Intramuscular Ketamine Research Articles

Effects of ketamine on EEG in baboons with genetic generalized epilepsy

Ketamine, a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, used as an anesthetic has been reported to induce seizures both in humans and baboons predisposed to epilepsy. In this study, we aimed to characterize the acute effects of ketamine on scalp (sc-EEG) and intracranial EEG (ic-EEG) in the baboon, which offers a natural model of genetic generalized epilepsy (GGE). We evaluated the electroclinical response to ketamine in three epileptic baboons. The raw EEG data were analyzed within 10 min of intramuscular ketamine (5–6 mg/kg) administration. Earliest EEG changes occurred after 30 s in sc-EEG and after 15 s in ic-EEG of ketamine administration. These initial changes involved increased paroxysmal fast activity (PFA) followed by slowing, the latter emerging first occipitally, and then spreading more anteriorly. Generalized spike-and-wave discharges (GSWDs) were evident on both sc-EEG and ic-EEG within two minutes, but focal occipital discharges were already increased on ic-EEG after 15 s. Occipital slowing emerged on ic-EEG after 30 s, before spreading fronto-centrally and orbito-frontally. By 60–120 seconds post-injection, ic-EEG demonstrated a parieto-occipital burst suppression (BS), which was not noted on sc-EEG. Ketamine waves and seizures, especially if the latter were subclinical, also appeared earlier on ic-EEG. This study highlights the anesthetic and proconvulsant effects of ketamine originate in the occipital lobes before fronto-central regions. We speculate that NMDAR concentration difference in cortical regions, such as the occipital and frontal cortices, are mainly involved in the expression of ketamine’s EEG effects, both physiological and epileptic.

Psychiatric Outcomes of Patients With Severe Agitation Following Administration of Prehospital Ketamine.

Ketamine is an emerging drug used in the management of undifferentiated, severe agitation in the prehospital setting. However, prior work has indicated that ketamine may exacerbate psychotic symptoms in patients with schizophrenia. The objective of this study was to describe psychiatric outcomes in patients who receive prehospital ketamine for severe agitation. This is a retrospective cohort study, conducted at two tertiary academic medical centers, utilizing chart review of patients requiring prehospital sedation for severe agitation from January 1, 2014, to June 30, 2016. Patients received either intramuscular (IM) versus intravenous (IV) ketamine or IM versus IV benzodiazepine. The primary outcome was psychiatric inpatient admission with secondary outcomes including ED psychiatric evaluation and nonpsychiatric inpatient admission. Generalized estimating equations and Fisher's exact tests were used to compare cohorts. During the study period, 141 patient encounters met inclusion with 59 (42%) receiving prehospital ketamine. There were no statistically significant differences between the ketamine and benzodiazepine cohorts for psychiatric inpatient admission (6.8% vs. 2.4%, difference= 4.3%, 95% CI= -2% to 12%, p=0.23) or ED psychiatric evaluation (8.6% vs. 15%, difference= -6.8%, 95% CI= -18% to 5%, p=0.23). Patients with schizophrenia who received ketamine did not require psychiatric inpatient admission (17% vs. 10%, difference= 6.7%, 95% CI= -46% to 79%, p=0.63) or ED psychiatric evaluation (17% vs. 50%, difference= -33%, 95% CI= -100% to 33%, p=0.55) significantly more than those who received benzodiazepines, although the subgroup was small (n=16). While there was no significant difference in the nonpsychiatric admission rate between the ketamine and benzodiazepine cohorts (35% vs. 51%, p=0.082), nonpsychiatric admissions in the benzodiazepine cohort were largely driven by intubation (63% vs. 3.8%, difference= 59%, 95% CI= 38% to 79%, p<0.001). Administration of prehospital ketamine for severe agitation was not associated with an increase in the rate of psychiatric evaluation in the emergency department or psychiatric inpatient admission when compared with benzodiazepine treatment, regardless of the patient's psychiatric history.

Investigation of the Effects of Spinal Dexamethasone Injection as a Premedication in Rabbit Anesthesia.

