Ketamine as an adjunct to patient-controlled analgesia: why, for whom, and how much?

Analgesic effect of perioperative ketamine for total hip arthroplasties and total knee arthroplasties: A PRISMA-compliant meta-analysis

BACKGROUND

Total hip arthroplasties (THA) and total knee arthroplasties (TKA) are always associated with a frequent incidence of postoperative pain. Effective pain management after surgery is quite essential for surgeons and patients. The purpose of the present meta-analysis is to evaluate the analgesic effect of perioperative ketamine after THA and TKA.

METHODS

Seven online databases, Embase, Cochrane Library, Pubmed, Web of Science, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), and Wanfang Data were searched for the related randomized controlled trials (RCT) by August 15, 2019. The qualities of the included studies were assessed based on the Cochrane Handbook for Systematic Reviews of Interventions 5.0. The visual analog scale (VAS), morphine equivalent consumption, and the side effects were used to evaluate the postoperative analgesic effect of ketamine by meta-analysis, which was performed by Review Manager version 5.3 software.

RESULTS

The VAS scores at 6 hours, 12 hours, 24 hours, and 48 hours after surgery were statistically lower in the ketamine group. The morphine equivalent consumptions in 24 hours and 48 hours after surgery were also significantly lower in the ketamine group. For the side effects, no statistical differences in odds ratio (OR) of sedation, dizziness, hallucination, sweating, pruritus, urinary retention, constipation, version trouble, nightmares, and delirium were observed between the ketamine group and the control group. But postoperative nausea and vomiting (PONV) showed lower OR in the ketamine group.

CONCLUSION

The present meta-analysis demonstrated perioperative ketamine could be used as a safe and effective analgesic agent for THA and TKA.

Current methods and challenges for acute pain clinical trials

This article reviews current methods and challenges and provides recommendations for future design and conduct of clinical trials of interventions to treat acute pain.

Introduction:

The clinical setting of acute pain has provided some of the first approaches for the development of analgesic clinical trial methods.

Objectives:

This article reviews current methods and challenges and provides recommendations for future design and conduct of clinical trials of interventions to treat acute pain.

Conclusion:

Growing knowledge about important diverse patient factors as well as varying pain responses to different acute pain conditions and surgical procedures has highlighted several emerging needs for acute pain trials. These include development of early-phase trial designs that minimize variability and thereby enhance assay sensitivity, minimization of bias through blinding and randomization to treatment allocation, and measurement of clinically relevant outcomes such as movement-evoked pain. However, further improvements are needed, in particular for the development of trial methods that focus on treating complex patients at high risk of severe acute pain.

Essential Elements of Multimodal Analgesia in Enhanced Recovery After Surgery (ERAS) Guidelines

Perioperative multimodal analgesia uses combinations of analgesic medications that act on different sites and pathways in an additive or synergistic manner to achieve pain relief with minimal or no opiate consumption. Although all medications have side effects, opiates have particularly concerning, multisystemic, long-term, and short-term side effects, which increase morbidity and prolong admissions. Enhanced recovery is a systematic process addressing each aspect affecting recovery. This article outlines the evidence base forming the current multimodal analgesia recommendations made by the Enhanced Recovery After Surgery Society (ERAS). We describe current evidence and important future directions for effective perioperative multimodal analgesia in enhanced recovery pathways.