Informed Consent OSCE - Amputation Consent in Diabetic | Free OSCE Practice

Case Overview

Age/Sex: 68-year-old female
Occupation: Retired schoolteacher
Setting: Emergency department / surgical ward pre-operative consent discussion
Chief complaint: "They say they need to take my leg — I’m here to talk about that"

Patient Script

Who I Am

I’m 68, I used to teach primary school, and I live alone but my daughter pops in most days.

What Brings Me In

They told me I need to decide about having part of my left leg taken off because of an infection that won’t get better.

My Story

About 3 weeks ago I noticed a small sore on the sole of my left foot after I bumped it on a chair. For the first couple of weeks it was just a sore that I kept covering. Over the last 5 days it has become much worse — it’s very painful, my toes have gone black, there’s a foul smell, and I’ve had fever and chills for 2 days. My left foot is swollen and I can’t put weight on it. I saw my GP who gave me some oral antibiotics 3 days ago but it hasn’t helped and the pain and smell got worse, so they sent me to hospital. They’ve been telling me it might be better if they cut the dead bit off so the infection doesn’t spread.

I also get pain in my legs when I walk sometimes for a while and I have had poor healing of cuts before. I had a small ulcer on my right foot last year that healed with dressings (that’s okay now). I also had a chest ache last month which I thought was indigestion and it went away, and I had a mild cough for two days last week.

My Medical Background

Type 2 diabetes mellitus for 18 years (mostly on insulin)
Hypertension
Ischaemic heart disease (stented 5 years ago)
Chronic kidney disease stage 3
Peripheral vascular disease / poor circulation in legs
Medications: insulin (basal-bolus), metformin (stopped previously), aspirin 75 mg OD, atorvastatin, lisinopril, amlodipine, occasional oral antibiotic prescribed by GP last week (unknown name)
Allergies: penicillin — rash (mild) (patient reports this)
Social: ex-smoker, 40 pack-year history (quit 5 years ago), drinks a glass of wine occasionally, lives alone with daughter nearby
Family history: father died of heart disease, mother had type 2 diabetes

What I Think & Worry About

I’m scared they will cut off my leg and I’ll never be able to look after myself again.
I think the doctors are worried the infection will spread and make me very ill.
I worry about being a burden to my daughter and being stuck in a care home.

If You Ask Me About Other Symptoms...

Pain: "It’s a terrible burning and throbbing pain in my left foot, worse at night, I can’t sleep well."
Fever: "I’ve felt hot and shaky for two days, I had one night of sweating."
Chest: "I had a bit of chest discomfort a few weeks ago but it felt like indigestion and went away — I’m not short of breath now."
Mobility: "I could walk a little about the house before this, now I can’t put weight on that foot."
Bladder/Bowels: "No problems, I’m peeing a bit more than usual."
Medication adherence: "I usually take my insulin but I missed a dose yesterday because of the pain."
Prior antibiotic: "My GP gave me antibiotics last week but the sore got worse after that."
Wishes: "If there’s any way to keep my leg I’d like to try, but I don’t want to die of infection."

Clinical Summary

Examination

General: alert, anxious, older female; T 38.4°C, HR 110 bpm, BP 95/60 mmHg, RR 22/min, SpO2 96% on air
Cardiorespiratory: heart sounds normal but tachycardic; lungs clear
Abdomen: soft, non-tender
Left lower limb: black, necrotic toes and forefoot with foul-smelling purulent discharge; surrounding erythema extending to midfoot; swelling and tense soft tissues; crepitus palpable over forefoot; very tender to touch
Pulses: femoral and popliteal pulses present; posterior tibial and dorsalis pedis pulses absent on the left; capillary refill >4 seconds in toes
Right lower limb: peripheral pulses palpable, no ulceration
Neurological: reduced sensation in both feet consistent with diabetic neuropathy

