and its effects on TBI-induced inflammation have not been fully investigated. We hypothesized that ketamine would attenuate both LPS- and TBI-induced inflammatory responses.

METHODS

Male rats received intraperitoneal (i.p.) ketamine (70 mg/kg, 7 mg/kg, or 1 mg/kg) or saline 1 hour before LPS (20 mg/kg i.p.) or saline. Five hours after LPS, rats were killed. Serum was collected for cytokine analysis. In other experiments, male rats were given ketamine (7 mg/kg i.p.) or saline 1 hour before induction of TBI with controlled cortical impact (or sham). One hour and 6 hours after injury, brain was extracted for analysis of cerebral edema and cytokine production.

RESULTS

LPS increased the serum concentrations of interleukin (IL)-1α, IL-1β, IL-6, IL-10, tumor necrosis factor-α, and interferon-γ. Ketamine dose dependently attenuated these changes. TBI caused cerebral edema and increased concentrations of cerebral IL-1α, IL-1β, IL-6, IL-10, and tumor necrosis factor-α. However, ketamine had minimal effect on TBI-induced inflammation.

CONCLUSIONS

Although ketamine did not seem to exert any beneficial effects against TBI in the rat, it did not exacerbate cytokine production or enhance cerebral edema as some studies have suggested.

Ketamine does not inhibit interleukin-6 synthesis in hepatic resections requiring a temporary porto-arterial occlusion (Pringle manoeuvre): a controlled, prospective, randomized, double-blinded study

INTRODUCTION

Previous studies have shown that interleukin-6 (IL-6) levels correlated with mortality in critically ill patients.

GOAL

To determine the effect of ketamine on IL-6 levels in liver resections patients with a temporary porto-arterial occlusion (Pringle manoeuvre).

MATERIALS AND METHODS

Controlled, prospective, randomized, double-blinded study. One group (n = 21) received ketamine whereas the other group (n = 17) received placebo. IL-6 levels were obtained at baseline, 4, 12, 24 h, 3 and 5 days.

RESULTS

There were no significant differences in IL-6 levels between the groups (basal P = 089, 4 hP = 0.83, 12 h P = 0.39, 24 h, P = 0.55, 3 days P = 0.80 and 5 days P = 0.45). Both groups had elevated IL-6 levels that became almost undetectable by day 5. There was no major morbidity and no mortality in either group.

CONCLUSIONS

  Ketamine does not seem to have an effect on plasma levels of IL-6. This could be interpreted as a potential finding associated with outcome as we did not encounter any deaths or major complications. Further studies will likely be needed to determine the range of IL-6 levels associated with survival and mortality, and whether it could be a predictor of survival.

Elevated postoperative inflammatory biomarkers are associated with short- and medium-term cognitive dysfunction after coronary artery surgery

PURPOSE

We tested the hypothesis that elevated postoperative interleukin-6 (IL-6) and C-reactive protein (CRP) concentrations are associated with short- and medium-term impairment of cognitive functions in patients after coronary artery surgery using cardiopulmonary bypass.

METHODS

Eighty-six age- and education-balanced patients ≥55 years of age undergoing elective coronary artery bypass surgery with cardiopulmonary bypass and 28 nonsurgical controls with coronary artery disease were enrolled. Recent verbal and nonverbal memory and executive functions were assessed before surgery and at 1 week and 3 months after surgery using a cognitive test battery. IL-6 concentrations were measured before surgery and 4 h after cardiopulmonary bypass, and CRP concentrations were measured before surgery and at 24 and 72 h after anesthetic induction. Overall cognitive function between high and low biomarker concentration groups was analyzed by the Wilcoxon rank-sum test.

RESULTS

Recent memory was at least 1 standard deviation (SD) impaired at 1 week and 3 months in the high-CRP compared with low-CRP and in the high-IL-6 compared with low-IL-6 concentration groups. Overall cognitive function was significantly (P = 0.04 and P = 0.01, respectively) different between the high- and low-CRP concentration groups (CRP assayed 24 h after anesthetic induction) at both 1 week and 3 months. Overall cognitive function was also significantly (P = 0.04) different between the high and low-IL-6 concentration groups at 1 week after surgery.

CONCLUSION

The results suggest that elevated postoperative IL-6 and CRP concentrations are associated with the subsequent development of short- and medium-term impairment of cognitive functions after coronary artery surgery.

Postdural puncture headache in complex regional pain syndrome: a retrospective observational study

OBJECTIVE

To describe the unusual course of postdural puncture headache (PDPH) after pump implantation for intrathecal baclofen (ITB) administration in patients with complex regional pain syndrome (CRPS)-related dystonia.

DESIGN

Case series based on data collected from 1996 to 2005. Setting. Movement disorders clinic, university hospital.

PATIENTS

A total of 54 patients with CRPS-related dystonia who were treated with ITB.

RESULTS

A high incidence (76%) and prolonged course (median 18 days, range 2 days to 36 months) of PDPH was found. Radionuclide studies performed in two patients with long-lasting symptoms (12-16 months) did not reveal cerebrospinal fluid (CSF) leakage. In patients without signs of CSF leakage (N = 38), epidural blood patches administered in 24 patients were effective in 54%, while ketamine infusions administered in six patients were effective in 67%.

CONCLUSIONS

Our observations may suggest that other mechanisms besides intracranial hypotension play a role in the initiation and maintenance of PDPH in CRPS and stimulate new directions of research on this topic.

