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Background: There is a paucity of literature around sedation and anesthesia in patients with severe anorexia nervosa. Chronically malnourished patients are known to have myopathy, neuropathy, and altered neurotransmitter signaling. Ketamine is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist that is an established general anesthetic and short-acting dissociative analgesic agent. It generally has a reassuring adverse event profile and rarely has been reported to result in apnea. We aim to raise awareness of this untoward adverse event in patients with severe anorexia nervosa among sedation providers and those referring patients for hospitalization or sedation., Case Presentation: We describe an episode of apnea, a rare adverse event of ketamine, which was given for procedural sedation to a severely malnourished 13-year-old female with anorexia nervosa, generalized anxiety disorder, and high-functioning autism spectrum disorder. She had no history of apnea nor of ketamine sedation. She was given a standard dose of ketamine and had no other central nervous system depressants within 24 h. Within 1 min after slow medication administration, she had a 9-min period of apnea without laryngospasm. She was supported with bag-valve-mask ventilation throughout this period and did not require intubation. She returned to baseline shortly after procedural sedation., Conclusions: This case describes apnea after ketamine sedation in a patient with severe anorexia nervosa. It supports the importance of a thorough pre-procedure review of a patient's underlying medical problems and the consideration of how sedatives may interact with these conditions. We aim to alert those who care for this complex population of the possible altered neurotransmitters, myopathy, and adverse response to sedation, anesthetics, and analgesics., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Electroconvulsive therapy (ECT) remains the most effective treatment for major depressive disorder. Ketamine is an anesthetic gaining attention for its rapid antidepressant effect. Numerous randomized controlled trials have investigated the effect of ketamine anesthesia in ECT on various clinical outcomes. Previous systematic reviews have not found benefit for overall depression response, although some have found evidence of benefit early in the ECT course. Clear quantitative conclusions have not been established regarding other outcomes, particularly while only using data from high-quality studies. We aimed to examine all data from double-blind randomized controlled trials comparing ketamine to other anesthetics via meta-analysis, to make recommendations regarding ECT practice and future research. Data were extracted for depressive symptoms, seizure duration and electrical dose, neuropsychological performance, and adverse effects. Effect sizes were calculated using Hedge's g and odds ratios. Eighteen studies (n = 915) were included in the meta-analysis. Ketamine was not found to enhance improvement of depressive symptoms, either early in ECT course or at end of study. Ketamine had a large effect on increasing seizure duration both overall (Hedge's g = 0.71, P = 0.038) and in the subgroup receiving ketamine in combination with another anesthetic (Hedge's g = 0.78, P < 0.01), and on decreasing electrical dose (Hedge's g = 1.98, P = 0.039). There was no significant effect of ketamine on any individual neuropsychological domain. Ketamine was not associated with increased adverse effects, except for hypertension in patients receiving ketamine monotherapy. Significant heterogeneity was present for many outcomes, and sensitivity analyses suggested a relation to methodological variation in most cases. This study supports the finding that ketamine does not enhance ECT's antidepressant effect, including on early improvement, but provides substantial evidence for enhancing seizure duration and reducing electrical dose. No significant benefit was found on neurocognitive outcomes, but analysis was limited by small sample sizes and high heterogeneity. Ketamine is generally safe in ECT, particularly as a coanesthetic. Our findings provide meta-analytic support to the recommendations in ECT clinical guidelines for use of coadjuvant ketamine in ECT where seizures are suboptimal. Further studies targeting neurocognitive outcomes are encouraged.

Background: We conducted a randomized clinical trial to determine whether adjunctive lidocaine diminishes the incidence of adverse effects in pediatric patients sedated with ketamine., Methods: This case-control study involved 586 consecutive pediatric patients necessitating anesthesia. Then systolic blood pressure, heart rate, respiratory rate, and blood oxygen saturation were observed. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (BUN), and creatinine (Cr) levels were tested. General dose of ketamine, the time of onset and duration of anesthesia and postoperative recovery, anesthesia effect, and adverse reaction were subsequently compared. High-performance liquid chromatography was employed to detect ketamine concentration at different time points after administration, and the postoperative cognition function was further evaluated., Results: Intra- and post-operation, the rising degree of ALT, AST, BUN, and Cr in patients treated with ketamine was higher than those in patients treated with the ketamine-lidocaine complex. General dose of ketamine, the time of onset and duration of anesthesia, postoperative recovery time, and the incidence rate of adverse reaction in patients treated with ketamine-lidocaine complex were lower, but the concentration of ketamine was higher compared to the patients treated with ketamine. In patients treated with the ketamine-lidocaine complex, elimination half-life of ketamine was prolonged, the area under curve was increased, and the plasma clearance rate was decreased relative to those with ketamine alone., Conclusions: Ketamine combined with lidocaine may be beneficial in shortening the onset of anesthesia, promoting postoperative awake, prolonging elimination half-life, increasing area under curve, and decreasing plasma clearance rate and incidence of adverse reactions., (© 2019 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals, Inc.)

