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

I. Preparation of Patients for Surgery

• Goal: Optimize physical and mental condition, reduce perioperative risk, and prepare a safe operative plan
• Preoperative care begins when operation is indicated and continues until induction of anesthesia
• Main principle → Correct reversible risk factors before elective surgery; do not delay lifesaving emergency surgery unnecessarily

Assessment

1. Confirm diagnosis and indication
2. Further investigations if diagnosis/stage/anatomy is unclear
3. Patient condition → Heart, lung, kidney, liver, nutrition, blood, comorbidities
4. Surgical risk → Type/extent of operation, expected blood loss, emergency vs elective, contamination, duration
5. Anesthesiological risk → Airway, cardiopulmonary reserve, ASA class, previous anesthesia problems
6. Medication and allergy review
7. Informed consent

• Comorbidities → Hypertension, diabetes mellitus, ischemic heart disease, heart failure, COPD/asthma, renal failure, liver disease
• Blood problems → Anemia, thrombocytopenia, anticoagulation, antiplatelet therapy, bleeding disorder
• Previous operations/anesthesia → Difficult intubation, malignant hyperthermia, PONV, adhesions, surgical scars

Risk Assessment

• ASA classification → General anesthetic/operative risk estimate from I-V
• Cardiac risk → Symptoms, functional capacity, ECG if indicated, RCRI or local scoring for major surgery
• Pulmonary risk → COPD/asthma control, smoking, sleep apnea, chest infection, type of incision
• Thromboembolic risk → Cancer, immobility, previous VTE, obesity, thrombophilia, major pelvic/orthopedic surgery
• Frailty/sarcopenia → Important in elderly, cancer patients and major surgery

Preoperative Investigations

• Do not order every test routinely → Test according to age, comorbidities and surgical magnitude
• Common labs → CBC, electrolytes, renal function, liver function, glucose, coagulation if indicated
• Blood group / screen / crossmatch → If significant blood loss is possible
• ECG → Elderly patient, cardiac disease/risk, major surgery, symptoms
• Chest X-ray / pulmonary tests → Cardiopulmonary disease, major thoracic/upper abdominal surgery, symptoms
• Pregnancy test → Women of childbearing potential if relevant

Medication Management

• Continue usually → Beta-blockers, statins, most inhalers, anti-epileptics
• Anticoagulants → Warfarin/DOAC/LMWH plan according to bleeding risk + thrombotic risk
• Antiplatelets → Continue or stop depending on stent/thrombotic risk and operation bleeding risk
• Diabetes medication → Adjust insulin/oral drugs; avoid perioperative hypo-/hyperglycemia
• Steroids → Continue; consider stress-dose steroid if adrenal suppression risk
• Immunosuppressants/biologics → Individual plan with surgical/internist specialist input

Informed Consent

• Explain diagnosis, proposed operation, anesthesia plan if relevant, expected benefit and alternatives
• Explain common and serious complications
• Discuss expected recovery, restrictions, drains/stoma/ICU possibility if relevant
• Consent must be voluntary and documented
• Emergency exception → If patient cannot consent and delay risks death/serious harm, life-saving treatment can proceed according to local law/protocol

Psychological Preparation

• Patient education → What will happen before, during and after surgery
• Reduce anxiety by clear explanation and realistic expectations
• Discuss pain control, mobilization, breathing exercises, nutrition and discharge plan
• Consider psychological support in cancer, major amputation, stoma formation, high anxiety

Homeostasis and Comorbidity Optimization

• Correct dehydration/hypovolemia
• Correct acid-base and electrolyte disturbance
• Treat anemia and coagulation disorders when possible
• Optimize blood pressure, glucose control, heart failure, arrhythmia, COPD/asthma
• Treat active infection if elective surgery can wait
• Smoking cessation and alcohol reduction if time allows

Hygienic Preparation

• Preoperative bathing/showering; antiseptic wash according to local protocol
• Hair removal only if it interferes with operation/dressing
• Use clippers immediately before operation; avoid razor shaving because it increases skin microtrauma
• Skin antisepsis in operating room before incision

Fasting and Tubes

• Preoperative fasting reduces aspiration risk during anesthesia
• Elective surgery general rule → Solids/light meal until 6 h before anesthesia; clear liquids until 2 h before anesthesia
• Longer fasting / full-stomach precautions → Emergency surgery, ileus, delayed gastric emptying, vomiting, severe reflux risk according to anesthesia decision
• Nasogastric tube → Not routine; use if ileus, gastric outlet obstruction, vomiting, gastric distension or selected upper GI surgery
• Urinary catheter → Lower abdominal/pelvic operation, long surgery, strict fluid balance, epidural/regional anesthesia, urinary tract surgery

Antibiotic and Thromboembolism Prophylaxis

• Antibiotic prophylaxis → According to operation field, contamination class, implant/prosthesis, local protocol
• Give before incision so effective tissue concentration is present at incision
• Re-dose if long operation or major blood loss; avoid unnecessary prolonged postoperative prophylaxis
• VTE prophylaxis → Based on patient risk + operation risk
• Methods → Early mobilization, compression stockings/intermittent pneumatic compression, LMWH, DOAC in selected procedures
• Balance thrombosis prevention against bleeding risk

II. ERAS Protocol

• ERAS: Enhanced Recovery After Surgery
• Multimodal, evidence-based perioperative pathway for planned operations
• Goal → Reduce surgical stress response and organ dysfunction, maintain physiology, accelerate recovery
• Not one intervention → Combination of preoperative, intraoperative and postoperative elements

