Compartment Syndrome

D. Decreased serum osmolarity (e.g., nephrotic syndrome)

E. External pressure:

. Excessively tight dressing or cast

. Prolonged recumbency on a limb

F. Other causes:

. Infiltrated intravenous line

. High-pressure transfusion, as in a trauma resuscitation

. Tumor metastases to muscles within compartments

. Acute rhabdomyolysis

. Tendon avulsion

. Excessive tourniquet time during extremity surgery (a form of ischemia-reperfusion injury)

. High-pressure injections (e.g., paint injection injuries)

. Duchenne’s muscular dystrophy

III. ANATOMY

A. The forearm contains 3 muscle compartments:

. Anterior compartment: finger flexors (flexor digitorum superficialis and profundus), thumb flexor (flexor pollicis longus), wrist flexors (flexor carpi radialis, flexor carpi ulnaris, palmaris longus), pronator teres, pronator quadratus

. Posterior (dorsal) compartment: finger extensors (extensor digitorum communis, extensor indicis proprius, extensor digiti quinti), thumb extensors (extensor pollicis longus, extensor pollicis brevis), ulnar wrist extensor (extensor carpi ulnaris), long thumb abductor (abductor pollicis longus), and supinator

. Mobile wad: brachioradialis, two radial wrist extensors (extensor carpi radialis longus, extensor carpi radialis brevis)

B. The hand contains 10 muscle compartments:

. Dorsal interosseous muscles (4)

. Palmar interosseous muscles (3)

. Thenar muscle compartment

. Adductor pollicis

. Hypothenar muscle compartment

IV. PATHOPHYSIOLOGY

A. Increased tissue pressure reduces the local arteriovenous gradient and local blood flow, resulting in tissue ischemia of all tissues contained within the compartment.