Enhanced Recovery After Surgery (ERAS)

Meet the patient

A 64-year-old man is listed for an elective laparoscopic sigmoid colectomy for a T3 node-negative tumour. He is otherwise fit, walks two kilometres a day, and asks the pre-admission nurse the question every patient asks: "When do I have to stop eating, and how long will I be in?" Two pathways diverge from that chair.[2]

The old way — the one your consultants trained under — was nil by mouth from midnight, four litres of mechanical bowel prep, an opioid-heavy anaesthetic, a nasogastric tube pinned to his nose, a drain and a urinary catheter, three litres of crystalloid, and three days in bed before he was "allowed" to eat. He went home on day 8, deconditioned, with a chest infection. The ERAS way — the one you will deliver — is a carbohydrate drink tonight and again at 6 am, no bowel prep, a TAP block with regular paracetamol, no NG tube, no drain, the catheter out on day 1, and food and feet on the floor by the evening of surgery. He goes home on day 3.[3][6]

The two questions that decide every ERAS stem: which elements make up the bundle, and why does each one matter (which limb of the stress response it dismantles)? Hold those two and the protocol stops being a list and becomes a mechanism.[2]

ERAS is a bundle, not a menu — fidelity matters

ERAS is not a single intervention; it is a structured bundle of about twenty discrete elements, and the bundle is greater than the sum of its parts. Each component carries level I evidence, but the components act synergistically — drop one and you lose a disproportionate share of the cumulative benefit. A protocol applied at 70 percent adherence roughly halves complications versus one applied at under 50 percent, and the dose-response is linear in between.[1][6]

The central insight belongs to Henrik Kehlet, a Copenhagen surgeon who in the 1990s asked the heretical question every modern perioperative service is now built on: why does elective surgery make patients so sick for so long? His answer was that traditional perioperative care amplifies the metabolic and neuroendocrine stress of surgery — prolonged fasting, dehydration, mechanical bowel prep, opioid-heavy analgesia, fluid overload, hypothermia, invasive monitoring, nasogastric tubes, drains, and bed rest each independently worsen outcome. Kehlet called his dismantling of this "fast-track surgery"; the formalised, audited, society-endorsed version is what we now call ERAS.[2][3]

For viva gold: "fast-track surgery" was Kehlet's original 1990s term; the ERAS Society (founded 2010 in Stockholm — Kehlet, Ljungqvist, Fearon and Lobo among the founders) is the body that formalised it into audited guidelines and the ERAS Society Interactive Audit System (EIAS), now tracking element adherence and outcomes across more than 80 countries.[6]

The bundle spans the whole perioperative journey, and the cleanest way to hold it is by phase:[1]

[1]

The classic trap: cherry-picking the easy elements and quietly dropping the hard ones. The team that keeps the carbohydrate drink but leaves the routine NG tube in, or mobilises on day 0 but still writes for PRN morphine, loses most of the benefit and tells itself the protocol "doesn't work here". Low fidelity is the single most common reason an ERAS programme underperforms — and it is invisible unless you audit.[6]

Consultant confession: the technical content of ERAS is the easy part; the hard part is winning the team. Pick a protocol champion in anaesthesia, surgery and nursing; agree a one-page checklist; audit element adherence and outcomes prospectively (EIAS does this cleanly); and feed the numbers back to the multidisciplinary team every month. Programmes that audit outperform programmes that don't, by a wide margin, even with identical protocols. Treat compliance as a vital sign.[6]

Dismantling the stress response — one limb at a time

Every ERAS element exists to dismantle a specific limb of the surgical stress response — the neuroendocrine, inflammatory and metabolic cascade that tissue injury triggers. Traditional perioperative care amplifies each limb; ERAS counteracts each one. Learn the six limbs and the protocol stops being a list of rules and becomes a mechanism.[2][4]

The neuroendocrine limb. Surgical injury fires a sympathoadrenal surge, switches on the HPA axis (cortisol), and releases counter-regulatory hormones (glucagon, growth hormone). The net effect is hyperglycaemia, insulin resistance, and a catabolic state that breaks down muscle. An unfed postoperative patient loses about 0.5 kg of lean body mass a day — weakening respiratory muscles (atelectasis, pneumonia) and slowing wound healing.[1]

