Ketamine

Ketamine for Super-Refractory Status Epilepticus in Palliative Care. A Case Report and Review of the Literature

We report a case of super refractory status epilepticus uncontrolled by multiple anti-seizure medications in an individual with acute liver failure due to hepatic cirrhosis and an obstructive ileocecal mass plus multiple bilateral lung lesions presumed to be metastatic. A ketamine infusion was initiated late in his hospitalization which eliminated the convulsive seizures in less than an hour. The abatement of convulsive seizures allowed his grieving wife to return to her husband's bedside to witness the withdrawal of life sustaining treatment and be present during the final 24 hours of his life. We review the medical literature on the role of Intravenous (IV) Ketamine in the treatment of super refractory status epilepticus.

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

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

Magnesium-induced ketamine toxicity

A 62-year-old man with metastatic duodenal cancer was admitted to a hospice for a trial of ketamine to manage complex neuropathic abdominal pain. The patient was incrementally established on a dose of 150 mg orally four times day with no adverse effects. Following treatment of hypomagnesaemia intravenously, the patient experienced marked symptoms of ketamine toxicity, known as a 'K-hole' amongst recreational users, following the next dose of ketamine. Ketamine and magnesium are both antagonists of the N-methyl-D-aspartate receptor, which plays a part in central sensitisation to pain. There is some evidence that correction of hypomagnesaemia may improve analgesia and that there is synergism between ketamine and magnesium in analgesia, but this relationship is poorly understood. This is the first report suggesting that blood magnesium levels may affect the side effects of a stable dose of ketamine.

Diabetes insipidus related to sedation in the intensive care unit: A review of the literature

PURPOSE

To identify cases of diabetes insipidus (DI) related to sedation in the ICU to determine which medications pose the greatest risk and understand patterns of presentation.

MATERIALS AND METHODS

We searched PubMed, Embase, Scopus, Google Scholar, and Web of Science. Search terms included "polyuria," "diabetes insipidus," "hypnotics and sedatives," "sedation," as well as individual medications. Case reports or series involving DI or polyuria related to sedation in the ICU were identified.

RESULTS

We identified 21 cases of diabetes insipidus or polyuria in the ICU attributed to a sedative. Dexmedetomidine was implicated in 42.9% of cases, followed by sevoflurane (33.3%) and ketamine (23.8%). Sevoflurane was implicated in all 7 cases in which it was used (100%; 95% CI 59.0%, 100.0%), dexmedetomidine in 9 of 11 cases (81.8%; 95% CI 48.2, 97.7), and ketamine in 5 of 9 cases (55.6%; 95% CI 21.2%, 86.3%).

CONCLUSIONS

Awareness of the potential for sedatives to cause DI may lead to greater identification with swifter medication discontinuation and subsequent resolution of DI.

Curcumin alleviates ketamine-induced oxidative stress and apoptosis via Nrf2 signaling pathway in rats' cerebral cortex and hippocampus

AIMS

To investigate curcumin's protective effect on nerve damage caused by ketamine anesthesia via the Nrf2 signaling pathway. Rats and PC12 cells were used in this experiment to investigate the mechanism of nerve injury caused by ketamine anesthesia. Furthermore, our findings suggest that curcumin may affect oxidative stress and apoptosis by targeting the Nrf2 pathway, thereby alleviating the nerve injury caused by ketamine.

METHODS

The rat cerebral cortex and hippocampus were stained with Nissl and immunohistochemistry to determine the number of neurons and the expression of Caspase-3, Bcl-2, and Bax. CCK-8 assay was used to determine the optimal concentration of ketamine, curcumin, and H₂ O₂ in PC12 cells. Flow cytometry was used to detect changes in reactive oxygen species and the rate of apoptosis in each group. To determine whether Nrf2 entered the nucleus, immunofluorescence was used. Both tissues and cells were subjected to RT-PCR and Western blotting detection at the same time. The levels of oxidative stress were determined using a malondialdehyde (MDA) and superoxide dismutase (SOD) assay kit.