Background: Postanesthetic shivering is a common complication of anesthesia, which accounts for much discomfort in postoperative patients and may increase postoperative complications in high-risk patients. Due to the lack of high-quality evidence, it is difficult to draw a conclusion about optimal anti-shivering medication. The main purpose of this meta-analysis was to analyze and evaluate the efficacy and safety of prophylactic use of ketamine for preventing postanesthetic shivering., Methods: We searched the following databases: Medline, Embase, and the Cochrane Central Register of Controlled Trails for randomized controlled trials. The primary outcome observed was the difference of the incidence rate of postanesthetic shivering between ketamine group and placebo group. The secondary outcomes were the sedation score and incidence of the side effects caused by ketamine and any other drugs utilized in the studies., Results: In this meta-analysis, we analyzed a total of 16 trials including 1485 patients. Ketamine reduced the incidence rate of postanesthetic shivering compared to a placebo (odds ratio [OR]: 0.13, 95% confidence interval [CI]: 0.06 to 0.26, P<0.01). Regarding side effects, there was no evident variability of the incidence of nausea and vomiting. Usage of ketamine was associated with a lower rate of hypotension and bradycardia when compared to a placebo. Hallucinations were more frequently observed in patients who received higher doses of ketamine. No significant difference was found in the incidence of postanesthetic shivering with ketamine versus other pharmacological interventions., Conclusions: Ketamine can prevent postanesthetic shivering without severe side effects. However, ketamine shows no advantage over other anti-shivering drugs.

Two anesthetic protocols in adult giraffe were compared by retrospective study. Thirteen anesthesia records for medetomidine-ketamine (MK) and seven for medetomidine-ketamine with a potent opioid (MKO) were evaluated for differences in demographic, behavioral, drug, and respiratory parameters. Giraffe stood significantly more quickly with MKO vs MK though MK animals were physically restrained to preclude premature standing as part of normal recovery practices (5.5 min vs 21.4 min, P = 0.01). Regurgitation was recorded in 5/13 and resedation in 4/13 MK animals. The range of values for blood lactate was higher in MKO (5.18-11.25 mM/L) than in MK giraffe (0.78-6.08 mM/L). Despite limitations of a retrospective study, both MK and MKO giraffe anesthesia protocols exhibit benefits and side effects. Awareness and management of these factors will improve outcomes until standardized, prospective studies of giraffe immobilization offer more comprehensive guidance on protocol selection.

The objective was to assess the feasibility and safety of the ̳Every Second Matters for Emergency and Essential Surgery - Ketamine' (ESM-Ketamine) package in support of obstetric and gynecologic emergency and essential surgery when no anesthetist is available. A consecutive case series was conducted in twelve hospitals across five severely resource-limited counties in Kenya. 530 women underwent obstetric or gynecological operative procedures supported by non-anesthetist clinicians using the ESM-Ketamine package between November 1, 2013 and September 30, 2017. Main outcomes included reasons for ESM-Ketamine activations and ketamine-related adverse events. There were two (0.4%) prolonged (>30 seconds) oxygen desaturations below 92%. Brief oxygen desaturations (<30 seconds) below 92% occurred in 15 (2.8%) cases and 113 (21.3%) were administered diazepam to treat hallucinations or agitation. There were no ketamine-related deaths or injuries. The ESM- Ketamine package appears feasible and safe for use in support of obstetric and gynecologic surgeries when no anesthetist is available.

Two jaguars were anesthetized with dexmedetomidine, ketamine, and isoflurane. Arterial blood samples analyzed shortly after darting revealed no abnormalities. Samples analyzed 2 and 1.5 hr after darting revealed moderate hyperkalemia in both animals (6.8 and 6.2 mEq/L, respectively). Shortly after hyperkalemia was recognized, one jaguar developed electrocardiographic abnormalities (sinoventricular rhythm and widened QRS complexes), and a few minutes later, suffered cardiopulmonary arrest. Resuscitation with chest compressions, intermittent positive-pressure ventilation, and epinephrine was successful, and autonomous breathing and circulation resumed within a few minutes. Anesthesia-related hyperkalemia has been reported in a variety of large felids but has not been reported previously in jaguars. In all reports, α-2 adrenergic agonists were used as part of the immobilization protocol. Due to the presumptively high incidence and mortality caused by this complication, frequent monitoring of electrolyte concentrations and prompt treatment of hyperkalemia is recommended when anesthetizing large felids, including jaguars.

Background: Major depressive disorder (MDD) is a common and debilitating condition that can be challenging to treat. Electroconvulsive therapy (ECT) is currently the therapeutic gold standard for treatment-resistant MDD. We tested our hypothesis that ketamine-based anesthesia for ECT results in superior improvement in treatment-resistant MDD outcomes compared with propofol-based anesthesia., Methods: Patients with treatment-resistant MDD were enrolled in a randomized clinical trial with assignment to ketamine- or propofol-based anesthesia arms. Using a modified intention-to-treat analysis, we compared the median number of ECT treatments required to achieve a 50% reduction (primary outcome) and a score ≤ 10 (secondary outcome) on the Montgomery-Asberg depression rating scale (MADRS) between anesthesia groups., Results: The study was terminated as significant results were found after the first planned interim analysis with 12 patients in each of the ketamine (intervention) and propofol (control) groups. All ketamine patients achieved at least a 50% MADRS reduction after a median of two ECT treatments whereas ten propofol patients (83%) achieved the same outcome after a median of four ECT treatments. All ketamine patients and seven propofol patients (58%) achieved MDD remission (MADRS ≤ 10). Log rank tests showed that both time-to-50% reduction and remission differed significantly between groups. Adverse events and recovery time were similar between groups., Conclusions: In this early-terminated small-sized study, ketamine-based anesthesia compared with propofol-based anesthesia provided response and remission after fewer ECT sessions., Trial Registration: www.clinicaltrials.gov (NCT01935115). Registered 4 September 2013.

