Effect of Perioperative Intravenous Lidocaine Infusion on Acute and Chronic Pain After Breast Surgery: A Meta-Analysis of Randomised Controlled Trials. Chang Y-D, et al. Pain Practice 2016 February 23
This meta-analysis looked at three studies comparing lidocaine infusion with placebo or routine treatment with 167 patients in total. The results were that there were no differences in post-operative pain scores out to three days, but at three days the Lidocaine group had consumed fewer analgesics. In two studies of 97 patients, patients in the Lidocaine group had a significantly lower risk for the development of chronic pain (relative risk 0.332, 95% confidence interval 0.14 – 0.78; P = 0.012)
Comment:
The strength of this study lies in the fact that a single surgical entity was examined, namely breast surgery. The corollary of this is that the number of studies were small, leading to the potential for a Type II error. Nevertheless, a relative risk of 0.3 for subsequent chronic pain is a profound outcome for a simple treatment of bolus dosing of Lignocaine 1.5mg/kg on anaesthetic induction, followed by running an infusion of 2mg/kg/hour until two hours had elapsed in the recovery room. Ideally, an adequately powered definitive RCT should now be considered, given these encouraging findings, and I believe that this is something that should be considered by the NHMRC and the ANZCA Clinical Trials Working Group.
Physiotherapy for Pain and Disability in Adults with Complex Regional Pain Syndrome (CRPS) Types I and II. Smart K M, et al. Cochrane Database Systematic Reviews 2016 February 24
In this Cochrane Review, 18 randomised controlled trials with 739 participants were evaluated. The quality of the trials was judged to be low with a high risk of bias, according to the GRADE approach. There was low quality evidence that graded motor imagery, multimodal physiotherapy and mirror therapy as providing benefit to patients. The best available data showed the most promise for graded motor imagery.
Comment:
Although this adds nothing new to our knowledge for physical therapy in CRPS, it does, at least, qualify the degree of robustness of the clinical trials and shows that there is significant room for further improvement with subsequent clinical studies.
The Effectiveness of Transcutaneous Electrical Nerve Stimulation in the Management of Patients with Complex Regional Pain Syndrome: A Randomised, Double-Blinded, Placebo-Controlled Prospective Study. Bilgili et al. Journal of Back and Musculoskeletal Rehabilitation 2016 February 16
In this study 32 patients were treated with either conventional TENS or sham TENS therapy. Both groups received fifteen sessions of standard physical therapy. The verum TENS group had significantly greater improvement in pain intensity, reduction in oedema and improvement in the LANSS neuropathic pain scale, compared to the sham TENS group.
Comment:
The addition of TENS to a physical therapy program would appear to be complementary and add an additional component of improvement for patients suffering from CRPS. However, we do know that current state of the art for physical therapy for CRPS consists of graded motor imagery and it is not clear whether TENS would have any additional benefit being added to a graded motor imagery physical therapy program.