Enhanced recovery after surgery (ERAS)

Contents

Overview

Enhanced Recovery After Surgery (ERAS) is a multimodal, evidence-based perioperative care pathway designed to attenuate the surgical stress response, maintain physiological homeostasis, and accelerate return of function. First developed for colorectal surgery in the 1990s by Henrik Kehlet, ERAS protocols have since been extended to upper gastrointestinal, hepatobiliary, pancreatic, urological, gynaecological, thoracic, orthopaedic, and cardiac surgery.

ERAS is a team-based approach requiring coordination across surgery, anaesthesia, nursing, nutrition, physiotherapy, and pharmacy. Compliance with individual protocol elements is independently associated with reduced complications and length of stay.

Preoperative Elements

Patient education and expectation-setting: Patients who understand what to expect — including early mobilisation, oral intake, and drain removal targets — have better compliance and faster recovery.

Nutritional assessment and optimisation: Malnutrition is a major risk factor for complications. MUST score identifies at-risk patients. Nutritional prehabilitation (increasing protein intake in the weeks before surgery) reduces postoperative complications in malnourished patients.

Preoperative carbohydrate loading: Patients drink carbohydrate-rich fluids (typically 800 mL the evening before and 400 mL 2 hours before surgery) to reduce insulin resistance, attenuate the postoperative catabolic response, and improve wellbeing. Clear fluids are safe to consume up to 2 hours before anaesthesia induction.

Anaemia management: Iron deficiency anaemia should be treated preoperatively with IV iron (oral is used when time allows) to reduce transfusion requirements.

Prehabilitation: Preoperative exercise programmes improve cardiorespiratory fitness, reduce pulmonary complications, and may shorten hospitalisation, particularly in patients undergoing major abdominal or thoracic surgery.

Smoking and alcohol cessation: Cessation 4–6 weeks before surgery reduces pulmonary complications and wound healing problems.

Medication management: Stop anticoagulants and antiplatelet agents per anaesthetic protocols. Continue or initiate beta-blockers if indicated. Avoid long-acting opioid premedication.

Bowel preparation: Mechanical bowel preparation for colorectal surgery is not recommended in standard ERAS protocols — it increases dehydration without reducing anastomotic leak or infection.

Intraoperative Elements

Minimally invasive surgical approach: Laparoscopic surgery reduces surgical trauma, pain, pulmonary complications, and hospital length of stay. Robotic-assisted surgery offers similar benefits for selected procedures.

Hypothermia prevention: Maintains normal immune function, coagulation, and reduces shivering-related oxygen demand postoperatively. Achieved with warming blankets, warm IV fluids, and warmed insufflation gas.

Fluid management: Goal-directed fluid therapy (GDFT) using cardiac output monitoring to guide fluid administration targets adequate intravascular filling without excess. Oesophageal Doppler or less-invasive devices (pulse-pressure variation, PICCO) are used to guide fluid boluses in real time.

Anaesthetic technique: Short-acting agents are preferred to allow rapid awakening. Total intravenous anaesthesia (TIVA) with propofol reduces PONV.

Multimodal analgesia: The ERAS approach avoids opioid-centred analgesia. Techniques include:

  • Thoracic epidural analgesia (TEA) for open abdominal and thoracic surgery — gold standard for pain control and reduces paralytic ileus
  • Transversus abdominis plane (TAP) block or rectus sheath block for laparoscopic procedures
  • Intrathecal morphine for major abdominal or hip/knee surgery
  • Regular paracetamol and NSAIDs (if renal function permits)
  • Surgical site infiltration with long-acting local anaesthetic (ropivacaine or liposomal bupivacaine)

Avoiding drains and nasogastric tubes: Routine nasogastric drainage and abdominal drains are not beneficial in most colorectal operations and delay mobilisation. They are omitted unless specifically indicated.

Short-acting neuromuscular blockade: Sugammadex reversal of rocuronium allows complete reversal with reduced risk of residual block and respiratory complications.

Postoperative Elements

Early oral intake: Oral fluids are encouraged within hours of surgery, and solid food from day 1. Early feeding reduces gut mucosal atrophy, maintains mucosal barrier function, and reduces infection risk. Parenteral nutrition is avoided if enteral feeding is possible.

Early mobilisation: Patients are mobilised to the chair on the evening of surgery and walked by day 1. Physiotherapy-led mobilisation is incorporated into the ward round.

Fluid restriction: Intravenous fluids are stopped as soon as the patient is tolerating oral intake. Avoiding positive fluid balance reduces anastomotic oedema, pulmonary complications, and length of stay.

PONV prophylaxis: Two or more antiemetics (ondansetron, dexamethasone, cyclizine, droperidol) based on individual PONV risk (Apfel score).

Urinary catheter removal: Catheters are removed by day 1 in most laparoscopic colorectal procedures. In operations requiring epidural analgesia, catheter removal aligns with epidural removal.

