Can Intraoperative Low-Dose R,S-Ketamine Prevent Depressive Symptoms After Surgery? The First Meta-Analysis of Clinical Trials

S-ketamine Infusion on Chronic Postoperative Pain Following Breast Cancer Surgery: A Randomized Double-Blind Placebo-Controlled Trial

BACKGROUND

Chronic postoperative surgical pain (CPSP) is a frequent complication following breast surgery and poses a challenge in terms of treatment. We hypothesized that the incidence of CPSP would be reduced at 3 months post-breast surgery with the administration of S-ketamine compared to a placebo.

PATIENTS AND METHODS

Participants were recruited and randomly assigned to either the S-ketamine group (S) or the control group (C). In group S, S-ketamine was administered as a 1.5 mg kg-1 bolus followed by 2 mg kg-1h-1 infusion, while in group C, a placebo of 0.9% saline was administered in the same volume and rate as S-ketamine. The primary outcome was the incidence of CPSP, measured using a 0-10 numeric rating scale (NRS), at 3 months postsurgery.

RESULTS

A total of 72 patients scheduled for mastectomy were enrolled (group S, n = 33; group C, n = 32). The incidence of CPSP at 3 months postsurgery was significantly lower in group S compared to group C (18.2% vs. 48.3%, P < .05). There was no statistical difference between the 2 groups in terms of the incidence of moderate to severe pain. NRS scores for postoperative pain at rest and during movement were significantly lower at 4 h and 24 h post-surgery (P < .05, respectively). Patients in Group S had lower Patient Health Questionnaire-9 (PHQ-9) scores at one week and 3 months post-surgery compared to Group C (P < .05, respectively).

CONCLUSION

S-ketamine infusion reduces the incidence of CPSP 3 months after breast surgery.

Effects of ketamine on the severity of depression and anxiety following postoperative mechanical ventilation: a single-blind randomized clinical trial in Iran

BACKGROUND

In this study, we compare the effects of ketamine and the combination of midazolam and morphine on the severity of depression and anxiety in mechanically ventilated patients after discharge from the intensive care unit (ICU).

METHODS

This randomized single-blind clinical trial included 50 patients who were candidates for craniotomy and postoperative mechanical ventilation in the ICU of 5 Azar Teaching Hospital in Gorgan City, North Iran, from 2021 to 2022. Patients were allocated to two groups by quadruple block randomization. In group A, 0.5 mg/kg of ketamine was infused over 15 minutes after craniotomy and then continued at a dose of 5 µ/kg/min during mechanical ventilation. In group B, midazolam was infused at a dose of 2-3 mg/hr and morphine at a dose of 3-5 mg/hr. After patients were discharged from the ICU, if their Glasgow Coma Scale scores were ≥14, Beck's anxiety and depression inventories were completed by a psychologist within 2 weeks, 2 months, and 6 months after discharge.

RESULTS

The mean scores of depression at 2 months (P=0.01) and 6 months (P=0.03) after discharge were significantly lower in the ketamine group than in the midazolam and morphine group. The mean anxiety scores were significantly lower in the ketamine group 2 weeks (P=0.006) and 6 months (P=0.002) after discharge.

CONCLUSIONS

Ketamine is an effective drug for preventing and treating anxiety and depression over the long term in patients discharged from the ICU. However, further larger volume studies are required to validate these results.

Single low-dose ketamine infusion for women with prenatal depressive symptoms undergoing cesarean delivery: A pilot randomized trial

Background

Ketamine is approved for antidepressant therapy, but evidence regarding its use in women with perinatal depression is lacking. Herein, we investigated the effects of low-dose ketamine in women with prenatal depressive symptoms and tested the feasibility of a future large randomized trial.

Methods

This was a randomized, double-blind, placebo-controlled pilot trial. Sixty-six women with prenatal depressive symptoms who were scheduled for elective cesarean delivery were randomized to receive either low-dose ketamine (0.5 mg/kg) or placebo (normal saline). The study drugs were intravenously infused over a 40-minute period after clamping the umbilical cord. The primary outcome was depression score assessed with the Edinburgh Postnatal Depression Scale at 48 h postpartum. Among other and safety outcomes, occurrence of nausea or vomiting was observed, pain intensity was assessed with the numeric rating scale. The feasibility of implementing the protocol was also evaluated.

Results

A total of 64 parturients were included in the intention-to-treat analysis. The depression score at 48 h did not differ between groups: median 9 (interquartile range 6 to 13) with ketamine vs. 8 (6 to 10) with placebo; median difference 1, 95% CI -1 to 3; P = 0.608. The pain intensity at 4 h postpartum was less severe in the ketamine group (median difference -1, 95% CI -1 to 0, P = 0.002). Among safety outcomes, intraoperative nausea or vomiting was less common in patients given ketamine (0.0% [0/33] with ketamine vs. 21.2% [7/33] with placebo, P = 0.011). Recruitment was satisfactory and the protocol was acceptable to participants and clinicians.