The inflammatory limb. Tissue injury releases interleukin-1, interleukin-6 and TNF-alpha, producing fever, tachycardia, endothelial activation, and capillary leak. Capillary leak drives third-space losses and interstitial oedema.[1]

The metabolic limb — postoperative insulin resistance. Within hours of surgery the patient develops insulin resistance of a magnitude comparable to type 2 diabetes, proportional to the surgical insult, and it persists for up to three weeks. It worsens hyperglycaemia (infective complications, poor wound healing), accelerates catabolism, and impairs muscle function. Carbohydrate loading is the specific countermeasure — switching the patient from a fasted to a fed state cuts postoperative insulin resistance by about 50 percent.[4]

The fluid limb. Surgery releases ADH and aldosterone, retaining sodium and water; capillary leak then locks it in the interstitium. Liberal fluid therapy (more than 3 L positive balance) independently prolongs ileus, impairs anastomotic perfusion, and causes pulmonary oedema. Goal-directed fluid therapy is the countermeasure — fluid only to optimise stroke volume, near-zero balance.[6]

The immune limb. Surgery transiently suppresses cell-mediated immunity (T-cell and NK-cell function), contributing to infective complications and, in cancer surgery, possibly to worse oncologic outcomes. Blood transfusion independently worsens both — which is why preoperative anaemia correction with IV iron (avoiding transfusion) is an ERAS priority.[1]

The gut limb — postoperative ileus. Sympathetic overdrive, opioids, electrolyte disturbance and bowel oedema all contribute to delayed return of gut function. ERAS counteracts this by minimising opioids, avoiding routine NG tubes, feeding early, and mobilising early.[1]

[1]

No more NPO from midnight — pre-op carbohydrate load

The single most preventable error of traditional care is sending a starved, dehydrated patient to theatre. ERAS replaces "nil by mouth from midnight" with the 2-4-6 rule: clear fluids until 2 hours, breast milk until 4 hours, and a light meal or solids until 6 hours before anaesthesia. The stomach empties of clear fluid within two hours; fasting longer gains nothing and loses intravascular volume, comfort, and insulin sensitivity.[5]

Carbohydrate loading is the specific intervention against postoperative insulin resistance. A 12.5 percent maltodextrin drink — 400 mL the evening before and 200 mL at 2 to 3 hours preop — switches the patient from a fasted to a fed state, cutting postoperative insulin resistance by about 50 percent. Avoid it in type 1 diabetes (insulin omission risks ketoacidosis) and in poorly controlled type 2 diabetes or gastroparesis; in well-controlled type 2 diabetes (HbA1c under 8.5 percent) it is safe.[4]

No routine mechanical bowel prep for colonic surgery. The exception is the low rectal anastomosis with a planned diverting stoma, where combined mechanical plus oral antibiotic prep is still used. Mechanical prep dehydrates the patient, disturbs electrolytes, and is uncomfortable — the very things ERAS is designed to avoid.[6]

VTE prophylaxis starts before the incision: enoxaparin 40 mg SC 12 hours preop, continued for at least 7 to 10 days postoperatively (extended to 28 to 35 days for major cancer or pelvic surgery), with intermittent pneumatic compression boots intraoperatively. Avoid long-acting sedative premedication — short-acting anxiolytics only if essential; a sleepy patient does not mobilise on day 0.[1]

Why carbohydrate loading works — the fed state and insulin signalling

A fasted patient arrives in theatre with depleted glycogen, high glucagon, and a metabolism primed for catabolism. The 12.5 percent maltodextrin drink (a complex, isotonic carbohydrate) taken 2 to 3 hours preop produces a small, sustained insulin pulse that switches the liver to an anabolic, glucose-storing state — the same state a normal breakfast produces. The result is roughly half the postoperative insulin resistance of a fasted patient, less hyperglycaemia, less muscle breakdown, and less thirst and preoperative discomfort.[4]

Goal-directed fluids and normothermia — the intra-op bundle

Inside theatre, four intra-operative elements do most of the heavy lifting: minimally invasive surgery, goal-directed fluids, normothermia, and regional anaesthesia. Each independently dismantles a limb of the stress response; together they are synergistic.[6]

