Eleven scores used in pre-operative assessment and after surgery. Choose a score, answer the questions, and the result updates as you go. Each score explains what it predicts and what to do with the answer.
ASA physical status classification
Predicts: overall fitness for anaesthesia and surgery. Use: every patient. It is a description of the patient, not of the operation.
Revised Cardiac Risk Index (Lee index)
Predicts: the risk of death, myocardial infarction or cardiac arrest within 30 days of non-cardiac surgery. Use: adults, age 45 and over or with cardiovascular disease.
Functional capacity (METs)
Predicts: whether the heart and lungs can meet the stress of major surgery. One MET is the energy used sitting at rest. Ask: what is the hardest thing the patient can do without stopping?
STOP-BANG
Predicts: the risk of obstructive sleep apnoea, which is often undiagnosed and makes opioids, sedation and the airway more dangerous. Use: every adult, especially before bariatric surgery.
ARISCAT
Predicts: post-operative pulmonary complications: chest infection, respiratory failure, bronchospasm, atelectasis, pleural effusion or pneumothorax. Use: any surgery under general or regional anaesthesia.
Clinical Frailty Scale
Predicts: complications, longer stay, loss of independence and death after surgery. Use: age 65 and over. Score the patient’s usual state two weeks before this illness.
Caprini score: VTE risk in surgical patients
Predicts: the risk of venous thromboembolism (DVT or PE) after surgery, and guides prophylaxis. Use: every surgical inpatient, on admission and when their condition changes.
1 point each
2 points each
3 points each
5 points each
Risk groups and recommendations follow the American College of Chest Physicians guideline for general and abdominal surgery (Gould et al., 2012). Always weigh the bleeding risk too. Read the VTE prophylaxis guide.
Wells score for DVT
Predicts: how likely a swollen or painful leg is to be a deep vein thrombosis. Use: a patient with suspected DVT — this is a diagnostic score, not a prophylaxis score.
Wells score for pulmonary embolism
Predicts: how likely a breathless or chest-pain patient is to have a PE. Use: suspected PE, for example the breathless patient on day 5 after surgery.
CHA₂DS₂-VASc: stroke risk in atrial fibrillation
Predicts: the risk of stroke and systemic embolism in atrial fibrillation. Use before surgery: a patient with AF on warfarin or a DOAC, to judge the thromboembolic risk while anticoagulation is stopped, and whether bridging could ever be needed.
Thromboembolic risk bands for interrupting warfarin follow the 2017 ACC expert consensus pathway. The 2024 ESC guideline uses CHA₂DS₂-VA, which drops the sex point; the bands here still use CHA₂DS₂-VASc.
HAS-BLED: bleeding risk on anticoagulation
Predicts: the risk of major bleeding in a patient on anticoagulation. Use before surgery: alongside CHA₂DS₂-VASc, to weigh clotting against bleeding when planning when to stop and restart anticoagulation.
What these scores cannot do
A score supports a decision; it does not make one. Each was developed in particular populations and operations, and none replaces a careful history, examination and a conversation with the patient. Use them to structure your assessment, to communicate risk, and to decide the level of care after surgery.
Don’t confuse these: HEART score versus RCRI
| HEART score | RCRI (Lee index) | |
|---|---|---|
| Patient | Chest pain in the emergency department | Before non-cardiac surgery |
| Predicts | Major adverse cardiac events within 6 weeks | Cardiac complications within 30 days of surgery |
| Items | History, ECG, age, risk factors, troponin | High-risk surgery, ischaemic heart disease, heart failure, stroke, insulin, creatinine |
| Use before surgery? | No: never validated for surgical risk | Yes, with functional capacity and NT-proBNP |
Choosing the HEART score to assess cardiac risk before an operation is a common exam mistake. For surgical risk, use the RCRI and functional capacity.