Effect of ketamine–bupivacaine combination in multilevel ultrasound- assisted thoracic paravertebral block on acute and chronic post-mastectomy pain

The Efficacy of Ketamine for Acute and Chronic Pain in Patients with Cancer: A Systematic Review of Randomized Controlled Trials

Managing cancer-related pain poses significant challenges, prompting research into alternative approaches such as ketamine. This systematic review aims to analyze and summarize the impact of ketamine as an adjuvant to opioid therapy for cancer-related pain. We conducted a literature review in MEDLINE, EMBASE, and Scopus from 1 January 1982 to 20 October 2023. Abstracts were screened against inclusion criteria, and eligible studies underwent a full-text review. Data was extracted from the included studies, and a framework analysis approach summarized the evidence regarding ketamine's use in patients with cancer. A total of 21 randomized clinical trials were included, and the quality of all the included studies was good or fair. Significant improvements in pain scores and reduced morphine consumption were consistently observed with intravenous ketamine administration for postoperative pain control, particularly when combined with other analgesics such as morphine. Ketamine was less effective when used as an analgesic for chronic pain management, with several studies on neuropathic pain or chemotherapy-induced neuropathy finding minimal significant effect on reduction of pain scores or morphine requirements. The efficacy of ketamine in pain management appears to depend on factors such as dosage, route of administration, and patient population.

"Post Mastectomy Pain Syndrome: A Systematic Review of Prevention Modalities"

Background

Post-mastectomy pain syndrome (PMPS) is a surgical complication of breast surgery characterized by chronic neuropathic pain. The development of PMPS is multifactorial and research on its prevention is limited. The objective of this systematic review is to synthesize the existing evidence on interventions for lowering the incidence of persistent neuropathic pain after breast surgery.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a comprehensive search of the electronic databases of MEDLINE, Cochrane Library, Embase, CINAHL, PsycINFO, Web of Science, and ClinicalTrials.gov using a combination of database-specific controlled vocabulary and keyword searches. Two reviewers independently screened all unique records. Publications on chronic (>3-month duration) pain after breast cancer-related surgery were included. Studies were classified by modality.

Results

Our literature search yielded 7092 articles after deduplication. We identified 45 studies that met final inclusion criteria for analysis, including 37 randomized-controlled trials. These studies revealed seven major intervention modalities for prevention of PMPS: physical therapy, mindfulness-based cognitive therapy, oral medications, surgical intervention, anesthesia, nerve blocks, and topical medication therapy.

Conclusion

High-quality data on preventative techniques for PMPS are required to inform decisions for breast cancer survivors. We present a comprehensive assessment of the modalities available that can help guide breast and reconstructive surgeons employ effective strategies to lower the incidence and severity of PMPS. Our review supports the use of multimodal care involving both a peripherally targeted treatment and centrally acting medication to prevent the development of PMPS.

The Effect of Ketamine on Acute and Chronic Wound Pain in Patients Undergoing Breast Surgery: A Meta-Analysis and Systematic Review

INTRODUCTION

Perioperative use of ketamine has been discussed widely in many kinds of surgery. The aim of our study was to evaluate the short-term and long-term benefits and safety of ketamine after breast surgery.

METHOD

We performed a quantitative systematic review. We included randomized controlled trials that compared intravenous administration of ketamine to a placebo control group, or compared bupivacaine in combination with ketamine to bupivacaine alone in thoracic paravertebral blocks or pectoral blocks among patients undergoing breast surgery. The primary outcome was postoperative pain intensity. Secondary outcomes included cumulative opioid consumption during the 0- to 24-hour postoperative period, the effect on postmastectomy pain syndrome, the effect on postoperative depression, and the adverse events associated with the use of ketamine.

RESULTS

Thirteen randomized controlled trials with 1,182 patients were included for analysis. Compared with placebo, intravenous ketamine was effective in reducing wound pain intensity during the first 6 hours after surgery (weighted mean difference [WMD] -0.83; 95% confidence interval [CI] -1.65, -0.01; P = 0.048) and during the first 24 hours after surgery (WMD -0.65; 95% CI -0.95, -0.35; P < 0.001), and in decreasing opioid consumption (WMD -4.14; 95% CI -8.00, -0.29; P = 0.035) during the first 24 hours after surgery, without increasing the risks for gastrointestinal and central nervous system adverse events. Adding ketamine to bupivacaine in thoracic paravertebral blocks was also effective in reducing postoperative wound pain during the first 6 hours after surgery (WMD -0.59; 95% CI, -1.06, -0.12; P = 0.014) and during the first 24 hours after surgery (WMD -0.90; 95% CI -1.27, -0.53; P < 0.001), and in decreasing opioid consumption (WMD - 4.59; 95% CI -5.76, -3.42; P < 0.001) during the first 24 hours after surgery. Perioperative use of ketamine was associated with improved postoperative depression symptoms (standardized mean difference -0.80; 95% CI - 1.34, -0.27; P = 0.003) and less incidence of postmastectomy pain syndrome (relative risk 0.79; 95% CI 0.63, 0.99; P = 0.043).

CONCLUSION

Ketamine is an effective and safe multimodal analgesic in patients undergoing breast surgery, administered both intravenously and when added to bupivacaine in paravertebral blocks. In addition, ketamine showed a long-term benefit for preventing postoperative depression and postmastectomy pain syndrome.