Enhanced recovery after bariatric surgery: an Italian consensus statement

Background Enhanced recovery after bariatric surgery (ERABS) is an approach developed to improve outcomes in obese surgical patients. Unfortunately, it is not evenly implemented in Italy. The Italian Society for the Surgery of Obesity and Metabolic Diseases and the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care joined in drafting an official statement on ERABS. Methods To assess the effectiveness and safety of ERABS and to develop evidence-based recommendations with regard to pre-, intra-, and post-operative care for obese patients undergoing ERABS, a 13-member expert task force of surgeons and anesthesiologists from Italian certified IFSO center of excellence in bariatric surgery was established and a review of English-language papers conducted. Oxford 2011 Levels of Evidence and U.S. Preventive Services Task Force Grade Definitions were used to grade the level of evidence and the strength of recommendations, respectively. The supporting evidence and recommendations were reviewed and discussed by the entire group at meetings to achieve a final consensus. Results Compared to the conventional approach, ERABS reduces the length of hospital stay and does not heighten the risk of major post-operative complications, re-operations, and hospital re-admissions, nor does it increase the overall surgical costs. A total of 25 recommendations were proposed, covering pre-operative evaluation and care (7 items), intra-operative management (1 item, 11 sub-items), and post-operative care and discharge (6 items). Conclusions ERABS is an effective and safe approach. The recommendations allow the proper management of obese patients undergoing ERABS for a better outcome.


Results
The evidence and recommendations concerning the primary safety and efficiency endpoints are summarized in Table 4. A total of 25 recommendations were proposed, covering pre-operative evaluation and care (7 items), intra-operative management (1 item, 11 sub-items), and post-operative care and discharge (6 items). The levels of evidence and recommendations for each item in the ERABS protocol are summarized in Table 4.

Effectiveness and safety of ERABS
Compared to the conventional approach, ERABS reduces the LOS [8][9][10], independently of the type of surgical procedure performed [11,12]. The more successful ERABS items the multidisciplinary team adopts, the greater the likelihood of a reduced post-operative LOS [13].

Preoperative counseling
Preoperative information and counseling are key items for managing the expectations of patients and preparing them for early discharge [16]. Counseling was one of the most frequently used items in a retrospective multicenter study [17] and one of the key items in 11 of the 13 studies considered in Table 1 Grading of level of evidence (from Oxford Centre for Evidence-Based Medicine 2011 Level of Evidence) [6] *Level may be graded down on the basis of study quality, imprecision, indirectness (study PICO does not match questions PICO), because of inconsistency between studies, or because the absolute effect size is very small; Level may be graded up if there is a large or very large effect size **As always, a systematic review is generally better than an individual study Question Step 1 (Level 1*) Step 2 (Level 2*) Step 3 (Level 3*) Step 4 (Level 4*) Step 5 (Level 5*) How common is the problem? Local and current random sample surveys (or censuses) Systematic review of surveys that allow matching to local circumstances** Local non-random sample**  [8]. A retrospective study on the safety of an early postoperative discharge following bariatric surgery identified the receipt of preoperative information on early ambulation and refeeding, as well as pain and postoperative nausea and vomiting (PONV) management, as one of the more important protocol items of the ERABS pathway [18].

Preoperative patient optimization
Smoking cessation for at least four weeks reduced postoperative surgical and pulmonary complications by 41% [19], supporting the argument that smoking should be discontinued for at least four weeks before bariatric surgery [20]. Physicians should inform patients of the increased risk of morbidity and mortality in smokers. This risk decreases the longer smoking is ceased before surgery [21].
Preoperative weight loss reduces liver volume and may technically facilitate the operation [22]. However, whether weight loss reduces postoperative complications remains controversial [21,23]. A Swedish registry study reported a decrease in complications after gastric bypass surgery [24].
Optimizing the preoperative fasting blood glucose level through diet, physical activity, and pharmacotherapy is mandatory [20,21,23]. A value greater than 180 mg/dl was associated with increased perioperative complications and mortality [20].
Obstructive sleep apnea (OSA) carries an increased risk of postoperative cardiorespiratory complications [25]. Although this aspect has been debated in bariatric surgery [26,27], increased complications and LOS have been observed in OSA patients who underwent bariatric surgery [28][29][30]. The use of noninvasive ventilation (NIV) (e.g., continuous positive airway pressure [CPAP]) was reported to Table 2 Grading of quality of evidence (from US Preventive Services Task Force) [7] Grade Description

A
The available evidence usually includes consistent results from multitude of well-designed, well-conducted, studies in representative care populations. These studies assess the effects of the service on the desired health outcomes. Because of the precision of findings, this conclusion is, therefore, unlikely to be strongly affected by the results of future studies. These recommendations are often based on direct evidence from clinical trials of screening, treatment, or behavioral interventions. High-quality trials designed as "pragmatic" or "effectiveness" trials are often of greater value in understanding external validity B The available evidence is sufficient to determine the effects of the service on targeted health outcomes, but confidence in the estimate is constrained by factors such as the number, size, or quality of individual studies in the evidence pool; some heterogeneity of outcome findings or intervention models across the body of studies; mild-to-moderate limitations in the generalizability of findings to routine care practice. As more information becomes available, the magnitude or direction of the observed effect could change, and this change may be large enough to alter the conclusion C The available evidence is insufficient to assess effects on health outcomes. Evidence is insufficient because of the very limited number or size of studies Inconsistency of direction or magnitude of findings across the body of evidence; critical gaps in the chain of evidence; findings are not generalizable to routine care practice; a lack of information on prespecified health outcomes; lack of coherence across the linkages in the chain of evidence. More information may allow an estimation of effects on health outcomes

