Executive Summary
Enhanced Recovery After Surgery (ERAS) is a multi-modal interdisciplinary approach to change the surgical field by decreasing complications and length of stay in patients undergoing necessary surgical procedures. Studies suggest that the effects of these protocol implications have a profound effect by decreasing complications and length of stay by 10-50%1,2 through the support of nursing, anesthesiology, and the surgical team, to provide evidenced-based care through communicating with one another. ERAS is supported by years of research by Olle Ljungqvist, the founder of ERAS, by focusing on the patient’s journey in the hospital. There is still some resistance, as many surgeries are performed without utilization of ERAS in more traditional methods. Although there are many components of ERAS that are utilized to provide adequate care even in traditional practice. These are seen in pre-operative, peri-operative, and postoperative care modes that provide best care practices for patients. ERAS focuses on the utilization of communication among professionals to provide better care as an integrative discussion by auditing the processes and outcomes of patient care. Dr. Ljungqvist’s findings note that patients have half of their complications, reduction in their stay, and changes in clinical outcomes. This is due to the knowledge and research found in understanding metabolism, endocrine, and immunological complications from surgical interventions.
Research has shown that ERAS can save money, time, lives, and resources by altering the methodology of surgery to be less invasive and more progressive. Through laparoscopic surgery and early ambulation and adequate nutrition a patients risk of infection, length of stay and overall mortality decreases through the utilization of ERAS protocol.
Background Information
Enhanced Recovery After Surgery (ERAS) is a process utilized by a multi-disciplinary team to minimize the physiologic changes from surgery through the continuation of nutrition; decreasing opioid interactions, and avoiding deconditioning to allow the surgical area to heal.1 The hope through this approach would be to lower the impact of surgical stress on the patient post-operative from their physiologic and physiological responses. This is done through enhancing the hospital organization to embrace to best practices and develop a team that works and communicates from start to finish instead of departments that the patient flows through (clinic, surgery, anesthesiology, intensive care).2 The team consists of the pre-operative and post-operative team, nursing, the surgeon and the surgical team, anesthesiologist, and dietitian. The original use of ERAS was developed for colorectal patients, however, this is expanding to various kinds of major surgery as methods are perfected for gastrointestinal surgeries, hence why this is such a pertinent feature to understand in the clinical nutrition world.2 There have been multiple journals published with evidence pinpointing that ERAS’ multimodal approach has evidence-based benefits ‘ decreasing length of stay, decreasing the use of analgesics, cost, and increasing comfort of patient.2
Specific ERAS components that the ERAS Society has approved of across all ERAS protocol include the following procedures for each stage. The first stage is the pre-admission where the surgeon or dietitian may suggest pre-operative nutritional support for a malnourished patient complete cessation of smoking and supplement usage by the patient, with the team suggesting medical optimization and information available for the patient.(figure 1) Preoperative preparation for the patient is the usage of a bowel cleanser, preoperative carbohydrates up to 2 hours before surgery, and antibiotic prophylaxis medications. Intra-operative measures are with minimally invasive techniques and minimal drainage, regional analgesia and minimal opioid use, as well as balanced control of temperature and fluids. Post-operative is removal of drains and tubes and cessation of intravenous fluids, no usage of nasogastric tubes, minimal opioid-based pain control with reliance on other medications, early mobilization of the patient, and early oral intake of fluids and calories for initial gut motility, and a patient follow up practices (figure 1, figure 2).
Specific medical nutrition therapy methods used are pre-counseling; this will inform the patient what to expect, as well as notify them it may be different than what they have experienced if they have had prior surgeries before using ERAS or traditional methods.2 There is also the use of pre-operative and post-operative nutritional interventions to enhance the recovery of the patient. Pre-op nutrition includes an oral liquid carbohydrate loaded beverages up to two hours before surgery.3 Evidence has shown that carbohydrate supplementation of a carbohydrate-rich formula given two hours before surgery has a profound effect on decreasing length of stay in the hospital compared to traditional surgical methods.4 Post-operative interventions for nutrition will be through a liberal oral intake to stimulate insulin release.5 Other components related to nutrition include early mobilization of the patient and an adequate fluid intake to improve healing outcomes.
ERAS has also had a renowned effect of saving hospitals money long-term through the ERAS Society protocol measures. A financial analysis found using the budget from a quaternary hospital, the initial implementation cost of ERAS was $552,783. However, this was offset by the first year savings of the hospital from the ERAS program of $948,500, yielding a net savings of $395,717.4 Long term, the implications of ERAS have only a positive impact on facility utilization if ERAS methods are followed correctly and well maintained. Facilities that adhere to only a portion of ERAS protocol and their procedures may see marginal changes in their patient length of stay and cost fluctuations.