Objective: This randomized controlled pilot study examines the differences in response to electroconvulsive therapy (ECT) as defined by an improvement of depressive symptoms between ketamine and methohexital as the primary anesthetic agent. Adverse effects and cognitive tolerability were also examined., Methods: Subjects undergoing ECT for unipolar or bipolar depression were randomized to receive ketamine or methohexital as the anesthetic agent. Primary outcome measure includes the Hamilton rating scale for depression (17-item). Secondary outcome measures included the mini-mental status examination and Beck depression inventory. All ratings were conducted masked to anesthetic agent. Because of multiple outcome measures obtained over time, mixed models were used to account for the correlations among the measurements within the subjects. Because outcomes were either normally distributed or approximately normally distributed, general linear mixed models were fit with a random intercept specified., Results: A total of 21 subjects were enrolled, and 16 were randomized (methohexital, n = 8; ketamine, n = 8). The 2 treatment groups did not differ statistically in any demographic characteristic. No statistical difference was found between the ketamine and methohexital groups for an improvement in depressive symptoms (P = 0.6); however, subjects in both groups showed significant improvement in depression over time (ketamine, P < 0.0001; methohexital, P < 0.0001). Mini-mental status examination results did not differ between groups, and fatigue was reported more in subjects receiving ketamine (P = 0.03)., Conclusions: The results of this pilot study are inconclusive because they lack power to support an advantage of ketamine anesthesia compared with methohexital in ameliorating depressive symptoms for electroconvulsive therapy.

Objectives: This review will discuss ECT efficacy and cognitive outcomes when using ketamine as an ECT anaesthetic compared to other anaesthetics, taking into account important moderator variables that have often not been considered to date. It will also include information on safety and other ECT outcomes (seizure threshold and quality)., Methods: A systematic search through MEDLINE, PubMed, PsychINFO, Cochrane Databases and reference lists from retrieved articles was performed. Search terms were: "ketamine" and "Electroconvulsive Therapy", from 1995 to September 2016. Meta-analyses, randomised controlled trials, open-label and retrospective studies published in English of depressed samples receiving ECT with ketamine anaesthesia were included (n = 24)., Results: Studies were heterogeneous in the clinical populations included and ECT treatment and anaesthetic methods. Frequently, studies did not report on ECT factors (i.e., pulse-width, treatment schedule). Findings regarding efficacy were mixed. Tolerance from repeated use may explain why several studies found that ketamine enhanced efficacy early in the ECT course but not at the end. The majority of studies did not comprehensively examine cognition and adverse effects were not systematically studied. Only a minority of the studies reported on seizure threshold and expression., Conclusions: The routine use of ketamine anaesthesia for ECT in clinical settings cannot yet be recommended based on published data. Larger randomised controlled trials, taking into account moderator variables, specifically reporting on ECT parameters and systematically assessing outcomes are encouraged.

Background: The worldwide human resource gap in anesthesia services often presents a barrier to accessing life-saving and life-improving surgeries. This paper assessed the impact of a ketamine anesthesia package, Every Second Matters-Ketamine (ESM-Ketamine)™, for use in emergency and life-improving surgeries by non-anesthetist clinicians in a resource-limited setting when no anesthetist was available., Methods: We analyzed prospectively collected data from 193 surgeries constituting a pilot implementation of the ESM-Ketamine package, among three sub-district hospitals in Western Kenya. The study population comprises patients who required emergency or life-improving surgery when no anesthetist was available. Non-anesthetist clinicians in three sub-district hospitals underwent a 5-day training course in ESM-Ketamine complemented by checklists and an ESM-Ketamine Kit. Data were collected prospectively every time the ESM-Ketamine pathway was invoked. The training cases, although primarily tubal ligations, were included. The primary outcome measures centered on capturing the ability to safely support emergency and life-improving surgeries, when no anesthetist was available, through invoking the ESM-Ketamine pathway. The registry was critically examined using standard descriptive and frequency analysis., Results: 193 surgical procedures were supported using the ESM-Ketamine package by five ESM-Ketamine trained providers. Brief (<30 s) patient desaturation below 92% and hallucinations occurred in 16 out of 186 (8.6%) and 23 out of 190 patients (12.1%), respectively. There were no reported major adverse events such as death, prolonged desaturations (over 30 s), or injury resulting from ketamine use., Conclusion: This study provides promising initial evidence that the ESM-Ketamine package can support emergency and life-improving surgeries in resource-limited settings when no anesthetist is available.

