Perioperative care and surgical equipment — day surgery, ERAS, thromboembolism, stomas, diathermy, sutures, drains

Definition / Overview

• Enhanced Recovery After Surgery (ERAS) is an evidence-based, multimodal, multidisciplinary perioperative care framework designed to attenuate the surgical stress response, accelerate functional recovery, and optimise patient outcomes.
• The concept originated in the mid-1990s, initially termed "Fast-Track Surgery", before formal ERAS Society guidelines were established in the early 2000s.
• ERAS departs from traditional perioperative care, which was characterised by prolonged fasting, liberal IV fluid use, routine nasogastric tube insertion, delayed feeding, and narcotic-heavy analgesia, practices that collectively delay return of normal physiological function.
• The primary goals of ERAS are:
  • Reduce length of hospital stay
  • Reduce postoperative complication rates
  • Improve patient-reported outcomes (quality of life, return to daily activities)
  • Reduce healthcare costs
  • Facilitate outpatient migration of select procedures
• ERAS pathways span the entire perioperative period: preoperative, intraoperative, and postoperative phases.

Pathophysiology: The Surgical Stress Response

Understanding ERAS requires a firm grasp of what it is designed to counteract.

Neuroendocrine Activation

• Surgical trauma triggers afferent nociceptive signals to the hypothalamus, activating the hypothalamic-pituitary-adrenal (HPA) axis and the sympathoadrenal system.
• Resultant catecholamine and cortisol surges drive:
  • Hyperglycaemia (insulin resistance, gluconeogenesis, glycogenolysis)
  • Protein catabolism and negative nitrogen balance
  • Sodium and water retention (via ADH and aldosterone)
  • Immunosuppression (impaired neutrophil and lymphocyte function)

Inflammatory Cascade

• Tissue injury releases cytokines (IL-1, IL-6, TNF-α) that amplify the stress response and contribute to systemic inflammation.
• Uncontrolled inflammation prolongs ileus, impairs wound healing, and predisposes to organ dysfunction.

Postoperative Ileus

• Results from a combination of:
  • Sympathetic inhibition of gut motility
  • Opioid-mediated $\mu$-receptor activation in the enteric nervous system
  • Inflammatory mediators (prostaglandins, nitric oxide)
  • Electrolyte disturbance (particularly hypokalaemia)
• Ileus is a major driver of delayed oral intake, prolonged IV access, and extended hospital stay.

Muscle Catabolism and Functional Decline

• Perioperative starvation, immobility, and cortisol-driven proteolysis rapidly deplete lean muscle mass, particularly dangerous in the elderly or sarcopaenic patient.
• Even brief bed rest leads to measurable loss of lower-limb muscle strength and cardiorespiratory reserve.

ERAS Principles by Phase

Preoperative Phase

Patient Optimisation and Education

• Preoperative counselling sets realistic expectations, reduces anxiety, and prepares patients for their active role in recovery (including stoma education if applicable).
• Prehabilitation: exercise, nutritional supplementation, and psychological support in the weeks before surgery to improve physiological reserve, particularly relevant for frail, elderly, or cancer patients.
• Anaemia management: identify and treat iron deficiency preoperatively; transfusion triggers are deferred where possible.
• Smoking cessation (ideally $\geq 4$ weeks preoperatively) reduces pulmonary complications and impairs wound healing if continued.
• Alcohol reduction: heavy alcohol use impairs immune function, increases bleeding risk, and predisposes to alcohol withdrawal postoperatively.

Nutritional Optimisation and Carbohydrate Loading

• Traditional "nil by mouth from midnight" regimens cause dehydration, insulin resistance, and patient discomfort.
• Modern fasting guidelines allow:
  • Solids: nil for 6 hours preoperatively
  • Clear fluids: permitted up to 2 hours before induction of anaesthesia
• Carbohydrate loading (typically 800 mL of a clear carbohydrate-rich drink the evening before, and 400 mL 2 hours preoperatively) blunts the postoperative insulin-resistant state, reduces proteolysis, and reduces thirst and anxiety.
• Contraindicated in diabetics with gastroparesis or those at aspiration risk.

