The skin is cleansed with an antiseptic solution, and the needle is inserted into the muscle of the compartment. The pressure in the system is boosted by gently depressing the plunger of the syringe. A rise in tissue pressure can then be assessed by the reading on the mercury manometer. While opinions differ on what value actually constitutes a diagnosis, many practitioners believe that when tissue pressure rises to 10 mmHg to 30 mmHg, there is not adequate perfusion to sustain tissue viability. At this point, time is of the essence.
Immediate treatment can prevent tissue ischemia and loss of function.
Typically, compartmental pressures greater than 30 mmHg indicate the need for surgical fasciotomy, which involves incising the fibrous sheath covering the muscle allowing expansion of the swollen muscle. This emergency procedure relieves the internal pressure caused by the expanding compartment. Depending on which compartment is affected, there may be up to four longitudinal incisions. The surgeon may also make a transverse incision to facilitate decompression of the space. Debridement of the ischemic tissue must also be done.