Background: Electroconvulsive therapy (ECT) is a well-established, safe and effective treatment for severe psychiatric disorders. Ketamine is known as a core medication in anesthesiology and has recently gained interest in ECT practice as there are three potential advantages: (1) ketamine has no anticonvulsive actions, (2) according to recent studies ketamine could possess a unique intrinsic antidepressive potential and (3) ketamine may exhibit neuroprotective properties, which again might reduce the risk of cognitive side effects associated with ECT., Objectives: The use of ketamine in psychiatric patients has been controversially discussed due to its dose-dependent psychotropic and psychotomimetic effects. This study was carried out to test if the occurrence of side effects is comparable and if seizure quality is better with ketamine when compared to thiopental., Material and Methods: This retrospective study analyzed a total of 199 patients who received ketamine anesthesia for a total of 2178 ECT sessions. This cohort was compared to patients who were treated with thiopental for 1004 ECT sessions., Results and Discussion: A repeated measurement multiple logistic regression analysis revealed significant advantages in the ketamine group for seizure concordance and postictal suppression (both are surrogates for central inhibition). S-ketamin also necessitated the use of a higher dose of urapidil and a higher maximum postictal heart frequency. Clinically relevant psychiatric side effects were rare in both groups. No psychiatric side effects occurred in the subgroup of patients with schizophrenia (ketamine: n = 30). The mean dose of S-ketamine used increased in the first years but stabilized at 63 mg per patient in 2014. From these experiences it can be concluded that S-ketamine can be recommended at least as a safe alternative to barbiturates.

Most anesthetic agents used for electroconvulsive therapy (ECT) have few intrinsic adverse effects. Ketamine, however, is well known to be associated with a variety of adverse effects including nausea, dizziness, and psychotomimetic phenomena. Over the past several decades, there have been numerous reports on the use of ketamine for ECT anesthesia, with varied assessments on how prominent these adverse effects are in the ECT situation. Ketamine has received a resurgence of interest as an ECT anesthetic of late owing to its established independent antidepressant effects and to theoretical reasons why it might lessen the cognitive adverse effects of ECT. In this case series, the author reviews the experience with 14 patients who had undergone ECT who were switched to ketamine as anesthetic from methohexital at the preference of the treating anesthesiologist. All 14 patients spontaneously reported a strong preference not to be given ketamine again due to bothersome adverse effects. The latter consisted of either vestibular-type symptoms (nausea/vomiting, dizziness, and vertigo) or psychotomimetic effects (dissociative phenomena). It is concluded that ketamine is not free of adverse effects when used as an ECT anesthetic. Electroconvulsive therapy clinicians should be vigilant about assessing for these effects when ketamine is used, and consideration should be given to using a benzodiazepine such as diazepam or midazolam at seizure termination when ketamine anesthesia is used to prevent bothersome adverse effects seen upon awakening.

Purpose of Review: Progress in medical technology, diagnostic procedures and imaging techniques results in a growing demand for well tolerated sedation regimens, devoid of respiratory and haemodynamic complications. Moreover, rapid turnover time dictates the need for rapid onset of effect and rapid recovery. Recent literature regarding the use of dexmedetomidine, ketamine and remifentanil for sedation outside the operating room is reviewed. As procedural sedation is often performed by nonanaesthesiologists, articles from journals other than anaesthesiology journals are also included., Recent Findings: Dexmedetomidine seems an attractive choice for sedation, because of the lack of respiratory depression. It has been studied as a sole sedation agent or in combination with benzodiazepines or opioids. As premedication, it can be administered intranasally. Disadvantages are a rather slow onset and recovery. Bradycardia and hypotension are common. Ketamine got renewed attention mainly by nonanaesthesiologists performing procedural sedation. Psychogenic adverse effects and slow recovery limit its use. Psychiatrists are interested in its antidepressive effect. Ketamine has a potential role in lowering the risk of chronification of pain, modified by analgesic and anti-inflammatory effects. Remifentanil as an ultra-short-acting agent is less well studied outside the operating room. Its unique pharmacology permits its use in patient-controlled analgesia and sedation, in target-controlled infusion or in a combined technique., Summary: Recent literature is reviewed regarding dexmedetomidine, ketamine and remifentanil for its use outside the operating room. Sedationists have to keep in mind the pharmacokinetics and pharmacodynamics of the currently used agents in adults and children.

In spaceflight beyond low Earth's orbit, medical conditions requiring surgery are of a high level of concern because of their potential impact on crew health and mission success. Whereas surgical techniques have been thoroughly studied in spaceflight analogues, the research focusing on anesthesia is limited. To provide safe anesthesia during an exploration mission will be a highly challenging task. The research objective is thus to describe specific anesthesia procedures enabling treatment of pre-identified surgical conditions. Among the medical conditions considered by the NASA Human Research Program Exploration Medical Capability element, those potentially necessitating anesthesia techniques have been identified. The most appropriate procedure for each condition is thoroughly discussed. The substantial cost of training time necessary to implement regional anesthesia is pointed out. Within general anesthetics, ketamine combines the unique advantages of preservation of cardiovascular stability, the protective airway reflexes, and spontaneous ventilation. Ketamine side effects have for decades tempered enthusiasm for its use, but recent developments in mitigation means broadened its indications. The extensive experience gathered in remote environments, with minimal equipment and occasionally by insufficiently trained care providers, confirms its high degree of safety. Two ketamine-based anesthesia protocols are described with their corresponding indications. They have been designed taking into account the physiological changes occurring in microgravity and the specific constraints of exploration missions. This investigation could not only improve surgical care during long-duration spaceflights, but may find a number of terrestrial applications in isolated or austere environments.

