Acute compartment syndrome (ACS) is a surgical emergency in which rising pressure within a muscle compartment compromises tissue perfusion, potentially leading to irreversible muscle and nerve damage within hours. Prompt recognition and fasciotomy are essential to prevent long-term functional loss or limb-threatening complications. The diagnosis can be particularly challenging, as hallmark signs such as pain out of proportion to injury, tight compartments, and paresthesia are nonspecific and may be masked in certain settings.

The use of regional anesthesia (RA) for analgesia in trauma or orthopedic surgery has traditionally raised concern due to its potential to obscure the early signs of ACS, particularly in alert patients who would otherwise report disproportionate pain. However, this association remains controversial. Although case reports link prolonged nerve blocks with delayed ACS diagnosis, evidence also shows that ACS has been diagnosed and successfully managed in patients receiving single-shot or catheter-based RA.

Upper limb fractures, including those of the humerus (proximal, shaft, and distal), are considered to have a low risk of ACS, largely due to the relatively compliant fascia and anatomical communication with the shoulder girdle, which accommodates swelling more easily than the lower limb.

Nevertheless, clinicians should remain vigilant postoperatively, especially in the setting of high-energy trauma, and ensure protocols are in place for timely reassessment should symptoms suggestive of ACS arise.