The case for invasive placebo - is the devil in the detail?

The authors comment on the study "Analgesic Efficacy of Pre-operative Stellate Ganglion Block on Postoperative Pain Relief: A Randomised Control Trial" published within the issue. The authors discuss the contributions of the study in terms of tramadol consumption administered to patients through analgesia, the methods of evaluating the benefits of analgesic intervention and ways by which the study has prompted a debate on whether including an invasive placebo in a clinical trial is appropriate.