Las presiones intramusculares no influyen en el resultado de la fractura tibial.

White TO, Howell GE, Will EM, Court-Brown CM, McQueen MM

Elevated intramuscular pressure is the hallmark of compartment syndrome, but there is no consensus on what level of pressure should be used as the indication for fasciotomy. Previously, absolute pressures of 30-40 mmHg were considered diagnostic of compartment syndrome and, at that level, an absolute indication for fasciotomy. Perfusion pressure, or the difference between the intramuscular pressure and the patient's blood pressure, is now being used to diagnose and treat compartment syndrome. McQueen and Court-Brown[1] define perfusion pressure as the difference between the diastolic blood pressure and the intramuscular pressure. Fasciotomy should be performed when the perfusion pressure is greater than 30 mmHg; McQueen has found that using this definition reduced the need for fasciotomy without increasing morbidity from missed compartment syndrome.

In this study, 101 patients with tibia fractures had continuous measurement of their intramuscular pressure and satisfactory perfusion pressures. Forty-one patients had persistently elevated intramuscular pressures greater than 30 mmHg. These patients were compared with the 60 remaining patients who had pressures less than 30 mmHg throughout the period of monitoring. The authors assessed return to function and muscle strength in all patients during the year after injury. No differences were found between the 2 groups of patients, possibly because elevated intramuscular pressures themselves do not influence outcome. The authors suggest that patients with elevated intramuscular pressures can be safely observed as long as their leg perfusion pressure remains adequate (above 30 mmHg).

This research further supports the concept of perfusion pressure as a valid diagnostic criterion for compartment syndrome. It must be noted that these patients had isolated injuries and could also be assessed clinically for symptoms of compartment syndrome. It would be prudent to repeat this study with patients who cannot be clinically evaluated (such as those on ventilators). Until then, a lower threshold for compartment decompression may still be appropriate.