Anesthetic Management for Enhanced Recovery After Major Surgery (ERAS)

Function

ERAS pathways are evidence-based approaches critical to providing safe care and improving patient mortality, morbidity, and satisfaction in the perioperative period. These interventions optimize care in the perioperative period. Components of ERAS pathways can be subdivided into the preoperative, intraoperative, and postoperative periods. The preoperative period allows medical personnel to evaluate the patient to determine whether or not the patient is stable enough for surgery, the type of surgery, the type of anesthetic, and the anticipation of postoperative location.[4] This period consists of interventions such as providing preoperative education, following preoperative fasting guidelines, eliminating bowel preps, and providing routine antiemetic, venous thromboembolism, and antimicrobial prophylaxis. Preoperative education to patients and patient's families to set realistic expectations regarding their surgical and anesthetic experiences and postoperative pain relief. In addition, it also includes encouraging the patient to accelerate their progress postoperatively, including mobilization, ie, early ambulation to prevent deep venous thrombosis, using incentive spirometry to improve postoperative atelectasis, thereby preventing pneumonia, and encouraging early oral intake.[5]

A big part of preoperative management also includes optimizing the patient before surgery, including managing their comorbidities, ie, diabetes mellitus, hypertension, CAD, anemia, COPD, etc. Patients are also educated regarding their smoking use and alcohol consumption. ERAS protocols also focus on various strategies to optimize the patient, including providing education about sleep hygiene, relaxation strategies to reduce anxiety and dietary modifications.[6] While patients are required to be nil per os typically 8 hours before surgery, it has been suggested that maintaining hydration during the fasting period and minimizing the duration of the fasting period by continuing clear liquid until 2 hours before the procedure. Allowing carbohydrate loading via intake of a clear carbohydrate drink two hours before surgery helps the patient to remain close to their normal physiologic state. Carbohydrate loading has been shown to expedite the return of bowel function, reduce insulin resistance, and maintain lean body mass and muscle strength, in addition to decreasing patient discomfort and anxiety.[7] The principle behind carbohydrate loading resides in the fact that this intervention prevents the body from entering a catabolic state which results from preoperative fasting.

Intraoperative ERAS protocols include providing multimodal non-opioid analgesics and antiemetics, incorporating regional anesthesia, antibiotic prophylaxis, normothermia, lung-protective mechanical ventilation, euvolemia, and minimizing drains and tubes such as early removal of foley catheters, surgical drains, and nasogastric tubes. Integration of prevention of surgical site infections and thromboembolic prophylaxis measures have already been instituted at many hospitals across the country and have been incorporated into ERAS protocols. Preventative measures for surgical site infections include the use of chlorhexidine alcohol skin wipes, glove/instrument change with antibiotic irrigation before closure, intravenous antibiotics before incision, and providing antibiotics with bowel prep.[8]

Anesthetic management in the perioperative period plays a critical role in the ERAS system implementation. By facilitating the implementation of these protocols through communication and collaboration between personnel in the different perioperative periods, the anesthesiology team significantly improves patient satisfaction with their smooth transition from the preoperative to the intraoperative to the postoperative period. In addition, the anesthesia team can profoundly impact patients' recovery postoperatively by choosing shorter-acting premedications and using reduced levels of volatile anesthetics, or using total intravenous anesthesia, minimizing the use of opioids and adequate pain management, maintaining euvolemia, normothermia, and administering prophylactic antiemetics.

Postoperative nausea and vomiting (PONV) is one of the most significant incapacitating factors concerning anesthesia. PONV is a common reason for a prolonged length of hospital stay as well as patient dissatisfaction. The administration of prophylactic antibiotics during preoperative and intraoperative periods was found to be very effective against PONV. Certain risk factors include younger age, female gender, prior history of postoperative nausea and vomiting, non-smokers, and history of motion sickness.[9] The anesthesia team can identify the factors and use measures to reduce nausea and vomiting. The use of a multimodal approach, prophylactic use of combination antiemetic therapy, including preoperative use of dimenhydrinate and intraoperative use of dexamethasone, ondansetron, and propofol can be very effective. A transdermal scopolamine patch is recommended for patients with a high risk for PONV.  Intraoperative measures include minimizing volatile anesthetics, avoiding nitrous oxide, minimizing opioids, and maintaining euvolemia, which was found to be effective against PONV.