Ketamine inhibits maturation of bone marrow-derived dendritic cells and priming of the Th1-type immune response

BACKGROUND

Dendritic cells (DCs) play a key role as antigen-presenting cells and growing evidence suggests that DCs influence T-cell activation and regulate the polarity of the immune response. Ketamine has been reported to have immunomodulatory properties that affect immune cells, including macrophages and natural killer cells. However, the effect of ketamine on DCs has not been characterized. We examined the immunomodulation of DCs by ketamine.

METHODS

We used bone marrow-derived DCs induced by granulocyte-monocyte-colony stimulating factor and interleukin (IL)-4 from bone marrow and analyzed the expression of costimulatory molecules (CD40, CD80, and CD86), major histocompatibility complex class II molecules, and secretion of IL-12p40. Furthermore, we evaluated the immune response in mixed cell cultures of DCs and T cells and the contact hypersensitivity response in a whole animal.

RESULTS

Ketamine suppressed the expression of CD40, CD80, and major histocompatibility complex class II molecules in DCs. DCs treated with ketamine also secreted less IL-12p40 and displayed greater endocytosis. In mixed cell cultures with CD4+ T cells and DCs, ketamine-treated DCs showed less propensity to stimulate the proliferation of CD4+ T cells and the secretion of interferon from CD4+ T cells. Furthermore, ketamine-treated DCs impaired the induction of a cell-mediated immune response.

CONCLUSION

Our findings suggest that ketamine inhibits the functional maturation of DCs and interferes with DC induction of Th1 immunity in the whole animal. These novel findings provide new insight into the immunopharmacological role of ketamine.

Ketamine attenuates post-operative cognitive dysfunction after cardiac surgery

BACKGROUND

Post-operative cognitive dysfunction (POCD) commonly occurs after cardiac surgery. Ketamine exerts neuroprotective effects after cerebral ischemia by anti-excitotoxic and anti-inflammatory mechanisms. We hypothesized that ketamine attenuates POCD in patients undergoing cardiac surgery concomitant with an anti-inflammatory effect.

METHODS

Patients randomly received placebo (0.9% saline; n=26) or an i.v. bolus of ketamine (0.5 mg/kg; n=26) during anesthetic induction. Anesthesia was maintained with isoflurane and fentanyl. A nonsurgical group (n=26) was also included as control. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after surgery or a 1-week waiting period for the nonsurgical controls. Serum C-reactive protein (CRP) concentrations were determined before surgery and on the first post-operative day.

RESULTS

Baseline neurocognitive and depression scores were similar in the placebo, ketamine, and nonsurgical control groups. Cognitive performance after surgery decreased by at least 2 SDs (z-score of 1.96) in 21 patients in the placebo group and only in seven patients in the ketamine group compared with the nonsurgical controls (P<0.001, Fisher's exact test). Cognitive performance was also significantly different between the placebo- and the ketamine-treated groups based on all z-scores (P<0.001, Mann-Whitney U-test). Pre-operative CRP concentrations were similar (P<0.33, Mann-Whitney U-test) in the placebo- and ketamine-treated groups. The post-operative CRP concentration was significantly (P<0.01, Mann-Whitney U-test) lower in the ketamine-treated than in the placebo-treated group.

CONCLUSIONS

Ketamine attenuates POCD 1 week after cardiac surgery and this effect may be related to the anti-inflammatory action of the drug.

Systemic inflammation in the brain-dead organ donor

Brain death itself impairs organ function in the potential donor, thereby limiting the number of suitable organs for transplantation. In addition, graft survival of kidneys obtained from brain-dead (BD) donors is inferior to that of kidneys obtained from living donors. Experimental studies confirm an inferior graft survival for the heart, liver and lungs from BD compared with living donors. The mechanism underlying the deteriorating effect of brain death on the organs has not yet been fully established. We know that brain death triggers massive circulatory, hormonal and metabolic changes. Moreover, the past 10 years have produced evidence that brain death is associated with a systemic inflammatory response. However, it remains uncertain whether the inflammation is induced by brain death itself or by events before and after becoming BD. The purpose of this study is to discuss the risk factors associated with brain death in general and the inflammatory response in the organs in particular. Special attention will be paid to the heart, lung, liver and kidney and evidence will be presented from clinical and experimental studies.

Effect of low-dose ketamine on inflammatory response in off-pump coronary artery bypass graft surgery

BACKGROUND

Off-pump coronary artery bypass graft surgery (OPCAB) is still associated with a marked systemic inflammatory response. The aim of this study was to investigate whether pre-emptive, low dose of ketamine, which has been reported to have anti-inflammatory activity in on-pump coronary artery bypass surgery, could reduce inflammatory response in low-risk patients undergoing OPCAB.

METHODS

In this prospective randomized-controlled trial, 50 patients with stable angina and preserved myocardial function undergoing OPCAB were randomly assigned to receive either 0.5 mg kg(-1) of ketamine (Ketamine group, n=25) or normal saline (Control group, n=25) during induction of anaesthesia. Inflammatory markers including C-reactive protein (CRP), interleukin (IL)-6, tumour necrosis factor-alpha (TNF-alpha), and cardiac enzymes were measured previous to induction (T1), 4 h after surgery (T2), and the first and second days after the surgery (T3 and T4).

RESULTS

There were no significant intergroup differences in the serum concentrations of the CRP, IL-6, and TNF-alpha and cardiac enzymes. Pro-inflammatory markers and cardiac enzymes, except TNF-alpha, were all increased after the surgery compared with baseline values in both groups.

CONCLUSIONS

Low-dose ketamine administered during anaesthesia induction did not exert any evident anti-inflammatory effect in terms of reducing the serum concentrations of pro-inflammatory markers in low-risk patients undergoing OPCAB.