Low-dose Intravenous Ketamine Research Articles

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).

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

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

Intravenous low-dose ketamine in addition to systemic analgesia versus systemic analgesia alone for post-operative pain management in laparotomies:Adouble-blind randomised controlled study

The use of Ketamine, an NMDA receptor antagonist, in sub-anesthetic doses for analgesia is increasingly being administered in inpatient settings with acute pain service guidance and in outpatient settings under a variety of models. At sub-anesthetic doses, ketamine possesses centrally mediated analgesic properties with minimal effects on consciousness and cognition.In this study we have compared the efficacy of IV low-dose Ketamine as an adjunct to conventional systemic analgesia to examine preventive effect on post-operative pain and opioid consumption in patients undergoing laparotomies.The study was carried out on 50 patients, 25 patients received a pre-incisional IV bolus of 0.15 mg/kg of Ketamine,10 mins before the incision followed by IV infusion of 2mcg/kg/min continued for 24 hours postoperatively in addition to systemic analgesia (Group K)and 25 Patients received IV bolus of Normal Saline 10 min before the incision, followed by an IV infusion of normal saline (Group C) till 24 hours post-op and systemic analgesia alone. Saline bolus and infusion were given at equivalent volume/rate of the study group. The analgesic efficacy was judged by NRS (Numeric Pain Rating Scale), Time to first rescue analgesia (TFA) and Total opioid consumption (Tramadol in mg) in 24 hours. Ketamine related side effects were also recorded.Patients in the Ketamine group had significantly lower Mean total opioid consumption (88.04 ± 29.07 mg vs. 210 ± 23.93 mg)and Numerical pain Rating Scale (NRS) (3.13 +0.34 vs. 4.44+ 0.77). Time to first rescue analgesia was significantly delayed in Ketamine group as compared to Control group (20.65 ± 9.2 mins vs. 5.4 ± 5.38 mins). Ramsay Sedation scores (RSS) were significantly higher in the Ketamine group (2.4 +0.76vs. 1.52 +0.51)in the immediate post-operative period. There were no demonstrable side-effects related to Ketamine in Group K.Pre-emptive IV low-dose Ketamine is an effective adjunct to systemic analgesia in abdominal surgeries as it significantly prolongs the time to first rescue analgesia (TFA), reduces mean total analgesic requirement and lowers pain scores (NRS) in the post-operative period with negligible side effects.

Comparison of Ketamine to Haloperidol for Preventing Delirium in ICU Elderly Patients

Background: Delirium is a common concern among elderly intensive care unit (ICU) patients. Ketamine’s effectiveness in preventing delirium remains controversial despite its demonstrated neuroprotective properties and cognitive benefits in previous studies. Objectives: This study aimed to compare the safety and efficacy of ketamine and haloperidol in preventing delirium in elderly ICU patients. Methods: This randomized clinical trial involved 44 non-intubated patients aged over 65 years in a general ICU. The patients received low-dose intravenous ketamine (20 mg) or intramuscular haloperidol (2.5 mg). Delirium was assessed using the Richmond Agitation Sedation Scale (RASS) at 5, 10, and 15 minutes. The primary outcome was the percentage of patients achieving adequate sedation (RASS ≤ +1). The secondary outcome was time to reach adequate sedation. Adverse effects and physician satisfaction were evaluated after 60 minutes. Results: No significant difference in delirium was observed between the groups after interventions or within each group over time. However, the ketamine group had significantly lower delirium incidence at 5 minutes. The percentage of patients achieving adequate sedation was higher in the ketamine group (86.4%) than in the haloperidol group (36.4%) (P = 0.002). There was a delirium difference between groups at 10 minutes (P = 0.31) or 15 minutes (P = 0.082). Physician satisfaction did not differ significantly (P = 0.144). Conclusions: The present study suggests that the administration of low-dose ketamine to elderly ICU patients might reduce delirium incidence, supporting its beneficial effect for delirium control.