RESULTS

Ketamine reduced the number of neurons in the cortex and hippocampus of rats. The proteins Bax and Caspase-3 were upregulated, while Bcl-2 was down-regulated in the cortex and hippocampus. The viability of PC12 cells has decreased. MDA content increased while SOD activity decreased in cortex, hippocampus, and PC12 cells. Ketamine had an effect on the expression of some genes in the Nrf2 signaling pathway as well as apoptosis. Curcumin pretreatment may be able to prevent ketamine-induced damage.

CONCLUSIONS

The oxidative stress and apoptosis caused by ketamine during growth of the cerebral cortex, hippocampus, and PC12 cells may be decreased by curcumin's activation of the Nrf2 signaling pathway. Our research provides a potential strategy for the secure administration of anesthetics in medical settings.

Determining the effective dose of esketamine for mitigating pain during propofol injection by Dixon's up-and-down method: a double-blind, prospective clinical study of drug dose response

BACKGROUND

Propofol is an intravenous (IV) anesthetic medication widely used for procedural sedation, operative anesthesia, and in intensive care unit (ICU), but the incidence of pain during IV infusion can reach 28-90%. Ketamine can attenuate pain associated with IV propofol injection through local and central analgesic effects. Ketamine is gradually being transitioned to its S-enantiomer, esketamine, which has a similar mechanism of action. The purpose of our study is to determine the half effective dose (ED₅₀), 95% effective dose (ED₉₅), and 99% effective dose (ED₉₉) of esketamine for attenuating propofol injection pain using Dixon's up-and-down method to provide a reference for optimal dose selection for surgeries and procedures.

METHODS

Thirty gynecological patients undergoing hysteroscopic surgery were enrolled in a sequential method to determine the effective dose of esticketamine for analgesic propofol injection in order of operation. This study was based on the sequential allocation up-and-down rule designed by Dixon, and each patient was induced by esticketamine combined with propofol. During induction, the target dose of esketamine was first given via venous access in the left hand of the patient, and 30 s later, a fixed dose of 2 mg/kg (1 ml/s) of propofol was given. Patient perception of pain was scored with the verbal rating scale (VRS) every 5 s after the start of the propofol infusion, and the evaluation was stopped once the patient became unresponsive. The dosage of esketamine was increased or decreased up or down according to the patient's pain response. The initial dose of esketamine was 0.2 mg/kg, and the gradient of adjacent dose was 0.02 mg/kg. If the pain response assessment of the upper patient was positive (+), the dose of esselketamine in the next patient was increased by 0.02 mg/kg; if the pain response assessment of the upper patient was negative (-), the dose of esselketamine in the next patient was decreased by 0.02 mg/kg. The tests were carried out sequentially, with the pain response changing from positive to negative or from negative to positive, and the tests were stopped after at least 6 crossover points, and the effective dose of esticketamine was calculated using probit probability regression analysis.

RESULTS

The ineffective group comprised patients with a positive pain response and the effective group comprised patients with a negative pain response. The 95% CI was set as the confidence interval of effective dose ED value，and we found esketamine's ED₅₀ = 0.143 mg/kg (0.120, 0.162 mg/kg), ED₉₅ = 0.176 mg/kg (0.159, 0.320 mg/kg), and ED₉₉ = 0.189 mg/kg (0.167, 0.394 mg/kg). The esketamine dose and VRS score during propofol injection were significantly different between the two groups (P < 0.05), whereas surgical duration, emergence time, visual analogue scale (VAS) score of postoperative uterine contraction pain, and Riker sedation/anxiety scale (SAS) score were not significantly different. Bradycardia occurred in only one patient during anesthesia induction, while hemodynamics was stable in the rest of the patients without obvious adverse reactions.

CONCLUSION

Small doses of esketamine combined with propofol can be safely and effectively used for hysteroscopic surgery. We recommended a dose of 0.2 mg/kg IV esketamine before induction of anesthesia to reduce the pain of propofol injection.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100048951. Date of registration: July 19, 2021.

