Dexamethasone for increasing analgesic duration of single-shot inter-scalene block

摘要

Editor-We read with great interest the article by Desmet and colleagues about their randomized trial comparing analgesic duration of ropivocaine alone, ropivacaine with perineural dexamethasone, and ropivacaine with i.v. dexamethasone for shoulder surgery. The authors describe their analysis as 'intention-to-treat', yet the actual analysis did not include outcome data from a subset of randomized patients. Specifically, Desmet and colleagues state that 'six patients had no primary or secondary outcome result because of inadherence to the protocol. These patients were not included in the intention-to-treat (ITT) analysis'. The exclusion of the six patients from analysis, in fact, precludes the label of ITT. Strict ITTanalysis requires that all randomized patients are analysed according to the original treatment allocation, regardless of what subsequently occurred. Thus, we believe that their analysis would be more aptly described as 'per protocol'.