Goal-directed fluid therapy (GDFT) titrates fluid to stroke volume, not to a fixed rate. Give 250 mL boluses of balanced crystalloid until stroke volume no longer rises by more than 10 percent (the plateau of the Frank-Starling curve), then a minimal background of 1 to 2 mL/kg/h. The aim is near-zero fluid balance — both dehydration and liberal fluids (more than 3 L positive) are harmful. Under neuraxial or regional anaesthesia, treat vasodilatory hypotension with vasopressors (noradrenaline infusion, metaraminol boluses) rather than repeated fluid challenges.[1]

Normothermia — core temperature at or above 36 degrees Celsius, with forced-air warming, warmed IV fluids, and a warm theatre. Hypothermia triples the rate of surgical site infection and increases bleeding. It is the single most preventable cause of wound infection in the perioperative period.[1]

Protective lung ventilation (tidal volume 6 to 8 mL/kg ideal body weight, PEEP 4 to 6 cm water) and PONV prophylaxis (ondansetron 4 mg IV plus dexamethasone 4 to 8 mg IV at induction; add droperidol or cyclizine for the high-Apfel-score patient) round out the intra-op bundle. Prophylactic antibiotics go in within 60 minutes of incision (co-amoxiclav 1.2 g IV or cefuroxime 1.5 g IV plus metronidazole 500 mg IV for colorectal), re-dosed at 4 hours or after blood loss above 1500 mL.[1]

Goal-directed fluid therapy in detail — how you titrate at the bedside

GDFT monitoring options include the oesophageal Doppler, arterial pulse contour analysis (LiDCOrapid, FloTrac or Vigileo, PiCCO), and stroke volume optimisation — give 250 mL boluses of crystalloid until stroke volume plateaus (no further rise of more than 10 percent). Dynamic indices such as stroke volume variation (SVV) and pulse pressure variation (PPV) predict fluid responsiveness in the mechanically ventilated patient. Day 1 bloods (FBC, U and E) flag AKI from over-restriction; a rising CRP from day 3 onwards, combined with tachycardia and pelvic pain, mandates a CT to exclude anastomotic leak.[1]

Opioid-sparing analgesia gets the gut moving

The anaesthetic that gets the gut moving is the one that uses the least opioid. Opioids cause ileus, PONV, sedation, and respiratory depression — each one a direct hit to early recovery. ERAS analgesia is paracetamol 1 g QDS regular, plus an NSAID (diclofenac 50 mg TDS, ibuprofen 400 mg TDS, or ketorolac), plus regional or neuraxial blockade, with tramadol or a weak opioid only as breakthrough. Minimise the morphine.[14]

Regional or neuraxial blockade is the keystone. A mid-thoracic epidural (T6 to T9) for open colorectal or upper GI surgery blocks afferent nociceptive signalling, dampens the stress response, and delivers excellent opioid-sparing analgesia. For laparoscopic surgery the epidural benefit is smaller and may be outweighed by epidural-induced hypotension delaying mobilisation — many centres prefer a spinal or a transversus abdominis plane (TAP) block for laparoscopic cases, and local infiltration anaesthesia (LIA) for joint replacement.[14]

The classic trap: opioid monotherapy freezing the ileus. The patient who is "comfortable" on a morphine PCA on day 2, not eating, not mobile, with a silent abdomen, is the patient whose pathway has failed — and the analgesic choice is the cause. Rewrite the chart: regular paracetamol and NSAID, a regional block, and a non-opioid breakthrough, and the gut usually wakes up.[14]

Why regional anaesthesia beats opioid analgesia — the afferent blockade

Neuraxial blockade interrupts the afferent nociceptive traffic from the surgical field to the spinal cord and brain, dampening the sympathoadrenal and HPA response at its source rather than treating the pain it produces. The downstream effects — less cortisol, less catecholamine, less interleukin-6, less insulin resistance, less opioid use, earlier gut function — are exactly the limbs ERAS targets. The trade-off is epidural-induced hypotension, which is why laparoscopic cases with smaller incisions often do better with a TAP block.[2]

Each removed tube shortens the stay

Every tube you leave in is a reason the patient stays in. Routine nasogastric tubes, surgical drains, and urinary catheters each independently prolong recovery, and ERAS removes them by default unless there is a specific indication.[1]

