We have discussed the changing thoughts regarding the sign and symptoms of Tension Pneumothorax in the past (see here: Rethinking Tension Pneumothorax). Although this study was broad, it did not address in detail the implications of different locations of one of the more popular treatments of tension pneumothorax: needle decompression. Due to an increased incidence of iatrogenic effects of improper needle placement, one of the recent topics of discussion among TCCC trainers has centered around locations (i.e., anterior vs lateral) of needle placement. Improper anterior placement in the mid-line direction can led to severe vascular injuries. Some have advocated for moving the primary location for needle insertion to the lateral location to mitigate iatrogenic effects. This location, however, raises other issues, specifically chest wall thickness in comparison to the anterior location, even as needles have increased in length.
A recent study published* in Academic Emergency Medicine seeks to answer one of the questions that have emerged from the debate by identifying the optimal site of needle insertion with respect to anterior wall thickness limitations. The results are interesting. Average chest wall thickness at the right side anterior second intercostal space, lateral forth and fifth mid-axillary locations were 46.4 mm, 53.8 mm and 63.7 mm, respectively. When considering the one factor of chest wall thickness as it relates to successful penetration of the plural space, the researchers concluded, the anterior location is superior. Furthermore, attempting to overcome the increased chest wall thickness at the lateral mid-axillary locations by using a longer catheter is risky, for it increases the risk of damaging surrounding vascular structures.
While this study does not address the larger issue of practitioners misplacement at the anterior location, it does illicit and attempt to answer an important question of impulsively changing training doctrine to emphasize the lateral location.
*Anterior Versus Lateral Needle Decompression of Tension Pneumothorax: Comparison by Computed Tomography Chest Wall Measurement by Sanchez, Leon, MD, MPH, et al. Academic Emergency Medicine 2011; 18:1022-1026 by the Society for Academic Emergency Medicine