Enhanced recovery after surgery in bariatric and metabolic surgery

Introduction

Enhanced recovery after surgery (ERAS) protocol is an extensive, evidence based, multimodal and multidisciplinary protocol for surgery. ERAS aims to enhance pre-intra and postoperative physiology and optimization of recovery after surgery. The concept of ERAS and to provide shortened length of stay (LOS) with more physiological recovery initiated with Khelet in the late 1990s (1). Khelet et al. designed a multimodal programme in colorectal surgery and have been shown reduced complications and shortened LOS. The benefits of ERAS programme has been shown and documented several meta-analyses comprising other surgical disciplines (2-4). Subsequently, this idea against conservative approach and the surgical dogmas evolved into a multidisciplinary instrument integrating several perioperative elements, and with the use of minimally invasive surgery it has been adapted bariatric surgery. Today, number of official ERAS Society Guidelines for Perioperative Care in Bariatric Surgery is accepted worldwide and now it is recognized as enhanced recovery after bariatric surgery (ERABS). Unlike the “fast track surgery”, ERAS actually encompasses whole perioperative phases ad provide not only accelerated discharge but focused primarily on the quality of recovery. Scientific evidence suggests that implementation of ERAS programme boosts patient satisfaction, reduced morbidity, decrease recovery times and hospital costs in dedicated centres (5-7).

This article aims to increase understanding of ERABS based on the best evidence available. ERAS Society guidelines on bariatric surgery and other specialties are accessible on www.erassociety.org.

Evidence based recommendations from Bariatric ERAS guideline (8)

Preoperative interventions (Table 1)

Preoperative information, education and counselling

Althought, preoperative information has been found to decrease anxiety and increase compliance to postoperative planned course, recovery, LOS and outcomes there is little evidence (9,10). A systematic review identified the impact of preoperative information on surgical outcomes but confirmed results were in minority (11).

Prehabilitation and exercise

Despite all of the logical basis of prehabilitation and exercise before surgery, the evidence is sparse and the generalisation of current studies to bariatric and metabolic surgery patients is questionable. In an analysis of recent systematic review, eight RCTs assessing the impact of preoperative exercise on cardiovascular and respiratory function and recovery after surgery was concluded that the evidence which shows physiological improvement with prehabilitation was limited (12).

Smoking and alcohol cessation

Tobacco smoking increases morbidity and mortality after surgery with decreased tissue oxygenation, pulmonary complication and thromboembolism (13). Marked reduction in postoperative complications with smoking cessation has been shown, also at least 4 weeks of smoking cessation was found to be more effective (13,14).

Daily intake of 36 g ethanol or more has been found to increase postoperative complications (15). Retrospectively studied wide population of patients who undergoing elective (including bariatric) surgery shown that, consumption of >24 gr ethanol per day within 2 weeks of surgery was an independent factor for development of pneumonia, sepsis, wound infection and hospital stay (15). Alcohol cessation of at least 4 weeks before surgery is recommended current ERAS guidelines for colorectal surgery.

Preoperative weight loss

Preoperative weight loss is found to reduce liver volume by 16–20%, surgeon’s perceived complexity of the procedure and postoperative complications (16,17). The positive effect of preoperative weight loss on postoperative complications has not been confirmed in diabetic patients. On the other hand, it was shown that, weight loss prior to surgery is the only positively associated factor for postoperative weight loss (16,18).

Glucocorticoids

Anti-inflammatory effects of glucocorticoids have long been used in a variety of elective surgery to decrease surgical stress, postoperative nausea and vomiting (PONV) (19,20). Althought it was not found to be associated with overall complication rate and the safety of anastomosis in colorectal surgery, they were shown to reduce complication rates and LOS in a recent meta-analysis (21). To achieve effect on PONV, >2.5–5 mg dexamethasone must be given 90 minutes before anaesthesia induction (22). Meta analyses show that, a single dose glucocorticoids usage has no adverse effect, but due to the hyperglycaemia effect of glucocorticoids and associated increase on postoperative infective complications, blood glucose should be monitored preoperatively (21,23). In bariatric surgery patients, one retrospective study has shown that, to achieve a successful discharge within 24 hours, a steroid bolus was useful (24).