Purpose: Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter through activation of GABA receptors. Volatile anesthetics activate type-A (GABA(A)) receptors resulting in inhibition of synaptic transmission. Lung epithelial cells have been recently found to express GABA(A) receptors that exert anti-inflammatory properties. We hypothesized that the volatile anesthetic sevoflurane (SEVO) attenuates lung inflammation through activation of lung epithelial GABA(A) receptors., Methods: Sprague-Dawley rats were anesthetized with SEVO or ketamine/xylazine (KX). Acute lung inflammation was induced by intratracheal instillation of endotoxin, followed by mechanical ventilation for 4 h at a tidal volume of 15 mL/kg without positive end-expiratory pressure (two-hit lung injury model). To examine the specific effects of GABA, healthy human lung epithelial cells (BEAS-2B) were challenged with endotoxin in the presence and absence of GABA with and without addition of the GABA(A) receptor antagonist picrotoxin., Results: Anesthesia with SEVO improved oxygenation and reduced pulmonary cytokine responses compared to KX. This phenomenon was associated with increased expression of the π subunit of GABA(A) receptors and glutamic acid decarboxylase (GAD). The endotoxin-induced cytokine release from BEAS-2B cells was attenuated by the treatment with GABA, which was reversed by the administration of picrotoxin., Conclusion: Anesthesia with SEVO suppresses pulmonary inflammation and thus protects the lung from the two-hit injury. The anti-inflammatory effect of SEVO is likely due to activation of pulmonary GABA(A) signaling pathways.

Objectives: Studies now provide strong evidence that the N-methyl-D-aspartate receptor antagonist ketamine possesses rapidly acting antidepressant properties. This study aimed to determine if a low dose of ketamine could be used to expedite and augment the antidepressant effects of electroconvulsive therapy (ECT) treatments in patients experiencing a severe depressive episode., Materials and Methods: Subjects with major depressive disorder or bipolar disorder referred for ECT treatment of a major depressive episode were randomized to receive thiopental alone or thiopental plus ketamine (0.5 mg/kg) for anesthesia before each ECT session. The Hamilton Depression Rating Scale (HDRS) was administered at baseline and at 24 to 72 hours after the first and sixth ECT sessions., Results: Electroconvulsive therapy exerted a significant antidepressant effect in both groups (F2,24 = 14.35, P < 0.001). However, there was no significant group effect or group-by-time interaction on HDRS scores. In addition, post hoc analyses of the time effect on HDRS showed no significant HDRS reduction after the first ECT session for either group., Conclusions: The results of this pilot study suggest that ketamine, at a dose of 0.5 mg/kg, given just before ECT, did not enhance the antidepressant effect of ECT. Interestingly, the results further suggest that the coadministration of ketamine with a barbiturate anesthetic and ECT may attenuate the immediate antidepressant effects of the N-methyl-D-aspartate antagonist.

Purpose: Propofol and ketamine have become progressively popular in electroconvulsive therapy (ECT) anesthesia, although propofol shortened seizure duration and ketamine might cause cardiotoxicity, psychotic episodes, and delayed recovery. Ketofol is a combination of ketamine and propofol, and the current study was designed to evaluate the effect of ketamine, propofol, and ketofol on hemodynamic profile, duration of seizure activity, and recovery times in patients undergoing ECT., Methods: Ninety patients (44 women, mean age 27.8 ± 7.2 years) in one ECT session were enrolled and randomized to the propofol, ketamine, or ketofol group. Hemodynamic profile duration of seizure activity and recovery times were recorded., Results: Motor seizure duration in the propofol group was significantly decreased compared to other groups (p < 0.001), whereas spontaneous breathing time in the ketamine group statistically increased compared to the propofol group (p = 0.001), and also eye-opening time (p < 0.001) and obeying-command time (p < 0.001) was significantly increased in the ketamine group compared to other groups. Heart rate (HR) at induction (ketamine 91.2 ± 13.6 vs. propofol 77 ± 13.4 and ketofol 79.9 ± 15.6; p < 0.013; p < 0.08, respectively) was statistically significantly increased in the ketamine group compared to other groups, and HR at the third minute (ketamine 92 ± 12.9 vs. propofol 79.4 ± 9.3 and ketofol 81.5 ± 14.2; p < 0.012, p < 0.048) was also statistically significantly increased in ketamine group compared to other groups., Conclusion: The ketofol 1:1 mixture is associated with longer mean seizure time than propofol, and shorter mean recovery times than ketamine, with better hemodynamic stability, without any important side effects in ECT anesthesia.