Core ERAS Principles

• Patient education and active participation
• Avoid prolonged fasting
• Carbohydrate loading before elective surgery when appropriate
• Minimally invasive surgery when possible
• Opioid-sparing multimodal analgesia
• Balanced/goal-directed fluid therapy
• Normothermia maintenance
• Early oral intake and early mobilization
• Avoid unnecessary tubes, drains and catheters

Preoperative ERAS Elements

• Preoperative counseling → Explain pathway, mobilization, feeding, pain control, discharge criteria
• Nutrition screening and correction of malnutrition
• Smoking and alcohol cessation
• Clear fluids allowed until 2 h before anesthesia in suitable elective patients
• Light meal/solid food until 6 h before anesthesia
• Carbohydrate drink → Often evening before + 2-3 h before anesthesia in non-high-risk elective patients

• Avoid carbohydrate loading in emergency/full-stomach patients and patients with delayed gastric emptying
• Diabetes → Individual decision/protocol; avoid uncontrolled hyperglycemia

Intraoperative ERAS Elements

• Minimally invasive procedure if oncologically/technically appropriate
• Regional/epidural anesthesia or local blocks when useful
• Multimodal analgesia → Reduce opioid dose and ileus/PONV
• Goal-directed fluids → Avoid both hypovolemia and fluid overload
• Maintain normothermia
• PONV prophylaxis
• Avoid routine nasogastric tube and unnecessary drains

Postoperative ERAS Elements

• Early oral fluids/feeding as tolerated
• Early mobilization, usually on day of surgery or first postoperative day
• Optimal pain management with opioid-sparing strategy
• Early removal of urinary catheter, IV lines and drains when safe
• Prevention/treatment of PONV
• VTE prophylaxis and respiratory physiotherapy according to risk
• Discharge based on function, pain control, oral intake and complication status

Benefits

• Less surgical stress and insulin resistance
• Faster return of bowel function
• Fewer complications in suitable pathways
• Shorter hospital stay
• Faster return to normal function

III. Prehabilitation

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

Indications / Target Patients

• Elderly or frail patients
• Cancer patients before major resection
• Major abdominal, thoracic, vascular or orthopedic surgery
• Sarcopenia, malnutrition, poor functional capacity
• Multiple comorbidities, high ASA class
• Smokers or high alcohol intake before elective surgery

Components

• Physical conditioning → Aerobic training + resistance/strength training + breathing exercises
• Nutritional optimization → Protein/calorie supplementation, correction of deficiencies, dietitian involvement
• Psychological support → Anxiety reduction, coping strategies, expectation setting
• Smoking cessation → Reduces pulmonary and wound complications
• Alcohol reduction/cessation → Reduces infection, bleeding, withdrawal and cardiopulmonary risk
• Chronic disease optimization → Diabetes, anemia, hypertension, COPD, heart failure

Practical Points

• Prehabilitation should not delay urgent cancer/emergency surgery without clear benefit
• Program must be individualized to baseline fitness and operation type
• Even short programs may improve education, nutrition and exercise behavior
• Measure function when possible → Walking distance, stair climbing, hand grip, frailty score

IV. Perioperative Nutrition

• Importance: Malnutrition increases infection, wound complications, delayed healing, length of stay and mortality
• Nutrition is part of surgical treatment, especially in major surgery, cancer, elderly/frail patients and upper GI disease
• Principle → Use the gut if it works: oral/enteral preferred over parenteral

Nutrition Screening

• Screen before major elective surgery
• Look for → Unintentional weight loss, low BMI, reduced intake, sarcopenia, low muscle strength, inflammation/cancer
• Tools → NRS-2002, MUST, SGA depending on local practice
• Albumin/prealbumin can support risk assessment but are also inflammation markers, not pure nutrition markers

Preoperative Nutrition

• Normal nutrition if well nourished and normal intake
• 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 oncologically/surgically safe

• Examples of severe risk → Major weight loss, very low BMI, minimal intake for days, severe sarcopenia, obstructing upper GI cancer

Preoperative Fasting

• Purpose → Reduce aspiration risk after anesthesia
• Elective surgery → Solid/light meal until 6 h before anesthesia
• Clear liquid → Until 2 h before anesthesia
• ERAS → Avoid unnecessary overnight fasting
• Carbohydrate drink → 2-3 h before surgery in suitable elective patients according to protocol
• Do not apply standard short fasting blindly to full-stomach/high aspiration-risk patients

Postoperative Nutrition

• Early oral/enteral nutrition is preferred as tolerated
• ERAS encourages oral intake within 24 h in many operations
• Start with clear fluids/soft diet only if required by operation; many patients can progress earlier
• High-protein supplements if poor intake, frailty, sarcopenia, cancer or large wound
• Enteral feeding tube if oral intake remains insufficient and gut works
• Parenteral nutrition only if gut is not functional, enteral feeding is contraindicated, or needs cannot be met enterally for a prolonged period

Special Situations

• Upper GI obstruction → Enteral access distal to obstruction or parenteral nutrition if not feasible
• Major GI surgery/cancer → Early nutrition planning, often dietitian involvement
• Diabetes → Avoid both fasting hypoglycemia and stress hyperglycemia
• Renal/liver failure → Adjust protein, fluid and electrolyte plan individually
• Sepsis/critical illness → Nutrition together with source control, hemodynamic stabilization and metabolic monitoring