Preoperative fasting

Opposite to the surgical dogmas, in a recent study on bariatric patients who included a program which was consist of drinking 300 mL of clear fluid 2 hours before anaesthesia induction, no differences was found in residual gastric fluid volume (RGFV) and gastric pH compared with nil-per-os (25-27). Similar findings were found in diabetic bariatric patients (with/without autonomic neuropathy) (28). Now, clear fluids and solids intake 2 and 6 hours before the surgery is recommended in anaesthesia guidelines in healthy and obese patients (29,30).

Carbohydrate loading

Preoperative carbohydrate loading with iso-osmolar beverages ingested 2–3 hours before anaesthesia induction, decreased postoperative insulin resistance, regulated postoperative nitrogen and protein balance and LOS (31-33). In patients with type II diabetes (mean BMI 28.6 kg/m²), gastric emptying times with preoperative carbohydrate loading were similar like healthy subjects (34). In bariatric patients preoperative carbohydrate loading has not showed an association with an increase in aspiration-related outcomes, and in a RCT (laparoscopic sleeve gastrectomy) no differences was found between the groups (35,36).

Intraoperative interventions (Table 2)

Perioperative fluid management

Sharp and correct assessment of volume status and therefore perioperative fluid management in morbidly obese patients are challenging. Because, they have physiological differences, comorbidities, poly-pharmacy, preoperative diets-driven deficits (37). Notedly, while obese patients have increased total blood volume, volume/weight rate is reduced when compared with non-obese patients (50 mL/kg compared with 75 mL/kg) (38). Despite decreased rate of rhabdomyolysis (RML) with laparoscopy (2%) than laparotomy (5–77%), predisposing factors like >4 hours operation time and intraoperative hypotension must be avoided (39,40).

Althougt, in bariatric patients, “liberal” fluid regimens (40 mL/kg, found to be associated with reduced RML, PONV, postoperative acute renal failure and LOS) is supported in non-randomised studies, more conservative approach (15 mL/kg) reported no differences in terms of postoperative RML (41-44).

PONV

Recent guidelines recommend a multimodal approach include Propofol for anaesthesia induction and maintenance, minimalisation of volatile anaesthetics, avoidance of intra-postoperative opioids and avoidance of fluid overload (45). In a randomised trial assessing laparoscopic sleeve gastrectomy patients, a triple combination of haloperidol, dexamethazone and ondansetron found to demonstrate better than a single or double combination of them (46).

Anaesthetic maintenance

In other specialties, usage of short-acting agents and opioid avoidance within a ERAS programme appears to decrease cost, complications and LOS. In bariatric surgery, there are no verified evidence and recommendations about anaesthetic regimen (47).

Airway management

Correct sizing endotracheal intubation is especially important in obese patients.

Ventilation strategies

In a systematic review on ventilation strategies in obese patients has not been demonstrate any superiority on ventilation modes, volume control or pressure control (48). On the other hand, lung protective ventilation (LPV) strategies were found to be associated with important reduction in complication rates (49).

Althougt, the “beach chair” and “leg flexion” positions have been shown to be better from straight, supine position regardless of Trendelenburg angle in the absence of the intraoperative pneumoperitoneum they are not confirmed in laparoscopic surgery of obese patients (50).

Neuromuscular blockade

Deep block; may improve surgical maneuverability with lesser pressure insufflation intraoperatively (51). But, this effect on bariatric procedures have yet to be reported.

Residual blockade; remaining neuromuscular blockade depth in the recovery period, which called residual depth, seems obese population have increased relevance may have deleterious effects on this population. Returning high level of neuromuscular function is related with patient perceived satisfaction with increased recovery quality (52).