Traditional Methods
More commonly, there are standard procedures for all operations used in the hospital setting. The more widely used practice is similar to that of ERAS with steps taken in pre-operative, intra-operative and post-operative, but more focused on the recovery of the patient receiving active treatment via medication pre-op and post-op, and decreasing pre-operative nutritional input through fasting. Patient admission is preferable three days before surgery, however, this is not always possible based on hospital resources available.5 The patient is then risk screened, and should see a dietitian if they are at a nutritional risk, in poor nutritional status, or with a wound upon admission.6
Traditional methods for pre-operative nutrition are an encouragement of overnight fasting. This model was thought to prevent any risk of aspiration while there is an endotracheal tube in the airway for breathing during intubation during surgery.5 There is also a concern that the food in the gastrointestinal tract may also become a risk factor if their bowel is perforated during surgery.5 There is a downside to this as well such as discomfort from thirst, hunger, headaches, and anxiety for the patient as they are unable to eat for an extended period.5 However, latest studies reflect that the intake of clear fluids taken up until two hours before anesthesia does not increase the gastric volumes.3 As many surgical procedures are being altered to be done as minimally invasive and laparoscopically, the overall healing time has increased significantly in both traditional and ERAS surgical procedures.6
Other components of traditional surgery are to increase urine output, therefore, intravenous fluids are administered liberally to output fifty milliliters an hour or more.7 Additional methods of output measures are the utilization of catheters, drainage of the surgical site, and a nasogastric tube to drain any bowel contents. The change in surgical methods from traditional to ERAS methods, like the removal of catheters and decreased medication administration, have been beneficial for those utilizing 80% of ERAS practices or more. However, there is still lots of resistance to change traditional practices because of the relative unknown potential effects of ERAS in surgical subsets that have not had ERAS preformed before.6
Surgery and Nutritional Status
Risk assessments are used upon admission for patients to assess the nutritional status. This is looking for the risk of malnutrition pre-operatively through two different assessment screenings. The patient has a BMI of under 18.5 kg/m2 meaning they are underweight, or the patient has experienced weight loss >10% in six months or >5% over one month and reduced BMI.8 It’s important to assess the patient for risk of malnutrition because it can be detrimental as a post-surgical outcome.6 This is especially true for larger surgeries where surgical stress leads to a catabolic and inflammatory state for the patient.7 Preoperative care and dietitian-led practices such as nutritional education and counseling to patients undergoing surgery through ERAS may be a suggested next step to establish adequate nourishment in patient populations prior to surgery, since that has the best optimal chances for a success.10 The largest concern nutritionally is at the patient is at risk for developing a nosocomial infection, therefore, increasing their needs for calories and protein due to additive stress on the bodies immune system.9 There are many factors that determine these needs such as age, clinical status, and weight, however, using preventable methods to increase optimal health and decrease nutritional risk is always in the patients best interest.9 Nutritional interventions such as early oral interventions and increased protein intake, as well as addressing any deficiencies post-operatively can be utilized to provide energy during acute catabolism from surgical stress. Grade A evidence from the ASPEN Guidelines suggests that in ERAS patients, traditionally oral intake or clear liquids should be initiated within hours after surgery to offset some of the surgical complications like loss of gut integrity seen in patient populations.8
Metabolism After Surgery
After surgery, the body goes through two phases of initial decrease and then subsequent increase in metabolic changes. Initially, the body undergoes an ‘ebb’ metabolism, also known as shock. The body slows down for the first twenty-four to forty-eight hours to assess the damage before entering the flow phase.11 The flow phase is characterized by mass inflammation, hyper-metabolism, and insulin resistance for anywhere between three to ten days.11 The body eventually moves out of the hyper-catabolic state into an anabolic state while it tries to reserve energy stores and heal surgical sites.
The ‘ebb’ metabolism is from the release of shock hormones by the adrenal glands in the endocrine system from stimulation in the brain. The patients basal metabolic rate, core temperature, and carbon dioxide levels all decrease from the shock since the body went through a variety of trauma.11 The release of factors such as catecholamines, cortisol, aldosterone as well as hypovolemia from surgery are influencing factors on the ebb state.11 The role of catecholamines like norepinephrine and epinephrine during the ebb phase allows the body to undergo shock and cascading effects of tachycardia and hypertension through the sympathetic activity.12 This phase lasts only up to two days, where the body’s immune system kicks in and gears the body to a catabolic state.