The aim of this study was to evaluate the effect of a ketamine:propofol combination ('ketofol') for electroconvulsive therapy on seizure activity, haemodynamic response and recovery parameters, and to compare with these with the effects of propofol alone. Twenty-four patients underwent a total of 144 electroconvulsive therapy sessions, allocated in this prospective, double-blind, crossover study. Patients were randomly assigned to receive 1 mg/kg ketofol (0.5 mg/kg propofol plus 0.5 mg/kg ketamine) or 1 mg/kg propofol 1% for anaesthesia induction. Seizure duration and quality, haemodynamic data, recovery parameters and side-effects were recorded and analysed between groups. Both motor and electroencephalography seizure durations in the ketofol group (29 ± 17 and 41 ± 17 seconds, respectively) were similar to that in the propofol group (28 ± 13 and 38 ± 16 seconds, respectively). Postictal suppression index was higher in the ketofol group (89.63 ± 7.88) than in the propofol group (79.74 ± 14.6) (P <0.05). In the ketofol group, heart rate after the seizure ended and mean arterial pressures, recorded at 0 and 5 minutes after the seizure ended, were higher than in the propofol group. Time to obeying commands was longer in the ketofol group (P <0.05). There were no untoward psychological reactions following ketofol. Although no superiority to propofol in terms of seizure duration, haemodynamic or recovery parameters was found, the ketofol mixture selected in our study provided better seizure quality than propofol. We conclude that ketofol can be an alternative strategy to enhance the seizure quality and clinical efficiency of electroconvulsive therapy.

Objectives: To report our experience of providing anesthesia for noncardiac procedures in children with in situ Berlin Heart EXCOR Pediatric ventricular assist devices and to suggest principles of anesthetic management., Background: With the initiation of the first North American training and support center for Berlin Heart at our institution in 2006, we have been asked to provide anesthesia for noncardiac procedures to these children. No current anesthetic approach to these children has been reported., Methods/materials: Anesthetic records for all noncardiac procedures for children with Berlin Heart between August 2006 and February 2009 in a tertiary care pediatric hospital were retrospectively reviewed. Charts were reviewed for demographic and clinical data, perioperative management, and occurrence of hypotension., Results: Twenty-nine procedures were performed on 11 patients. Hypotension was a common occurrence with all anesthetic induction and maintenance agents even at low doses. Ketamine induction, however, was less likely to produce hypotension, odds ratio for hypotension 0.1333 (95% confidence range 0.021-0.856). Hypotension was responsive to fluid bolus (60%) and alpha-receptor agonists (100%). Preoperative stability and presence of biventricular ventricular assist device (BiVAD) did not predict intraoperative hemodynamic course., Conclusions: Unlike patients with other ventricular assist devices, these children do not tolerate reductions in systemic vascular resistance (SVR) because of the relatively fixed cardiac output of this device. Agents that reduce SVR should be avoided where possible. Preoperative stability is not predictive. Fluids and alpha-agonists should be first-line response to hypotension in this population. Further study of this unusual population is warranted to further delineate best anesthetic practice.

Introduction: In this study the impact of 25 mg of ketamine racemate given just before surgery on recovery times and postoperative analgesic needs in patients undergoing vaginal hysterectomy and receiving propofol-remifentanil anaesthesia was investigated., Methods: With ethics committee approval 70 female patients aged 25-65 years were enrolled. All patients received a total intravenous anaesthesia with remifentanil and propofol with the propofol infusion being controlled to a Narcotrend index of 40. Patients in the ketamine group (n=35) received additionally a bolus dose of 25 mg ketamine racemate intravenously 3 min before skin incision. In addition to monitoring haemodynamics and circulation parameters, recovery times, postoperative pain and opioid needs were also recorded. Patients were also questioned on their satisfaction with the pain therapy., Results: All 70 patients completed the study and the groups were similar with respect to demographic data. The haemodynamics of the patients were stable in both groups and the postoperative pain measured over a 24-h period as well as the opioid needs were also comparable. However, recovery times were significantly prolonged in the ketamine group, e.g. the times to extubation were 8.3+/-4.0 min with ketamine compared to 6.1+/-2.1 min in the control group (p<0.01). Undesired side effects were overall rare but occurred to the same extent in both groups., Conclusions: This study demonstrated that 25 mg ketamine racemate given just before surgery significantly prolongs recovery times without reducing post-operative analgesic needs when applied to patients undergoing vaginal hysterectomy and receiving propofol-remifentanil anaesthesia. A bolus dose of 25 mg ketamine racemate cannot therefore be recommended for preemptive analgesia under these conditions.