Adequate analgesia is another factor that can be debilitating to the postoperative patient. Multimodal analgesia is encouraged in the ERAS protocols, use of drugs such as acetaminophen, nonsteroidal anti-inflammatory drugs, and gabapentinoids when indicated, during the preoperative period for pain prophylaxis. Limiting the amount of opioid use to prevent postoperative ileus. In addition, surgical field block and regional anesthesia can be used as adjuncts for pain relief in the intraoperative and postoperative periods. Regional anesthesia methods include continuous or single-shot peripheral nerve blocks or neuraxial anesthesia such as epidural catheter placement, intraoperative and postoperative use of medications like magnesium, dexmedetomidine,  ketamine, and lidocaine infusion when indicated. Multiple factors are considered when developing a multimodal pain management plan, including patients' medical history and comorbidities, type of surgery and anticipated postoperative pain, emotional and psychological status, baseline pain tolerance, and the risk-benefit of the various medications.[10]

Temperature monitoring and maintaining normothermia during the intraoperative and postoperative periods is another important element of the ERAS protocol. Hypothermia is associated with adverse effects such as delayed wound healing, increased wound infection, increased blood loss, cortisol levels, and significantly increased oxygen consumption which could precipitate cardiac events.[11] Temperature can be managed by using fluid warmers to warm intravenous fluids, using forced warmed air devices and warmed humidified gases, and carefully monitoring temperature intraoperatively and postoperatively.

Monitoring and maintenance of intravascular volume status are crucial. The main goal of fluid management in ERAS protocols is to maintain euvolemia and avoid excess water and salt. Maintaining a euvolemic state allows for an accelerated return to bowel function, reduces urinary tract and surgical site infections, and decreases renal and pulmonary complications.[12] Lastly, removing unnecessary tubes, catheters, and drains allows for an earlier physiologic return and decreases gastrointestinal, pulmonary, and infectious complications.

Glycemic control is a vital component of the ERAS pathway, the prevalence of diabetes in surgical patients is 10% to 40%.[13] Perioperative hyperglycemia is linked with an increased risk of infection and cardiovascular morbidity and mortality postoperatively in diabetic and non-diabetic patients.[14][15] Perioperative hyperglycemia develops due to the hypermetabolic stress response responsible for increased glucose production and insulin resistance.[16] Perioperative glycemic control begins in the preoperative period, which includes advising diabetic patients regarding antidiabetic medications and insulin administration the night before and on the day of the procedure. Perioperative blood glucose levels are monitored and maintained between 80 and 180 mg/dL in both diabetic and non-diabetic patients throughout the perioperative period. More aggressive control is avoided as this incurs the risk of hypoglycemia and associated perioperative complications.[17]

Postoperative interventions in the postoperative protocol include early mobilization/ambulation, early oral intake, and the use of multimodal non-opioid analgesics. In recent studies, it has been shown that the postoperative period plays the most critical role in expediting the recovery of the post-surgical patient. Early oral intake improves wound healing, decreases infection, improves insulin resistance, and allows for faster return of muscle function.[2] Early ambulation (mobilization) decreases the incidence of ileus, reduces pulmonary and thromboembolic complications, allows for faster organ recovery, and improves muscle strength. These interventions and a close abidance of ERAS protocols allow for a faster return to the physiologic baseline.