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

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

Long-term safety of ketamine and esketamine in treatment of depression

INTRODUCTION

Ketamine is an NMDA receptor antagonist that can produce rapid-acting antidepressant effects. Esketamine (Spravato), the S-enantiomer of racemic ketamine, was approved by the FDA for treatment-resistant depression in 2019. Here we review what is known about the long-term safety of both racemic ketamine and esketamine as therapies for psychiatric disorders.

AREAS COVERED

In this article, we conducted a safety review of ketamine and esketamine. In looking at ketamine and esketamine long-term safety effects, we considered data available from experimental studies and several phase-three clinical trials.

EXPERT OPINION

Based on available data, the most common side effects of ketamine/esketamine are generally transient, mild, and self-limited. These include dissociation, nausea, headache, elevated heart rate, and blood pressure. Treatment with esketamine may lead to an increased risk of lower urinary tract symptoms, such as dysuria or urgency. However, severe bladder pathology has not been reported among patients receiving doses of esketamine/ketamine in line with prescribing guidelines for depression. There is considerable data that ketamine at high doses can lead to long-term impairments in cognition. However, the esketamine clinical trials found that cognition generally remains stable or improves over time, suggesting that when used appropriately, there is no increased risk of cognitive impairment.

Repeated or Continuous Medically Supervised Ketamine Administration Associated with Hepatobiliary Adverse Events: A Retrospective Case Series

Introduction

Emerging off-label medical uses of ketamine for the treatment of persistent conditions such as depression and chronic pain often require repeated administration. Cases reported by other countries suggest that long-term and repeated exposure to ketamine may be associated with several risks, including but not limited to hepatobiliary damage.

Objective

We aimed (1) to characterize the association between repeated administration of ketamine for off-label medical use and hepatobiliary events and (2) to describe recent trends in the use of ketamine across different clinical settings.

Methods

We conducted a retrospective case series analysis, utilizing reports identified from the US Food and Drug Administration Adverse Event Reporting System database as well as the medical literature. We included all cases reported through July 2018 describing both repeated exposure to ketamine in a hospital or ambulatory setting and a hepatobiliary adverse event. We excluded cases describing ketamine abuse. We identified adverse hepatobiliary events using the Medical Dictionary for Regulatory Activities (MedDRA^®) and summarized various case characteristics including: patient demographics, route of ketamine administration, dose, time to onset of event, type of event, and pre-existing risk factors for hepatobiliary disease. To assess trends in the demand for ketamine, we used IQVIA, National Sales Perspectives™ to provide the nationally estimated number of vials sold for ketamine from the manufacturer to all US channels of distribution from 2013 through 2017.

Results

We identified 14 unique cases that met selection criteria with 21 hepatobiliary adverse events including liver enzyme elevation in all cases, biliary dilation with liver cirrhosis (n = 1), biliary dilation with cholangitis (n = 1), and pericholeductal fibrosis (n = 1). Most cases received ketamine for the treatment of complex regional pain syndrome or chronic pain. In cases with a reported time to onset, the majority of events occurred within 4 days. The nationally estimated number of ketamine vials sold in the USA from manufacturers to various channels of distribution increased from 1.2 million in 2013 to 2.1 million in 2017.

Conclusions

We report an association between repeated or continuous administration of ketamine and hepatobiliary adverse events. Increased awareness among clinicians may mitigate these adverse outcomes, especially in the context of growing ketamine sales.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01120-9.

Antisuicidal efficacy of ketamine infusion in suicidal patients of depressive disorder

BACKGROUND

The efficacy of ketamine in the rapid alleviation of depressive and suicidal symptoms has been observed over the past few years around the globe. Exploration of rapid antisuicidal efficacy of ketamine in Indian subpopulation can be a good preventive pharmacological option for unprecedented rise in suicides in India.

AIM

To assess efficacy of ketamine infusions on suicidal patients of depressive disorder. Severity of depression and suicidality were quantified daily over 1 week.

