Inclusion criteria for the review were broadly defined. Only one relevant database was searched. There was potential for language bias as only articles in English were included. Risk of publication bias was not assessed and could not be ruled out. Attempts were made to reduce reviewer error and bias during study selection and quality assessment; whether the same attempts were made for data extraction was unclear. Details of the included trials (including comparators, patient characteristics and doses) were not fully reported.
Details of the quality assessment criteria were not reported and this made it difficult to interpret the results. The authors noted that definitions of shock reversal varied across the trials and this may have introduced bias. One trial also allowed trial entry up to 72 hours after shock onset. Methods used to pool the data were not reported. Statistical heterogeneity was not reported.
Reporting of review methodology, quality assessment and results were poor and made it difficult to determine the reliability of the authors’ conclusions.