Laparoscopy

With laparoscopy, significantly shorter hospital stay, reduced rate of incisional hernia and decreased intraoperative blood loss, reduced postoperative pain and easier recovery were reported in RCTs (53,54). But, in terms of weight loss, there are no scientific data in comparison of open and laparoscopic surgery. On the other hand, robotic surgery in bariatric patients have similar overall major and minor complications but costs for robotic surgery were higher (55).

Nasogastric tube

In a wide retrospective cohort study, the assessment of the use of postoperative nasogastric tube has not been showed any difference between with or without the tube usage in 1067 gastric bypass patients, in terms of complication rates (56). In the gastric cancer patients who underwent gastrectomy, without nasogastric/nasojejunal tube while the number of respiratory complications and anastomotic leakage were similar, time to oral diet was significantly shorter (57). And when, there are need to apply nasogastric tubes during surgery, it should be removed before the end of the operation.

Abdominal drainage

detecting postoperative leakage with abdominal drainage is controversial, the sensitivity rate is varied between 0 and 94%, and the efficacy rate of non-operative treatment of leakage in Roux-n-y gastric bypass patients with only drainage is between 12.5% and 100% (58). On the other hand, non-operative leakage treatment with abdominal drainage was reported in one out of three patients in one study (59). And, the efficacy of prophylactic drainage use in bariatric and metabolic surgery has not been evaluated in any RCTs. In a recent study, similar leakage and reoperation rates showed between routine drain and without, retrospectively (59). Althought, the evidence is limited in obesity surgery, routine use of abdominal drains adds any benefits as known in other types of gastrointestinal surgery (60).

Postoperative interventions (Table 3)

Postoperative analgesia

Obesity, itself induces restrictive syndrome and this patient population prone to development of atelectasia. Sedative drugs lead the upper airway obstruction and postoperative hypoxemia (61). Thus, effective analgesia in obese population after surgery is critically important and currently it should be based on two strategies.

Multimodal systemic analgesia

Non-opioid analgesic agents like intravenous acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) must be used systemically and the dosage must be adopted to ideal weight (62,63). If opioid use is necessary, patient-controlled analgesia regimens with as possible as increased period between i.v. drug boluses should be preferred rather than continuous i.v. infusion, especially in obese patients with obstructive sleep apnoea (OSA) (64).

Nerve block and infiltration

Althought, there are no specific study on bariatric surgery, wound or periton infiltration with long-acting local anaesthetics has been used extensively with success in variety of laparoscopic procedures. Efficacy of the use of local anaesthetic aerosolisation techniques and pre-incisional infiltration has been shown and long-acting agents like ropivacaine or levobupivacaine seems to be more effective than lidocaine (short-acting agents) (65,66). Also, ultrason-guided transversus abdominus plane block was reported with effective and safe results in bariatric and metabolic surgery, but the optimal technique from RCTs are limited.

Thoracic epidural analgesia (TEA) related recovery advantage has been reported in laparotomy but the data for usage in laparoscopic surgery is limited, even the application of TEA may lead complication in obese patients (67).

Thromboprophylaxis

Obese patients prone to thromboembolic complications and morbidity and 50% mortality after bariatric surgery is related with thromboembolic events (68). Other risk factors known as; venous thromboembolism history, older age, tobacco smoking, having varicose veins, cardiorespiratory failure, OSA, thrombophilia and the usage of oestrogen oral contraception (69).

Mechanical methods such as intermittent pneumatic compression or graduated compression stockings are not found to be effective to avoid the development of mortal pulmonary embolism, it should be used. Early postoperative mobilisation and calf-length compression stocking were decreased deep venous thromboembolism in bariatric patients (70).

As obesity surgery population have moderate risk of thromboembolic events, pharmacological prophylaxis and mechanical methods should be combined. Comparison of low molecular weight heparins (LMWH) and unfractionated heparin (UFH) were showed similar efficiency or adverse events in bariatric surgery (71). A more predictable and easier dose response, better bioavailability and longer effect on plasma after subcutaneous application with once-daily dosing, reduced thrombocytopenia and osteoporosis in longer usage, LMWH has a number of advantages over UFH (72). Twice dose usage of LMWH is not supported in studies, recommended first injection should be applied 8–12 hours after surgery (73). BMI adjusted increased dose regimen (i.e., for BMI >30 kg/m² 6,000 U of enoxaparin, for BMI >40 kg/m² 8,000 U, for BMI >50 kg/m² 10,000 U) has been found to be safe without increased risk in terms of bleeding, and 3–4 weeks of treatment recommended (74,75).