Mechanical Bowel Preparation (MBP)

• Routine MBP is no longer recommended for elective colorectal surgery in isolation, evidence does not support a reduction in anastomotic leak or SSI rates with MBP alone.
• Oral antibiotics combined with MBP (oral antibiotic bowel preparation) has re-emerged as evidence-based practice for elective colonic resection, reducing SSI rates.
• Systemic IV antibiotic prophylaxis (e.g. second- or third-generation cephalosporin + metronidazole) remains standard and should be given within 60 minutes of incision.

Venous Thromboembolism Prophylaxis

• Risk-stratified mechanical (compression stockings, intermittent pneumatic compression) and pharmacological (LMWH) prophylaxis should be planned preoperatively.

Intraoperative Phase

Minimally Invasive Surgery

• Laparoscopic and robotic approaches reduce surgical trauma, attenuate the stress response, and are associated with less pain, earlier return of gut function, and shorter hospital stay compared to open surgery.

Anaesthetic Technique

• Total intravenous anaesthesia (TIVA) or volatile-based anaesthesia with short-acting agents (e.g. propofol, remifentanil, desflurane) support rapid awakening.
• Avoidance of long-acting opioids intraoperatively reduces postoperative ileus and nausea.
• Multimodal analgesia (see below) minimises systemic opioid requirements.

Goal-Directed Fluid Therapy (GDFT)

• Traditional liberal or restrictive fluid strategies carry opposing risks:

• GDFT uses dynamic haemodynamic monitoring (stroke volume variation, pulse pressure variation, oesophageal Doppler) to titrate fluid administration to optimise cardiac output and tissue oxygen delivery.
• Vasopressors (e.g. noradrenaline, vasopressin) are used to maintain MAP rather than administering excess crystalloid, reducing total fluid load.
• Balanced crystalloid (e.g. Hartmann's / Plasma-Lyte) is preferred over normal saline for large volumes, to avoid hyperchloraemic metabolic acidosis.

Temperature Management

• Hypothermia increases bleeding, impairs platelet function, delays drug metabolism, and increases SSI rates.
• Active warming (forced-air warming blankets, warm IV fluids) should maintain normothermia throughout the procedure.

Nasogastric Tubes

• Routine insertion of nasogastric tubes is not recommended, their use delays return of oral intake, increases discomfort, and does not reduce anastomotic complications.
• If inserted intraoperatively, remove before extubation.

Perioperative Analgesia

Multimodal Analgesia: the Cornerstone of ERAS

Effective pain control that minimises opioid use is central to ERAS. The analgesic "ladder" in ERAS uses agents with complementary mechanisms:

Thoracic Epidural Analgesia (TEA)

• Gold standard for major open abdominal surgery.
• Local anaesthetic infusions (bupivacaine ± low-dose opioid) provide superior analgesia to systemic opioids.
• Dual benefit: analgesia AND promotion of gut motility, TEA blunts sympathetic inhibition of the gut, facilitating earlier return of peristalsis.
• Risks: hypotension (sympatholysis), epidural haematoma (check anticoagulation timing), urinary retention.

Transversus Abdominis Plane (TAP) Block

• Ultrasound-guided injection of local anaesthetic into the fascial plane between internal oblique and transversus abdominis muscles.
• Provides somatic analgesia to the anterior abdominal wall (T10-L1).
• A suitable alternative to epidural for laparoscopic cases or when epidural is contraindicated.

Prevention of Postoperative Ileus

• Avoid excess opioids, the single most impactful intervention.
• Alvimopan: peripherally acting $\mu$-opioid receptor antagonist; blocks opioid-induced gut dysmotility without reversing central analgesia; reduces time to first bowel motion and hospital stay in open colorectal surgery (less evidence in laparoscopic cases).
• Early oral feeding (see postoperative phase).
• Adequate electrolyte replacement, hypokalaemia prolongs ileus.
• Minimise IV fluids, bowel oedema impairs wall compliance and motility.
• Gum chewing, stimulates cephalic-phase gut reflexes via the vagus nerve; modest evidence for benefit.
• Coffee, promotes colonic motility via adenosine antagonism and cholecystokinin release.