Anesthesia and analgesia are important in human and veterinary medicine, especially in surgical procedures. Rodents, avians, and exotic species are required to be anesthetized using an appropriate anesthetic regimen. This study aimed to suggest a new anesthetic drug and method in order to facilitate anesthesia as well as analgesia among rabbits, laboratory animals, and humans. Spinal injection of dexamethasone combined with intramuscular ketamine among rabbits can play the role of premedication agents. A total of 24 healthy white adult rabbits from New-Zealand were equally assigned into four groups. Groups 1, 2, 3, and 4 were subjected to spinal xylazine (5mg/kg) with ketamine (35mg/kg,IM), spinal dexamethasone (0.37mg/kg-four times diluted) with ketamine (35mg/kg,IM), dexamethasone (4mg/kg,IM) with ketamine (35mg/kg,IM), and spinal dexamethasone (0.37mg/kg-four times diluted), respectively. The results showed that there was a significant difference in terms of clinical reflexes recorded for group 2, compared to groups 1 and 3. A significant difference was also observed regarding clinical reflexes between group 2 and the other groups. Furthermore, no abnormality was observed in terms of histological sections within groups 2 and 4. Spinal dexamethasone can be used as a premedication combined with ketamine in rabbit anesthesia.

Differential effects of sevoflurane and propofol on swine cardiac conduction system

ObjectiveTo compare the effects of sevoflurane and propofol on the porcine cardiac conduction system. Study designA prospective, comparative study of electrophysiological properties of anaesthetics agents in an experimental porcine model. AnimalsA total of 36 hybrid Landrace-Large White pigs. MethodsAfter premedication with 20 mg kg−1 of intramuscular ketamine, anaesthesia was induced with 4.5 mg kg−1propofol intravenously. In 18 consecutive animals, anaesthesia was maintained with propofol (13 mg kg−1 hour−1) and in the remaining 18 animals with 2.66% sevoflurane. The femoral artery and vein were canalized for invasive monitoring, analytical blood gas sampling and intracardiac catheter insertion. Following instrumentation and after a period of stabilization, a customary electrophysiological evaluation was performed. We compared the electrophysiology of the sinus and atrioventricular node (AV) node under sevoflurane or propofol anaesthesia, and the effects of both anaesthetics on atrial and ventricular refractoriness. ResultsThere was a significant difference in sinus node recovery time between sevoflurane and propofol (907 ± 231 versus 753 ± 146 ms, p = 0.02). Sevoflurane in comparison with propofol significantly prolonged specialized AV conduction times, represented by an increased Wenckebach cycle length (272 ± 54 versus 235 ± 40 ms, p = 0.03) and AV nodal refractoriness (327 ± 34 versus 287 ± 30 ms, p = 0.002). In addition, sevoflurane prolonged ventricular refractoriness (298 ± 27 versus 255 ± 38 ms, p = 0.007) and the QT corrected interval (0.50 ± 0.05 versus 0.46 ± 0.09 ms, p = 0.005). Conclusions and clinical relevanceSevoflurane in comparison with propofol, depresses several parameters of sinus and AV nodal function and prolongs the ventricular refractoriness of the porcine cardiac conduction system. These findings should be taken into consideration for the choice of anaesthetic agents in clinical and experimental settings.

Rapid agitation control with ketamine in the emergency department (RACKED): a randomized controlled trial protocol

BackgroundThe rapid control of patients presenting to the emergency department (ED) with psychomotor agitation and violent behavior is paramount for the safety of patients and ED staff. The use of intramuscular (IM) ketamine in the pre-hospital and ED settings has demonstrated promising preliminary results to provide rapid and safe behavioral control. A prospective, randomized controlled trial is required to measure the potential superiority of IM ketamine compared to current standard care (IM benzodiazepines plus antipsychotics).MethodsThis will be a parallel, prospective, randomized, controlled trial of 5 mg/kg IM ketamine compared to a combination of 5 mg IM midazolam and 5 mg IM haloperidol. The study will enroll approximately 184 patients, randomized equally to two study arms. There will be one study visit during which study medication will be administered and assessments will be completed. A follow-up safety visit will occur on day 3. The primary objective of this study is to compare IM ketamine to a combination of IM midazolam and haloperidol with regards to the time required for adequate behavioral control, in minutes, in patients presenting to the ED with psychomotor agitation and violent behavior, as measured by the Richmond Agitation-Sedation Scale (RASS).DiscussionWe present a novel study to determine whether ketamine is a rapid and safe option, compared to a combination of midazolam and haloperidol for the sedation of patients presenting to the ED with psychomotor agitation and violent behavior. To our knowledge, this study is the first randomized controlled trial to compare ketamine to current standard care for this indication. We have attempted to address numerous logistical issues with the design of this study including a waiver of consent, ensuring adequate blinding of outcome assessors, patient enrolment, and data monitoring.Trial registrationClinicaltrials.gov, NCT03375671. Registered on 18 December 2017.