Bridging LMWH; to achieve effective bridging, vitamin K antagonists agents should be stopped 5 days before surgery and resumed 12–24 h after with combination (76).

Vena cava filters use in current practice is not recommended due to many adverse events and lacking evidence for its efficacy (77).

Postoperative nutrition

All patients should undergo an appropriate nutritional evaluation before bariatric surgery, it is particularly important for malabsorptive procedures.

Early postoperative nutritional care

Before and after bariatric and metabolic surgery, nutritional counselling must be provided to patients and their family. Clear liquids could be initiated a couple of hours after surgery and protocol-derived staged progression should be adhered with the help of dietician. For optimal fibre consumption fruits and vegetables intake recommended. Especially after malabsorptive procedures, protein malnutrition causes 1% hospitalisation and results with morbidity (78). Average protein intake should be 60–120 g daily, and should be avoided from concentrated sweets for calori reduction and minimise symptoms of dumping after gastric bypass surgery. Minimal recommended nutritional supplementation should include 1–2 servings of multi vitamin-mineral supplements containing iron, calcium (1,200–1,500 mg/d) and vitamin B12 (79). To maintain adequate hydration fluids should be consumed in sufficient amount (more than 1.5 L per day) with slowly.

Management of diabetes mellitus and lipids

To achieve goals on postoperative glycaemic control fasting blood glucose and postprandial glucose should remain ≤110 mg/dL and ≤180 mg/dL, and the team (physician and ward nurses) should be trained for glycaemic targets (80). Scheduled insulin therapy should be use in obese patients with type I diabetes, in type II diabetes patients insulin requirement may be ended early after bariatric and metabolic surgery, but the metformin continuation is usually recommended (80). Any existing anti-lipid therapy for triglyceride and LDL-cholesterol should be continued until the goals of desired levels are reached (81).

Postoperative oxygenation

Obese patients without obstructive sleep apnoea (OSA)

Compared with normal weight patients, obese patients are prone to aspiration and atelectasis; thus, irrespective from the presence of OSA all obese patients should be accepted as high risk for respiratory complications (82,83). To prevent postoperative respiratory complications preoperative incentive spirometry assessed but showed no benefit, so routine use is not recommended (84). Postoperative tissue oxygenation has been found to be lower in obese patients, despite normal oxygen saturation on pulse oximetry (85). On the other hand, tissue oxygenation and respiratory function have been shown to return to normal within the first 24 h after surgery. But there is not enough data to recommend a optimum duration of oxygen support, so it should be individualised according to patients pulmonary compliance. To prevent pulmonary atelectasis, semisitting or head-elevated postoperative positioning or prone position (if feasible) recommended (82). If there are any sign of insufficient oxygenation such as decreased arterial saturation, tachypnoea, unexpected tachycardia or hypercarbia, positive pressure ventilation should be used.

Obese patients with OSA

For preoperative screening of OSA, STOP-BANG questionnaire should be used in preoperative assessment, and determined patients with moderate to high risk, should be evaluated for positive airway pressure support postoperatively, and close monitorisation of pulmonary function must be done (86). In patients with OSA, oxygen therapy should be used carefully, because while it improves oxygen saturation it can lead to increase the duration of apnoea-hypopnea events. American Academy of Sleep Medicine recommends the avoidance of opioid based patient-controlled analgesia in this group of patients (87).

Non-invasive positive pressure ventilation (NIPP)

Continuous positive airway pressure (CPAP), non-invasive ventilation and bi-level positive airway pressure (BiPAP) are called as NIPP support.