No routine nasogastric tube. Routine NG decompression for more than 24 hours increases pneumonia and delays the return of gut function. Remove the intraoperative NG before reversal unless there is a specific indication — the undistended stomach at the end of the case is the norm, not the exception.[1]

No routine surgical drains. Drains do not prevent anastomotic leak, they do not detect it early, and they cause pain, immobilise the patient, and track infection. The randomised evidence is clear — leave a drain only for a specific surgical reason, and remove it early.[1]

Remove the urinary catheter on day 1 unless an epidural or spinal is still in situ (in which case remove within 24 to 48 hours of catheter removal). A catheter is a tether — it stops the patient walking, and a tethered patient is a patient who stays.[1]

The classic trap: the routine NG tube "just in case", or the drain "to monitor for a leak". Neither prevents the complication you fear; both cause the complications you have — pneumonia, immobility, infection, and a longer stay. The default is no tube; the exception needs a reason.[1]

Early oral intake and mobilisation on day 0

Feed them and walk them on the day of surgery, and the rest of the protocol follows. The two elements that most visibly accelerate recovery — early oral intake and early mobilisation — both happen on day 0, and both are safe.[8]

Early oral intake within 4 to 6 hours: sips of water, then free fluids, then a light diet on the evening of surgery. The persistent myth that "feeding stresses the anastomosis" is contradicted by ERAS evidence — early feeding does not increase the anastomotic leak rate. A fed patient is an anabolic patient, with less catabolism, better wound healing, and an earlier return of gut function.[8]

Early mobilisation on day 0: sit out of bed for at least 2 hours on the evening of surgery, with structured mobility goals on days 1 to 3 (walking distance, time upright). Early mobilisation prevents DVT, pneumonia, deconditioning, and ileus — and the frail elderly paradoxically derive the greatest benefit, because they have the most to lose from bed rest.[1]

Everyone forgets: the biggest enemy of day-0 mobilisation is not the patient, it is the tether — the urinary catheter, the drain, the IV pole, the epidural-induced hypotension. Remove the tubes, normalise the blood pressure, and the patient walks.[1]

The day-0 to day-3 trajectory — expected milestones

ERAS replaces the slow, complication-laden convalescence of traditional care with a structured, milestone-driven trajectory — and deviation from that trajectory is itself a red flag. Know the expected milestones by day, and you will spot the failing pathway on day 1, not day 4.[1]

• Hour 0 to 4 (recovery): sips of water, then free fluids; first mobilisation to the chair.
• Evening of day 0: light diet tolerated, out of bed at least 2 hours, pain and PONV controlled on the opioid-sparing regimen.
• Day 1: urinary catheter out, full diet, walking in the bay, structured mobility goals.
• Day 2 to 4 (procedure-dependent): independent mobility, adequate oral analgesia, tolerating a solid diet — discharge ready.[1]

Discharge is permitted when all of the following are met: tolerating a solid diet, adequate oral analgesia, independently mobile (or back to baseline function), stable observations (afebrile, stable heart rate and blood pressure, adequate urine output), stable haemoglobin, no signs of complication, and the patient agreeable. Passing flatus or stool is desirable but not an absolute requirement — modern ERAS does not insist on it.[1]

Who is fit for ERAS — risk stratification and prehab

ERAS is a care protocol, not a disease entity, so there are no patient-level risk factors in the disease sense — but several factors modify applicability and benefit, and the pre-admission clinic is where you find them.[1]

Risk stratification uses validated tools. ASA physical status grade (I to VI) is coarse but universal. Cardiopulmonary exercise testing (CPET) is the gold standard for major resection in the elderly or comorbid — an anaerobic threshold under 11 mL/kg/min or a VE/VCO2 slope above 34 marks high risk and flags the patient for level 2 to 3 care postoperatively. P-POSSUM predicts operative mortality and morbidity. Frailty scores (Clinical Frailty Scale 1 to 9, Edmonton) independently predict complications and length of stay — and the frail derive the greatest benefit from early mobilisation.[1]

