Enhanced recovery after surgery (ERAS) is a multimodal, multidisciplinary evidence-based perioperative care approach developed to improve recovery of patients undergoing major surgery. Dr Henrik Kehlet, a Danish colorectal surgeon, studying perioperative practices to decrease length of stay and improve outcomes after surgery, hypothesized that multimodal interventions may lead to a major reduction in the undesirable sequelae of surgical stress injury with accelerated recovery and reduction in postoperative morbidity and overall costs.¹,² In 2001, a group of European academic surgeons, led by Ken Fearon and Olle Ljungqvist, founded an ERAS Study Group. The group aimed to develop a multimodal surgical care pathway, based on literature evidence, in order to improve quality of practice and reduce complications at their respective academic centers. The ERAS Society was officially established in 2010 in Sweden to promote and share ERAS research, improve practice protocols, expand education around perioperative care, and assist with implementation and program auditing. The Society has since hosted many symposia and facilitated the first implementation programs in Swedish medical institutions, followed by those in Switzerland, Canada, the United States, and Spain. As of 2016, implementation programs and the ERAS Interactive Audit System have further extended to France, Germany, Norway, Portugal, the Netherlands, the United Kingdom, Mexico, Brazil, Colombia, Argentina, Singapore, the Philippines, New Zealand, Israel, Uruguay, and South Africa.³

Enhanced recovery after surgery protocols involve comprehensive multimodal perioperative care pathways aimed at attenuating the surgical stress response and reducing end-organ dysfunction through integrated perioperative pathways. The various components of the ERAS protocol are grouped according to the timing of intervention into preoperative, intraoperative, and postoperative.⁴ The key elements include counseling and nutritional strategies, including fluid and carbohydrate loading and avoidance of prolonged fasting, standardized anesthetic and analgesic regimens utilizing multimodal and regional therapies, perioperative fluid balance and normothermia maintenance, early mobilization and nutrition postoperatively and appropriate thromboprophylaxis. Details of the ERAS protocols are carefully designed based upon the specific surgical procedure that is being performed and are usually derived from high-quality published literature.

Optimizing nutrition status with correction of baseline nutritional deficiencies are critical components of ERAS protocols as poor nutrition status is detrimental to postoperative
outcomes. Proper management can avoid hyperglycemia and attenuate postoperative insulin resistance, reduce protein loss, and improve muscle function as well as reduce complications such as hospital length of stay and cost.⁵ The intraoperative regimens employ short-acting anesthetic agents with epidural, regional, and nonopioid pain management techniques, where appropriate. Additional components include avoidance of fluid or salt overload, prevention of nausea and vomiting, early removal of indwelling catheters, avoidance of drain placement, appropriate use of antibiotic prophylaxis and thromboprophylaxis, and maintenance of normothermia with the use of fluid warmers and body warming devices. The goals of these approaches include optimizing analgesia and recovery to mitigate ongoing nociceptiveinduced stress responses while allowing early mobilization in the recovery unit and beyond, return of bowel function, and prevention of prolonged postoperative ileus.

Patient education plays an important role in optimizing the postsurgical outcome. Patients should be informed about the stress and deconditioning associated with surgery. ERAS protocols encourage an active role in preparation and conditioning.⁶ Sleep hygiene, exercise, and preoperative carbohydrate loading have demonstrated benefits, and if patients are educated about the benefit of these modalities, they are more likely to participate in their care and outcome of surgery. In regard to these interventions, carbohydrate loading decreases preoperative nausea, perioperative insulin resistance, and hospital length of stay.⁶ Smoking cessation for 4-6 weeks prior to surgery decreases airway reactivity and secretions. Smoking cessation also decreases complications such as wound infections leading to prolonged hospitalization or readmission.⁶ Alcohol abuse is also associated with complications and a longer length of hospital stay.⁶ Thus, alcohol cessation interventions should be utilized prior to elective surgery. Patients should also receive education in regard to postoperative rehabilitation and steps they will need to take in order to resume their presurgical activity level. If a patient’s anesthetic includes regional anesthesia, they should be educated about the benefits and potential complications associated with it. Occasionally, when a patient receives continuous regional anesthesia, they might be sent home with a peripheral nerve catheter, which can potentially result in complications such as catheter dislodgement and infection if not cared for properly. Furthermore, patients should be educated about expectations in regard to pain control associated with the nerve catheters. All of these questions and concerns can be addressed at the initial preoperative visit to adequately prepare patients to actively participate in their care.