Effect of Intramuscular Ketamine versus Haloperidol on Short-Term Control of Severe Agitated Patients in Emergency Department; A Randomized Clinical Trial.

Objective:To evaluate the efficacy and safety of intramuscular ketamine and haloperidol in sedation of severely agitated patients in emergency department (ED). Methods: This randomized, double-blind clinical trial study was performed on agitated patients referring to two university educational hospitals. Patients were randomly assigned to receive intramuscular (IM) haloperidol (5 mg) or IM ketamine (4 mg/kg). The primary outcome was time to adequate sedation (AMSS ≤ +1). Secondary outcomes included the need for additional sedatives, required intubation, duration of hospitalization, and side effects. Results:The 90 agitated patients were enrolled. The mean age was 30.37±7.36 years (range 18–56); 74% (67/90) were men. The mean time to adequate sedation in ketamine group (7.73 ± 4.71 minutes) was significantly lower than haloperidol group (11.42 ± 7.20 minutes) (p= 0.005). 15 minutes after intervention, the sedation score did not differ significantly in both groups (Ketamine:0.14 ± 0.59 vs. Haloperidol: 0.30 ± 0.60; p=0.167). The incidence of complications was not significantly different between groups. The physician's satisfaction from the patients’ aggression control was significantly higher in ketamine group. Conclusion:These data suggest ketamine may be used for short-term control of agitated patients, additional studies are needed to confirm if ketamine is safe in this patient population. Given rapid effective sedation and the higher physician satisfaction of ketamine in comparison to haloperidol, it may be considered as a safe and appropriate alternative to haloperidol.IRCT Code: IRCT20180129038549N5

Medetomidine–ketamine–sevoflurane anaesthesia in juvenile Nile crocodiles (Crocodylus niloticus) undergoing experimental surgery

ObjectiveTo describe the anaesthetic, physiological and side effects of intramuscular (IM) medetomidine and ketamine, followed by inhalational anaesthesia with sevoflurane, in Nile crocodiles (Crocodylus niloticus). Study designObservational trial. AnimalsTen juvenile captive-bred Nile crocodiles undergoing surgical implantation of skeletal beads and muscular electrodes. MethodsDuring preanaesthetic examination, the following variables were assessed: heart (HR) and respiratory (fR) rates, and response to palpebral, corneal and toe- and tail-pinch withdrawal reflexes. The crocodiles were injected IM with an initial combination of medetomidine and ketamine and re-evaluated at 5 minute intervals for 20 minutes, or until they appeared unresponsive. If that did not occur, the drugs were redosed according to a decision tree based on the observed effects. The righting, biting and palatal valve reflexes were assessed in the unresponsive crocodiles, and used to confirm anaesthetic induction. Anaesthesia was maintained with sevoflurane in oxygen. At the end of surgery, medetomidine was antagonized with IM atipamezole. ResultsThe decision tree identified 0.3 mg kg−1 medetomidine and 15 mg kg−1 ketamine as a useful drug combination, which resulted in anaesthetic induction and surgical anaesthesia 16 ± 8 and 16 (25–20) minutes after injection, respectively. Compared to baseline, HR and fR significantly decreased after anaesthetic induction (p < 0.001), but then remained stable throughout surgery. Intraoperatively, cloacal temperature [27 (26–30) °C] did not change over time (p = 0.48). The total dose of atipamezole was 2 (1–3) mg kg−1 and time to recovery was 36 (20–60) minutes. Perioperative complications were not observed. Conclusionsand clinical relevance Medetomidine and ketamine, injected IM and followed by sevoflurane anaesthesia, may be regarded as a useful anaesthetic technique for juvenile Nile crocodiles undergoing minimally invasive experimental surgery.

