Journal Club Summary
Methodology: 2.2/5
Usefulness: 3/5
Laan DV,et al.
Injury. 2016 Apr;47(4):797-804.
This systematic review and meta-analysis has found that the 4th/5th intercostal space at the anterior axillary line has the lowest mean chest wall thickness and lowest predicted failure rate of needle decompression with a 5 cm angiocatheter. This may suggest re-evaluation of the recommended location for needle thoracostomy in tension pneumothorax at the 2ndintercostal space midclavicular line by the ATLS guidelines, however concerns over considerable heterogeneity and search strategy call the results into question.
By: Dr. Lauren Lacroix
Epi lesson:
The sample size of a clinical trial must be adequately powered to show a minimal clinically important difference (MCID) between the intervention and control arms. MCID is the absolute difference in outcome proportions that would have to be shown by the study intervention for clinicians to accept the new treatment as better. In an effort to keep sample size low, investigators sometimes estimate an MCID much larger than is reasonable or use an outcome that is not the most important, e.g. 4-hour survival rather than survival to discharge. This is often generated by pre-study consensus (ideally by a survey, but often by the team of study investigators). This risks a negative result when the real problem is that the study is underpowered for the true MCID.
By: Dr. Jeff Perry
