Pre-Operative Assessment

ℹ️ About

• There is a big difference between elective and emergency surgery, with many procedures falling in between.
• The perioperative team must weigh risks vs benefits and act in the patient’s best interests.

🩺 General Principles

• Surgery is a physiological stressor affecting the cardiovascular, respiratory, coagulation, and wound healing systems.
• The physician’s role: identify and optimise medical problems to support safe anaesthesia and surgery.
• Final decision to operate: made jointly between surgeon, anaesthetist, and patient (with shared decision-making).

❤️ Cardiac Disease

• Ischaemic heart disease: Angina or equivalents ➝ red flags; requires cardiology assessment.
• Assess breathlessness/exercise tolerance as a marker of reserve. Refer to cardiology if uncertain.
• Antithrombotics in patients with stents or valve replacements require careful perioperative planning.
• All patients: baseline ECG (for ischaemia, AF, hypertension, structural heart disease, conduction defects).
• MI: Elective surgery usually delayed for ≥6 months post-MI; risk highest in first 6 weeks.
• Hypertension: Often discovered perioperatively. Urgent review if unstable (e.g. chest pain, encephalopathy, LVF). Otherwise, GP follow-up next day.
• Arrhythmias: Identify and manage (e.g. AF). Chronic/complex arrhythmias ➝ cardiology input.
• Heart failure: Optimise therapy before surgery; perioperative fluid balance crucial.
• Endocarditis prophylaxis: Patients with prosthetic valves, PDA, septal defects, or past endocarditis may require antibiotic cover (specialist advice).

🌬️ Respiratory Disease

• Encourage smoking cessation ≥6 weeks before surgery.
• Routine CXR is limited; rely on history/exam (early COPD, asthma, etc.).
• Severe lung disease ➝ consider pre-op respiratory review and formal lung function tests.
• Perioperative care: early mobilisation, pain control, chest physio ➝ reduce hypostatic pneumonia.
• VTE prophylaxis to reduce pulmonary embolism risk.

🩸 Diabetes Mellitus

• Risks: hypoglycaemia, ketoacidosis, plus vascular disease, renal failure, infection.
• Diet-controlled: Usually no special measures beyond glucose monitoring. Omit oral hypoglycaemics morning of surgery; restart once eating.
• Major surgery / prolonged NBM: Use variable-rate insulin infusion (VRII) with close monitoring.
• Insulin-dependent: VRII perioperatively. Monitor blood sugar and ketones. Resume SC insulin once diet restarts.

🩸 Coagulation Disorders

• VTE risk: Previous DVT/PE, thrombophilia, obesity, malignancy, immobility, smoking, OCP use.
• Modify risks (e.g. stop combined OCP 4 weeks pre-op).
• Prophylaxis: LMWH, compression stockings, intermittent calf compression.
• Bleeding risks: Haemophilia, anticoagulants, antiplatelets, chronic liver disease ➝ specialist planning.
• Consider perioperative replacement (Vit K, clotting factors, platelet transfusion) as needed.

🍺 Liver Disease

• Risks: coagulopathy (Vit K/factor deficiency), altered drug metabolism, low albumin, increased infection risk.
• Correct deficiencies with Vit K if responsive.
• Careful perioperative fluid balance essential.
• Alcohol history ➝ anticipate withdrawal risk.

🧂 Renal Disease

• Common in patients with diabetes, hypertension, vascular disease.
• Avoid perioperative hypotension; monitor urine output closely.
• Recognise and treat oliguria/anuria early.
• Maintain hydration post-op.
• Avoid NSAIDs where possible.

🚨 Emergency Surgery

• Limited time ➝ may not be possible to optimise all co-morbidities.
• Rapid assessment of cardiac, respiratory, metabolic, and endocrine disease is key.
• Baseline investigations: ECG, CXR, U&E, FBC, coagulation studies; ABG if indicated.
• Correct anaemia, fluid/electrolyte imbalance, and cardiac failure where possible before theatre.
• Always assess and provide VTE prophylaxis perioperatively.