Nutritional screening uses MUST (Malnutrition Universal Screening Tool) or NRS-2002, with Subjective Global Assessment for definitive assessment. Significant malnutrition is a MUST score at or above 2 or weight loss above 10 percent in 6 months — a relative contraindication to immediate surgery, warranting 7 to 14 days of preoperative nutritional support (do not delay cancer surgery by more than 4 weeks).[1]

Prehabilitation corrects what is correctable before the day of surgery: smoking and alcohol cessation (at least 4 weeks), anaemia correction with IV iron (ferric carboxymaltose 1000 mg, plus or minus erythropoietin) to avoid intraoperative transfusion, glycaemic control (HbA1c under 8.5 percent in diabetes), and exercise-based prehabilitation to raise aerobic capacity. Iron studies flag deficiency (ferritin under 30 micrograms/L, transferrin saturation under 20 percent).[1]

Special populations — who needs the protocol modified

ERAS applies to almost everyone, but a handful of populations need specific modifications — and the viva loves them.[1]

• Elderly and frail paradoxically derive the greatest benefit from early mobilisation (less delirium, pneumonia, DVT, deconditioning), but watch carefully for hypotension and AKI. Frailty assessment (Clinical Frailty Scale) and CPET are mandatory before major resection.
• Diabetic patients — the 12.5 percent maltodextrin drink is safe in well-controlled type 2 diabetes (HbA1c under 8.5 percent), avoided in type 1 diabetes and in poorly controlled type 2 or gastroparesis. For poorly controlled diabetes, use a variable rate IV insulin infusion (VRIII).
• Pregnant patients — ERAS principles apply to elective caesarean section (early feeding, early mobilisation, spinal with intrathecal diamorphine), but the carbohydrate drink is avoided because of delayed gastric emptying and aspiration risk (Mendelson syndrome).
• Obese and bariatric patients — high VTE risk (increase LMWH to enoxaparin 40 mg SC BD or weight-based tinzaparin, continue 28 to 35 days), minimise opioids (obstructive sleep apnoea), continue CPAP perioperatively. The carbohydrate drink is safe in obesity.
• Malnourished patients — preoperative oral nutritional supplements or enteral feeding for 7 to 14 days (parenteral if the gut is unusable); do not delay cancer surgery by more than 4 weeks.
• Anticoagulated patients — bridge warfarin or DOAC per protocol; neuraxial timing per ASRA or ESRA guidelines (LMWH stopped 12 hours before and after neuraxial insertion or removal; DOACs held 48 to 72 hours depending on renal function).
• Emergency surgery — apply ERAS-e: abbreviated preoperative optimisation, but full intra-operative (GDFT, normothermia, opioid-sparing, protective ventilation) and post-operative (early feeding, mobilisation, no routine tubes) elements.[1]

When the protocol fails — the differential of delayed recovery

When a patient on an ERAS pathway is not recovering as expected, the protocol has either not been delivered (low compliance) or a complication has supervened — and the differential of delayed recovery is short and learnable.[1]

1. Postoperative ileus — the commonest; minimised by ERAS but still occurs with opioid use, hypokalaemia, or fluid overload.
2. Early small bowel obstruction — usually adhesional; distinguishes from ileus by colicky pain, absent flatus, and dilated loops with a cut-off on imaging.
3. Anastomotic leak — classically day 5 to 7 with fever, tachycardia, rising CRP, pelvic or abdominal pain. Early feeding does not increase the leak rate — the persistent myth that "feeding stresses the anastomosis" is exactly backwards.
4. Intra-abdominal collection — fever and raised inflammatory markers; CT with contrast.
5. Pneumonia — prevented by mobilisation and avoidance of NG tubes; productive cough, hypoxia, focal consolidation.
6. Acute kidney injury — risk if GDFT is too restrictive or the patient is hypovolaemic; monitor urine output (target above 0.5 mL/kg/h) and creatinine.
7. Pulmonary embolism — despite prophylaxis; sudden dyspnoea, pleuritic chest pain, right heart strain on CT pulmonary angiogram.[1]

The bedside red flag: a rising CRP from day 3 onwards, combined with tachycardia and pelvic pain, is an anastomotic leak until proven otherwise — CT with water-soluble contrast, resuscitate, antibiotics, and most often a return to theatre.[1]

