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Friday, April 7, 2023

Compartment Syndrome in Crush Injuries

 Original Article


BY JOSEPH ALTON MD







The group medic in survival scenarios will face a number of challenges not normally seen today. Even in normal times, however, there are many areas away from cities where the ambulance isn’t just around the corner. Take a cross-country road trip and you’ll realize that there’s a lot of territory where medical help may not be readily at hand. One case that’s particularly challenging to the off-grid medic is that of crush injuries.

Crush injuries can be seen in many types of situations. Automobile crashes, explosions, earthquakes, and rockslides are just some of the circumstances where the medic may find themselves caring for a crush victim.

Crush injuries are problematic when they happen and when they’re treated. Bleeding vessels may be disguised if the skin isn’t broken. They may present, instead, as severe bruising or an accumulation of blood in body tissues known as a “hematoma”. In the chest and abdomen, hemorrhage is hard to control even with modern facilities available. Direct pressure in certain areas may cause bleeding to abate, but pressure at the suspected site would be more effective if there were a skin breach that allowed visualization of the wound and packing with dressings.

In reality, crush damage may be worst, not at the time of injury, but when pressure is released from the affected area. As blood re-enters an oxygen-starved extremity, cellular toxins released from dying cells can disrupt cardiac and renal function, as well as metabolic status. This can develop several hours after removal of the offending weight.

For example, as muscle cells rupture due to crushing from a blunt injury, they release a variety of chemicals, enzymes, and proteins into the area. The body attempts to remove these to maintain the delicate balance of potassium, sodium, calcium, magnesium and other substances required for proper cellular function. Ruptured muscles release these ions uncontrollably to great detriment.

A complication of significant crush injuries is known as “compartment syndrome”. Groups of organs or limb muscles are supported in sections by tough connective tissue known as “fascia”. These form compartments in the body. The purpose is to provide strength to the structures surrounded, but in a crush injury, excessive pressure builds up due to volumes of free blood pooling internally or the weight of the impacting body itself.

As a result, muscles may swell or blood may accumulate in one or more of these compartments. Because of the fascia, there is nowhere to go. The increased pressure prevents good circulation, leading to a lack of oxygen in the area.  The end result is sometimes irreparable damage to nerves and other tissues. Paralysis, organ failure, or even death may ensue.

At the point of injury, the first sign of compartment syndrome is, as you might imagine, severe pain. This is followed by “pins and needles” sensations. The limb becomes swollen and shiny, losing sensation and function the longer the crushing weight is upon it.  As muscle cells swell in response to the injury, inflammation from cytokines (remember “cytokine storm” from our COVID articles?) worsen the situation and increase the chance for compartment syndrome.

If the injury is confined to a small area, say only a part of the foot, the effects are usually confined to the local vicinity. When larger areas are involved, however, the situation becomes much more complex.

Releasing a person who has been under a crushing weight for a significant period of time is called “reperfusion syndrome”.  Dying muscles and organs release toxins that can not only cause local effects like paralysis of the affected area or dysfunction of the particular organ, but also overwhelms the kidneys’ ability to eliminate those toxins, leading to renal failure. These toxins include potassium, which can be released in large quantities throughout the body when pressure from the crush injury is released, causing life-threatening irregular heart rhythms.

Remember the 5 P’s of compartment syndrome caused by crush injuries:

  • Pain and lots of it (at first).
  • Pale, ashen skin (also known as “pallor”).
  • Paresthesia – strange sensations like numbness, tingling, or pins and needles.
  • Pulse abnormalities (lack of it beyond the level of the injury or a rapid, irregular heartbeat).
  • Paralysis due to nerve damage.

When first approaching a crush injury victim, follow the MARCH series from our previous articles to address any immediate life-threatening issues. Begin IV fluids with Normal Saline if available (difficult for the off-grid medic due to its prescription status) and follow oxygen saturation with a pulse oximeter (widely available).  These and other interventions are often started by emergency medical personnel before removing the weight.

The extrication process is tricky. A pinned extremity would benefit from tourniquet placement to prevent excessive potassium and other possible toxic releases into the bloodstream. If the affected area has been under crushing pressure for a short period of time, say 10-15 minutes, try to lift the weight off them. Longer than that, let emergency medical personnel make the decision. They will often administer IV hydration, oxygen, and certain medications before removing the weight.

Fasciotomy

Once at the hospital, surgeons will often have to make an incision in the fascia (“fasciotomy”) to release the pressure in the compartment. It doesn’t get easier from here. Intensive care personnel will have to monitor the victim for kidney failure, arrythmias, and a host of other issues.

In survival settings, it goes without saying that the lack of modern medical facilities will force the medic to make the same decisions as modern providers without the materials needed to assure a good outcome. Essentially, it will  be like being thrown back to the 19th century medically. Other that stabilization, there’s not much more the medic can do with a crush victim in an earthquake without modern medical and surgical care. In especially dire circumstances, the medic may choose to cut the fascia in the affected area to release pressure on the compartment, a risky proposition even in survival settings. Besides the crush itself, fractures, sprains, and internal bleeding combine to truly challenge the lone medic off the grid.

As such, expect some tragic outcomes off the grid despite your best efforts. Do what you can, where you are, with what you have.

Joe Alton MD

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