Issues of Concern

An issue of concern that is to be noted about ERAS protocols is the increasing complexity. For example, for colorectal surgery, 16 elements comprise the ERAS guidelines. Having this many components in these pathways leads to difficulty in implementing these protocols, and there is room for error as components may be missed or forgotten. In addition, it is also difficult to distinguish which component of the ERAS protocol is producing a positive impact on the enhanced recovery of patients. For example, while having laparoscopic surgery may lead to quicker recovery times than open surgery, choosing minimally invasive surgery in addition to using lower amounts of volatile agents, thereby reducing postoperative nausea and vomiting synergistically, allows for a quicker recovery from surgery. This can be further proven by studies that have demonstrated that complying with the ERAS protocol has been shown to have better postoperative outcomes indicating that components of ERAS pathways are most successful when implemented together.[18]

Clinical Significance

ERAS pathways have immense clinical significance, both to the patient and the healthcare system as a whole. Meta-analysis has shown that ERAS protocols have decreased the average hospital length of stay by 2.3 days.[19] ERAS protocols have also demonstrated effectiveness in reducing stress induced by surgery and preserving patients' physiologic baseline throughout the perioperative process. Compared to patients who have undergone traditional care, patients who have gone through ERAS protocols had lower levels of inflammatory mediators such as interleukin-6 and C-reactive protein. This has significant clinical implications in that patients are more satisfied with their level of care, are spending fewer days postoperatively in the hospital, and there is a reduced number of postoperative complications across the many surgical subspecialties. The ERAS system has revolutionized the perioperative period by allowing for an earlier return of organ function, reducing the duration of postoperative ileus, and preventing pulmonary complications, thereby improving patient quality of life in the immediate period.[2] According to a study, patients who had undergone the ERAS pathway reported increased satisfaction, quicker resumption of normal activities after surgery, and reduced sick days taken.

Other Issues

While the ERAS pathway seems ideal to implement in the perioperative system, its successful implementation is crucial. The ERAS system was first implemented two decades ago and therefore is not universally used across hospitals. These pathways require uprooting the traditional perioperative pathway and replacing it with evidence-based protocols. Other challenges include having adequate personnel to implement the system, proper communication, and the required collaboration between the different areas in the perioperative period.

Enhancing Healthcare Team Outcomes

Successful implementation of ERAS protocols requires collaboration, communication, and teamwork between medical personnel in the three different perioperative periods, including the patient, who plays a vital role in understanding and thereby facilitating the pathway. Adherence to the ERAS protocols allows for a seamless transition of the preoperative patient to when the patient is ready for discharge from surgery, whether on the same day or a few days later. The anesthesiologist plays an essential role in facilitating the implementation of the protocols because they are key decision-makers in the factors that can be debilitating to the progression of recovery from surgery.

Nursing, Allied Health, and Interprofessional Team Interventions

Perioperative nurses and medical personnel play a vital role in the implementation of the ERAS protocols. Successful implementation of the protocols requires a good understanding of the ERAS pathways and knowing the implications.[20] Due to the multifaceted nature of the pathways, there needs to be communication and collaboration between members of the preoperative team with the intraoperative team and the intraoperative team with the postoperative team. This can be facilitated through hand-offs when information is communicated regarding the patient, their history, the surgery they are having, and the interventions that have been done in each period.

Nursing, Allied Health, and Interprofessional Team Monitoring

The ERAS system, due to its relatively new venture into the healthcare system, requires systemic auditing to improve outcomes continually. Auditing will identify pitfalls in communication, and issues with collaboration between teams, and improve compliance and adherence to ERAS protocols. However, due to the multidisciplinary approach of this pathway and the many medical personnel involved, it can serve as an impediment to implementation. The team members of the ERAS system include physicians, pre-admission testing staff, nurses, dieticians, physiotherapists, occupational therapists, and social workers. This entire cohort needs to be familiar with ERAS principles and must be willing to implement them. This requires changing their mindset from the traditional view of postoperative care to one that is evidence-based and collaborative.