The anastomotic leak — recognise it on day 5 to 7

A patient who was recovering well after a colorectal anastomosis develops fever, abdominal pain, and tachycardia around day 5 to 7. This is an anastomotic leak until proven otherwise — CT with water-soluble contrast, resuscitation, antibiotics, and most often a return to theatre for defunctioning or revision. Risk is highest in low rectal anastomoses, the malnourished, and the patient on steroids, which is why a defunctioning ileostomy protects a low anastomosis. Crucially, this is not caused by early feeding — the leak rate is unchanged whether you feed on day 0 or day 5.[8]

The specialty deltas — same principles, procedure-specific tweaks

ERAS was built for elective colorectal surgery and is best evidenced there, but the principles are generic — the ERAS Society now publishes procedure-specific guidelines for a dozen specialties, each with a few signature modifications.[6][10][11][12][13]

[6] [7]

The evidence base — the numbers that made ERAS standard

The clinical payoff is among the most robust in all of perioperative medicine. Meta-analyses of randomised trials show ERAS reduces total complications by about 50 percent, length of stay by 2 to 3 days, and hospital costs, without any increase in readmission or mortality. The effect is dose-dependent on compliance — adherence at or above 70 percent halves complications versus adherence below 50 percent, and compliance is the dominant modifiable determinant of benefit.[7][8][9]

[1]

Named traps — the recurring trainee errors

These are the errors that quietly halve the benefit of the protocol or harm the patient. Name them and you will not make them.[1]

• Cherry-picking the easy elements — low fidelity loses the benefit. Audit element adherence; the bundle is greater than the sum of its parts.
• Sending the patient to theatre starved and dehydrated — clear fluids until 2 hours, carb drink until 2 to 3 hours; never nil by mouth from midnight.
• Carbohydrate drink in type 1 diabetes — insulin omission risks ketoacidosis; avoid. Also avoid in poorly controlled type 2 diabetes or gastroparesis.
• Routine mechanical bowel prep for colonic surgery — dehydrates, disturbs electrolytes; exception is the low rectal anastomosis with diverting stoma.
• Opioid monotherapy freezing the ileus — regular paracetamol and NSAID plus regional block, and minimise the opioid.
• Routine NG tube or surgical drain "just in case" — neither prevents the complication you fear; both cause pneumonia, immobility, and infection.
• Liberal fluids (more than 3 L positive balance) — tissue oedema, prolonged ileus, impaired anastomotic healing, pulmonary oedema.
• Hypothermia — core temperature under 36 degrees triples the surgical site infection rate.
• Premature discharge before discharge criteria are met — readmission risk; use a structured checklist.
• Neuraxial anaesthesia without anticoagulation timing — follow ASRA or ESRA guidelines (LMWH stopped 12 hours before and after neuraxial insertion or removal) to prevent spinal haematoma.[1][6]

The mantra, and the mnemonic

[1]

The mantra: dismantle the stress response, feed early, move early, lose the tubes.[1][6]

Ward-round test — three stems

Stem 1 — the day-1 patient with a silent abdomen (answer)

A 68-year-old man is on day 1 after an open sigmoid colectomy. He is comfortable on a morphine PCA, has not passed flatus, has a soft but silent abdomen, and has not been out of bed. The trainee charts "awaiting return of gut function". What has gone wrong, and what do you change? Model: The analgesic choice is the problem — opioid monotherapy is freezing the ileus, and the morphine PCA is the tether keeping him in bed. Rewrite the chart: regular paracetamol 1 g QDS and an NSAID, a regional block (epidural or TAP), and a non-opioid breakthrough; stop the PCA. Remove the urinary catheter and any drain, and mobilise him today. The gut usually wakes up when the opioid goes down and the patient stands up. Early feeding does not increase the anastomotic leak rate, so do not wait for flatus to feed.[8][14]

Stem 2 — the routine nasogastric tube (answer)

A colleague routinely leaves a nasogastric tube after colorectal resection "to protect the anastomosis and rest the gut". What is the evidence, and what do you advise? Model: Routine NG decompression for more than 24 hours increases pneumonia and delays the return of gut function — it does not protect the anastomosis and does not prevent ileus. The ERAS default is no routine NG tube; remove the intraoperative NG before reversal unless there is a specific indication. The same logic applies to surgical drains, which neither prevent nor detect anastomotic leak and cause pain, immobility, and infection. Every tube left in is a reason the patient stays in.[1]