Purpose of Review: This review discusses the place of the old anesthetic ketamine in pediatric anesthesia., Recent Findings: Despite the availability of modern alternatives, ketamine remains a frequently used drug particularly for anesthesia in high-risk children and for procedures outside the operating room. In adult patients undergoing surgery, a renewed interest in this drug is noted. It is the consequence of recent demonstrations of the following effects. First, ketamine is highly effective against surgery and opiate-induced hyperalgesia. Second, it has original antiproinflammatory properties. In other words, it promotes self-limitation of the inflammatory response that follows surgery. In the pediatric population, these benefits wait to be confirmed. Finally, questions arise about the safety of ketamine anesthesia. Ketamine is a potent proapoptotic drug. In rodents treated during the critical period for central nervous system development, long-term behavioral deficits were noted after an anesthetic dose of ketamine. The exact consequences of these proapoptotic properties on human brain tissue development have to be exactly determined and are still debatable., Summary: Ketamine has not yet revealed all its interactions in humans. Recent discoveries indicate interesting properties on the one hand and potentially deleterious effects on the other.

Ketamine is a non-competitive antagonist to the phencyclidine site of N-methyl-d-aspartate (NMDA) receptor for glutamate, though its effects are mediated by interaction with many others receptors. It has been introduced in clinical use since 1960's but today it is not largely employed as a general anaesthetic for its undesired psychic effects (emergence reactions) occurring in approximately 12% of patients. In the last decade, there has been a renewed interest in the use of subanaesthetic doses of ketamine for the treatment of acute and chronic pain. In the late 1990's, multiple prospective, randomised, controlled study has shown the efficacy of low dose of ketamine for postoperative pain relief, for analgesia during regional or local anaesthesia, and for opioid-sparing effect. At present, non-definitive conclusion can be drawn. More data are needed to define the possible long term effects and the clinical goal of ketamine use.

The effects of ketamine anesthesia on both hematological and serum biochemical variables were investigated in 19 male and 15 female cynomolgus monkeys. Blood samples were obtained from the cephalic vein within 30 minutes of an intramuscular injection of ketamine hydrochloride (10 mg/kg). Ketamine anesthesia caused a reduction in leukocyte counts and a significant reduction in lymphocytes percentages. Ketamine anesthesia also increased the serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine phosphokinase (CPK), but reduced the serum concentrations of glucose, inorganic phosphate, sodium and potassium. The alterations of hematological and serum biochemical values will be discussed. These alterations should be considered when designing studies for and interpreting data from cynomolgus monkeys.

The study was conducted on 10 buffalo calves with a weight of 98.5 +/- 3.9 kg and age 9.7 +/- 1.3 months. Ten trials of two treatments were carried out using a randomized block design. Atropine at the dose of 0.02 mg/kg bodyweight was administered in both the groups. The animals of group I received romifidine at the dose of 10 microg/kg i.v., 10 min after atropine administration, whereas, animals of group II received triflupromazine at the dose of 0.3 mg/kg i.m. and 10 min later romifidine at the dose of 10 microg/kg i.v. immediately followed by ketamine at the dose of 5 mg/kg i.v. The onset of action of romifidine in group I occurred within 2 min and the animals remained under mild sedation for 31 +/- 4.8 min. In group II, the triflupromazine-romifidine-ketamine combination induced anaesthesia for 14 +/- 2.3 min. Hypothermia, significant bradycardia and respiratory depression was noticed in both groups at different time intervals.

Twelve captive wild-caught adult arctic foxes (Alopex lagopus) were anesthetized a total of 24 times for an equal number of surgical procedures involving implantation of heart rate (HR) and core body temperature transmitters (Tb) between October 1995 and April 1997. Xylazine-ketamine and medetomidine-ketamine anesthesia was used, resulting in an unacceptably high death rate. One out of four foxes anesthetized with xylazine-ketamine died, whereas two of nine foxes anesthetized with medetomidine-ketamine died out of a total of 20 surgical procedures. Durations of the surgeries for implantation of Tb transmitters and HR transmitters were 73 +/- 7 min and 95 +/- 13 min, respectively.

Objectives: To describe our experience using ketamine sedation to facilitate pediatric critical care procedures, and to document the safety profile of ketamine in this setting., Design: Retrospective consecutive case series., Setting: Pediatric intensive care unit of a tertiary children's hospital., Patients: Children receiving ketamine for procedural sedation over a 5-year period., Interventions: We reviewed patient records to determine indication, dosing, adverse events, inadequate sedation, and recovery time for each sedation., Outcome Measures: Descriptive features of sedation including adverse events., Results: During the study period, children in our pediatric intensive care unit received ketamine at total of 442 times to facilitate a wide variety of critical care procedures, most commonly central line placement, esophagogastroduodenoscopy, and wound debridement. Most study children had substantial underlying illness (ASA > or = 3 in 88%; ASA > or = 4 in 39%). Inadequate sedation was noted in only nine (2%) procedures. Adverse effects included transient laryngospasm (n = 9), transient partial airway obstruction (n = 5), apnea with bradycardia (n = 1), emesis during the procedure (n = 2), emesis during recovery (n = 9), mild recovery agitation (n = 10), moderate-to-severe recovery agitation (n = 1), and excessive salivation (n = 4). There were no adverse outcomes attributable to ketamine., Conclusion: Pediatric intensivists skilled in ketamine administration can safely and effectively administer this drug to facilitate critical care procedures. Despite the ill nature of our patient sample, adverse effects were uncommon.