Trends in Prehospital Analgesia Administration by US Forces From 2007 Through 2016

Background: Tactical Combat Casualty Care (TCCC) guidelines regarding prehospital analgesia agents have evolved. The guidelines stopped recommending intramuscular (IM) morphine in 1996, recommending only intravenous (IV) routes. In 2006, the guidelines recommended oral transmucosal fentanyl citrate (OTFC), and in 2012 it added ketamine via all routes. It remains unclear to what extent prehospital analgesia administered on the battlefield adheres to these guidelines. We seek to describe trends in analgesia administration patterns on the battlefield during 2007–2016.Methods: This is a secondary analysis of a Department of Defense Trauma Registry data set from January 2007 to August 2016. Within that group, we searched for subjects who received IM morphine, IV morphine, OTFC, parenteral fentanyl, or ketamine (all routes).Results: Our predefined ED search codes captured 28,222 subjects during the study period. Of these, 594 (2.1%) received IM morphine; 3,765 (13.3%) received IV morphine; 589 (2.1%) received OTFC; and 1,510 (5.4%) subjects received ketamine. Annual rates of administration of IM morphine were relatively stable during the study period, while those for OTFC and ketamine generally trended upward starting in 2012. In particular, the proportion of subjects receiving ketamine rose from 3.9% (n = 995/25,618) during the study period preceding its addition to the TCCC guidelines (2007 to 2012) to 19.8% thereafter (2013–2016, n = 515/2,604, p < 0.001).Conclusions: During the study period, rates of prehospital administration of IM morphine remained relatively stable while those for OTFC and ketamine both rose. These findings suggest that TCCC guidelines recommending the use of these agents had a material impact on prehospital analgesia patterns.

Neuromuscular blockade of atracurium in permissive hypercapnic versus normocapnic swine undergoing laparoscopy.

Neuromuscular blocking agents (NMBAs) are commonly used in experimental laparoscopy in swine undergoing carbon dioxide pneumoperitoneum. Hypercapnia may be present and may prolong NMBAs’ pharmacologic activity. The aim of this study is to evaluate the effect of permissive hypercapnia on the neuromuscular blockade of atracurium in swine. Six Large White swine weighing 30.5 ± 1.6 kg were sedated with intramuscular ketamine and medetomidine, after which anaesthesia was induced with propofol and maintained with sevoflurane. Atracurium 0.4 mg/kg was administered intravenously and the neuromuscular block monitored by acceleromyography during normocapnic and hypercapnic conditions (PaCO2 range 35–45 mmHg and 60–70 mmHg, respectively). Onset time and time to reach a train of four ratio (TOFR) of 0.7 and 0.9 were recorded. Cardiorespiratory parameters, electrolytes and acid-base status were measured under both conditions. Onset time was similar between the two conditions. Time to reach a TOFR of 0.7 and 0.9 (duration of the neuromuscular block) was longer in hypercapnic compared to normocapnic animals being 1325 ± 300 vs 855 ±111 (p = 0.002) and 1823 ± 434 vs 1218 ± 210 seconds (p = 0.005), respectively. Three hypercapnic swine had a TOF count of 2 and 1 instead of a count of 4 with fade. Permissive hypercapnia was associated with a decrease in pH from 7.444 ± 0.039 to 7.257 ± 0.025 (p < 0.001). No differences were observed for heart rate, end-tidal concentration of sevoflurane, body temperature and arterial haemoglobin saturation. Nonetheless, hypercapnic swine had a statistically significant increase in mean arterial pressure (p = 0.020) and plasma potassium concentration (p = 0.003). The values of PaCO2 achieved during hypercapnia were well tolerated in swine undergoing CO2 pneumoperitoneum for laparoscopy. Permissive hypercapnia increased the duration of the atracurium effect and caused an increase in the intensity of the neuromuscular block in few swine.

Intramuscular Ketamine Protocol as an Alternative to Physical Restraints for Electroconvulsive Therapy Administration in a Psychotic Patient

Intramuscular Ketamine Protocol as an Alternative to Physical Restraints for Electroconvulsive Therapy Administration in a Psychotic Patient

Population Pharmacokinetics of Intramuscular and Intravenous Ketamine in Children.