Investigations

CBC: WBC 18.2 x10^9/L (neutrophil predominant) (leucocytosis consistent with infection)
CRP: 210 mg/L (marked inflammation)
Blood glucose: 16.0 mmol/L (hyperglycaemia)
HbA1c: 9.2% (poor chronic glycaemic control)
Renal: creatinine 160 µmol/L (baseline ~110) (AKI on CKD stage 3)
Blood cultures: pending
Wound swab: mixed Gram-negative and Gram-positive organisms (preliminary, culture pending)
X-ray left foot: soft tissue gas in forefoot, no obvious bony destruction on plain film (suggests gas-forming infection)
Ankle-brachial pressure index (ABPI) left: 0.3 (severe peripheral arterial disease)
ECG: sinus tachycardia, no acute ischaemic changes

Diagnosis

Primary: Severe infected diabetic foot with wet gangrene and soft-tissue gas formation in the left forefoot, on a background of critical limb ischaemia and systemic inflammatory response (sepsis) — clinical picture supports urgent limb amputation (below-knee vs. above-knee) to control infection.
- Evidence: black necrosis of toes, foul-smelling purulent discharge, soft-tissue gas on x-ray, systemic signs (fever, tachycardia, hypotension), high WBC/CRP, ABPI 0.3 indicating poor distal perfusion.
Differentials:
- Gas gangrene (clostridial myonecrosis): possible given soft-tissue gas, but slower progression and mixed organisms on swab point to polymicrobial diabetic foot infection.
- Severe necrotizing fasciitis: considered, but distribution and musculature involvement less clear; would be managed similarly urgently.
- Osteomyelitis of metatarsals: possible if infection extends to bone; plain film not diagnostic — MRI if time and renal function permit.
- Critical limb ischaemia without infection: there is infection present; ischaemia contributed to necrosis.
- Cellulitis alone or deep venous thrombosis: less likely to explain necrosis, foul discharge and gas.

Management

Immediate/urgent steps:
- Treat sepsis: start broad-spectrum IV antibiotics urgently (e.g., if penicillin allergy mild rash reported, consider vancomycin plus piperacillin–tazobactam alternatives after allergy clarification; adjust per local guidelines and cultures).
- Resuscitation: IV fluids as tolerated, monitor urine output, correct hyperglycaemia with insulin sliding-scale; commence analgesia and antiemetics as needed.
- Surgical: urgent vascular/orthopaedic/vascular-led limb surgery consult for planned amputation — likelihood of below-knee amputation given level of disease but discuss possibility of above-knee if infection or perfusion requires higher level.
- Investigations and optimization: cross-match blood, continue sepsis labs, blood cultures, check coagulation, consider urgent duplex/angiography only if it will change immediate management (contrast use limited by renal function).
- Consent/capacity: assess capacity; conduct a frank consent discussion covering the reason for amputation, benefits (control infection, reduce risk of death), risks (bleeding, wound infection, need for higher-level amputation, myocardial infarction, need for ICU, death), and reasonable alternatives (conservative debridement, revascularization if feasible but unlikely/contraindicated given ABPI and renal function). Invite family/next-of-kin if patient wishes. Document discussion clearly.
- Multidisciplinary planning: involve anaesthetics for perioperative risk assessment (ischaemic heart disease, CKD), physiotherapy/occupational therapy and social work for post-op rehabilitation and home support planning.
- Thromboprophylaxis and perioperative measures: start DVT prophylaxis when safe; ensure perioperative antibiotics and glycaemic control.

Key Learning Points

In diabetics with poor peripheral perfusion, the combination of necrosis, foul discharge, systemic inflammatory response and soft-tissue gas mandates urgent surgical management — medical therapy alone is unlikely to control infection.
Consent for major limb amputation requires clear explanation of indication, alternatives (including limitations such as poor revascularization options), risks, likely outcomes (possible higher-level amputation, rehabilitation needs), and assessment of capacity with documentation and involvement of family/support.
Multidisciplinary perioperative optimization (antibiotics, glycaemic control, fluid resuscitation, cardiac assessment, and early physiotherapy/rehab planning) is essential to reduce morbidity and plan realistic functional recovery.