Terboven et al. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine (2019) 27:45 https://doi.org/10.1186/s13049-019-0623-5

Conclusion: Especially in small children risk of iatrogenic injury to vital structures by needle decompression is considerably high. The 4th ICS AAL offers a smaller chest wall thickness, but the width of the ICS is smaller and the risk of injury to the intercostal vessels and nerve is greater. Deviations from correct angle of entry however are accompanied by higher risk of injury to intrathoracic structures at the 2nd ICS. Furthermore, we found the heart and the thymus gland to be directly adjacent to the thoracic wall at the 2nd ICS MCL in a few children. From our point of view this puncture site can therefore not be recommended for decompression in small children. We therefore recommend 4th ICS AAL as the primary site of choice