Biweekly vs Triweekly low dose intravenous ketamine acute series for severe major depression: A case report

BackgroundOne third of the patients with Major Depression Disorder (MDD) fail to respond to conventional antidepressant treatments - treatment resistant depression (TRD). Low-dose IV ketamine (LDIVK) treatment has become a promising solution for these patients. However, infusion regimens for LDIVK acute series have not been standardized yet. Also, evidence is scarce for retrialing LDIVK treatment to manage MDD symptom recurrences. MethodsThis is a case study of a 45-year-old female experiencing MDD TRD, who completed a triweekly and a biweekly acute course (4 week) of LDIVK treatment three years apart. Treatment effectiveness was assessed by comparing baseline to weekly depression severity scores using validated psychiatric scales to determine changes in depression symptoms. Tolerability was assessed by systematically registering side effects through the infusions. ResultsIn both acute series, the patient achieved symptomatic response equivalent to remission. On the triweekly acute course the patient achieved symptom remission by the second week and in the biweekly acute course by the third week. Reported side effects were mild and transient. LimitationsResults of only one patient included in this report and a different number of LDIVK infusions in each acute course, with the triweekly vs biweekly course providing four additional infusions in four weeks. ConclusionsThese results suggest that implementing a triweekly regimen may be well-tolerated and result in a faster treatment response in certain patients, compared to a biweekly regimen. Furthermore, this case also supports the possibility of a ketamine retrial in case of major depressive recurrences.

Ketamine as a pre-emptive analgesia in patients undergoing caesarean delivery under spinal anesthesia

BACKGROUND &amp; OBJECTIVES: Lower segment caesarean section (LSCS) leads to moderate to severe pain in the patient. Pain severity is directly proportional to the functional limitations and depression in the postpartum period, making it essential to provide good pain relief after surgery. Maternal wellbeing and better nursing care of newborn requires good postoperative analgesia with minimal side effects. The main objective of the study was to evaluate the analgesic effect of intravenous low-dose ketamine, when administered pre-emptively, in patients undergoing caesarean delivery under spinal anesthesia.&#x0D; METHODOLOGY: Two groups were made, each with 50 full-term pregnant females with a plan of caesarean section under spinal anesthesia. Group-A received spinal anesthesia with bupivacaine 0.5% along with intravenous placebo of 2cc normal saline, whereas group-B received 0.5mg/kg ketamine intravenously after administration of spinal anesthesia but before the start of surgical incision. Pain intensity was monitored using a visual rating pain scale (VRS), till the need for the first analgesic dose postoperatively.&#x0D; RESULTS: Both groups were comparable in terms of age and weight. Analgesia was markedly prolonged, and postoperative pain scores were significantly less in Group-B (ketamine group) as compared to Group-A; with p-value&lt; 0.001, demonstrating analgesic properties of ketamine when administered pre-emptively as an intravenous dose.&#x0D; CONCLUSION: Our study concluded that pre-emptive analgesic dose of ketamine (administered before surgical incision), leads to prolong analgesia in post-operative period in patients who underwent LSCS under spinal anesthesia.

Subanesthetic Ketamine Infusion Reducing Symptoms of Depression in a Patient With End-Stage Heart Failure Enrolled in Hospice Care: A Case Report.

Background: The development of major depressive disorder in patients at end of life often goes undiagnosed, as it is difficult to distinguish from preparatory grief and/or hypoactive delirium in this unique patient population. If this preliminary barrier of appropriate diagnosis is overcome, it can be quite difficult to properly select and adjust pharmacological therapy. Many well-established antidepressants take four to five weeks for maximal effectiveness (which may be far too long of a titration period for patients at end of life), have various contraindications to patients' comorbid chronic conditions (particularly patients with cardiovascular disease), or may simply be ineffective. Case: We present a case report of severe treatment-resistant depression in an end-stage heart failure patient enrolled in hospice care. Discussion: We discuss the potential use of a single low-dose intravenous racemic ketamine infusion to reduce end-of-life suffering related to depression, despite the theoretical contraindication of ketamine use in such patients, in part, due to its sympathomimetic secondary effect.

Low-dose ketamine infusion for the treatment of multiple sclerosis fatigue (INKLING-MS): Study protocol for a randomized, double-blind, active placebo-controlled phase II trial

BackgroundFatigue is one of the most common symptoms of people with Multiple Sclerosis (MS). However, currently-used medications for the treatment of fatigue probably do not work better than a placebo. In a pilot trial, we showed that one infusion of low-dose ketamine significantly improved fatigue severity measured four weeks after the infusion. MethodsThe proposed study is a single-center, phase II, randomized, double-blind, parallel-group, active-placebo-controlled trial of intravenous low-dose ketamine in patients with MS fatigue. Participants will be randomized 1:1:1 into three groups: receiving either one or two infusions of ketamine (0.5 mg/kg over 40 min) or zero to one infusion of the active placebo (midazolam, 0.05 mg/kg over 40 min).Eligibility criteria include adult patients diagnosed with MS based on the latest criteria, complaining of fatigue as one of the main symptoms, and having a screening MFIS score higher than a pre-specified threshold. ResultsOne hundred and ten participants will be randomized over 30 months at Johns Hopkins MS Center. Complete enrollment is expected by mid-2025. The study's primary outcome will be the MFIS score at the end of week 4, comparing two-thirds of the participants who received ketamine with one-third who received midazolam. The secondary and exploratory outcomes (measured four weeks after the second infusion) will show how long the effects of a single infusion last and if two infusions of ketamine are better than one in improving MS fatigue. ConclusionThis study can show whether intervening in the glutamatergic pathways would improves MS fatigue.