Ketamine is an N-methyl D-aspartate receptor antagonist used off-label to facilitate dissociative anesthesia in children undergoing invasive procedures. Available for both intravenous and intramuscular administration, ketamine is commonly used when vascular access is limited. Pharmacokinetic (PK) data in children are sparse, and the bioavailability of intramuscular ketamine in children is unknown. We performed 2 prospective PK studies of ketamine in children receiving either intramuscular or intravenous ketamine and combined the data to develop a pediatric population PK model using nonlinear mixed-effects methods. We applied our model by performing dosing simulations targeting plasma concentrations previously associated with analgesia (>100ng/mL) and anesthesia awakening (750ng/mL). A total of 113 children (50 intramuscular and 63 intravenous ketamine) with a median age of 3.3years (range 0.02 to 17.6years), and median weight of 14kg (2.4 to 176.1) contributed 275 plasma samples (149 after intramuscular, 126 after intravenous ketamine). A 2-compartment model with first-order absorption following intramuscular administration and first-order elimination described the data best. Allometrically scaled weight was included in the base model for central and peripheral volume of distribution (exponent 1) and for clearance and intercompartmental clearance (exponent 0.75). Model-estimated bioavailability of intramuscular ketamine was 41%. Dosing simulations suggest that doses of 2mg/kg intravenously and 8mg/kg or 6mg/kg intramuscularly, depending on age, provide adequate sedation (plasma ketamine concentrations>750ng/mL) for procedures lasting up to 20minutes.

Effect of Ondansetron on the Incidence of Ketamine Associated Vomiting in Procedural Sedation and Analgesia in Children: A Double-Blind, Randomized, Placebo-Controlled Trial

Background Vomiting is a common side effect of ketamine in children's sedation and there is still controversy about the use of an anti-emetic drug along with ketamine to reduce this complication. The aim of this study was to evaluate the effectiveness of ondansetron in controlling vomiting induced by intramuscular (IM), and intravenous (IV) ketamine for procedural sedation and analgesia in children in the emergency department (ED). Materials and Methods In a double-blind, randomized, placebo-controlled clinical trial, children aged 1 to 10 years who received ketamine for ED procedures were randomized into four groups receive IV ketamine (1.5 mg/kg), and placebo, IM ketamine (5mg/kg) and placebo, IV ketamine and IV ondansetron (0.15 mg/kg), and IM ketamine and oral ondansetron. The incidence of nausea and vomiting and ED length of stay were compared as the outcome of the study. Results One hundred eighty children were enrolled and randomized to four groups; 29 patients (15.0%) had nausea and vomiting. The incidence of vomiting was 26.7% in the IV ketamine-placebo group and 8.9% in the IV ketamine/ IV ondansetron group (P = 0.02). The incidence of vomiting was 17.8% in the IM ketamine-placebo group and 11.1% in the IM ketamine/oral ondansetron group (P = 0.17). ED length of stay was similar between groups. Conclusion According to current results, children administered IV ondansetron before IV ketamine experienced a significantly reduced incidence of vomiting but did not significantly affect length of ED stay and the addition of oral ondansetron to IM ketamine dose not reduce vomiting.

Treatment of Behavior Disturbances with Ketamine in a Patient Diagnosed with Major Neurocognitive Disorder

A 77-year-old woman who had been previously diagnosed with a major neurocognitive disorder became highly agitated and aggressive in a long-term care facility. She did not respond to intramuscular (IM) haloperidol plus lorazepam and had to be transported to the local emergency department (ED). In the ambulance, she remained highly agitated and was given 200 mg IM ketamine. Within minutes of receiving this, she de-escalated dramatically with no apparent adverse effects and remained stable for several days. Although ketamine has been used recently in pre-hospital settings and EDs to reduce agitated behavior, there has been little if any investigation of its potential for reducing behavior disturbances in patients who suffer from major neurocognitive disorders. Ketamine could potentially be a promising treatment option for this population, but more research is needed.

Efficacy of Postoperative Analgesia of Local Ketamine Wound Instillation Following Total Thyroidectomy: A Randomized, Double-blind, Controlled Clinical Trial.

Total thyroidectomy is recommended as a line of management of thyroid cancer in many cases. Our aim was to compare postoperative analgesic effect of local ketamine 1 mg/kg instilled in the wound to that of intramuscular (IM) ketamine and placebo after total thyroidectomy. A total of 90 patients aged 18 to 60 years, American Society of Anesthesiologists (ASA) class I to II, with a body weight of 50 to 90 kg, scheduled for total thyroidectomy were enrolled after ethics committee approval in this prospective, randomized, double-blind, controlled study and divided randomly into 3 groups to receive treatment after hemostasis. Group (I) received 1 mg/kg ketamine in a total volume of 10 mL normal saline instilled in the wound. Group (II) received 1 mg/kg of IM ketamine. Group (III) received 10 mL of normal saline instilled in the wound. Total amount of morphine consumption, first request of analgesia, and side effects were recorded. Visual analog scale at rest and movement and hemodynamics were assessed immediately, 1, 2, 4, 6, 12, and 24 hours postoperatively. Total morphine consumption was reduced and first request of analgesia was delayed in group I compared with that in groups II and III, and in group II compared with that in group III (P=0.000). Visual analog scale at rest and movement were decreased immediately postoperatively in groups I and II in comparison with their values in group III; group II had higher sedation scores. Local wound ketamine instillation provided superior postoperative analgesia with lower incidence of side effects in comparison with IM ketamine and placebo following total thyroidectomy.

