Cold, Painful, Pale, Pulseless Leg/Foot Station

Presenting Complaint: 

Sudden, severe pain in the left leg starting a few hours ago, associated with numbness and a cold sensation.

Quote: "I woke up fine this morning, but then out of nowhere, my left leg started to really hurt—sharp and deep, like someone’s twisting it from the inside. Now it’s gone cold and feels numb… it’s honestly quite frightening."

SOCRATES – Left leg pain:

• Site: Left calf and thigh
  "Mainly the calf but now it's spreading up."
  
  
• Onset: Sudden, 4 hours ago, nil trauma
  "One minute I was fine, the next I was doubled over."
  
  
• Character: Sharp, cramping, deep pain
  "It feels like the muscle is being strangled."
  
  
• Radiation: None
  "It’s just that one leg."
  
  
• Associated Symptoms:
  • Coldness
  • Pallor
  • Numbness
  • Paraesthesia
  • Inability to move toes properly
  • Anxiety and panic

           "It’s gone cold and looks white compared to the other leg."

           "I can’t really wiggle my toes anymore."

• Timing: Constant since onset 4 hours ago. Progressive pain leading to increasing numbness and paraesthesia
  "It’s been like this since mid-morning. Initially the pain was getting worse but now it’s started to get numb with pins and needles."
  
  
• Exacerbating/Relieving Factors: None known
  "Nothing helps. Even lying down doesn’t ease it."
  
  
• Severity: Pain 9/10. Unable to stand or walk due to pain and weakness.
  "It’s really intense—makes me feel sick with pain."
  
  

Summary list of symptoms:

• Severe left lower limb pain
• Cold, pale left leg
• Paraesthesia and reduced movement
• Anxiety and distress

Systemic Symptoms:

• No fevers, night sweats, fatigue or weight loss
• No bowel or urinary changes, no back pain
• No confusion or weakness elsewhere
• No chest pain, SOB, dizziness, pain elsewhere

Past Medical History:

• Hypertension
• AF
• Type 2 Diabetes Mellitus (10 years, diet and metformin controlled)
• Hyperlipidaemia
• Ischaemic Heart Disease (MI in 2018; stented)
• Nil history of intermittent claudication

Drug History:

• Amlodipine 10mg OD
• Apixaban 5mg BD
• Metformin 1g BD
• Atorvastatin 80mg ON
• Aspirin 75mg OD
• Ramipril 5mg OD

Nafisa admits to poor compliance with medications.

Allergies:

• Penicillin → Rash and breathlessness
  "I once had penicillin and came out in a rash and couldn’t breathe properly."

Family History:

• Father: MI at age 60, passed away
• Mother: Type 2 diabetes
• Sister: Stroke in her 50s
• No known genetic clotting disorders

Social History:

• Occupation: Retired secondary school English teacher
• Functional status: Independent in all ADLs until today
• Marital status: Widowed, lives alone
• Home: Lives in a bungalow, uses public transport
• Smoking: Smoked 10 cigarettes/day for 20 years; quit 15 years ago
• Alcohol: Occasionally (1–2 glasses of wine/month)
• Exercise: Walks regularly in park, light gardening

Ideas, Concerns, and Expectations:

• Ideas: "Could it be a clot? My leg looks dead—it’s terrifying."
• Concerns: "What if I lose my leg? I live alone—I can’t manage with one leg."
  
• Expectations: "I need to know what's happening quickly, and I want to stop this pain. Will I need surgery? I just want to be back to normal again.”

Observations:

Respirations: 22 breaths/min

Oxygen Saturation: 97% on air

Air or Oxygen?: Air

Blood Pressure: 142/87 mmHg

Pulse: 96 bpm, irregularly irregular

Consciousness: Alert (A on AVPU)

Temperature: 36.9°C

NEWS Total Score: 3

Physical Examination:

General Inspection:

• Pale and visibly distressed
• Left leg: pale, mottled, cold

Author: James Heilman, MD. Accessed via Wikimedia Commons. CC BY-SA 3.0.

Legs:

• Left leg:
  
  
  • Pale, cold to touch, mottled appearance
  • Cap refill >4s
  • No palpable dorsalis pedis or posterior tibial pulse, no palpable popliteal pulse
  • Femoral pulses palpated bilaterally
  • Power: 2/5 at ankle, 0/5 (no movement) at toes
  • Sensation: reduced in foot
  • No obvious swelling
    
    
• Right leg: Normal findings compared with left side. Warm and well perfused, pulses palpable, neurologically intact.

Special Tests:

• Doppler (if asked for): Absent arterial signals in all left foot arteries

Patient Questions:

1. “What’s happened to my leg?”

"You’ve got a sudden blockage in one of the big arteries in your leg. That’s stopping blood from getting to your foot properly, which is why it’s cold, painful and numb. It’s a medical emergency and we need to act quickly to try to save your leg and get the blood flowing again. This might involve surgery or a procedure to remove the clot. We’ll give you blood thinners and pain relief straight away, and get in touch with the surgeons."

2. "Am I going to lose my leg?"

