Post-engagement Hearing Loss and Factors Affecting the Use of Diagnostics

One of the challenges associated with tactical medicine is the lack of diagnostic equipment at the point of injury and throughout the evacuation process. The tactical situation can limit the ability to use exam lights (of any color) and post-engagement hearing loss or environmental noise can eliminate your ability to use a stethoscope or to hear at all.

It is important to practice different techniques for assessing your casualties’ status that do not require the use of diagnostic tools or one specific sense. Hearing is the most regularly affected sense in the combat environment and it is the sense medics rely on the most heavily. Large blasts or firing a weapon can cause a significant ringing or a muffle in your ears. Therefore, when listening for slight variations in breath sounds or a fading pulse, it can be next to impossible to hear. That is why you must learn alternate methods for assessing your casualties’ status.

One skill that is often affected is measuring blood pressure. If you don’t know how to take a palp. blood pressure or know how pulse presence roughly correlates to levels of BP, you need to learn and practice the techniques. They also come in handy when working in the back of a helicopter or loud vehicle such as a track-vehicle or Stryker that are on the move. Here are some examples of pulse pressures associated with the presence of a pulse in various locations.

Pulse Location/Correlating Pulse pressure

Dorsalis-pedis pulse/90
Tibialis-posterior pulse/90
Radial pulse/80
Femoral pulse/70
Carotid pulse/60

These are very rough estimates and should only be used when no other means of measuring pressure are available. Studies have shown that this method often causes medical personnel to overestimate their patients’ pressure. We suggest this method be used to note which pulses are palpable during the initial set of vitals. Mark the location of these pulses with a Sharpie® when they are found. If a pulse that was present becomes weaker or disappears as time elapses, your casualty may be deteriorating, and you need to do something to address the cause of that deterioration. As stated earlier, this method should not be used if an accurate pressure is required.

The inability to use the sense most suited for the evaluation of a casualty is not just limited to taking blood pressure. It affects your ability to assess a needle decompression in a helicopter, looking for unilateral rise and fall of the chest, feeling for injuries and many other portions of your assessment. Regular practice of alternate methods of assessment should be included in your training regimen, because it’s too late to practice after your ears are ringing from the IED blast.

2 replies
  1. starlight_cdn
    starlight_cdn says:

    All excellent info for an unconcious pt. I would like add observe your cas. A awake cas with zero anxiety, good color, and/or is mentating normally (normal for them) is not a priority. Move on!!!

    The difficulty lies with LN, Host nations SF, and some Coalition allies. The language barrier to determines LOC may be an issue at the early stages. Most ‘terps lack medical/tactical English to be of great assistance.

    You know this is the only place I blog!!!! 🙂

    Reply
  2. samson ferrell
    samson ferrell says:

    i agree, in most cases you dont have time to do much assessing.. the fight has to move on…if cas can speek, good color seems to have good LOC ….red cem light and move!!!! if i have time to take a BP then i am in the tactical field care phase of care, so i can move to a place where i can hear, but on the other hand i understand and think that all medics should be able to do it by feel alone. because we never know how an assault will go or what will happen, so be redy for it all..

    Reply

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