When leg pain is not 'just' musculoskeletal

Recently, I came across a case where a hospitalized patient reported sudden, new onset severe pain in one leg. The nurse responded appropriately and obtained an order for IV pain medication and promptly medicated the patient. But the pain turned out to be related to an acute arterial occlusion, not a musculoskeletal reason. The patient did have a history of peripheral  arterial disease but that was not the reason for his inpatient admission. The patient ended up requiring a 'BKA' or below knee amputation.  

Classic findings of acute limb ischemia include the “six Ps”: pain, pallor, pulselessness, poikilothermia or coolness, paresthesia, and paralysis. I know we learn about those six Ps in nursing school but it is not something that we tend to see often in clinical practice and so it is easy to overlook as the first cause for pain. These findings do not necessarily appear simultaneously. Pain may be the first indication that something is wrong and it is important to complete a focused assessment that should include:

• The onset, location, severity, and progression of the pain

• Comparison of color and temperature between extremities

• Assessment of peripheral pulses, including Doppler assessment when indicated

• Capillary refill, sensation, and motor function

• Prompt communication of the findings and the concern for possible vascular compromise

• Reassessment and further escalation when the condition worsens or the initial notification does not produce a timely response

From a legal perspective, a delayed diagnosis of acute limb ischemia is often reconstructed through the nursing timeline. When did the patient first report pain? What assessment was performed? What objective findings were documented? Who was notified, what information was communicated, and how quickly did someone respond? If the patient continued to deteriorate, did the nurse reassess and use the chain of command?

The central issue is not whether the nurse made the medical diagnosis of acute limb ischemia. It is whether a reasonably prudent nurse would have recognized that the findings were inconsistent with routine musculoskeletal pain and escalated the concern.

Practice takeaway

Sudden or worsening limb pain is not merely a pain-management problem. It is an assessment problem. Nurses do not have to diagnose an arterial occlusion, but they must recognize the warning signs, communicate the urgency, and continue to escalate until the concern is addressed appropriately. In acute limb ischemia, that response may determine whether a limb remains salvageable.

Reference: Gornik HL, et al. 2024 ACC/AHA Guideline for the Management of Lower Extremity Peripheral Artery Disease.