Unlabelled: The use of ketamine as a sole anesthetic induces marked central sympathetic stimulation, causing increased heart rate, blood pressure (BP), and oxygen consumption (VO2). Both alpha 2-agonists and benzodiazepines have been used to attenuate these potentially harmful ketamine-induced responses. This double-blind, randomized, placebo-controlled study was designed to compare the perioperative metabolic, hemodynamic, and sympathoadrenal responses to IM clonidine (2 micrograms/kg) and midazolam (70 micrograms/kg) premedication during ketamine anesthesia. VO2 was measured continuously using indirect calorimetry in 30 ASA physical status I patients. The patients received ketamine, mivacurium, and fentanyl for the induction of anesthesia. Anesthesia was maintained using a ketamine infusion and fentanyl boluses i.v. Preoperatively, both VO2 and BP decreased significantly after the administration clonidine and midazolam compared with placebo (P < 0.01). Intraoperatively, VO2 was higher in the midazolam group than in the placebo and clonidine groups (P < 0.05). Postoperatively, there were no significant differences in BP and VO2, although they stayed at lower level in the clonidine group during the whole postoperative period. Clonidine decreased pre- and postoperative plasma catecholamine concentrations (P < 0.05). Our results indicate that a midazolam-ketamine combination may induce potentially harmful metabolic stimulation, whereas the sympatholytic effects of clonidine on ketamine-anesthetized patients may be beneficial, as perioperative VO2 was decreased., Implications: Ketamine causes sympathetic stimulation with an ensuing increase in oxygen consumption. Anticipating that clonidine might attenuate this response, we measured oxygen consumption in patients undergoing surgery during ketamine anesthesia. Patients treated with a clonidine-ketamine combination had lower intra- and postoperative oxygen consumption than those treated with a midazolam-ketamine combination.

Combinations of medetomidine with either propofol or ketamine were compared for the sedation and induction of anaesthesia in dogs undergoing a variety of surgical (60 per cent) and non-surgical (40 per cent) procedures. Eighty-four dogs were used at four sites. Medetomidine was administered intramuscularly at a dose of 1000 micrograms/m2 body surface area 10 to 15 minutes before the induction of anaesthesia by the administration of propofol (n = 44) or ketamine (n = 40) dosed to effect. The dogs became sedated by medetomidine after a mean (sd) time of 6.7 (5.4) minutes, and their heart rates and respiration rates decreased. Sixteen of the dogs suffered an adverse effect, 13 of them vomited. Anaesthesia was induced by the intravenous administration of propofol (2.1 [0.7] mg/kg) or ketamine (3.7 [1.9] mg/kg), and further doses of the anaesthetic were given, depending on the length of the operation, once in 17 per cent, twice in 11 per cent and three or more times in 24 per cent of the cases. The heart rate of the dogs anaesthetised with ketamine was significantly higher than that of the dogs anaesthetised with propofol, but there were no other significant physiological differences. There were 11 adverse side-effects in the ketamine group compared with five in the propofol group and they were generally more severe. The quality of the recovery from anaesthesia was considered to be smooth in 89 per cent of the propofol group but in only 63 per cent of the ketamine group.

A combination of tiletamine hydrochloride and zolazepam hydrochloride in a 1:1 ration by weight was used successfully to sedate mountain brushtail possums, Trichosurus caninus, in the field. A standard total dose of 50 to 60 mg provided adequate sedation for the completion of a range of handling procedures. We describe the induction time, dose rate and side-effects associated with the use of tiletamine and zolazepam in T caninus.

The purpose of this survey was to identify complications occurring in horses with colic during anaesthesia and recovery from anaesthesia; and to determine any relationships between these complications and drugs used for induction or maintenance of anaesthesia. Two hundred and thirty nine horses were anaesthetised on a total of 250 occasions for colic surgery between January 1985 and May 1987. Of these, 189 recovered from 200 anaesthetic episodes. Most horses received xylazine and guaifenesin with either thiobarbiturate (68 per cent) or ketamine (24 per cent) and anaesthesia was maintained with either halothane (51 per cent), isoflurane (43 per cent), or first halothane then isoflurane (6 per cent). Sixty nine per cent also received an opioid. Hypotension or tachycardia were recorded in 15 and 13 per cent of anaesthesias, respectively. Arterial PO2 was less than 13.3 kPa in 17 per cent of 175 anaesthesias. None of these complications was associated with a specific anaesthetic agent. Hypertension was recorded in 11.5 per cent of anaesthesias and occurred more frequently during isoflurane anaesthesia (P < 0.05). The mean duration of anaesthesia was 126 mins (range, 50-270 mins), and was not different for horses receiving thiobarbiturate or ketamine, halothane or isoflurane. The time taken to stand after anaesthesia recorded on 149 occasions and was 63 +/- 24 mins (range, 15-135 mins). This was not different for the different anaesthetic agents. Horses that were excited or had difficulty standing up during recovery had a significantly longer duration of anaesthesia (165 +/- 51 mins) (P < 0.05) but no specific anaesthetic agent was involved. Of the 189 horses, 148 (75 per cent) survived and were discharged from the hospital. Horses that did not survive had a significantly increased prevalence of anaesthetic complications, and longer durations of anaesthesia.