Generally oxygen therapy alone is not sufficient for patients with OSA (88). Recent meta-analyses showed that higher FiO₂s levels might increase the risk of apnoea/hypopnea events in bariatric patients postoperatively (89). Therefore, when a patient with OSA have signs of respiratory deterioration CPAP should be used in preference to oxygen therapy alone.

Prophylactic use of CPAP has been showed no clear benefit in oxygenation (90), but in BMI >60 kg/m² patients, with need of reoperation for complications it may be considered (91).

Postoperative CPAP/NIV requirement of obese patients can be divided into following subgroups

Obese patients without diagnosed OSA

Routine oxygen therapy (via nasal cannula or face-mask), upright postoperative positioning and early mobilisation is generally sufficient fort his group of patients.

Patients with OSA-not using preoperative CPAP therapy

In this group of patients, regional anaesthesia regimen and short-acting anaesthetic agents recommended (92). Patient related risk factors, which lead to increased need for NIPP use include OSA (moderate to severe), male gender, BMI >60 kg/m², age >50 years, pulmoner comorbidity, open surgery and the need for reoperation. In the immediate postoperative period, oxygen saturation below 90%, tachypnoea or hypercarbia indicates need for NIPP.

Obese patients with OSA on home CPAP therapy

Patients using CPAP on home, must continue preoperative CPAP treatment postoperatively, because it decreases complications (93).

Patients with obesity hypoventilation syndrome (OHS) (“Pickwickian syndrome”)

Baseline awake decreased oxygenation and hypercarbia with raised serum bicarbonate (27 mmol/L) are defined as OHS in severely obese patients. OHS patients are prone to postoperative pulmonary complication, irrespective of the route of administration (intravenous/central neuraxial) they are highly sensitive to opioid agents and the use of them might lead sustained and life threatening pulmonary depression in the postoperative period (94). Therefore, opioid-free anaesthesia regimen with a preference of local anaesthetics using regional anaesthesia and prophylactic nasal BiPAP/NIV for postoperative 24–48 h are recommended (95).

The clinical results of ERAS in bariatric and metabolic surgery patients

Mostly performed bariatric and metabolic operations are all studied with ERAS protocol, and some of them were compared. In a cohort of 1,967 patients, a significant decrease of procedural times and LOS were shown after implementation of ERAS (96). Dogan et al. showed that an ERAS programme after laparoscopic Roux-n-y gastric bypass improves patients recovery and reduce the use of resources, with no significant differences in terms of surgical outcome (97). Additionally, recovery cost advantage was found with ERAS protocol in another study (98).

Despite the reported advantage of ERAS in abdominal surgery, some surgeons are still concerned about reducing hospital stay because of the consideration about increased complication rate, readmissions of ER and repeated hospitalisation, and the unnecessary utilization of the resources. Despite, the data on successful and safe discharge within 24 hours of surgery without meaningful increase in mortality, morbidity, and readmission rates in bariatric surgery patients (99-101), it was shown that LOS of ≤1 day for LRYGB patients was associated with a significantly increased risk of early mortality and early serious complications (102). On the other hand, cost saving approach shifts daily practice from he inpatient to outpatient. Similar findings were reported in a recent matched-cohort study of ERAS in one anastomosis gastric bypass (OAGB) by Aktimur et al., they concluded that the ERAS programme on morbidly obese patients undergoing OAGB significantly reduces the LOS and the number of 30-D ER visits (103).

Conclusions

Current evidences and years spend with using ERAS elements in variety of surgical procedures shows that the use of systematic ERAS pathway according to structured ERAS guidelines on bariatric surgery may have the potential to improve outcomes after bariatric and metabolic surgery.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned by the Guest Editor (Mehmet Mahir Ozmen) for the series “Bariatric and Metabolic Surgery” published in Annals of Laparoscopic and Endoscopic Surgery. The article has undergone external peer review.

Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/ales-19-254). The series “Bariatric and Metabolic Surgery” was commissioned by the editorial office without any funding or sponsorship. The author has no other conflicts of interest to declare.

Ethical Statement: The author is accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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