Limb threatening ischaemia - acute & chronic
Questionnaire/history:
Acute leg pain?Persistent pain in the forefoot and toes?
- Worse at night?
- Woken up in the early hours with pain?
- Relieved by hanging legs down?
(Note: often no history of intermittent claudication)(Note: patients with peripheral neuropathy may present with chronic limb-threatening ischaemia (CLTI) with NO pain due to the neuropathy)
Pulselessness (absent ankle pulses)?
Pallor (or mottling or cyanosis)?
Coldness?
Paraesthesia or reduced sensation (late, limb-threatening signs)?
Paralysis (late, limb-threatening signs)?
Past medical history?
- Risk factors (eg IHD, stroke, diabetes, smoking)?
Current medication?
Known drug allergies?
Examination:
Foot pulses?
(Note: substantial false positive and negative rate even by experienced vascular surgeons)
Pallor?
Coldness?
Non-healing foot wound +/- infection?
(Note: foot often looks pink or red with apparently normal capillary refill time when sitting with the foot down, due to hyperaemia)
Buerger’s (lay patient down, elevate both legs to 45 degrees for 1-2 minutes and look for pallor; then hang legs down at 90 degrees and look for reactive hyperaemia)?
Investigations:
Ankle-brachial pressure index (ABPI)
- ABPI ≤ 0.9 = PAD
- ABPI ≤ 0.5 = severe PAD (ulceration risk, low threshold for referral)
- ABPI > 1.2 suggests a falsely elevated reading due to calcified arteries
(Note: ABPI is unreliable in suspected CLTI and should not be used in primary care to determine referral in patients in whom CLTI is suspected, it should not be used to exclude PAD in diabetics based on a normal or raised ABPI alone)
Management:
Urgent admission to vascular surgeon
Resource(s):