In the catabolic state, the body goes into a negative nitrogen balance due to the circulating levels of catecholamines to the liver, pancreas, and kidneys.12 The literature states that nutritional interventions must be made sooner because of this metabolic shift.13 This increases energy expenditure and needs of the organs affected by metabolic, endocrine, and immunological shifts. This enables the body to self-mend from surgical trauma.13 Insulin resistance is commonly seen as a metabolic marker for metabolic stress due to the pancreas hormonal response to a glucagon release as a graded response for the operation.3 Decreased glucose uptake, alongside the loss of lean body mass in this actable state, increases the nutritional needs of the patient.3 There are two kinds of cells, the non-insulin sensitive and insulin sensitive cells like immune cells, endothelial cells, and neural cells.3 These cells intake the excess glucose and undergo glycolysis but have no storage capacity ‘ creating free oxygen radicals that increase inflammation in the body.3 By utilizing early nutritional interventions such as an early oral intake and immune-enhancing drinks this can decrease the resistance of insulin sensitivity in the EBB phase.11
Carbohydrate metabolism shifts and blood sugar levels rise due to glycogenolysis and gluconeogenesis caused by the elevated levels of cortisol and catecholamines circulating.14 There is generally little insulin being released peri-operatively and post-operatively from surgical stress, therefore hyperglycemia may be an acute symptom until the body heals and the effects from stress hormones decrease.12 The body also has direct effects on protein and fat metabolism as well. Cortisol concentrations increase the utilization of gluconeogenesis and proteolysis for break down of skeletal muscle.14 The free amino acids can be used for formation of other proteins or changed to glucose for the cells metabolism.14 Cortisol and catecholamines also break down fatty acids through lipolysis and gluconeogenesis for energy formation from glucose and ketone bodies.13 This is important to note that free-fatty acids are the primary sources of energy after trauma and surgery, especially in the liver cells where triglycerides are 50-80% of energy consumed.14 By inducing oral stimulation through ERAS protocol, the body does not break down as much during the catabolic flow state because there is food in the bowel instead to utilize. This promotes gastric motility and the body can begin to regulate itself better than if it was in a fasting state.
Endocrine Systems
During surgical stress, the body goes through endocrinological changes to adapt to the trauma inflicted on the body. These responses are to protect and heal the body post-surgery through the release of pituitary hormones and activation of the sympathetic nervous system.11 These are activated after the ebb state, in which the body shifts toward a state of catabolism and negative nitrogen balance. One example is the release of adrenocorticotrophic hormone (ACTH) from the pituitary glands which respectively releases cortisol and aldosterone from the adrenal cortex. (table 1) Another component that is released by the pituitary gland is growth hormone (GH), which has an anti-insulin effect and direct role in metabolism factors.
Other factors are the Anti-diuretic hormone (ADH) which also is released by the pituitary gland in the brain. It has a direct effect on the retention of water and sodium to raise blood pressure in the body to maintain cardiovascular homeostasis.11 Table 2 reflects all hormonal fluctuation values of catabolism. Within the ERAS guidelines, a placement of an epidural on the (t-4-t9) thorastic spinal cord can block a majority of these effects and therefore, also have a remarkable influence on decreasing insulin resistance in recovering patients.3
The sympathetic nervous system also becomes affected releasing catecholamines that cause tachycardia, tachypnoea, and vasoconstriction. From there after 24-48 hours the body shifts and begins releasing noted hormones such as ACTH, GHR, ADH. These systems work together resulting in a catabolic state of shock in which the body is trying to regain control to self-heal.
