Medline ® Abstracts for References 2,15,54,55

Acute compartment syndrome is a potentially devastating condition in which the pressure within an osseofascial compartment rises to a level that decreases the perfusion gradient across tissue capillary beds, leading to cellular anoxia, muscle ischemia, and death. A variety of injuries and medical conditions may initiate acute compartment syndrome, including fractures, contusions, bleeding disorders, burns, trauma, postischemic swelling, and gunshot wounds. Diagnosis is primarily clinical, supplemented by compartment pressure measurements. Certain anesthetic techniques, such as nerve blocks and other forms of regional and epidural anesthesia, reportedly contribute to a delay in diagnosis. Basic science data suggest that the ischemic threshold of normal muscle is reached when pressure within the compartment is elevated to 20 mm Hg below the diastolic pressure or 30 mm Hg below the mean arterial blood pressure. On diagnosis of impending or true compartment syndrome, immediate measures must be taken. Complete fasciotomy of all compartments involved is required to reliably normalize compartment pressures and restore perfusion to the affected tissues. Recognizing compartment syndromes requires having and maintaining a high index of suspicion, performing serial examinations in patients at risk, and carefully documenting changes over time.

OBJECTIVES: To review the efficacy of the current diagnostic methods of acute compartment syndrome (ACS) after leg fractures.

DATA SOURCES: A Medline (PubMed) search of the English literature extending from 1950 to May 2007 was performed using "compartment syndromes" as the main key word. Also a manual search of orthopaedic texts was performed.

STUDY SELECTION AND EXTRACTION: The results were limited to articles involving human subjects. Of 2605 primary titles, 489 abstracts limited to compartment syndromes in the leg and 577 articles related to the diagnosis of compartment syndromes were identified and their abstracts reviewed. Further articles were identified by reviewing the references. Sixty-six articles were found to be relevant to diagnostic techniques for compartment syndrome in the leg and formed the basis of this review.

CONCLUSIONS: Early diagnosis of an ACS is important. Despite its drawbacks, clinical assessment is still the diagnostic cornerstone of ACS. Intracompartmental pressure measurement can confirm the diagnosis in suspected patients and may have a role in the diagnosis of this condition in unconscious patients or those unable to cooperate. Whitesides suggests that the perfusion of the compartment depends on the difference between the diastolic blood pressure and the intracompartmental pressure. They recommend fasciotomy when this pressure difference, known as the Delta p, is less than 30 mm Hg. Access to a precise, reliable, and noninvasive method for early diagnosis of ACS would be a landmark achievement in orthopaedic and emergency medicine.

In the future, the indications for HBO therapy in acute peripheral ischemic injuries will likely be based on objective criteria rather than, as at present, on clinical diagnoses alone. This chapter offers objective criteria for using HBO in crush injuries and compartment syndromes. The pathophysiology of ATPI are well defined. Hyperbaric oxygen mediates the effects of ATPI through four mechanisms: hyperoxygenation, vasoconstriction, reperfusion, and host factors. The cost benefits of using HBO will be substantial, since complications from ATPI are very expensive. As objective criteria replace the presently used subjective criteria, hyperbaric oxygen therapy will become an integral part of trauma management of these injuries.