Preparatory Mindset
Perioperative care = preoperative preparation + postoperative management. The exam tests: ASA classification, preoperative risk assessment (cardiac, pulmonary, DVT, diabetes), optimization, and postoperative care (positioning, monitoring, early mobilization, common complications). The lecture (Zhangqing, 31KB) and the prep PDFs ("简述ASA分级", "为什么术后应早期下床活动") are the exact sources.
Exam mindset: The ASA grade is a guaranteed short-answer. "术后早期下床活动的优点" is a classic Q&A. Know the fasting rules, thromboprophylaxis, antibiotic prophylaxis, and the common postoperative complications with their timing.
Core Concepts
1. Preoperative preparation — assessment (MUST KNOW)
- History & exam: cardiac (MI within 6 months, HF, arrhythmia, severe valvular disease = high risk), pulmonary (COPD, smoking), renal (creatinine), hepatic (cirrhosis), diabetes (glycemic control), medications (anticoagulants, steroids, insulin), allergies, bleeding history, pregnancy
- Routine tests: CBC, electrolytes/renal, glucose, coagulation, ECG, CXR (age >40 or cardiac/pulmonary disease)
- Optimization: control BP, blood glucose, treat infection, correct anemia/electrolytes, stop smoking ≥4 weeks, optimize COPD (bronchodilators, steroids, physiotherapy), manage anticoagulation (bridge with LMWH)
2. ASA physical status classification (MUST KNOW)
| Class | Description |
|---|---|
| I | Healthy patient |
| II | Mild systemic disease, no functional limitation (e.g., well-controlled HTN, mild diabetes) |
| III | Severe systemic disease, definite functional limitation (e.g., severe COPD, uncontrolled diabetes, angina) |
| IV | Severe systemic disease that is a constant threat to life (e.g., severe HF, unstable angina, renal failure) |
| V | Moribund patient not expected to survive without the operation |
| VI | Brain-dead organ donor |
- "E" suffix = emergency operation (e.g., III-E)
- Prep PDF: "对于患有较严重并存病，体力活动受限，但尚能应付" = ASA III
3. Preoperative preparation specifics (MUST KNOW)
- Fasting (NPO): clear fluids 2 h, light meal 6 h, full meal 8 h before anesthesia (reduce aspiration risk); modern ERAS allows clear fluids until 2 h
- Antibiotic prophylaxis: within 60 min before incision (cefazolin for clean-contaminated surgery); redose for prolonged surgery/blood loss; stop within 24 h
- DVT prophylaxis (MUST KNOW): graduated compression stockings + intermittent pneumatic compression + LMWH (low-molecular-weight heparin) for moderate/high-risk patients; start LMWH preop or postop per risk
- Diabetes: target glucose ~6-10 mmol/L perioperatively; hold oral hypoglycemics (metformin) day of surgery; insulin sliding scale; avoid severe hypo/hyperglycemia
- Steroids: patients on chronic steroids need stress-dose steroids (avoid perioperative adrenal insufficiency)
- Cardiac: continue β-blockers/statins; hold anticoagulants (bridge); rate-control AF
- Informed consent, marking the surgical site, risk stratification
4. Postoperative care (MUST KNOW)
1. Increases lung vital capacity → fewer pulmonary complications (atelectasis/pneumonia) 2. Improves circulation → promotes wound healing; reduces venous stasis → fewer DVT/PE 3. Restores bowel & bladder function → less abdominal distension & urinary retention 4. Improves mental state & general recovery - Do it progressively (循序渐进), guided by the patient's tolerance
- Positioning: recovery in the lateral (recovery) position until awake; head-up for respiratory patients; specific positions per surgery
- Monitoring: vitals, urine output, drains, wound, pain, fluid balance; oxygen for 24 h post-op
- Drains: monitor output & character; remove when non-productive (e.g., chest drain when lung expanded & <50-100 ml/day; nasogastric tube after ileus resolves)
- Early mobilization (MUST KNOW — the classic Q&A): 术后早期下床活动优点:
- Pain control: multimodal (paracetamol, NSAIDs, opioids, regional blocks); PCA (patient-controlled analgesia); opioid-sparing in ERAS
- Fluid & diet: early oral intake when bowel sounds return (ERAS: early); NG tube not routine
- Urinary catheter: remove early (day 1-2) to reduce UTI unless monitored output needed