Stem 3 — the starved, dehydrated patient at 8 am (answer)

A patient is listed for an elective colorectal resection at 10 am. The nurse has kept him nil by mouth from midnight and cancelled the carbohydrate drink "in case the list moves". What is the harm, and what is the correct regimen? Model: Nil by mouth from midnight is the single most preventable error of traditional care — it dehydrates the patient, lowers intravascular volume, increases thirst and discomfort, worsens postoperative insulin resistance, and raises the risk of postoperative nausea and AKI. The ERAS regimen is the 2-4-6 rule: clear fluids until 2 hours and a light meal until 6 hours before anaesthesia, with the carbohydrate drink (12.5 percent maltodextrin) 400 mL the evening before and 200 mL at 2 to 3 hours preop. The stomach empties of clear fluid within two hours, so a moving list is not a reason to starve. Avoid the carb drink only in type 1 diabetes and in poorly controlled type 2 diabetes or gastroparesis.[4][5]

References

1. [1]Ljungqvist O, Scott M, Fearon KC. Enhanced Recovery After Surgery: A Review. JAMA Surg, 2017.PMID 28097305
2. [2]Kehlet H, Wilmore DW Multimodal strategies to improve surgical outcome. Am J Surg, 2002.PMID 12095591
3. [3]Kehlet H, Mogensen T Hospital stay of 2 days after open sigmoidectomy with a multimodal rehabilitation programme. Br J Surg, 1999.PMID 10100792
4. [4]Fearon KCH, Ljungqvist O, Von Meyenfeldt M, et al. Enhanced recovery after surgery: a consensus review of clinical care for patients undergoing colonic resection. Clin Nutr, 2005.PMID 15896435
5. [5]Lassen K, Soop M, Nygren J, et al. Consensus review of optimal perioperative care in colorectal surgery: Enhanced Recovery After Surgery (ERAS) Group recommendations. Arch Surg, 2009.PMID 19841366
6. [6]Gustafsson UO, Scott MJ, Hubner M, et al. Guidelines for perioperative care in elective colorectal surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations 2018. World J Surg, 2019.PMID 30426190
7. [7]Varadhan KK, Neal KR, Dejong CHC, Fearon KCH, Ljungqvist O, Lobo DN The enhanced recovery after surgery (ERAS) pathway for patients undergoing major elective open colorectal surgery: a meta-analysis of randomized controlled trials. Clin Nutr, 2010.PMID 20116145
8. [8]Zhuang CL, Ye XZ, Zhang XD, Chen BC, Yu Z Enhanced recovery after surgery programs versus traditional care for colorectal surgery: a meta-analysis of randomized controlled trials. Dis Colon Rectum, 2013.PMID 23575408
9. [9]Spanjersberg WR, Reurings J, Keus F, van Laarhoven CJ Fast track surgery versus conventional recovery strategies for colorectal surgery. Cochrane Database Syst Rev, 2011.PMID 21328298
10. [10]Melloul E, Lassen K, Roulin D, et al. Guidelines for perioperative care for pancreatoduodenectomy: Enhanced Recovery After Surgery (ERAS) recommendations 2019. World J Surg, 2020.PMID 32161987
11. [11]Melloul E, Hübner M, Scott M, Snowden C, Prentis J, Dejong CH, et al. Guidelines for Perioperative Care for Liver Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations. World J Surg, 2016.PMID 27549599
12. [12]Thorell A, MacCormick AD, Awad S, et al. Guidelines for perioperative care in bariatric surgery: Enhanced Recovery After Surgery (ERAS) Society recommendations. World J Surg, 2016.PMID 26943657
13. [13]Yamagata Y, Yoshikawa T, Yura M, et al. Current status of the enhanced recovery after surgery program in gastric cancer surgery. Ann Gastroenterol Surg, 2019.PMID 31131351
14. [14]Beverly A, Kaye AD, Ljungqvist O, Urman RD Essential elements of multimodal analgesia in Enhanced Recovery After Surgery (ERAS) guidelines. Anesthesiology Clinics, 2017.PMID 28526156