Postoperative Phase

Early Oral Nutrition

• Clear fluids within hours of surgery, advancing to free diet as tolerated, typically day 0 or 1.
• Early enteral nutrition reduces gut mucosal permeability, maintains intestinal immune function, prevents bacterial translocation, and reduces infectious complications.
• Nutritional supplements (high-protein drinks) are encouraged to meet caloric targets, particularly when solid food intake is limited.

Early Mobilisation

• Prolonged bed rest rapidly causes:
  • Muscle atrophy and deconditioning
  • Insulin resistance
  • Pulmonary atelectasis and increased VTE risk
• ERAS targets sitting out of bed on day 0, ambulation on day 1, and escalating mobility thereafter.
• Adequate pain control is a prerequisite, immobility from pain is a major barrier.
• Physiotherapy input should be integrated into the care pathway.

Drain and Catheter Removal

• Urinary catheters removed early (day 1 post-op, or earlier after laparoscopic procedures) to facilitate mobility.
• Routine use of surgical drains is not evidence-based for most elective colorectal cases; remove early when used.

Postoperative Nausea and Vomiting (PONV) Prophylaxis

• PONV delays oral intake and delays discharge.
• Risk stratification (e.g. Apfel score considers: female sex, non-smoking status, history of PONV/motion sickness, planned postoperative opioids).
• Multimodal PONV prophylaxis: ondansetron (5-HT₃ antagonist), dexamethasone, droperidol/haloperidol, combining agents from different classes is more effective than monotherapy.
• TIVA (propofol-based anaesthesia) reduces PONV compared to volatile agents.

Complications & Special Considerations

Barriers to ERAS Implementation

• Staff and system barriers: requires buy-in from surgeons, anaesthetists, nurses, dietitians, and physiotherapists, silos of practice undermine protocol adherence.
• Patient factors: anxiety, comorbidities, frailty, or patient expectation of "traditional" recovery.
• Compliance monitoring: auditing protocol adherence is essential, outcomes correlate with the number of ERAS elements implemented (dose-response relationship).

ERAS in High-Risk Populations

ERAS Across Surgical Specialties

• Originally developed for colorectal surgery, ERAS principles are now validated across:
  • Hepatopancreaticobiliary surgery (pancreatectomy, liver resection)
  • Upper GI (oesophagectomy, gastrectomy)
  • Bariatric surgery
  • Urological surgery (radical cystectomy)
  • Gynaecological oncology
  • Vascular and thoracic surgery
• Core elements remain similar; subspecialty-specific elements address procedure-specific physiology (e.g. pancreatic fistula risk, pulmonary toileting after oesophagectomy).

Evidence Summary

• Multiple randomised controlled trials and meta-analyses confirm ERAS reduces:
  • Length of stay (by 2-3 days in major colorectal series)
  • Overall complication rates (without increasing readmission rates)
• No significant difference in mortality or anastomotic complications compared to conventional care.
• Evidence supports equivalent safety with earlier discharge.
• Effect is dose-dependent on protocol adherence, implementation of more ERAS elements yields greater benefit.

Key ERAS Elements, Summary Table

Perioperative Management, GSSE Viva Points

• ERAS is not a single intervention, it is a bundled care pathway; the benefit arises from the synergistic effect of multiple elements delivered consistently.
• The surgical stress response drives the physiological rationale for every ERAS element, candidates must be able to explain why each intervention is included, not just what it is.
• Carbohydrate loading does not increase aspiration risk in elective patients without gastroparesis, clear fluids empty within 2 hours.
• Thoracic epidural provides dual benefit in open surgery: analgesia + gut motility promotion via parasympathetic facilitation.
• Fluid management: ERAS does not mean "give no fluid", it means GDFT, using dynamic markers rather than static pressure targets to guide therapy.
• Compliance with ERAS elements, not merely its adoption, determines outcome improvement, this is a common exam discussion point.
• The transition of procedures to day surgery enabled by ERAS represents a major healthcare system benefit, not merely a hospital efficiency measure.

Sources

• RACS position statements & curriculum (Royal Australasian College of Surgeons)
• Therapeutic Guidelines (eTG)