MATERIALS AND METHODS

This was a randomized control study, comprised sixty patients of age group 18-60 years, with a diagnosis of depressive episode, having the Modified Scale for Suicidal Ideations (MSSI) score >20 with exclusion of severe medical or surgical illness, pregnancy, and breast-feeding females. Patient were assigned to ketamine and normal saline group. Three infusions were given over 1 week on day 0, day 2, and day 4. Assessments were made at baseline using the 17-item Hamilton Depression Rating Scale (HAM-D17) and MSSI, for depression and suicidality, respectively. Assessments were repeated at 6 h after first infusion and then every day for 1 week.

RESULTS

There were significant reductions in HAM-D17 score and MSSI score within 6 h of the first dose in the ketamine group as compared to the normal saline group. Significant sustained improvement was seen on further days till 1 week in the ketamine group as compared to the normal saline group.

CONCLUSION

Ketamine might be a reasonable choice to fulfil the efficacy gap created by the delayed antisuicidal onset of standard treatments.

Optimizing Pain Control and Minimizing Opioid Use in Trauma Patients

Adverse effects of opioids and the ongoing crisis of opioid abuse have prompted providers to reduce prescribing opioids and increase use of multiple nonpharmacologic therapies, nonopioid analgesics, and co-analgesics for pain management in trauma patients. Nonopioid agents, including acetaminophen, nonsteroidal anti-inflammatory drugs, gabapentinoids, ketamine, central α2 agonists, and lidocaine, can be used as adjuncts or alternatives to opioids in the trauma population. Complementary therapies such as acupuncture, virtual reality, and mirror therapy are modalities that also may be helpful in reducing pain. Performing pain assessments is fundamental to identify pain and evaluate treatment effectiveness in the critically ill trauma patient. The efficacy, safety, and availability of opioid-sparing therapies and multimodal pain regimens are reviewed.

Repeated subcutaneous esketamine for treatment-resistant depression: Impact of the degree of treatment resistance and anxiety comorbidity

BACKGROUND

A large number of studies indicate that subanesthetic doses of ketamine induce a fast antidepressant effect. Limited studies have investigated the subcutaneous (SC) route, and it remains unclear for whom this treatment is most suitable.

AIMS

The aim of this study was to examine the effect on depressive symptoms of repeated subanesthetic doses of SC esketamine in unipolar and bipolar treatment-resistant depression (TRD) and clinical predictors of response.

METHODS

A retrospective analysis of 70 patients who received six SC esketamine doses weekly as an adjunctive treatment was carried out. Doses started at 0.5 mg/kg and it could be titrated up to 1 mg/kg, according to response. The primary outcome was reduction in depressive symptoms. Statistical analysis to investigate clinical predictors of effectiveness included logistic regression analysis using a dependent variable of a 50% reduction in rating scale scores at the end of treatment. Comparisons between groups were made through analysis of variance and treatment effects.

RESULTS

At baseline, our sample presented with severe treatment resistance in 65.7%, as assessed by the Maudsley Staging Method (MSM), and 47.1% had anxiety disorder comorbidity. The response rate was 50%. A better outcome was predicted by mild and moderate MSM scores (OR = 3.162, p = 0.041) and anxiety disorder comorbidity (OR = 3.149, p = 0.028).

CONCLUSIONS

Our results suggest that higher levels of treatment resistance may be associated with a poor response to SC esketamine. Unlike traditional pharmacotherapies, it might benefit those with poor prognosis such as patients with depression and comorbid anxiety. Therefore, future research could investigate whether esketamine should receive a more prominent place in the treatment algorithm for TRD.

Perioperative Diabetes Insipidus Caused by Anesthetic Medications: A Review of the Literature

Diabetes insipidus (DI) is an uncommon perioperative complication that can occur secondary to medications or surgical manipulation and can cause significant hypovolemia and electrolyte abnormalities. We reviewed and evaluated the current literature and identified 24 cases of DI related to medications commonly used in anesthesia such as propofol, dexmedetomidine, sevoflurane, ketamine, and opioids. This review summarizes the case reports and frequency of DI with each medication and presents possible pathophysiology. Medication-induced DI should be included in the differential diagnosis when intraoperative polyuria is identified. Early identification, removal of the agent, and treatment of intraoperative DI are critical to minimize complications.