Immunological Changes
Immunological functions also shift the post-op period towards an inflammatory state. The inflamed cells that have been affected by the surgical procedure release chemical mediators that recruit macrophages. 13 Macrophages release pro-inflammatory cytokines by in the affected area. Specific releases of such as IL-1”, IL-6, and TNF-” from the innate immune response to directly influence other cells in the area as well as recruit the active immune system in aiding in the healing process. 13 In the acute setting, these markers promote a healing environment to reduce infection at the operation site.12 Other innate immune responses are increasing the body’s temperature, vasodilation to increase blood flow and redness/swelling of the immediate area. Monitoring of infection and routine antibiotics are generally in effect after surgery to aide any risk of infection post-operatively. 12 Through the usage of anti-inflammatory nutritional interventions like HMB and Omega-3 Fatty acid supplementation, the inflammatory response is shortened and wound healing is promoted. Other measures are through the use of laparoscopic procedures and anti-biotic use. 2
Nutritional Therapy and Fluid Interventions
Preoperative nutrition interventions for ERAS patients entering the hospital are manifested as a diet order for clear liquid prior to their surgery that morning until two hours before pre-operation. However, the expectation is that the patient instead of fasting in traditional methods, the patient may have a high carbohydrate beverage before entering the hospital as part of the ERAS protocol.15 The patient will also take a bowel prep to cleanse the bowel to decrease the risk of infection incase of perforation of the bowel. The bowel prep’s purpose is to clean out the gastrointestinal tract, however, there is some concern of upsetting gastrointestinal function.15 Of course, nutritional assessments have to be taken account for to assess any necessary interventions for malnutrition. If a patient is malnourished, using immune-enriched enteral nutrition may be better than standard enteral nutrition in severely malnourished patients for ten to fourteen days before major surgery to improve surgical outcomes in pancreatic and bowel ERAS surgical patients.16 However, the dietitian should use discretion on what the patient may need through their assessment.
ERAS recommendations for fluid intake suggest that the patient will also have a very minimal fluid intake via intravenously and orally.8 This varies on the patient to prevent dehydration, however, the goal is to avoid bowel edema from fluid overload in the patient. However, adequate fluid should be given to meet any intravascular deficit, replace ongoing losses, or for maintenance need.15
Post-operative edema is common in patients who struggle to maintain their oncotic pressure which can be noted by over hydration, loss of blood, and low albumin levels. Some methods to that are utilized by ERAS decrease the risk of post-operative edema and it’s complications.15 This is seen through their components in removing drains and tubes, as well as stopping additional intravenous fluids to prevent over hydration of the patient.(Figure 1).
Other post-operative nutritional interventions are supplementation of arginine, glycine, ”-Hydroxy ”-Methylbutyrate (HMB), and omega-3 fatty acids to benefit the immune system, increase protein synthesis and muscle tissue, and decrease overall length of stay.12 Commonly, after surgery the patient may have a post-operative paralytic illeus which is seen in surgical patients especially after opioid dosing and extra fluid.8 This can postpone oral intake and ambulation and therefore, if the patient is at risk for malnutrition, other forms of nutrition should be utilized if the patient is at risk for further deterioration.
Enteral and Parenteral indications for ERAS Surgery
Enteral Nutrition (EN) may be administered to ERAS patients who are unable to feed orally post-operation after 7-10 days or for those who are not having an adequate intake orally after their surgical procedure. These patients generally are at risk for deterioration and are commonly found in the surgical intensive care unit (SICU) post-operative care. Infusion of EN has many benefits similar to those of oral interventions if initiated within 24-48 hours post-operatively for patients who cannot tolerate an oral intake, however, ASPEN guidelines suggest that EN is only utilized if the patient cannot tolerate oral intake.
Benefits include decrease of septic and malnutrition complications as well as a faster recovery period.17 This is because of the maintenance of the gut barrier function which has a direct role in immune systems as well as the tight junctions in the epithelial lumen lining of the bowel.18 Tailoring specific nutritional needs for the surgical patient is of course essential in surgical subsets and the individual. This would be through the performance of a nutritional assessment and gathering of clinical status to target necessary needs of the patient. Feeding patients as early as possible shows high evidence in preventing refeeding syndrome.10 Attention should still be made to checking labs and assessing the risk of developing refeeding syndrome despite the time of initiation of EN. Patients if on a short term need for EN should be using oral or nasogastric tubes, however, if it is needed longer than three weeks due to prolonged healing, a gastronomy tube should be assessed and placed to ensure continued use of the bowel is enabled.
Indications that the patient should be placed on Parental Nutrition according to the American Society of Parenteral and Enteral Nutrition (ASPEN) is when the gastrointestinal tract is no longer available to use due to ischemia or a chronic paralytic ileus; when the patient’s mean arterial pressure (MAP) is between 50-60, the abdomen is firm and distended, severe short bowel syndrome, mesenteric ischemia, paralysis of the intestinal muscles, small bowel obstruction, or a gastro-intestinal fistula.12 For those in the intensive care unit (ICU), the largest concern is for those who are at a high nutritional risk and enteral nutrition (EN) is not feasible due to one of the other factors listed. There are of course contradictions to these standards, such as patient expected to meet needs within 14 days, risk exceeds benefit or prognosis does not warrant aggressive nutrition support.10 Parenteral nutrition (PN) is the last resort for access in nutritional intervention and needs. Transferring the patient from parenteral nutrition to enteral nutrition whenever possible is preferred to maintain the integrity of the bowel function and prevent atrophy of the mucosal lining. Although ERAS does not directly state what to do in these conditions, ASPEN does have their guidelines to prevent deterioration in surgical patients regardless of the technique utilized.
