*2.3.2 Intraoperative fluid and electrolyte therapy*

Fluid management is crucial to maintaining intravascular volume, cardiac output, and tissue perfusion. The main aim is to reduce the hydrostatic pressure in pulmonary capillaries. Before ERAS, there was a restriction in fluid management where the rate for maintenance fluid was 1-2 ml/kg/hr., with perioperative fluid being <1500 ml or 20 ml/kg/24 hrs. In ERAS protocol, it is always a goal-directed therapy (GTD) for fluids, which reduces postoperative morbidity and decreases the length of stay in the hospital. Now balanced crystalloids at a rate of 1-4 ml/kg/hour are the fluid of choice over 0.9% normal saline (NS) but should be discontinued postoperatively. Again, liberal fluid management can also harm the patient postoperatively by intestinal edema and delayed return of bowel movements [36].

#### *2.3.3 Preventing intraoperative hypothermia*

Normothermia should be maintained throughout the surgery. This can be done by warming and humidifying anesthetic gases and warming intravenous and irrigation fluids.

#### *2.3.4 Drainage of the peritoneal cavity and pelvis*

Many published studies do not support the use of the intraperitoneal drain. It has no effect on clinical outcomes and should not be used routinely. The grade of recommendation is strong.

#### **2.4 Postoperative items**

#### *2.4.1 Nasogastric intubation*

Its aim was to reduce postoperative gastric distension and vomiting. A Cochrane meta-analysis does not support it. It should be used sparingly. If inserted intraoperatively, it should be removed before anesthesia reversal [37, 38].

#### *2.4.2 Anesthesia and pain relief*

In line with ERAS protocol, pain relief is a multimodal approach that uses regional anesthesia. It avoids the use of opioids. Relief from postoperative pain decreases immediate risks of hypoxemia, hypercarbia, increased myocardial work, arrhythmias, and ischemia. Therefore, enhanced recovery pathways must combine multimodal enteral and parenteral analgesia with regional analgesia or local anesthetic techniques. It should also be kept in mind that the impact of an anesthetic agent on organ function should be minimum. Depth of anesthesia should be appropriate to avoid an overdose. It is better to use short-acting agents than total intravenous anesthesia.

Postoperative pain is one of the most important reasons for immobilization, delayed oral intake, and prolonged hospital stay. Therefore, to avoid these, the protective role of epidural analgesia has become an essential element in ERAS protocol. It mainly reduces stress hormones secretion and insulin resistance. Usually, an epidural catheter is inserted just before the induction or during surgery; either a continuous infusion (4–10 ml/hr) or intermittent top-up of a local anesthetic agent (bupivacaine 0.1%) can be given along with a low dose of opioid (to avoid opioid related systemic side effects) via the epidural catheter. Usually, the catheter is kept for two days. No other mode of analgesia is required during this duration, and using another analgesic during those two days is not recommended.

Apart from this, there are other modalities for pain relief, such as paravertebral block, serratus anterior plane block, rectus abdominis block, and transversus abdominis block. However, all these are less proven for pain relief than epidural analgesia [39].

The surgical aspect of ERAS in pain relief is equally important for a better postoperative recovery. Prolonged and open surgeries hamper postoperative mobilization, pain control, and oral intake and even increase the length of hospital stay. Thus, minimally invasive approaches are recommended for their effectiveness in reducing postoperative complications, including hospital stays. It is seen that less tissue handling during surgery improves postoperative recovery [40].

Apart from epidural analgesia, enteral analgesics are also recommended to reduce pain, postoperative nausea, vomiting, and the start of oral feeds. Enteral analgesics that can be used are acetaminophen (most commonly) and NSAIDs (avoided in renal failure, Diabetic patients, and old age patients) [35]. For the facilitation of pain management protocol in ERAS, a PROSPECT (PROcedure-SPEcific Postoperative Pain Management) working group was constituted. This collaboration provides evidence-based, procedure-specific pain management recommendations (www. postoppain.org) [41, 42]. This approach improved compliance with pain management recommendations in an ERAS bundle.

### *2.4.3 Thromboprophylaxis*

Mechanical thromboprophylaxis and compression stockings or intermittent pneumatic compression should be advised to all high-risk surgical patients undergoing major surgery (malignancy, hypercoagulable state, steroid use, advanced age, and obesity) [43–45]. Mechanical thromboprophylaxis should be continued until discharge.

#### *2.4.4 Postoperative fluid and electrolyte therapy*

ERAS states that it should be neither restrictive nor liberal in giving fluid therapy both intraoperatively and postoperatively. Maintenance fluid should always be given according to the body weight, with supplementing electrolytes over 24 hrs. Too much fluid might lead to intestinal edema, resulting in decreased bowel movement and delayed oral intake. Thus increasing postoperative complications and increased length of hospital stay [46]. The patient should be encouraged to oral liquids when they are awake.