Nonopioid Approaches to Pain Management in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) and end-stage renal disease experience high pain and symptom burden, but management of chronic pain in this population remains challenging. Recent studies have shown a high rate of opioid prescription and use in patients with kidney disease. However, the concern for opioid-related morbidity and mortality suggests a need to reconsider the safety and efficacy of opioid use in patients with CKD. In this review, we describe the current approaches to pain management in CKD, highlight the evolving opioid-related risks and kidney-specific concerns, and offer both pharmacologic and nonpharmacologic nonopioid strategies for pain management in patients with kidney disease, emphasizing the importance of using a multimodal approach to optimize pain control.

Effects of Anesthesia on Postoperative Recurrence and Metastasis of Malignant Tumors

It is difficult to control the recurrence and metastasis of malignant tumors; furthermore, anesthesia is considered one of the main influencing factors. There has been increasing clinical attention on the effects of anesthetic drugs and methods on postoperative tumor growth and metastasis. We reviewed the effects of anesthesia on tumor recurrence and metastasis; specifically, the effects of anesthetic agents, anesthesia methods, and related factors during the perioperative period on the tumor growth and metastasis were analyzed. This study can provide reference standards for rational anesthesia formulations and cancer-related pain analgesia protocols for surgical procedures in patients with malignant tumors. Moreover, it contributes toward an experimental basis for the improvement and development of novel anesthetic agents and methods.

Low-Dose Oral Ketamine for Procedural Analgesia in Pediatric Cancer Patients Undergoing Lumbar Puncture at a Resource-Limited Cancer Hospital in India

Aim: The aim of this study was to evaluate the therapeutic efficacy and safety profile of orally administered low-dose ketamine for procedural pain management in pediatric cancer patients undergoing lumbar puncture (LP) in a resource-limited hospital setting. Methods: Patients between 4 and 15 years of age, with leukemia, undergoing LP were asked to participate. The study was designed as a two-armed blinded placebo-controlled trial where 0.8 mg/kg (bodyweight) of ketamine mixed in juice was given 30 minutes before the procedure to Group K (ketamine) compared with placebo, only juice, to Group P (placebo). In addition, topical analgesia (EMLA^®) was given according to established standard of care. Patients and caregivers assessed the pain using the Wong-Baker Faces Pain Rating Scale. Results: A total number of 52 patients, equally distributed between Group K and Group P, were included in the study. The placebo-controlled group had significantly higher self-reported pain score than the group receiving ketamine (p = 0.046), as well as in caregiver-assessed pain (p = 0.033). Only three incidents of mild adverse effects were reported. Conclusion: Low-dose oral ketamine can be safely administered for procedural analgesia in pediatric cancer patients undergoing LP in a resource-limited hospital setting and have significant pain-reducing effect compared with placebo.

Low-dose Oral Ketamine as a Procedural Analgesia in Pediatric Cancer Patients Undergoing Bone Marrow Aspirations at a Resource-limited Cancer Hospital in India

Aim:

Many pediatric cancer patients undergo repeated bone marrow aspirations (BMAs) for diagnostic and treatment evaluation purposes. Full anesthesia is the standard of care during this procedure in high-income countries. At hospitals with low resources in low/middle-income countries many children undergo these painful procedures without sufficient pain relief. This study aimed to evaluate the usefulness of low-dose oral ketamine as a procedural analgesic in a low-resource pediatric cancer care department.

Materials and Methods:

Pediatric patients, 4–15 years of age, who underwent BMAs between September 31 and November 30, 2018, were invited to participate. The study was designed as a placebo-controlled, single-blinded trial with three trial groups. Group K received 1.0 mg/kg of ketamine and Group KM received 1.0 mg/kg ketamine with an addition of 0.2 mg/kg midazolam, mixed in juice 30 min before procedures. Group P received placebo consisting of plain juice. All three groups also received the hospital's current standard treatment for procedural pain in BMAs. Patients and caregivers assessed the procedural pain, as did the performing doctors. For the patients, Faces Pain Scale – Revised was used and the Numeric Rating Scale-11 for caregivers and doctors.