Conclusion
Enhanced Recovery After Surgery has many benefits if implemented well for hospital surgical programs. These are but not limited to: decreasing length of stay, increasing the comfort of the patient and decreasing costs for the facility through strategic methods of patient care.2 This is done by integration of medical teams through a multi-disciplinary approach to change their practices and audit as needed for identifying problems and outcomes.2 Although updating from traditional methods may be hard to adhere by all staff, the benefits outweigh the costs of ERAS and further investigations should be encouraged for surgical patients. There is lots of research for elective and planned surgery, however, no publications have been released on ERAS methods for trauma and immediate surgery-related cases. This is because ERAS is relatively new to the surgical field as technology advances.
Nutrition should be considered as a major component in recovery and in teaching practices due to its ability to prevent post-operative mortality and optimize success for the patient.7 This is done by nutritional interventions which are mandatory for decreasing risk of post-operative infections, length of stay, and mortality in patient populations across the board. This is especially necessary with those who arrive at the hospital at a malnourished state, and assessments should be conducted to justify any nutritional support prior to surgical procedures.17 Nutritional interventions are the usage of carbohydrate dense drinks before surgery as well as early oral take for the patient post-operatively. 15
Through analysis of endocrine, immunological, and metabolic changes from surgical stress, key identifiers such as early nutrition intervention that influence outcomes can be utilized.19 Fluid restitution post operatively as well as encouragement of oral nutrition intake as soon as possible directly alter the prognosis of patient wellbeing and optimize health through maintenance of gastrointestinal integrity. 14 Those who undergo surgery in a state of malnourishment generally see larger complications and a higher risk of mortality, therefore assessments by the surgical staff, dietitian, and nursing team are essential in providing best care practices. However, if needed, nutrition support should be investigated as an alternative option for oral intake due to another complication or to meet necessary needs of the ERAS surgical patient if the patient is at risk for deterioration. ERAS has a positive impact on surgical methods and will continue to be a component in educational models across the board supported by the ERAS society and congressional board.20.
References
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3.Ljungqvist O. Jonathan E. Rhoads Lecture 2011. JPEN J of Parente Enteral Nutr. 2012;36(4):389-398.
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6. Nutrition and the surgical patient. Nutrition and the surgical patient – SurgWiki. http://www.surgwiki.com/wiki/Nutrition_and_the_surgical_patient. Published May 1, 2012. Accessed March 27, 2018.
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8. Weimann A, Braga M, Carli F, et al. ESPEN guideline: Clinical nutrition in surgery. J Clin Nutri. 2017;36(3):623-650.
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10. Mcclave, Stephen A., et al. ‘Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient.’ JPEN. J Parente and Enteral Nutri, vol. 40, no. 2, 2016, pp. 159’211.
11. Marian M. Surgery_trauma.ppt. 2018.
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13. Sugisawa N, Tokunaga M, Makuuchi R, et al. A phase II study of an enhanced recovery after surgery protocol in gastric cancer surgery. J Gastric Cancer. 2015;19(3):961-967.
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15. Steenhagen, Elles. ‘Enhanced Recovery After Surgery: It’s Time to Change Practice!’ Nut Clin Pract, 2015, vol. 31, no. 1,, pp. 18’29..
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17. Moore, Scott M., and Clay Cothren Burlew. ‘Nutrition Support in the Open Abdomen.’ Nut Clin Practi, vol. 31, no. 1, 2015, pp. 9’13.,
18. Fukushima R, Kaibori M. Enhanced Recovery after Surgery. Singapore: Springer Singapore; 2018.
19. Zhang J-M, An J. Cytokines, Inflammation, and Pain. Int Anesthesiol Clin. 2007;45(2):27-37. doi:10.1097/aia.0b013e318034194e.
20. Previous ERAS Congress. Eras. http://erassociety.org/about/history/eras-world-congress/. Accessed March 27, 2018. Figure 1
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