Onset and Effect Duration of Intrabuccal Space and Intramuscular Ketamine in Pediatrics.

Background:Painful diagnostic and therapeutic procedures performed for children are routine actions. Opioids and nonsteroidal anti-inflammatory drugs such as acetaminophens are among medications that can be used for this purpose. This study aimed to compare the onset and duration of action of intrabuccal (IB, submucosal) space and intramuscular (IM) injection of ketamine in pediatrics.Materials and Methods:This clinical trial study was carried out on 126 children of 1–15 years old referred to the emergency room of Al-Zahra and Kashani Hospitals in Isfahan and divided into two 63 populated groups of IM and IB. For one group randomly, 3 mg/kg IB ketamine was administered, and for another group, ketamine was injected intramuscularly at the dose of 5 mg/kg. The drug effect, surgeon satisfaction, and complications were evaluated. Data were analyzed using SPSS software.Results:The mean of time between injection and onset of drug effect in IM group was 5.71 min, whereas in IB group, it was 4.14 min (P < 0.0001). The mean of the duration of drug effect in IM group was 45.54 min, whereas in IB group, it was 24.63 min (P < 0.0001). Complications in IM group were significantly more reported than IB group (33.3% versus 11.1%, respectively, P = 003). The median of surgeon satisfaction in IM group was 3 and in IB group was 4 which was statistically significant (P = 0.007).Conclusions:IB method is preferred over IM method, and hence, it is recommended to use.

Impact of oral ketamine augmentation on hospital admissions in treatment-resistant depression and PTSD: a retrospective study.

Depressive episodes are the leading cause of mental health-related hospital admissions in Australia, and 44% of those admitted have a previous history of hospitalisations for depression (Admitted patient mental health-related care: (Australian Institute of Health and Welfare Aust Hospital Stat 2011-12, 2013). Despite numerous available antidepressant treatments, many patients do not respond to conventional therapy, having what is called 'treatment resistance' (Fava Biol Psychiatry 53:649-659, 2003). In recent years, ketamine has risen to prominence as an effective, rapidly acting antidepressant (Ketamine: a light in the darkness: Paleos and Ross 28-33, 2013). However, customary intravenous (IV) and intramuscular (IM) routes of administration and relapse rates after cessation remain barriers to more widely adopted usage. This study represents the largest retrospective review of patients receiving long-term oral ketamine for treatment-resistant depression and post-traumatic stress disorder (PTSD). Our purpose was to examine the safety and efficacy of oral ketamine therapy in an outpatient setting as measured by changes in hospitalisation for psychiatric episodes. Hospital records of 37 patients who received oral ketamine treatment were reviewed to compare the number and duration of psychiatric hospital admissions before and after treatment. Records were also screened for adverse medical events and changes in ketamine dosage over time. Following treatment, inpatient hospital days were reduced by 70%, and hospital admissions were reduced by 65%. The dose of ketamine patients required was stable over time with no evidence of tolerance building. There were no serious adverse events and no long-term negative effects associated with ketamine. Oral ketamine offers a promising pharmacologic adjunct to depression treatment. It may offer a more approachable alternative to IV or IM ketamine. The results warrant further investigation into the safety and efficacy of oral ketamine for psychiatric treatment.

Potential Role of Ketamine in the treatment of Schizoaffective Disorder, Depressive Type

Ketamine use for patients with severe treatment-resistant depression continues to be an area of interest due to the relatively limited number of treatment options for those patients. Although its use as a treatment option for patients with schizophrenia and schizoaffective disorder may seem counterintuitive, in this case report, we explore the efficacy of ketamine for depressive episodes in schizoaffective disorder. This patient who carried a diagnosis of schizoaffective disorder was given 300 mg of intramuscular ketamine for agitation. However, over the course of four days of inpatient stay, her depression drastically improved. She met criteria for remission with the Hamilton Rating Scale for Depression (HAM-D) score of 4, down from an initial score of 21. We advocate for a better understanding of the pros and cons of using ketamine for depression in schizoaffective disorders considering the controversy over the diagnosis of schizoaffective disorder, especially in African American population. At the urging of reducing the risk of suicide among this group and improving their quality of life as well as reducing financial burden by shortening total duration of hospitalization, it may be worthwhile to explore the feasibility of ketamine as a treatment option for severe depression in these patients, possibly as a last resort.

