Perioperative Medicine — Clinical Case

DCE Long Case

Patient brief (provided to trainee)

Patient: Mr Henare, 74 years old, retired farmer. [1]

Presenting referral: Referred to the perioperative physician two weeks before an elective anterior resection for a stage II rectal adenocarcinoma. The surgeon has asked for medical optimisation and clearance. [1]

Past history: Atrial fibrillation (apixaban 5 mg twice daily); type 2 diabetes for 20 years (insulin glargine 30 units nocte, rapid-acting insulin 12 units with each meal, empagliflozin 10 mg daily, metformin 1 g twice daily); COPD (FEV1 55 per cent predicted) on tiotropium and budesonide-formoterol; ischaemic heart disease with a drug-eluting stent inserted eight months ago after an NSTEMI, on aspirin 100 mg and clopidogrel 75 mg (cardiology plan to stop clopidogrel at 12 months); hypertension on perindopril 10 mg and bisoprolol 5 mg; stage 3 chronic kidney disease (eGFR 45, baseline creatinine 135). He smokes 10 cigarettes daily. [1]

Examination and investigations: BP 142/86, HR 68 irregular, SaO2 95 per cent on room air, RR 16. Chest: expiratory wheeze, prolonged expiration. Cardiovascular: irregularly irregular, no signs of heart failure. Abdomen: soft, no masses. He can walk on the flat but stops after one flight of stairs with breathlessness. HbA1c 64 mmol/mol. ECG: atrial fibrillation, no acute changes. Echocardiogram (6 months ago): left ventricular ejection fraction 55 per cent, no regional wall motion abnormality. Weight 92 kg, BMI 31. [1]

Candidate's structured presentation (model)

Opening statement (SASPOP): [1]

"Mr Henare is a 74-year-old retired farmer referred two weeks before an elective anterior resection for a stage II rectal cancer. He has atrial fibrillation on apixaban, insulin-treated type 2 diabetes also on an SGLT2 inhibitor and metformin, COPD with an FEV1 of 55 per cent, and ischaemic heart disease with a drug-eluting stent inserted eight months ago on aspirin and clopidogrel. He has hypertension and stage 3 chronic kidney disease. He smokes. His HbA1c is 64 and his functional capacity is poor — he cannot climb a flight of stairs without breathlessness." [1]

"His main problems are:

1. High perioperative cardiac risk — a Revised Cardiac Risk Index of at least three, with poor functional capacity, complicated by a recent coronary stent.
2. Perioperative diabetes requiring an SGLT2 inhibitor hold and a structured insulin infusion plan.
3. A complex anticoagulation and antiplatelet reconciliation — apixaban for AF, dual antiplatelet therapy with a recent stent, all around major cancer surgery.
4. COPD optimisation and smoking cessation.
5. Very high VTE risk requiring combined pharmacological and mechanical prophylaxis.
6. Chronic kidney disease affecting drug dosing. [1]

"My immediate priorities are to risk-stratify his heart and decide on functional testing, to produce a written perioperative medication and anticoagulation plan agreed with cardiology, to optimise his COPD and stop smoking, and to enrol him in an enhanced recovery pathway." [1]

Integrated management plan: [1]

1. Cardiac risk and the stent. RCRI at least three (high-risk intra-abdominal surgery, ischaemic heart disease, insulin-treated diabetes) with poor functional capacity (fewer than 4 METs) — arrange a dobutamine stress echocardiogram; a positive result prompts cardiology review, but I will not revascularise purely to clear him for surgery (CARP trial). Continue bisoprolol; do not initiate a beta-blocker acutely (POISE). Ensure he is on a statin. For the stent: continue aspirin through surgery, stop clopidogrel five days before for this major cancer resection, restart as soon as haemostasis is secure, and complete the full 12-month dual antiplatelet course — agreed with cardiology.
2. Apixaban for AF. No bridging needed. Stop 48 hours before surgery (two missed doses); restart once haemostasis is secure, 24 to 72 hours postoperatively. High CHA2DS2-VASc — minimise time off.
3. Diabetes. Stop empagliflozin three days before (euglycaemic DKA risk). Stop metformin on the morning of surgery given the CKD and the major procedure. Place first on the list. Continue glargine at 75 per cent of the dose; omit meal-time insulin while fasting. Start a variable-rate intravenous insulin infusion with a glucose substrate fluid, targeting 6 to 10 mmol/L. Resume usual basal-bolus once eating, overlapping the first subcutaneous dose; restart empagliflozin when eating and clinically stable.
4. COPD and smoking. Encourage smoking cessation now. Confirm inhaler technique; ensure maximal inhaled therapy. Treat any active exacerbation before surgery. Teach incentive spirometry. Plan regional analgesia as part of ERAS to permit early mobilisation and coughing.
5. Chronic medications. Continue bisoprolol and inhaled therapy. Hold perindopril morning dose (hypotension risk); restart once stable. Hold loop diuretic if any. Add a statin. Avoid NSAIDs (CKD, bleeding).
6. VTE prophylaxis. Very high Caprini risk. Enoxaparin 40 mg daily (acceptable at eGFR 45), first dose 6 to 12 hours postoperatively once haemostasis secure. Add mechanical prophylaxis after arterial assessment. Consider extended prophylaxis for four weeks given the cancer surgery.
7. ERAS pathway. Preadmission counselling and carbohydrate drink; goal-directed fluid; minimally invasive technique where possible; opioid-sparing multimodal analgesia with a regional block; early mobilisation on day one; early enteral feeding; no routine nasogastric tube or drains.
8. Communication. Written perioperative medication and anticoagulation schedule with dates. Quantified discussion of risk using the RCRI. Advance care planning and goals of care given his age and comorbidity. [1]

