4. Preoperative Care, ERAS Protocol, Prehabilitation, Perioperative Nutrition

I. Preoperative Care

• Goal: Optimize physical/mental condition → Reduce perioperative risk
• Principle: Elective surgery → Correct reversible problems first
• Emergency surgery → Resuscitation/preparation run parallel with operation planning

1. Assessment

• Diagnosis → Further investigation/staging/anatomy if unclear
• Patient condition: Heart, lung, kidney/liver, nutrition, blood, comorbidities

• Blood: Anemia, anticoagulation/antiplatelets, thrombocytopenia, bleeding disorder
• Comorbidities: HT, DM, ischemic heart disease, heart failure, COPD/asthma

• Surgical + anesthesiological risk assessment
• ASA classification: Basic anesthesia-risk classification
• Medication/allergy review: Anticoagulants, antiplatelets, steroids, immunosuppressants, diabetic drugs
• Previous anesthesia problems: Difficult intubation, allergy, PONV, malignant hyperthermia

2. Investigations and Consent

• Investigations depend on: Age, comorbidities, operation type, expected blood loss
• Common tests: CBC, electrolytes, renal/liver function, glucose, coagulation if indicated
• ECG/CXR/pulmonary tests → Elderly, symptoms, cardiopulmonary disease, major surgery
• Blood group/crossmatch → If significant blood loss is expected
• Informed consent: Procedure, risks, benefits, alternatives, recovery expectations

3. Optimization and Preparation

• Psychological preparation: Education, anxiety reduction, realistic expectations
• Nutrition → Fasting, enteral nutrition/feeding tube, parenteral nutrition if gut cannot be used
• Hygiene: Bathing/showering ± antiseptic wash; shaving/hair removal only if needed
• Correction of homeostasis: Fluid status, acid-base balance, electrolytes, glucose, anemia/coagulation
• Optimize comorbidities: HT, DM, heart failure/arrhythmia, COPD/asthma
• Urinary catheter: Lower abdominal/pelvic operation, long surgery, strict fluid balance
• Antibiotic prophylaxis: Give before incision when indicated
• VTE prophylaxis: Early mobilization, compression stockings/intermittent pneumatic compression, LMWH; DOAC in selected procedures

II. ERAS Protocol

• ERAS: Enhanced Recovery After Surgery
• Multimodal perioperative pathway for planned operations
• Goal → Reduce stress response + organ dysfunction → Faster recovery

1. Techniques

• Patient education and counseling
• Avoid prolonged fasting
• Carbohydrate loading 2-3 h before surgery in suitable elective patients
• Epidural/regional anesthesia or local blocks when useful
• Minimally invasive surgical procedures when appropriate
• Optimal pain management → Opioid-sparing multimodal analgesia
• Maintain normothermia and avoid fluid overload/hypovolemia
• Prevention/treatment of PONV
• Aggressive postoperative rehabilitation → Early feeding + early mobilization

• Avoid carbohydrate loading in full-stomach/high aspiration risk or uncontrolled diabetes

2. Benefits

• Less postoperative pain and ileus
• Faster bowel function and mobilization
• Fewer complications
• Shorter hospital stay

III. Prehabilitation

• Prehabilitation: Preoperative interventions to improve functional reserve before surgery
• Best for high-risk elective patients when there is time before operation
• Goal → Patient enters surgery stronger, better nourished and medically optimized

Components

• Physical conditioning: Aerobic + resistance/strength training, breathing exercises
• Nutritional optimization: Protein/calorie supplementation, correction of deficiencies
• Psychological support: Anxiety reduction, coping strategies
• Smoking and alcohol cessation
• Chronic disease optimization: DM, anemia, HT, COPD, heart failure
• Target patients: Elderly/frail, cancer before major surgery, malnutrition/sarcopenia, poor functional capacity
• Do not delay emergency surgery or urgent cancer surgery without clear benefit

IV. Perioperative Nutrition

• Importance: Malnutrition increases infection, wound complications, delayed healing, length of stay and mortality
• Principle → Use the gut if it works: Oral/enteral preferred over parenteral

1. Screening

• Screen before major elective surgery, especially cancer, elderly/frail and upper GI disease
• Look for: Weight loss, low BMI, reduced intake, sarcopenia, inflammation/cancer
• Tools: NRS-2002, MUST, SGA depending on local practice

2. Preoperative Nutrition and Fasting

• Normal oral intake if well nourished
• Oral nutritional supplements if intake is insufficient or nutritional risk exists
• Enteral nutrition / feeding tube → If oral intake is inadequate and GI tract works
• Parenteral nutrition → If oral/enteral nutrition is impossible or contraindicated
• Severe malnutrition before elective major surgery → Consider delaying surgery for nutritional support if safe
• Fasting purpose → Reduce aspiration risk after anesthesia

• Solids/light meal: 6 h before anesthesia
• Clear liquids: 2 h before anesthesia

• ERAS → Avoid unnecessary overnight fasting
• Do not apply short fasting blindly to full-stomach/high aspiration-risk patients

3. Postoperative Nutrition

• Early oral/enteral nutrition is preferred as tolerated
• ERAS → Oral intake within 24 h in many operations
• High-protein supplements if poor intake, frailty, sarcopenia, cancer or large wound
• Parenteral nutrition only if gut is not functional or enteral feeding is contraindicated