Conclusions

A single low-dose ketamine infusion did not decrease the depression score at 2 days, but reduced intraoperative nausea and vomiting and lowered pain intensity at 4 h after cesarean delivery among women with prenatal depressive symptoms. The study protocol is feasible for a large randomized trial.

Clinical Trial Registration

The study was registered with ClinicalTrials.gov (identifier: NCT03336541; 08/11/2017).

Effects of subanesthesia dose S-ketamine induction on postoperative psychiatric complications after gynecological surgery

Ketamine may become an important drug for multimodal analgesia regime again because of its strong analgesic effects and retaining the advantage of spontaneous breathing. The present study was designed to explore the influences of different dosages of S-ketamine anesthesia induction regimes on psychiatric complications and postoperative prognosis in patients undergoing gynecological operations. In this prospective, triple-blinded, randomized, controlled study, patients undergoing elective gynecological surgery were randomized to one of three treatment groups: low-dose S-ketamine (LDSK) group (a 0.3 mg/kg bolus for anesthesia induction), minimal-dose S-ketamine (MDSK) group (a 0.2 mg/kg bolus for anesthesia induction), and placebo (CON) group (a saline bolus for anesthesia induction). The main outcome measures were as follows: intraoperative vital signs, extubation time, anesthesia recovery time and postanesthesia care unit (PACU) stay duration, incidence of psychiatric complications, Ramsay sedation scale (RSS) 1, 2, 24, and 48 h, postoperatively, and overall prognosis. One hundred and eighty female participants were finally included in this study from April 2021 to December 2021. Significant differences were not observed in age, height, weight, American Society of Anesthesiologists physical status classification, or history of mental illness between the groups. No statistically significant differences were discovered with regard to intraoperative vital signs, extubation time and PACU stay duration, incidence of psychiatric complications, and RSS scores at 1, 2, 24, and 48 h postoperatively in the three groups. However, the visual analog scale (VAS) scores of the CON group at 10 min after extubation and at the time point leaving PACU were much higher than that of the LDSK and MDSK groups. The VAS scores at 48 h after surgery in the MDSK group were also lower than that of the CON group and the CON group had received more analgesic drug treatment in the surgical wards consequently. Postoperative nausea and vomiting (PONV) occurrence at 24 and 48 h, postoperatively, increased sharply in the CON group than in the other two experimental groups, which led to an increase in the use of postoperative antiemetic drugs in this group. According to the postoperative satisfaction survey, patients in the CON group had lower medical satisfaction. Our data demonstrate that a small dosage of S-ketamine anesthesia induction can reduce postoperative pain and the incidence of PONV without increasing hemodynamic fluctuations or psychiatric complications.

Perioperative Low-Dose Ketamine for Postoperative Pain Management in Spine Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

Although low-dose ketamine has been shown to be generally beneficial in terms of pain control in a variety of major surgery, there is no consensus regarding the effectiveness of supplemental ketamine analgesic use exclusively in spine surgery. The objective of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to assess the efficacy and safety of perioperative low-dose ketamine for pain management and analgesic consumption in patients undergoing spine surgery.

Methods

A comprehensive literature search was performed for relevant studies using PubMed, EMBASE, Web of Science, and Cochrane Library. Patients who received perioperative low-dose ketamine were compared to the control group in terms of postoperative pain intensity, opioid consumption, and adverse events. Patients were further categorized by ages and administration times for subgroup analysis.

Results

A total of 30 RCTs comprising 1,865 patients undergoing elective spine surgery were included. Significantly lower pain intensity and less opioid consumption at 12 h, 24 h, and 48 h postoperatively and lower incidence of postoperative nausea and vomiting (PONV) were observed in the ketamine group (all P < 0.05). There was no significant difference of central nervous system (CNS) adverse events between groups. However, different efficacy of low-dose ketamine was detected when patients were categorized by ages and administration times.

Conclusion

Perioperative low-dose ketamine demonstrated analgesic and morphine-sparing effect with no increased adverse events after spine surgery. However, this effect was not significant in pediatric patients. Only postoperative or intraoperative and postoperative administration could prolong the analgesic time up to 48 h postoperatively. Further studies should focus on the optimal protocol of ketamine administration and its effect on old age participants.

Ketamine as a therapeutic agent for depression and pain: mechanisms and evidence

Ketamine is an anesthetic drug which is now used to treat chronic pain conditions and psychiatric disorders, especially depression. It is an N-methyl-D-aspartate (NMDA) receptor antagonist with additional effects on α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, opioid receptors, and monoaminergic receptors. This article focuses on ketamine's role in treating depression and pain, two commonly comorbid challenging conditions with potentially shared neurobiologic circuitry. Many clinical trials have utilized intravenous or intranasal ketamine for treating depression and pain. Intravenous ketamine is more bioavailable than intranasal ketamine and both are effective for acute depressive episodes. Intravenous ketamine is advantageous for post-operative analgesia and is associated with a reduction in total opioid requirements. Few studies have treated chronic pain or concurrent depression and pain with ketamine. Larger, randomized control trials are needed to examine the safety and efficacy of intravenous vs. intranasal ketamine, ideal target populations, and optimal dosing to treat both depression and pain.