The utero-tonic effects of low dose intravenous ketamine in cesarean section under spinal anesthesia; A randomized double-blind clinical trial.

Recently, the prevalence of cesarean section (CS) has been on the rise and the proper uterine tone is an important issue. We investigated the effects of intravenous (IV) ketamine on intraoperative bleeding and the need for oxytocin in CS under spinal anesthesia (SA). This study, took place at Alzahra hospital during 2020. Pregnant women candidate for elective CS under SA were divided into two groups of ketamine and placebo. In group K, after umbilical cord clamping, 0.25 mg/kg ketamine and in group P 2ccs normal saline was injected. Mean arterial pressure and heart rate were recorded at baseline, before and 5 minutes after cord clamping and at the end of the surgery. The drop in hemoglobin values, the administrated units of oxytocin and side effects were also recorded. No significant difference was found in terms of patients' demographic data (P ≥ 0.05). The mean units of administrated oxytocin in group K was 34.61±6.63 and in group P; 48.47±12.15, which was significantly different (P=0.0001). The drop in Hb was less in group K, however not statistically significant (P=0.094). The need for methergine was significantly higher in group P (P=0.0001). The mean HR was significantly higher in group P (P=0.027), however, no significant difference was observed regarding the MAP (P=0.064). The incidence of hallucination (4.8%) and nystagmus (21%) was significantly higher in group K (P= 0.0001), but nausea and vomiting were more significant in group P (P= 0.027). Prophylactic administration of low-dose ketamine in CS under S.A could significantly reduce the administrated oxytocin units and the need for additional utero-tonics and was associated with less drop in Hb values.

Intravenous Low Dose Ketamine versus Lidocaine versus Placebo in Suppressing Fentanyl Induced Cough: A Comparative Study

Intravenous Low Dose Ketamine versus Lidocaine versus Placebo in Suppressing Fentanyl Induced Cough: A Comparative Study

Effect of low-dose intravenous ketamine on postoperative pain following cesarean section under spinal anesthesia: A prospective cohort study, Ethiopia

BackgroundFollowing cesarean delivery, mothers experience moderate to severe pain since postoperative analgesia of spinal anesthesia is limited by duration of local anesthetic agents used. Analgesic effect of local anesthetic agents could be extended and supported by adding either intravenous or intrathecal adjuvants. The primary outcome of this study is to assess effect of low-dose intravenous ketamine on postoperative pain following cesarean section under spinal anesthesia. Materials and methodsThis prospective observational cohort study recruits 60 parturients who underwent elective cesarean delivery under spinal anesthesia. Those parturients who received intravenous ketamine 0.25 mg/kg following spinal anesthesia were considered as exposed group/ketamine group. The Non-exposed group was those parturients who didn't receive intravenous ketamine following spinal anesthesia. Numerical rating scale pain score, time to request first analgesia and total analgesia consumptions were recorded starting from 1st hour to 24 h after the end of surgery. ResultsThe median and Inter quartile range (IQR) for postoperative numerical rating scale pain score was significantly higher in non-exposed group compered to ketamine group at 1st and 2nd hour after operation (P-value<0.05). Time to request first analgesia was significantly longer in ketamine group [192.5(140–210) minutes] compared to non-Exposed group [146(130–160) minutes] with P-value < 0.001. Tramadol consumption within 24 h postoperatively were significantly lower in ketamine group compared to non-exposed group (P-value < 0.001). ConclusionLow dose intravenous ketamine before skin incision was extended postoperative first analgesia request time by average of 45.5 min and decrease total analgesia consumption in 24 h.

Preemptive low-dose intravenous ketamine in the management of acute and chronic postoperative pain following laparoscopic cholecystectomy: a prospective randomized control study.

