Ischemic limb pain (ILP) is a dangerous condition, most often caused by diminished tissue perfusion. Peripheral arterial disease (PAD) is the most frequent cause of ILP, although it is also caused by vasculitis or deep venous thrombosis. It often manifests as distal lower extremity pain on exertion that subsides with rest — known as intermittent claudication (IC) — or as a more severe form of limb ischemia lasting > 2 weeks that results in non-healing ulcers or gangrene, critical limb ischemia (CLI).
ILP is habitually indicative of a systemic vascular illness, and it is often associated with coronary artery disease, chronic kidney disease, delirium, vascular dementia, and other chronic medical conditions. It is often progressive: 20% of patients with IC develop CLI. Of those, 20% of patients with CLI die within 6 months and 50% die within 5 years.
An ankle-brachial index (ABI) between 0.4 and 0.9 confirms the diagnosis of IC; CLI is associated with an ABI of ≤ 0.4. In patients with diabetes, renal disease, or advanced age, an ankle systolic pressure of ≤ 50-70 mmHg or a toe pressure of ≤ 30-50 can diagnose CLI.
Palliative care should be considered in patients with progressive ischemia.
If there is a suitable vascular target, revascularization
may be worth pursuing even in patients with a limited prognosis; it can prevent limb loss, promote wound healing, and improve quality of life by rapidly improving refractory pain. If revascularization is not possible, anticoagulation
and anti-platelet agents
may slow progression and play a role in analgesia.
Patients with CLI who are not candidates for revascularization or who have tissue necrosis may benefit from amputation
as a palliative intervention. It is associated with improved functionality, but has trade-offs that are important to consider (e.g., phantom limb pain, perioperative mortality rate, etc.).
A classic symptom of ILP is an activity-induced, achy pain consistent with IC. With time, the pain often progresses in intensity and also occurs at rest, when small changes in position may prompt pain flares.
An analgesic approach is often required, involving disease-directed interventions and symptom-based interventions:
- supervised exercise
- intermittent pneumatic compression therapy
- dependent leg positioning
- topical analgesics
- Cilostazol and pentoxifylline
- regional anesthesia
See reference for more information.
Adapted from Pickmans L, Smith MA, Keefer P, Marks A. Management of ischemic limb pain. Palliative Care Network of Wisconsin. Fast facts and concepts #352. Internet. Accessed on May 24, 2018.