Audit and feedback: ERAS coordinators prospectively collect compliance data. Regular audit of both process measures (protocol element adherence) and outcomes (complications, length of stay, readmission) drives ongoing improvement.

ICU Interface

Most ERAS patients return directly to the ward. ICU or HDU admission may be planned for:

  • High-risk or complex surgery (oesophagectomy, liver resection, major vascular)
  • Patients with significant cardiorespiratory comorbidity
  • Extended operative time with high-volume blood or fluid shifts

When an ERAS patient is admitted to ICU, the team should:

  • Identify which ERAS protocol elements can continue (early enteral feeding, early mobilisation, PONV management)
  • Avoid unnecessary interruptions to the protocol — routine ICU practices (prolonged ventilation, opioid infusions, fluid loading) can undermine ERAS principles
  • Recognise and investigate deviations from the expected recovery trajectory

Postoperative ileus is a common complication and ERAS deviation. Persisting beyond 3–5 days warrants review for anastomotic leak, intra-abdominal collection, or medication-related causes (opioids, anticholinergics). CT imaging guides further management.

Anastomotic leak typically presents with tachycardia, fever, and failure to progress on day 3–5. CT with rectal contrast confirms the diagnosis. Management ranges from radiological drainage to surgical re-operation.

Evidence Base

ERAS Society guidelines exist for multiple surgical specialties and are regularly updated. They cite evidence for each protocol element, graded by quality.

Colorectal ERAS: Multiple randomised trials and meta-analyses demonstrate 2–3 day reductions in hospital length of stay, reduced complication rates, and no increase in readmission.

Goal-directed fluid therapy: The OPTIMISE trial (Pearse et al., JAMA 2014) randomised 734 patients undergoing major gastrointestinal surgery to GDFT with cardiac output monitoring plus dopexamine vs usual care. GDFT reduced 30-day complication rates (36.6% vs 43.4%). Subsequent meta-analyses support benefit in high-risk patients, though the effect varies by baseline risk and fluid management practice.

Opioid-sparing analgesia: Epidural and regional anaesthesia reduce pulmonary complications and paralytic ileus, and improve analgesia quality. Multiple meta-analyses support thoracic epidural analgesia over systemic opioids for open abdominal surgery.

Viva Questions

What are the key components of an ERAS protocol and what is the evidence base?

ERAS protocols span the preoperative, intraoperative, and postoperative phases. Preoperatively, the key elements are patient education, carbohydrate loading, anaemia correction, prehabilitation, and optimisation of comorbidities. Intraoperatively, minimally invasive surgery, hypothermia prevention, multimodal opioid-sparing analgesia, goal-directed fluid therapy, and avoidance of routine drains are the core elements. Postoperatively, early oral intake, early mobilisation, fluid restriction, PONV prophylaxis, and early catheter removal are the principal components. The evidence base is strongest for colorectal surgery, where multiple randomised trials demonstrate a reduction in hospital length of stay of 2–3 days and a meaningful reduction in complication rates. Each individual element has an evidence base of varying strength; the overall ERAS package appears to have greater benefit than the sum of its individual parts, likely because physiological homeostasis is maintained across multiple domains simultaneously.

How does ERAS interact with the ICU admission pathway for high-risk surgical patients?

Most patients managed under an ERAS pathway do not require ICU admission. However, for high-risk surgery — oesophagectomy, hepatectomy, Whipple procedure, major vascular — planned postoperative ICU or HDU admission is appropriate for closer monitoring and management of expected physiological instability. The ICU team should be aware of the ERAS plan and continue protocol-consistent elements where possible: early enteral feeding, avoiding fluid excess, minimising opioids, and planning early extubation. The ICU environment introduces risks of ERAS deviation — prolonged mechanical ventilation, opioid sedation, positive fluid balance, and immobility — all of which slow recovery. The ICU team should aim for the shortest appropriate admission and facilitate step-down as soon as clinical stability allows.

A patient on an ERAS pathway develops an ileus on day 2 postoperatively. How do you assess and manage this?

Paralytic ileus is the most common reason for ERAS deviation after colorectal surgery. My first step is to assess for an underlying surgical complication: anastomotic leak, intra-abdominal collection, or bleeding. A tachycardia, fever, or white cell count above trend should prompt early CT imaging with rectal contrast. If the CT is normal and there is no evidence of a surgical complication, I would review the medication chart for opiate use (including any patient-controlled analgesia) and ensure adequate epidural or regional analgesia is in place to allow opioid reduction. Prokinetics (metoclopramide, erythromycin) should be started, and any electrolyte abnormalities — particularly hypokalaemia and hypomagnesaemia — corrected. Nasogastric free drainage relieves nausea and distension if the patient is vomiting. Oral intake may need to be temporarily reduced, but enteral feeding via NG tube can often continue. If ileus persists beyond 5 days despite these measures, repeat imaging is appropriate and nutritional support via parenteral route may be required while the bowel recovers.