The effect of intravenous ketamine on depressive symptoms after surgery: A systematic review

STUDY OBJECTIVE

The development of depressive symptoms is an important complication experienced by patients postoperatively and is associated with poor clinical outcomes. Ketamine is a feasible treatment option for depressive symptoms after surgery due to its known antidepressant effect. This meta-analysis aimed to evaluate the current body of research regarding the effects of intravenous ketamine on depressive symptoms after surgery.

DESIGN

A meta-analysis of randomized controlled trials.

SETTING

Perioperative care area.

PATIENTS

Adult surgical patients.

MEASUREMENTS

Systematic literature search was performed in the CENTRAL, MEDLINE, and EMBASE databases, for randomized controlled trials comparing the effect of intravenous ketamine versus placebo on postoperative depressive symptoms as the primary outcome, with no language restrictions. Two independent reviewers screened records for inclusion, extracted data, and assessed risk of bias. Random effects models were used to pool overall estimates. Postoperative pain intensity was also examined. The GRADE approach was used to assess the quality of evidence.

MAIN RESULTS

Out of 834 records screened, 9 studies met our inclusion criteria, comprising a total of 2468 patients. Compared with the control group, ketamine provided significant reduction of postoperative depression scale scores, by a standardized mean difference (SMD) of -0.89 (95% CI [-1.23, -0.73], P = 0.33, I² = 13%; 4 studies) on postoperative day (POD) 1, SMD -0.51 (95% CI [-0.99, -0.04], P < 0.001, I² = 93%; 4 studies) on POD 3, suggesting clinically relevant reduction in postoperative depressive symptoms. Postoperative depression scale scores on POD 7 were also reduced in patients receiving ketamine compared to the control group, with SMD -0.33 (95% CI [-0.52, -0.14], P = 0.36, I² = 2%; 3 studies), but the minimal clinical difference of 0.5 SMD was not reached. No significant difference was observed in the postoperative depression scale over the long term at 30 days' follow-up (SMD -0.13, 95% CI [-0.25, 0.00], P = 0.07, I² = 52%; 5 studies). A significant reduction of postoperative pain intensity on POD 1 was identified in patients following ketamine administration (SMD -1.29, 95% CI [-2.57, -0.01], P = 0.05, I² = 98%; 5 studies). However, administration of ketamine resulted in a significantly increased risk of nausea and vomiting (RR 1.71, 95% CI [1.25, 2.33], P = 0.17, I² = 35%; 6 studies), headache (RR 4.88, 95% CI [1.97, 12.06], P = 0.83, I² = 0%; 4 studies), and hallucination (RR 34.94, 95% CI [8.59, 142.17], P = 0.44, I² = 0%; 4 studies).

CONCLUSIONS

The current evidence supports intravenous ketamine administration for the treatment of depressive symptoms after surgery. While ketamine administration has clinically significant side effects, future studies are needed in surgical populations at high risk of complications.

Ready for a "breakthrough" with ketamine? A look at recent pharmacological insights!

PURPOSE OF REVIEW

To update pharmacological insights on ketamine integrating information from different disciplines for developing steps to "breakthrough" approaches in clinical challenges.

RECENT FINDINGS

Pharmacokinetic/pharmacodynamic (PK/PD) models have incorporated recirculation, ketamine metabolites, drug-drug interaction, and covariates such as age. Ketamine-induced relief from treatment-resistant depression has been explained by "disinhibition" of gamma-aminobutyric acid-ergic interneurons and synaptogenic mechanisms requiring neurotrophic signals. Neuroimaging/electroencephalographic investigations have shown an increase in gamma spectral power in healthy volunteers and patients with depression, but also opposite changes in functional network connectivity after subanesthetic ketamine. Volunteer data may not be transferable to clinical conditions. Altered states of consciousness induced by subanesthetic ketamine have been described by disruption of resisting-state functional networks and frontoparietal connectivity with preservation of multisensory and sensor-motor networks. This has been interpreted as a "disconnected consciousness".

SUMMARY

More precise PK/PD models may improve the ketamine use regimen. The findings from research on depression are an important discovery because ketamine's impact on neuronal plasticity and synaptogenesis in human brain disease has directly been documented. Psychic adverse effects with subanesthetic ketamine are related to a "disconnected consciousness". Overall, progress has been made, but the "breakthrough" still has to come.

Patients with psychiatric disease: implications for anesthesiologists

PURPOSE OF REVIEW

Psychiatric illness is common in patients presenting for surgery. Overall health and surgical outcomes are adversely affected by the presence of psychiatric comorbidities.

RECENT FINDINGS

As new treatment modalities become available, their perioperative implications need to be evaluated. These implications include drug-drug interactions, hemodynamic effects, bleeding risk, and factors affecting perioperative exacerbation of the underlying psychiatric illness.

SUMMARY

From our review of the recent literature we continue to support the continuation of psychoactive agents in the perioperative period, taking into consideration the effects these agents have on concomitant drug use in the perioperative period; and the risks of withholding them at a high-stress time.