As mentioned previously, if a vented chest seal is in place and there is evidence to suggest a tension pneumothorax has recurred, you can burp the chest seal; however, consider an NDC if symptoms do not improve.

If an NDC shows improvement in the casualty status but then the casualty shows signs of a tension pneumothorax again, then perform a second NDC near the same site. If there is no improvement, proceed to the assessment of circulation.

In cases where the initial NDC does not improve the casualty status, try the alternate site. If again there is no casualty improvement, then move on to the “C” in MARCH.