Results:

A total of 87 patients were included in the study distributed with 29 in Group K, 29 in Group KM, and 29 in Group P. Seven patients were excluded, one patient denied participation and the remaining did not meet the inclusion criteria. There was no significant difference between the pain reported by the groups. A total of 69% patients in Group KM and 35% in Group K had somnolence reported as a side effect compared to 14% in Group P.

Conclusion:

We found no significant effects on the procedural pain in any of the treatment groups compared to placebo. There were only mild side effects. The doses of ketamine might be insufficient for this painful and stressful procedure.

Stress and Ketamine, Bimodal Influence on Cognitive Functions

The glutamate N-methyl-D-aspartate receptor (NMDAR) non-selective antagonist, ketamine, has been recently repurposed as a rapidly acting antidepressant, catalyzing the vigorous investigation of glutamate-signaling modulators as novel therapeutic agents for depressive disorders. Beneficial effects of this drug in the quick-acting treatment of depression are recognized. The long-term effects of ketamine have not been known, including the cognitive sphere. It is well acknowledged that prolonged exposure to stress induces depression and cognitive impairment. It seemed reasonable to ask how the long-term ketamine administration would affect stressed animals in the aspect of cognitive functions. In the current study we tested whether it is possible for ketamine, used in prolonged-regimen in rats, to alleviate stress-evoked memory deficits? Stressed (restraint 2 h daily for 21 days) and non-stressed rats (6-weeks-old) were treated with ketamine for 21 days and next subjected to a battery of behavioral tests: for the assessment of working and reference spatial memory (Morris water maze (MWM) and Barnes maze (BM)), stereotypy (stereotypy test - ST), locomotor functions (Open field - OF) and anxiety behavior (Elevated plus maze - EPM). Ketamine administration resulted in a significant stereotype behaviour in rats tested in ST. Stressed rats displayed a significant decline in the spatial working and reference memory. The effect of chronic ketamine administration depended on the type of test and differed between control rats and animals simultaneously exposed to chronic stress. However, in the MWM the impact was quite unequivocal, as we observed an improvement in spatial memory in stressed animals and a deterioration in non-stressed animals after ketamine administration. In the BM, the effect of ketamine changed in successive attempts, from favorable in the initial period to negative at the end of the test in the group of stressed animals and without a significant impact on control animals. We found no significant effects of ketamine on locomotor performance and on the level of anxiety. Taken together, these findings demonstrate that ketamine potently abolishes or prevents some kinds of stress-induced memory impairments and cognitive decline in rats, although in some circumstances, it could even increase damage to memory, especially in unstressed animals. It seems that the prolonged use of ketamine in the prevention of stress-induced memory declines can fulfill its role.

A rectally administered combination of midazolam and ketamine was easy, effective and feasible for procedural pain in children with cerebral palsy

AIM

The aim of this study was to investigate how effective a combination of rectally administered midazolam and racemic ketamine was for reducing pain in paediatric cerebral palsy patients receiving intramuscular injections of botulinum neurotoxin A. The feasibility and safety of the pain relief were also explored.

METHOD

Children with cerebral palsy, aged one to 18 years, were recruited from a regional paediatric rehabilitation unit between April 2012 and May 2014. Pain intensity, feasibility, total time spent in the clinic and side effects were registered. Pain scores were recorded by parents and healthcare professionals using different pain scales.

RESULTS

We recorded 128 procedures in 61 children. The median scores were two (range: 0-10) for pain intensity and nine (range: 0-10) for feasibility. The median treatment time in the outpatient unit was 3.25 hours, and the most common side effects were nausea, pain and sleep disturbance. Gross motor function levels showed a negative correlation with the pain scores. This method could be an alternative to nitrous oxide/oxygen mixture for patients who do not tolerate inhalation analgesia.

CONCLUSION

Rectally administered midazolam and racemic ketamine provided effective pain relief for paediatric cerebral palsy outpatients receiving painful injections and was a viable alternative to inhalation analgesia.