A recent meta-analysis of 13 studies that were investigating needle decompression compared data of sample size, mean chest wall thickness, and decompression success rates. The meta-analysis concluded that the needle decompression catheter should be at least 6.5 cm in length to ensure that 95% of patients would have penetration into the pleural space. An 8 cm catheter would enter the pleural space 100% of the time with an anterior approach. International Trauma Life Support guidelines recommend a 6-9 cm catheter.
This is vital information because a tension pneumothorax is one of the causes of pulseless electrical activity (PEA) or obstructive shock so you need to use a long enough needle to optimize your success rate. Luckily, most of the needle decompression kits used by EMS personnel are 8 cm catheters which is the optimal length.
