Exposure to blasts and significant impacts from a fall or vehicle crash can lead to head injuries that are not always accompanied by obvious external signs. 

Altered mental status may be your first indication of a possible head injury. The initial rapid assessment of a casualty’s mental status comes from communicating with the casualty by asking them to follow commands and to answer questions during the trauma assessment. If the casualty is not responding appropriately (noted by observing their verbal and nonverbal responses), this may be a sign of altered mental status.

Mental status can be further assessed using the AVPU technique. This technique involves assessing for the level of responsiveness by validating whether the casualty is alert (the “A”), responds to your verbal commands appropriately (the “V”), responds to painful stimulation (the “P”), or is unresponsive (the “U”).

Keep in mind that in the combat or trauma setting, altered mental status may be secondary to hypovolemia and/or hypoxia in the presence of other injuries resulting in massive hemorrhage or altered respiratory status.