Communication and shared decision-making: Explain to Mr Henare that his main risks are a cardiac event and a stent thrombosis if the antiplatelet plan is wrong, and that the plan balances protecting the stent against surgical bleeding — he keeps his aspirin and stops only the clopidogrel briefly. Explain the diabetes plan in writing, including the SGLT2 inhibitor hold and the insulin infusion. Document the consent, the shared decision with cardiology and surgery, and the goals of care. [1]

Examiner discussion questions

Q: "He has a high RCRI and poor functional capacity. What would a positive dobutamine stress echo change?" [1]

"A positive stress echo showing significant inducible ischaemia would prompt me to involve cardiology to assess whether he has a flow-limiting coronary lesion that needs intervention for an independent cardiac indication — an acute coronary syndrome, unstable or severe angina, or ischaemia producing left ventricular dysfunction. What it would not change is a decision to revascularise purely to clear him for surgery — the CARP trial showed that prophylactic revascularisation before surgery did not improve survival or reduce perioperative cardiac events in stable disease. If the stress echo were negative, its high negative predictive value would reassure me and I would proceed with medical optimisation alone." [1]

Q: "He is eight months out from his stent. The surgeon would prefer to stop both antiplatelets. What do you say?" [1]

"I would not agree to stopping both antiplatelets. He is past the conservative minimum stent period of six months, which is reassuring, but the risk of acute stent thrombosis off all antiplatelet therapy carries a mortality of 30 to 50 per cent. The evidence-based compromise, agreed with cardiology, is to continue the aspirin — which carries a lower and acceptable bleeding profile — and to stop the clopidogrel for the shortest period that achieves an acceptable bleeding risk for a major cancer resection, typically five days before, restarting as soon as haemostasis is secure. POISE-2 showed aspirin did not reduce events in unselected surgical patients, but the coronary-stent population is the recognised exception where aspirin continuation is protective. If the bleeding risk were truly prohibitive and surgery unavoidable, the discussion would involve cardiology about the very high thrombotic risk of complete cessation." [1]

Q: "Why not just switch his apixaban to warfarin and bridge him?" [1]

"There is no benefit to switching an established DOAC to warfarin perioperatively, and there is harm — it adds an INR-monitoring burden, exposes him to the bleeding and thrombotic risks of the transition, and warfarin is the agent that actually requires bridging because of its slow offset and onset. The DOAC's advantage perioperatively is its rapid offset and onset, which means I stop it 48 hours before and restart it once haemostasis is secure, with no bridging. I would keep him on apixaban." [1]

Q: "He develops new atrial fibrillation with rapid ventricular rate on day two after surgery and his blood pressure is 96/60. How does that change your plan?" [1]

"I would assess him with ABCDE, establish that his low blood pressure reflects the new fast AF rather than bleeding or sepsis — check his surgical site, drains, haemoglobin, lactate and urine output. For haemodynamically tolerated new AF, rate control with intravenous amiodarone or a beta-blocker is first-line, but his blood pressure of 96 over 60 limits the beta-blocker and he is already on bisoprolol. Amiodarone would be my choice for rate and rhythm control in the unstable or borderline patient, with anaesthetic and cardiology input. I would check his electrolytes, treat any correctable precipitant — pain, sepsis, electrolyte disturbance, hypoxia — and anticoagulate appropriately once the acute episode settles, weighing his high stroke risk against his recent surgical bleeding. I would hold his apixaban until I was confident the surgical bleeding was controlled." [1]

