Enhanced Recovery After Surgery (ERAS)

Traditional perioperative care in the 1990s was characterised by prolonged fasting, mechanical bowel preparation, routine nasogastric tubes, bed rest, and liberal opioid analgesia — practices based on tradition rather than evidence. Henrik Kehlet, a Danish surgeon, published a series of landmark papers in the late 1990s articulating a revolutionary concept: that the surgical stress response could be attenuated through a multimodal, evidence-based bundle of perioperative interventions. His 1997 Lancet paper outlined the 'fast-track surgery' paradigm, demonstrating that combining regional anaesthesia, early nutrition, early mobilisation, and minimally invasive technique could achieve discharge after colonic resection in 2-3 days rather than the conventional 7-10 days. This was not a single intervention but a philosophy — and it challenged every specialty to re-examine its perioperative dogma.

The ERAS Society, founded in 2010, formalised Kehlet's principles into structured, procedure-specific protocols supported by systematic reviews. The LAFA trial (2011) provided randomised evidence that ERAS combined with laparoscopy achieved faster recovery than traditional open surgery with conventional care in colorectal resection. The EnROL trial (2012) demonstrated that ERAS protocols reduced length of stay after liver resection without increasing complications. Multiple meta-analyses confirmed that ERAS programmes consistently reduced hospital stay by 2-3 days and complication rates by 30-50% across surgical specialities including colorectal, urological, gynaecological, and thoracic surgery. Importantly, these benefits were achieved without increasing readmission rates — addressing the primary concern that 'faster' meant 'premature.'

ERAS has expanded far beyond colorectal surgery into virtually every surgical specialty. Procedure-specific ERAS guidelines now exist for cardiac, thoracic, hepatobiliary, pancreatic, gynaecological, urological, and orthopaedic surgery. A critical evolution has been the integration of opioid-sparing multimodal analgesia — combining regional anaesthesia, acetaminophen, NSAIDs, gabapentinoids, ketamine, and local infiltration to minimise opioid use. The RELIEF trial (2018) challenged the traditional liberal fluid paradigm within ERAS, showing no benefit of restrictive versus moderately liberal fluid therapy in abdominal surgery and suggesting that the goal-directed approach is more important than absolute restriction. ERAS compliance has emerged as a key quality metric, with evidence showing a dose-response relationship between protocol adherence and outcomes.

The ERAS Society has published over 20 procedure-specific consensus guidelines, each based on systematic reviews of individual pathway elements. The 2018 ERAS guidelines for colorectal surgery represent the most mature pathway, covering preoperative counselling, carbohydrate loading, avoidance of bowel preparation, short-acting anaesthetic agents, multimodal opioid-sparing analgesia, early oral nutrition, and early mobilisation. ASA and ESA perioperative guidelines now incorporate ERAS principles. The WHO has endorsed ERAS as a patient safety initiative. National surgical quality programmes in multiple countries have adopted ERAS compliance as a reportable quality metric.

ERAS is now the standard of care for elective surgery in high-income countries, with implementation varying widely by institution and specialty. The greatest challenge is not the evidence base but implementation science — achieving and sustaining high compliance rates with all pathway elements. Data from ERAS Interactive Audit System shows that compliance above 80% is associated with significantly better outcomes, yet average compliance hovers around 60-70% at many centres. The opioid crisis has given renewed urgency to the multimodal analgesia components. Current frontiers include prehabilitation (optimising patients weeks before surgery), personalised pathways using wearable monitoring, AI-driven prediction of readiness for discharge, and extension of ERAS principles into emergency surgery where recovery optimisation is arguably even more impactful.