Discussion

Upper extremity compartment syndrome is most commonly encountered in the forearm, which consists of three compartments—volar, lateral, and dorsal. While there are 11 designated compartments in the hand that can be affected, the hand is a relatively rare location for compartment syndrome [1, 2, 5]. The clinical presentation typically includes the ‘five Ps’: pain, pallor, pulselessness, paresthesia and paralysis, which commonly appear in this order as ACS progresses. The pain is often disproportionate to the magnitude of the injury and paresthesia is typically felt distal to the affected area. The most frequent examination findings are tense, swollen compartments with pain elicited by passive stretching of the muscles within that compartment. A neurologic examination is mandatory whenever compartment syndrome is suspected. It is essential to carefully document sensory and motor function distal to the compartment, focusing on the nerves that traverse the at-risk area. The loss of two-point discrimination is a relatively sensitive indicator of developing compartment syndrome [1]. In most cases, measurement of ICP is not required to confirm the diagnosis [1]. However, pressure measurements remain an important adjunct in equivocal cases, unconscious patients, or pediatric populations. The absolute pressure theory described by Matsen has been replaced by differential pressure models. In these models, fasciotomy is indicated when the “delta pressure”—the difference between the compartmental pressure and the arterial or venous blood pressure—falls below 30 or 20 mmHg, respectively [2].

Subcutaneous extravasation of contrast material is a recognized complication of imaging studies. Reported extravasation rates during CT scans vary significantly, with figures ranging from 0.03%–0.17% in some studies to as high as 0.25%–0.9% in others. While most extravasations cause only minimal swelling or erythema that resolves rapidly, skin necrosis, ulceration, and compartment syndrome can occur with large-volume extravasations. An increased incidence of ACS has been reported when extravasated contrast volumes exceed 50 ml, primarily due to the use of rapid infusion pumps and the rising frequency of CT imaging. Preventive measures include the use of low-osmolarity (non-ionic) contrast agents, careful selection of the intravenous administration site, and close patient monitoring during injection [6, 9, 10].

There is no universal consensus regarding the optimal management of extravasation. A large proportion of these injuries heal with a conservative approach: elevation of the limb, application of cold compresses, and administration of intravenous corticosteroids and analgesics. The injection of hyaluronidase—an enzyme that breaks down connective tissue to facilitate the absorption of extravasated fluids—has also been suggested for large-volume injuries. Although corticosteroids and vasodilators have been proposed, most studies have not definitively proven their efficacy [6, 9, 10]. Clinical indication for fasciotomy are the presence of a turgid compartment with pain upon passive muscle movement and any neurologic findings referable to a tense compartment [1]. Urgent surgical drainage and aspiration of the contrast agent within the first 6 hours have proven effective in cases of large-volume extravasation [9, 10]. When a patient does not experience symptoms relief after conservative measures or drainage within the first 6 hours, a hand fasciotomy is indicated. The specific surgical approach should be tailored to the symptoms, but all such patients should undergo a carpal tunnel release [1].