Predictors of emesis in children undergoing procedural sedation with intramuscular ketamine in a paediatric emergency department.

Emesis is one of the most common adverse events associated with ketamine sedation. However, its predictors have not been clearly studied among Asian children. This study aimed to determine the incidence and predictors of emesis in children undergoing intramuscular (IM) ketamine sedation in an emergency department (ED) in Singapore and to identify high-risk groups, so that antiemetics may be administered prophylactically. In a prospective observational study, all children requiring procedural sedation with IM ketamine in the paediatric ED between 1 April 2013 and 31 January 2015 were included. All cases of emesis following ketamine sedation were prospectively documented. Univariate and multivariate logistic regression analyses were performed to identify the predictors of emesis. 2,502 sedations were performed using IM ketamine in the ED during the study period. Overall incidence of emesis associated with IM ketamine sedation was 8.4%. Children aged ≥ 8 years were significantly associated with increased risk of emesis (odds ratio 4.636, 95% confidence interval 3.271-6.570; p < 0.001), with an emesis rate of 19.6%. Other variables such as initial dose (3 mg/kg vs. 4 mg/kg), total dosage (including top-ups), type and site of procedure, gender and ethnicity were not significant predictors. The number needed to treat for antiemetics in children aged ≥ 8 years was five. Age is a significant predictor of emesis. We recommend conducting a randomised controlled trial to compare the effects of prophylactic oral ondansetron in patients stratified into the age groups of ≥ 8 years and < 8 years.

A prospective study of ketamine as primary therapy for prehospital profound agitation

ObjectiveWe investigated the effectiveness of ketamine as a primary therapy for prehospital profound agitation. MethodsThis was a prospective observational study of patients receiving 5mg/kg of intramuscular ketamine for profound agitation, defined as a score of +4 on the Altered Mental Status Scale (AMSS), a validated ordinal scale of agitation from −4 (unresponsive) to +4 (most agitated). The primary outcome was time to adequate sedation (AMSS<+1). Secondary outcomes included need for additional sedatives, intubation frequency, complications associated with ketamine, and mortality. ResultsForty-nine patients were enrolled. Median age was 29years (range 18–66); 76% (37/49) were male. Median time to adequate sedation was 4.2min (95% CI: 2.5–5.9, range 1–25min) and 90% (44/49) had adequate sedation prehospital. Seven patients (14%) received a second sedative prehospital. Intubation occurred in 57% (28/49) of patients. Mechanical ventilation lasted <24h in 82% (23/28) of patients, and <48h in 96% (27/28) of patients. A single physician intubated 36% (10/28) of the patients. Complications related to ketamine included hypersalivation (n=9, 18%), vomiting (n=3, 6%), and emergence reaction (n=2, 4%). One patient died from complications of septic shock on hospital day 29, likely unrelated to ketamine. ConclusionsIn patients with prehospital profound agitation, ketamine provides rapid effective sedation when used as a primary therapy. Intubation was common but accompanied by a short duration of mechanical ventilation and appears to have been subject to individual physician practice variation.

Chemical Immobilization of Free-ranging Yellow Armadillos (Euphractus sexcinctus) for Implantation of Intra-abdominal Transmitters.

Free-ranging yellow armadillos (Euphractus sexcinctus) from the Brazilian Pantanal were captured for surgical implantation of intra-abdominal radio transmitters. During March 2014, 11 animals were chemically immobilized with a combination of intramuscular ketamine hydrochloride, xylazine hydrochloride, midazolam maleate, and atropine sulfate. The mean induction time and initial heart rate in males was higher than in females. The sex of armadillos did not affect the respiratory rate, which increased from the beginning to end of the monitoring time. The rectal temperatures of females remained almost unchanged, whereas the rectal temperatures of males suffered a slight drop through the procedure. The mean (±SD) total surgical time was 50±6.5 min, and the total anesthetic recovery time was 2.5±0.5 h. The armadillos were monitored for 24 h after surgery and released at their capture site. The anesthetic association was effective, promoting muscle relaxation and analgesia that allowed the performance of surgical procedures.