Along with patient education, a patient’s past medical history is important. Several chronic medical conditions are associated with poor perioperative outcomes if not optimized prior to surgery. Examples include poorly controlled diabetes, hypertension, unstable angina, heart failure, chronic obstructive pulmonary disease, anemia, kidney, or liver disease. Hyperglycemia is associated with poor wound healing and perioperative insulin resistance, and hypertension can significantly increase risk for stroke. Severe chronic obstructive pulmonary disease can lead to prolonged mechanical ventilation. Kidney and liver dysfunction can negatively impact the metabolism of several medications administered in the perioperative period. Thus, a surgical candidate’s history can guide any further testing or interventions that are required for optimization. Examples of testing and interventions include a transthoracic echocardiogram,
stress test, heart catheterization, or pulmonary function tests. While these options are available prior to elective surgery, a patient may present in emergent circumstances that do not allow for optimization.

Furthermore, a patient’s past medical history can preclude them from a certain type of anesthesia. Patients with severe aortic stenosis scheduled for total knee arthroplasty tend to receive general anesthesia rather than spinal anesthesia due to risks of more profound loss of sympathetic tone and cardiac output associated with spinal anesthesia. On the contrary, patient with end-stage renal disease scheduled for arteriovenous fistula repair may benefit from regional anesthesia as it has shown to improve outcomes due to improved fistula patency and reduced failure rates.⁷ It has been hypothesized that the improved fistula patency may be due to vasodilation secondary to the sympathectomy caused by regional anesthetics.⁷ Thus, gathering patients’ past medical history in regard to the type of surgery they are having opens conversations about what may be the most beneficial anesthetic in their situation.

Mental and emotional preparation is the next step. Oftentimes, the process of undergoing surgery is anxiety-provoking. This may be more noticeable in patients with preexisting anxiety and chronic pain. Some of these patients may have had prior poor experiences with health care providers and may also have other comorbid conditions such as substance abuse. If these issues are not addressed preoperatively, it can lead to delayed discharge, poorly controlled pain, and readmissions.⁸ A tailored preoperative visit provides patients with stress coping mechanisms, education about expected pain with surgery, and postoperative pain management strategies. These strategies help set real expectations of pain associated with surgery, what measures can be taken to address it, and informs the patient that they will not be completely pain free with these interventions, but the goal is to treat the pain to a tolerable level. Patients should also be educated about adverse effects of opioids and consequences of opioid dependence and addiction. If patients have substance use disorders, they can be scheduled with an addiction medicine clinic to prescribe medications such as methadone and buprenorphine, which may reduce risk of opioid withdrawal. These medications should be continued while the patient is hospitalized to treat their baseline level of pain, and additional pain medications should be scheduled for surgical pain. Preexisting anxiety or depression increases the risk for postoperative pain.⁸ Thus, it is imperative that these conditions get screened and adequately treated prior to elective surgery. Hospital Anxiety and Depression Scale is a questionnaire that can be used during the preoperative visit to screen for psychological disorders that may benefit from nonpharmacologic therapy such as mindfulness and cognitive behavioral therapy.⁸ Overall, a thoughtful and directed preoperative visit provides patients with additional resources prior to surgery and positively impacts both postoperative recovery as well as long-term wellness.

Preoperative fasting guidelines were developed in order to reduce the risk of pulmonary aspiration, complications associated with aspiration, the severity and extent of hypoglycemia, and improve patient comfort and satisfaction. Guidelines focus on determining adequate time required for fasting and to utilize pharmacologic agents known to decrease gastric volume and acidity when indicated. Current guidelines require waiting 2 hours after ingestion of clear
liquids prior to sedation that can impair upper airway protective reflexes. Guidelines require 4 hours after breast milk ingestion, 6 hours after full liquids, nonhuman milk, infant formula and light meals, and 8 hours after heavy meals. Several studies have been performed to determine these guidelines.⁹ No increased benefit was found when fasting for 2 hours after ingesting clear liquids vs 4 hours, but study participants had increased thirst and hunger with 4 hours of fasting.⁹ Agents used to aid in decreasing gastric volume and/or pH include dopamine antagonists, histamine antagonists, proton pump inhibitors, and antacids. Current recommendations indicate that these agents should not be routinely administered but can be given if a patient has risk factors for aspiration.⁹ It is important to understand the pharmacokinetics of these agents as summarized in Table 50.1, to ensure they are administered well in advance of the scheduled procedure to have the desired effect. Pulmonary aspiration can result in aspiration pneumonia, respiratory compromise, and significant morbidity and mortality for the patient. Thus, it is very important to preoperatively evaluate the patient and adequately prepare for a successful outcome. It is important to recognize which patients have a higher likelihood of developing aspiration based on their comorbidities such as ascites, diabetes, GERD, hiatal hernia, and ileus. These patients in particular need to be educated about their risk of aspiration and steps they can take to help minimize this risk.