#### *2.4.5 Urinary drainage*

Urinary catheterization can cause urinary tract infection (UTI), which is directly related to the duration of catheterization. So, the duration of catheterization should be individualized based on the risk factor of urinary retention (male gender, epidural anesthesia, pelvic surgery). In low-risk cases catheter should be removed on the first day of surgery, whereas in high risk, it should be kept for up to 3 days.

#### *2.4.6 Prevention of postoperative ileus*

It is a significant cause of postoperative discomfort and length of hospital stay. The ERAS items, like limiting the use of opioids and encouraging the use of multimodal analgesia, minimally invasive surgery, avoiding routine nasogastric tube insertion, and maintaining goal-directed fluid therapy, can limit the postoperative ileus [6].

#### *2.4.7 Postoperative glycaemic control*

The physiological response to surgical injury is insulin resistance which can persist for several weeks after elective surgery [47]. Hyperglycaemia is a risk factor for surgery. This can be prevented in the ERAS pathway by giving preoperative oral carbohydrate loading, laparoscopic surgery, and epidural analgesia.

#### *2.4.8 Postoperative nutritional care*

Early oral feeds are another essential element in ERAS protocol that reduces postoperative complications (postoperative ileus) and length of hospital stay. It also helps reduce any in-hospital infection. Studies have shown that there is no advantage in keeping nil by mouth for patients undergoing major surgeries, which instead hampers fast recovery. However, patients with early oral feeds are also at risk of nausea and vomiting. To prevent this, a targeted strategy should be planned. Use of anti-emetic drugs to be adopted and emetogenic drugs (opioids) should be avoided [48].

#### *2.4.9 Early mobilization*

Postoperatively patient has to mobilize as early as possible to avoid pulmonary complications, reduced muscle strength, risk of thromboembolism, insulin resistance, delayed bowel movements, and prolonged hospital stay [19].

#### **3. ERAS in emergency surgery**

This has been proven that ERAS has a defined role in elective surgery [49]. However, the effectiveness of these protocols in emergency abdominal surgeries has been nominally studied. The protocols that have been clearly defined for elective surgeries were not fully applicable in emergency surgeries, and there would be difficulty in compliance with the set protocols. However, some elements of the ERAS bundle can be included in emergency surgeries. The recent evidence showed a reduced length of stay and postoperative complications on implementing even tailored ERAS protocols in emergency abdominal surgeries [50]. Tailoring of the ERAS protocol can be done to include only critical items which can facilitate program implementation in emergency surgery. This has shown better outcomes and a reduction in the cost of care in emergency surgery. Recent studies have shown that 70% of the ERAS bundle is required to get the beneficial effects [51–53].

#### **4. Impact of ERAS**

ERAS is described as an intention to treat analysis. The compliance rate of ERAS may vary which depends on different surgical approaches and diseases. Minimally invasive surgery with minimal tubes and drains is considered a standard of care.

Postoperative pain management is one of the major elements in the ERAS bundle. It facilitates early ambulation and rehabilitation, ultimately reducing length of hospital stay [41, 54]. Inadequate postoperative pain relief may lead to chronic pain development and ultimately increase the readmission rate [54, 55]. The ERAS protocols reduce the length of hospital stay (3–5 days) as well as a significant reduction in overall morbidity (Relative Risk of 0.6,95% CI 0.46–0.76), without any higher readmission rate [56]. In addition to reduced length of hospital stay and morbidity, there is enhanced recovery, including reduced duration of ileus, preservation of lean body mass, and a more active lifestyle [57].

#### **5. Conclusion**

Enhanced recovery after surgery (ERAS) are specially designed multimodal perioperative care pathways for a speedy recovery. ERAS pathways are the standard of care, but their widespread dissemination is still challenging. Some elements of the ERAS bundle, like minimally invasive surgery and limiting tubes and drains, are standard of care and are being followed in most of the centers. However, the other elements of the ERAS bundle, like preoperative carbohydrate loading and postoperative early ambulation, still need to be implemented in routine clinical practice. There is considerable difficulty in adherence to the complete ERAS bundle. Postoperative pain management is one of the major elements in the ERAS bundle. Multimodal

*Enhanced Recovery after Surgery DOI: http://dx.doi.org/10.5772/intechopen.110343*

analgesia is the optimal modality for pain control. It facilitates early ambulation and rehabilitation. It also decreases the duration of ileus and morbidity, ultimately reducing the hospital stay and readmission rate. Current evidence recommends ERAS protocol as a whole and not as a few elements within it. However, each item within the protocol constantly changes over time, depending upon the evidence.
