Acute Limb Ischaemia John Gan Vascular Surgeon Specialists Without Borders Seminar in Surgery Rwanda, September 2010

Acute ischaemia – The six Ps Pain Paralysis Pallor Pulseless Parasthaesia (Pins and needles) Poikylothermia (Perishingly cold) Chronic ischaemia – Claudication – Rest pain – Ulcers – Gangrene

Acute limb ischaemia – Challenging problem – Mortality rate 25% – Limb amputation rate 35%

Acute Limb Ischaemia – Sudden arterial occlusion – Tissue hypoperfusion – Ischaemic symptoms

Acute limb ischaemia – Rapid occlusion leads to severe ischaemia the 6 Ps – Slow onset occlusion allows collateral formation and mild ischaemia claudication rest pain gangrene

Acute limb ischaemia – 4 to 6 hours ischaemic time causes irreversible effects – Propagation of thrombus – Occlusion of outflow vessels

Acute limb ischaemia – Compartment syndrome – Reperfusion injury – Systemic effects

Common causes – Embolism – Thrombosis – Trauma

Other causes – Thrombophilia – Other vasculopathy Aneurysm Compression syndromes vasculitis – Intra arterial injection

Presentation – Emergency – Unmistakable – The six Ps Pain Paralysis Pallor Pulseless Parasthaesia (pins and needles) Poikylothermia (perishingly cold)

Differential diagnosis – Venous ischaemia – Neurological condition – Low flow states

Natural history – Non salvageable limb – Limb loss – Death

Assessment – History – Examination – Special testing

History – Degree of disability – Time factors – Possible causes

Examination – Assess the affected limb The 6 ps – Compare to the “normal limb” – Assess the whole patient

Examination The six Ps – Pain – Paralysis – Pallor Pulseless Parasthaesia (pins and needles) Poikylothermia (perishingly cold)

Three groups of cases – Viable – Threatened Salvageable with immediate treatment Salvageable with timely treatment – Non salvageable

Viable – Limb still warm – Movement and sensation intact – Pain moderate or resolving

Threatened – immediate treatment required Six Ps present Absent movement Absent sensation Less than 4 to 6 hours Threatened – timely treatment required Moderate pain impaired movement impaired feeling

Non salvageable – Six Ps – greater than four to six hours – Fixed staining of skin – Woody feel to limb

Degree of ischaemia and causation – Embolism – Trauma – Acute on chronic

Special testing – Hand held doppler – Duplex ultrasound – Angiography

Management Viable cases – Observation

Management Non salvageable cases – Amputation

Management Threatened cases Revascularisation – Embolectomy – Bypass – Thrombolysis Compartment syndrome – fasciotomy Systemic supportive therapy – Cardiac/respiratory/renal

Summary – Arterial occlusion – Causation – Emergency – Six Ps – Three categories – Appropriate treatment

1. Acute occlusion of a previously normal artery results in severe ischaemic symptoms because: a. it occurs without warning b. occlusion of a normal artery is rare c. there are few collateral vessels to supply the limb d. embolism cannot occur in a diseased artery 2. Compartment Syndrome occurs in the ischaemic limb: a. leading to a reduction in pain b. because ischaemic muscle shrinks c. when muscle is re-perfused after a period of ischaemia d. due to reduced blood flow

3. Acute limb ischaemia caused by embolism occurs due to: a. acute thrombosis of a chronic stenosis b. occlusion of an artery when clot travels from one site to another c. thrombosis of an aneurysm d. clot moving from the venous to arterial circulation in some cases 4. Features of an acutely ischaemic limb requiring immediate treatment include: a. complete paralysis b. complete sensory loss c. absent pulse and Doppler signal d. all of the above