General Surgery Principles and Perioperative Care
The general surgery principles domain tests whether you can move a patient safely from the ward to the operating room and back: risk stratification, prophylaxis, nutrition, fluid and transfusion strategy, and recognition of the deteriorating postoperative patient. Questions usually pair a comorbidity with a specific operation and ask what must be done before incision.
Risk stratification
- ASA physical status predicts mortality but not procedure-specific risk; combine it with surgical severity (minor, intermediate, major) and, where available, an ACS NSQIP estimate.
- Cardiac risk: the Revised Cardiac Risk Index counts ischaemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, creatinine >177 µmol/L and high-risk surgery. Two or more factors means proceed only if the benefit is clear and optimise first.
- Do not order routine stress testing before non-cardiac surgery; it changes management only when the result would alter treatment.
- Continue beta-blockers already prescribed; do not start them on the day of surgery. Clopidogrel is stopped only when bleeding risk outweighs stent thrombosis, after cardiology discussion.
Prophylaxis
- Antibiotic prophylaxis within 60 minutes of incision (120 minutes for vancomycin or fluoroquinolones), re-dosed after blood loss >1500 mL or long operations, and stopped within 24 hours.
- VTE prophylaxis by Caprini score: early ambulation, intermittent pneumatic compression, and LMWH for high scores once bleeding risk allows.
- Glucose 6-10 mmol/L; smoking cessation at least four weeks before elective major surgery; correct malnutrition (NRS-2002 score ≥3) before elective resection.
- Wound classification (clean, clean-contaminated, contaminated, dirty) sets the expected infection rate and the reporting category.
Worked example
A 68-year-old man with insulin-treated diabetes and a previous myocardial infarction needs an elective open inguinal hernia repair. He takes aspirin and a beta-blocker. Reasoning: ischaemic heart disease plus insulin-treated diabetes gives two RCRI factors, but hernia repair is low-risk surgery, so continue both drugs, order no cardiac work-up, give a single dose of cefazolin within 60 minutes, add Caprini-based LMWH, keep glucose 6-10 mmol/L, and discharge the same day if he mobilises and voids.
Traps
- Giving prophylaxis after skin incision.
- Continuing therapeutic antibiotics for five days "because the case was contaminated".
- Ordering a resting echocardiogram to "clear" a patient for surgery; it does not stratify perioperative risk.
- Reading postoperative oliguria as hypovolaemia when it is sepsis, a bleeding drain or a leak.