Q: "What single intervention has the biggest effect on his pulmonary outcome?" [1]

"Smoking cessation. Stopping smoking, even in the weeks before surgery, reduces postoperative pulmonary and wound complications. I would also optimise his inhaled COPD therapy and teach incentive spirometry, and plan for regional analgesia so he can cough and mobilise early — but smoking cessation is the highest-impact single intervention." [1]

Q: "What is the most dangerous error a registrar could make in this patient?" [1]

"Stopping his aspirin perioperatively because of bleeding concerns, while he is within the coronary-stent period. Acute stent thrombosis is a frequently fatal event. The second most dangerous error is continuing the empagliflozin into the fasting and surgical-stress period, which risks euglycaemic diabetic ketoacidosis. The third is using a sliding-scale insulin regimen rather than a variable-rate intravenous insulin infusion." [1]

DCE Short Case — A Focused Perioperative Medication Review

Instruction

"This 68-year-old woman with atrial fibrillation, type 2 diabetes and a mechanical mitral valve is admitted for an elective cholecystectomy. Review her medications and give me your perioperative plan. You have 4 minutes to review and 6 minutes for discussion." [1]

Provided data: Warfarin (INR therapeutic at 2.8); metformin 1 g twice daily and gliclazide 80 mg twice daily; perindopril 10 mg; frusemide 40 mg; bisoprolol 5 mg. eGFR 50. HbA1c 60. Blood pressure 138/82. [1]

Presentation template

"This woman has atrial fibrillation with a mechanical mitral valve, type 2 diabetes on oral agents, and likely heart failure on an ACE inhibitor, beta-blocker and loop diuretic. She is facing elective cholecystectomy. My plan, drug by drug: her warfarin needs bridging because the mechanical mitral valve is the highest thrombotic-risk indication and valve thrombosis is usually fatal — I will stop warfarin five days before, bridge with therapeutic-dose LMWH giving the last dose 24 hours before, and restart warfarin with continued LMWH until the INR is therapeutic. Her metformin I will hold on the morning of surgery given the CKD and restart when she is eating and her renal function is stable. Her gliclazide I will hold on the morning of surgery for hypoglycaemia risk. Her bisoprolol I will continue. Her perindopril I will hold the morning dose for the intra-operative hypotension risk and restart once she is stable. Her frusemide I will hold the morning dose to avoid intra-operative hypovolaemia. She needs VTE prophylaxis — LMWH postoperatively plus mechanical. If she has an emergency bleed, her warfarin reverses with four-factor PCC plus intravenous vitamin K, not vitamin K alone, because PCC works in minutes and vitamin K takes 6 to 12 hours." [1]

Discussion

Examiner: "Why does the mechanical mitral valve require bridging when atrial fibrillation often does not?" [1]

"The BRIDGE trial showed that for atrial fibrillation, withholding perioperative bridging was non-inferior to bridging for arterial thromboembolism and caused significantly less major bleeding. But mechanical mitral valves, recent venous thromboembolism within three months, and severe thrombophilia were excluded from that trial. A mechanical mitral valve carries the highest annual thrombotic risk of any warfarin indication — much higher than atrial fibrillation — and a valve thrombosis is usually fatal and very difficult to treat. So the mechanical mitral valve remains a bridging indication regardless of the surgery." [1]

Examiner: "If her HbA1c were 78, how would your diabetes plan change?" [1]

"An HbA1c of 78 millimoles per mole is above the 69 threshold for poor control and indicates a significant hyperglycaemia risk perioperatively. I would still hold the oral agents on the morning of surgery, but I would convert her to a variable-rate intravenous insulin infusion from the evening before surgery rather than relying on oral agents, and I would aim to defer truly elective surgery to optimise her glycaemia — there is good evidence that an HbA1c above 69 is associated with increased postoperative infection. I would involve the diabetes team and consider her insulin regimen more broadly, because oral agents alone are unlikely to be adequate." [1]

Examiner: "Name three drugs you would never stop abruptly perioperatively." [1]

"First, a beta-blocker — abrupt cessation risks rebound tachycardia, hypertension and myocardial ischaemia, so continue it through surgery. Second, a levodopa-based Parkinson medication — withdrawal risks a neuroleptic-malignant-syndrome-like parkinsonism hyperpyrexia with severe rigidity that can compromise the airway, so continue it, giving doses via nasogastric tube if the patient is fasting. Third, a long-term systemic corticosteroid — abrupt withdrawal risks an adrenal crisis because the hypothalamic–pituitary–adrenal axis is suppressed; continue it and give a stress dose for major surgery. Each of these drugs causes more harm stopped than continued." [1]