Trauma Care 6: Compartment Syndrome
Rural emergency care teams should be aware of the possibility of compartment syndromes developing in any trauma patient or patient at risk. Compartment syndromes can occur from an external pressure like a tight cast or tight burn eschar or from a comatose patient lying on his or her arm. They may also occur because of increased pressure within a compartment due to bleeding or edema from an injury or hemorrhage in a patient with a coagulopathy defect or receiving anticoagulants.
The tissues within the compartments that are most sensitive to lack of capillary blood flow are the nerves and muscles. These tissues may be permanently damaged before the pressure reaches the point of decreasing blood flow through the arteries; so diminished pulse is not a criterion for the presence of a compartment syndrome. If the patient is awake, he or she will experience severe pain over the compartment. Either passive or active muscle movement exacerbates this. Paresthesias will occur in the distribution of the nerves traversing the compartment. The compartments themselves will feel tense to the touch.
The compartments most frequently involved are the compartments of the leg and of the thigh. Here are diagrams showing their positions and contents:
The thigh compartments are the next most frequently involved compartments. Tense swelling and pain are prominent findings.
The measurement of compartment pressures is a valuable tool in the diagnosis of compartment syndromes. There are devices for quickly and accurately determining compartment pressure. The Styker STIC Monitor and the Ace Intracompartmental Pressure Monitor are such devices. Published guidelines for the interpretation of pressures vary in their recommendations. Most references accept pressures of less than 10 mm Hg as within normal range. A compartment pressure reading of 30 mm Hg is generally considered grounds for immediate surgical decompression. Compartment pressures of 20 to 25 mm Hg are worrisome, but can be watched. Pressures of 25 to 30 mm Hg may demand surgical decompression based on clinical findings.
One “homemade” device consists of an 18-gauge needle connected by IV tubing to a stopcock. A 20 cc syringe is attached to the stopcock and used to draw a small amount of saline halfway into the tubing. The other port of the stopcock is attached by IV tubing to a blood pressure manometer. The final setup looks like this:
All ports of the stopcock are then opened and air is slowly injected with the syringe until the air/fluid column in the tubing begins to move toward the needle. The manometer pressure at which this happens approximates the tissue pressure.
Treatment of Compartment Syndrome:
Fascial release is the treatment of choice in acute compartment
syndrome.1 While “immediate” fasciotomy upon diagnosis is often
recommended; this is not typically an emergency bedside procedure.
Time-to-permanent-tissue-damage appears to be calculated in terms of
hours rather than minutes. Consult your surgeon or trauma referral
center. In the absence of compartment pressure measuring devices, many
trauma surgeons will perform a fasciotomy of the muscle compartments
based purely on clinical grounds. Tenseness, pain, paresthesia, and
weakness are the hallmarks of these syndromes. Pulseless paralysis is a
late sign of serious ischemia.2
References
- Black KP, et al. Current concepts in the treatment of common compartment syndromes in athletes.Sports Med. 1993;15:408-18.
- Callahan LR, et al. Overview of running injuries of the lower extremity. In: UpToDate, Rose BD (Ed), UpToDate, Wellesley, MA, 2002.
- Pedowitz RA, et al. Modified criteria for the objective diagnosis of chronic compartment syndrome of the leg. Am J Sports Med. 1990;18:35-40.
- Matsen FA. Compartmental syndromes. Hosp Pract. 1980;15:113-7.