"We’re doing everything we can to restore the blood flow. Time is crucial, and we will speak urgently with the surgeons to potentially organise an emergency operation. There is a small chance that amputation may need to be considered as a last resort if the leg is too damaged, in order to save your life, however the surgeons will try their best to stop that from happening."

3. "Will I still have pain if my leg gets cut off?"

"Major amputation, if required, will stop this severe pain you are experiencing now. However, it is important to be aware that many people suffer from ongoing phantom limb pain and sensation following amputation, in the area that is amputated. While we have medications to help with this, it is an important consideration."

4. "Will this happen again?"

"Once we treat this episode, we’ll look for the cause and try to prevent it from happening again by controlling risk factors, such as blood pressure, heart disease and abnormal heart rhythms."

Examiner Questions:

1. What are your differential diagnoses?

Most likely:

• Acute limb ischaemia (ALI) likely secondary to embolic occlusion – Rutherford category IIb
  • Sudden-onset pain, pallor, paraesthesia, pulselessness, paralysis, and perishing cold
  • Risk factors: AF, IHD, diabetes, hypertension, peripheral vascular disease
  • AF likely source of cardioembolism

Less likely:

• Acute-on-chronic peripheral arterial disease:
  • No prior claudication or PAD history
• DVT:
  • No swelling or redness; pulses absent
  • No obvious risk factors e.g. long-haul flight, recent surgery or immobility
• Compartment syndrome:
  • Would expect more swelling, pulses may be present, would have severe pain on passive stretch of muscle. May be a traumatic history
• Sciatic nerve compression/radiculopathy:
  • Would not cause absent pulses or mottling. No back pain in history

2. What are the 6 Ps of acute limb ischaemia?

• Pain
• Pallor
• Pulselessness
• Paraesthesia
• Paralysis
• Perishing cold
  

3. How do you classify ALI severity?

Rutherford Classification for ALI:

• I: Viable

• • • • No immediate threat
      • No sensory loss
      • No motor deficit
      • Audible arterial doppler
        
        

• IIa: Marginally threatened

• • • • Salvageable if promptly treated
      • Minimal sensory deficit (toes)
      • No motor deficit
      • Inaudible arterial doppler
        
        

• IIb: Immediately threatened

• • • • Salvageable if immediately revascularised
      • Sensory loss of more than toes, pain at rest
      • Mild/moderate motor deficit
      • Inaudible arterial doppler
        
        

• III: Irreversible

• • • Major tissue loss, permanent nerve damage inevitable, unsalvageable limb
    • Sensory loss profound
    • Motor deficit profound, paralysis
    • Inaudible arterial doppler
      

4. What are the main causes of acute limb ischaemia?

• Thromboembolism (AF, MI with mural thrombus, Infective endocarditis with cardiac vegetation)
• Thrombosis of atherosclerotic plaque
• Trauma to artery
• Aortic dissection
• Graft/stent occlusion

Embolism. Author: Bruce Blaus, Medical gallery of Blausen Medical 2014. Accessed via Wikimedia Commons. CC BY 3.0.

Ruptured atheromatous plaque. Author: Laboratoires Servier. Accessed via Wikimedia Commons. CC BY-SA 3.0.

5. What investigations would you order?

Bedside:

• ECG – investigate arrhythmia or MI as embolic source (post-MI mural thrombus can embolise)
• Capillary glucose
• Doppler ultrasound (handheld) – absent left foot signals
• Urinalysis – no protein/haematuria

Blood Tests:

• Baseline FBC, U&Es, CRP, LFTs 
• Lactate (can obtain with VBG/ABG)
• Clotting screen – baseline for anticoagulation and pre-op
• Group & save / crossmatch 4 units
• HbA1c – diabetes monitoring
• Troponin – rule out concurrent MI, baseline troponin in case of further MI
• Lipid profile – vascular risk assessment
• NTproBNP – investigate potential heart failure
  

Imaging:

• CT Angiogram (CTA) – arterial phase (aorta and peripheries):
  • Reveals abrupt occlusion of left distal superficial femoral artery/proximal popliteal artery
  • No distal reconstitution seen
  • No aneurysm or dissection
  • Right leg circulation normal
  • No obvious filling defects in the heart 

Occlusion of distal superficial femoral artery/proximal popliteal artery. Case courtesy of Kevan English, Radiopaedia.org, rID: 175353

• Echocardiogram (TTE)

Potentially at a later time after acute surgery to identify any cardioembolic cause e.g. infective endocarditis, mural thrombus

6. What is your management plan?

Immediate Actions:

• • IV unfractionated heparin bolus + infusion
  • NPO (nil by mouth) – surgical possibility
  • IV morphine + antiemetic for pain relief

• High-flow oxygen if no concerns for CO2 retention

• IV fluids – maintain perfusion, prevent AKI
• Urgent escalation to vascular surgery team
• Consent and prep for possible embolectomy or thrombolysis +/- amputation if non-viable
• Monitor neurovascular status hourly

7. What surgical options/procedures are there?

• Embolectomy
• Thrombolysis
• Angioplasty
• Bypass
• Fasciotomies if required
• Amputation if irreversible ischaemia