Preemptive analgesia with intravenous ketamine has been utilized as a part of multi-modal analgesia for acute postoperative pain following laparoscopic cholecystectomy with mixed outcomes. We tested the effectiveness of low-dose ketamine for acute and chronic postoperative pain after laparoscopic cholecystectomy in a randomized controlled experiment. The study involved 50 individuals who had a laparoscopic cholecystectomy under general anesthesia. All the patients were separated into two equal groups. The ketamine and control groups were given 0.5 mg/kg ketamine and 2 mL of normal saline, respectively, at 15 minutes before incision. Patients in the ketamine group had a significantly lower numeric pain rating scale score at 0 minutes than those in the control group. The numeric pain rating scale score of the ketamine group was considerably greater than the control group after a half-hour interval. At other time periods, there was no significant difference in numeric pain rating scale scores between the two groups. The ketamine group had a greater duration of analgesia and sedation score than the control group. The cumulative tramadol demand at 24 hours and the incidence of chronic pain did not differ significantly across the groups. Substantial analgesic effect of intravenous ketamine lasted only up to 30 min postoperatively. There was no discernible effect in terms of chronic pain prevention.

The Duration Of Postoperative Analgesia Using Low Dose Intravenous Ketamine In Patients Undergoing Elective Cesarean Section With Spinal Anesthesia A Randomized Controlled Trial

The Duration Of Postoperative Analgesia Using Low Dose Intravenous Ketamine In Patients Undergoing Elective Cesarean Section With Spinal Anesthesia A Randomized Controlled Trial

Inkk Trial .Çô Intraoperative ketamine for perioperative pain management following total knee endoprosthetic replacement in oncology: a double-blinded randomized trial

BackgroundThere has been a growing interest in the use of ketamine following orthopedic surgeries. We hypothesized that low dose intravenous ketamine during surgery would help in mobilization following total knee replacement (TKR) in oncology patients as assessed by the timed to up and go (TUG) test at 72.áhours post-surgery. Our secondary objectives were to compare the opioid requirement at the end of 72.áhours, pain scores, satisfaction with pain management, adverse effects, range of joint movement achieved in the post-operative period and the functional recovery at the end of 1 month. MethodsAfter the ethics commitee approval, registration of the trial with the Clinical Trial Registry - India (CTRI), and informed consent, this double-blinded trial was conducted. Using computer generated randomization chart, an independent team randomized the patients into ketamine group which received at induction, a ketamine bolus dose of 0.5.ámg.kg-1 before the incision followed by 10.á..g.kg-1min-1 infusion which was maintained intraoperatively till skin closure and the saline group received an equivalent volume of saline. Postoperatively, patient controlled morphine pumps were attached and the pain score with morphine usage were recorded for 72.áhours. The TUG tests and range of motion were assessed by the physiotherapists until 72.áhours. ResultsFifty-two patients were enrolled in the trial. Demographics were comparable. No significant intraoperative hemodynamic changes and post-operative adverse events were noted between the groups. A decrease in the TUG test, along with decreased opioid usage with a better range of movements was noted in the ketamine group, but this was not statistically significant. Day of discharge, patient satisfaction score, and functional recovery assessed by Oxford Knee Score (OKS) were comparable between the groups. ConclusionIn conclusion, low dose intraoperative ketamine infusion does not provide clinical benefit in perioperative pain management and postoperative rehabilitation following total knee endoprosthetic replacement in oncology.

Low dose intraoperative ketamine infusion with multilevel paravertebral block for pain after video-assisted thoracic surgery: a randomized-controlled study.

Intraoperative low-dose ketamine infusion has been reported to be an effective adjuvant to opioids for postoperative pain control without major side effects, but it has not been tested in video-assisted thoracic surgery (VATS). The aim of this study was to examine the effect of low-dose intraoperative intravenous ketamine infusion on 24-hour morphine requirement and acute postoperative pain following VATS for lung resection. This study was a single center, randomized, double-blind, placebo-controlled study. Thirty-two patients undergoing elective VATS for lung resection in a university hospital were included. Patients were randomly allocated (1:1 ratio) to receive either intraoperative low-dose ketamine (0.2 mg/kg/h) or normal saline infusion starting from intubation to the beginning of chest closure. All patients received multilevel thoracic paravertebral block (TPVB) and morphine was administered postoperatively via the patient-controlled analgesia pump using the same protocol. Time to first analgesia, postoperative cumulative morphine doses at 10, 30 minutes, and the consecutive 1, 2, 6, 12, 18, and 24 hours were recorded. Pain intensity during rest and deep breathing were also assessed by numeric rating scale (NRS) score at 1- and 24-hour postoperatively. There was no significant difference in median (P25, P75) cumulative 24-hour morphine requirement between the ketamine and the control groups [15 (5.5, 29.5) vs. 22.5 (15.3, 40.8) mg, P=0.090]. Patients in ketamine group had significantly longer median pain free time than the control group (27 vs. 2 minutes, P=0.006). No difference in overall NRS score at rest or during deep breathing at 1- and 24-hour postoperatively was demonstrated (P=0.861). Intraoperative low dose ketamine infusion in addition to TPVB does not reduce postoperative morphine consumption or pain intensity but may prolong pain free time in patients undergoing VATS for lung resection.