5. Common postoperative complications (MUST KNOW)
| Complication | Typical timing | Features & management |
|---|---|---|
| Atelectasis/pneumonia | Day 1-3 | Fever, ↓ breath sounds, hypoxia → incentive spirometry, mobilize, antibiotics if pneumonia |
| Wound infection (SSI) | Day 5-7 | Wound pain, erythema, purulent discharge, fever → open wound, culture, drainage, antibiotics |
| Urinary retention | Early | Distended bladder → catheterize (in & out then trial) |
| UTI | Day 3-7 | Fever, dysuria → urine culture, antibiotics, remove catheter |
| DVT/PE | Day 3-10+ | Calf pain/swelling; sudden dyspnea/chest pain (PE) → anticoagulation; diagnose with US/CTPA |
| Anastomotic leak | Day 3-7 | Fever, peritonitis, drain bilious content → imaging (CT with oral contrast), re-operation/radiology drain |
| Postoperative ileus | Days 1-3 | Distension, no flatus → NPO, fluids, mobilize; NG if persistent |
| Hemorrhage | Early (<24 h) | Falling BP, rising HR, drain blood → resuscitate, re-explore if ongoing |
| Delirium | Day 1-3 | Elderly, ICU — treat cause (hypoxia, sepsis, drugs, withdrawal) |
| Cardiac (MI/arrhythmia) | Day 0-3 | Chest pain, ECG changes → cardiology review |
| Acute kidney injury | Anytime | ↓ urine, ↑ creatinine → fluids, avoid nephrotoxins |
6. High-risk & emergency surgery
- Emergency surgery: optimize rapidly (correct hypovolemia/electrolytes as time allows), ASA-E
- Elderly: lower physiological reserve — aggressive complication prevention
- Laparoscopy: less pain, fewer complications, faster recovery (but CO2/positioning considerations)
High-Yield Points
- ASA: I healthy, II mild disease, III severe disease with functional limitation, IV constant threat to life, V moribund; "E" = emergency — III = "较严重并存病, 体力活动受限, 尚能应付"
- NPO: clear fluids 2 h / light meal 6 h
- Antibiotic prophylaxis: within 60 min pre-incision, cefazolin for clean-contaminated, stop ≤24 h
- DVT prophylaxis: stockings + IPC + LMWH
- Early mobilization benefits: ↑ vital capacity (fewer pulmonary complications), ↑ circulation (faster healing, ↓ DVT), restores bowel/bladder function, better recovery
- Stress-dose steroids for chronic steroid users
- Postop fever day 1-3 = atelectasis/pneumonia; day 5-7 = wound infection/UTI; day 7-10 = DVT/leak
- SSI timing: usually day 5-7
- Target glucose 6-10 mmol/L perioperatively
Topic Summary
Perioperative care = preparation + management. Assess ASA (I-V, E suffix), optimize cardiac/pulmonary/diabetic status, NPO rules (clear fluids 2 h), antibiotic prophylaxis (60 min before incision), DVT prophylaxis (stockings/IPC/LMWH), stress-dose steroids. Postoperatively: monitoring, positioning, drains, multimodal analgesia, early mobilization (increased vital capacity → fewer pulmonary complications; improved circulation → healing + ↓ DVT; bowel/bladder recovery), early feeding. Complications by timing: atelectasis (day 1-3), SSI (day 5-7), UTI, DVT/PE (day 3-10), anastomotic leak (day 3-7), hemorrhage (early). Know recognition & first-line management for each.
LMCHK OSCE Practice
- Preoperative clerking: take a full history (cardiac, pulmonary, DM, anticoagulants, allergies), examine, order appropriate tests, calculate ASA; identify optimization needs (e.g., stop smoking, bridge anticoagulation).
- ASA classification scenarios: classify given patients (healthy; well-controlled HTN; severe COPD; unstable angina; moribund).
- Consent discussion: explain risks/benefits/alternatives of a surgery; include specific risks (bleeding, infection, DVT, anesthetic risk).
- Postoperative fever workup: day 1-3 vs day 5-7 differentials; examine chest/wound/urine/legs; order CXR, cultures, US.
- DVT prophylaxis prescription: risk-stratify and prescribe mechanical + pharmacological prophylaxis; explain contraindications to LMWH (active bleeding, severe renal failure).
- Early mobilization counselling: explain to a post-op patient why getting out of bed early is important (the 4 benefits).
- Wound assessment & dressing: recognize SSI (erythema, purulence), when to open the wound, and antibiotic choice.