Analgesic effects of intravenous ketamine after spinal anaesthesia for non-elective caesarean delivery: a randomised controlled trial

ObjectivesThis study aimed to determine if low dose intravenous ketamine is effective in reducing opioid use and pain after non-elective caesarean delivery.DesignProspective, randomised, double-blind.SettingTertiary hospital, Bisheshwar Prasad Koirala Institute of...

Low-Dose Ketamine Is a Viable Option for Control of Acute Pain in the ED

To compare the analgesic efficacy of intravenous low-dose ketamine and morphine, researchers performed a systematic review and meta-analysis of

Low-Dose Intravenous Ketamine Bolus versus Conventional Technique for the Reduction of Upper and Lower Extremity Fractures in Children: A Randomised Controlled Clinical Trial

Low-Dose Intravenous Ketamine Bolus versus Conventional Technique for the Reduction of Upper and Lower Extremity Fractures in Children: A Randomised Controlled Clinical Trial

Ketamine for pain control of snake envenomation in Guinea: A case series

Snakebite envenomation is a global health crisis and is classified as a Category A neglected tropical disease by the World Health Organization (WHO). Snakebite envenomations account for a significant amount of morbidity and morbidity in tropical and subtropical regions. Recently, publications have illustrated the potential for snake envenomations causing post-traumatic stress disorder (PTSD) in a significant number of patients. Ketamine is on the WHO's list of essential medications and is used for a variety of pharmacologic applications including anesthesia and acute pain management. To date it has not been assessed for pain control in snakebite envenomations. Twelve patients who presented with severe pain secondary to Bitis, Causus, and Atractaspis envenomations were treated with low-dose intravenous ketamine. The patients included 7 males and 5 females with a median age of 37.5 (range 14–64) and a median presentation time of 5.75 h (range 5 min–96 h) after the initial bite occurred. Ten envenomations were presumed to have been caused by Bitis species resulting in extensive swelling and blistering of the affected extremities. One envenomation was presumedC. maculatus causing local swelling and pain. One envenomation was a presumed Atractaspis species causing significant local pain with minimal swelling. All patients expressed having significant pain but could not express the degree of their pain using an analogue pain scale. An initial median dose of 5 mg of ketamine (range 2.5–15 mg) was administered intravenously for pain control. Every patient expressed decreased pain and felt more comfortable within 1 min after administration of ketamine. Nine of the twelve patients only required a single dose. There were no adverse side effects. Ketamine appears to be an effective means of pain control for those suffering from painful envenomations. With minimal risk of significant side effects at acute pain management doses and the average cost per effective dose averaging between US$0.03–0.06, this may provide a cheap, safe, and effective solution for Sub-saharan Africa and other resource-limited settings. Controlled studies need to be done to critically assess our observations.

Next-Step Treatment Considerations for Patients With Treatment-Resistant Depression That Responds to Low-Dose Intravenous Ketamine.

Numerous short-term randomized trials support the acute-phase efficacy of low-dose intravenous (IV) ketamine for patients with treatment-resistant unipolar or bipolar depression. Ketamine's antidepressive effects generally have limited duration, highlighting the need for maintenance treatment after an acute-phase response. It is increasingly likely that psychiatrists will be called upon to manage the care of patients with treatment-resistant unipolar or bipolar depression who have responded acutely to ketamine and to recommend or initiate next-step treatments. However, there is a paucity of controlled evidence to guide best practices for managing treatment of patients with treatment-resistant unipolar or bipolar depression who have had a positive initial response to ketamine. This article reviews the available evidence supporting specific strategies for extending and maintaining acute antidepressive responses to low-dose IV ketamine in patients with treatment-resistant unipolar or bipolar depression and provides some preliminary considerations for clinical practice.