Postoperative nausea and vomiting prophylaxis
General anesthesia is associated with an increased risk of PONV [43]. The prevention of PONV in ERABS is recommended [4], and it is consistent with the guidelines for the general surgical population [43]. The polypharmacological approach to PONV prophylaxis is preferable to monotherapy [20,43] and was reported to decrease the incidence of PONV and the postoperative use of antiemetics, opioid analgesics, and liquid infusion [44].

Antibiotic prophylaxis
The incidence of surgical site infections in obese patients varies from 1 to 21.7%, depending on the procedure type [62]. The use of preoperative antibiotic prophylaxis is then recommended [20,21,23]. It should follow the standard guidelines for perioperative antibiotic prophylaxis [63]. The most frequently used antibiotic is cefazolin (dosage 1-4 g), with clindamycin recommended as an alternative in allergic patients [54,64]. A dose adjustment based on the patient's weight compared to a fixed dose of 2 g administered intravenously before surgical incision is preferable [65,66]. Higher dosages (cefazolin 3 g) in patients weighing > 120 kg should be considered [20]. Literature does not support prophylactic vancomycin or cefoxitin [64]. Intestinal preparation by antibiotic prophylaxis (whether or not combined with mechanical preparation) is not recommended in bariatric surgery [60]. Preoperative antibiotic prophylaxis, administered intravenously at the induction of anesthesia or 30-60 min before surgical incision, is reported to be one of the important items in ERABS [12,17,60,67].

Monitoring
The standard for anesthesia monitoring should be ensured in the perioperative period [4,20,33,68]. In obese patients, anesthesia depth monitoring ensures a more accurate induction of anesthesia with propofol and reduces the risk of  [69], as well as during intravenous and inhalational anesthesia [70]. The monitoring of the neuromuscular function helps reduce the risk of postoperative respiratory complications [71]. Temperature monitoring reduces the risk of hypothermia, improving postoperative recovery [72].

Standardized anesthesia approach
The standardized ERABS approach showed favorable outcomes compared to a non-standardized one [8][9][10][11][12][13][14]. Advances in the perioperative care of obese patients translated into a standardized anesthesiological approach have been proven to be effective and safe [73] in the ERABS context as well [39].

Pre-oxygenation
Adequate pre-oxygenation aiming for end-tidal oxygen concentrations of ≥ 90% before the induction of general anesthesia is suggested. Pre-oxygenation has been reported as important in prolonging safe apnea times following general anesthesia induction [82,83]. The NO DESAT (nasal oxygen during efforts securing a tube) technique, which uses a simple nasal cannula with standard cold dry oxygen may be considered [82]. Pre-oxygenation using a high-flow nasal cannula or positive pressure by CPAP/NIV seems more effective than the standard approach [82,[84][85][86][87][88][89][90][91] and may be beneficial for high-risk obese patients [20,32,33,82].

Tracheal intubation
An appropriate planned approach is recommended for airway management in obese patients [3,20,33]. In obese patients, videolaryngoscopes compared with Macintosh laryngoscopes increases the likelihood of successful intubation on the first attempt at laryngoscopy [92]. This result seems to be ensured more by the use of a videolaryngoscope with a tracheal tube guide than one without [93]. Second-generation extraglottic devices were recommended as rescue devices for pulmonary oxygenation/ ventilation in the case of difficult airway management and possible fibroscope-guided intubation [94][95][96][97][98]. The fibroscopic/endoscopic technique was essential when intubating conscious patients [99]. In awake patient, video laryngoscopy has been suggested as a valid alternative to fiberoptic intubation in experienced practitioners [100][101][102].

General anesthesia
General anesthesia is the approach of choice in ERABS [3,4,20,33]. There is no evidence supporting the superiority of inhalation versus intravenous anesthesia [3,4,20,33]. Anesthesia strategies based on short-acting, lowaccumulation drugs that promote rapid recovery from general anesthesia are suggested [4,20,33]. Desflurane has been associated with faster postoperative awakening and recovery than other inhalational anesthetics and propofol [103][104][105][106]. Intravenous anesthesia with propofol has demonstrated a lower risk of PONV in the general population [107] and in obese surgical patients [108]. PONV prophylaxis has been observed to reduce the risk of PONV incidence [109], particularly with inhalational anesthesia [20].

Analgesia and opioid
In the general surgical population, opioid use was associated with an increased risk of PONV [110], as well as upper airway obstruction and hypoventilation [111]. In obese patients, intraoperative opioid use was associated with an increased risk of PONV [112] and postoperative respiratory complications [113]. Opioid-sparing or opioidfree anesthesia should be preferred when managing obese surgical patients [20,33] under ERABS [4], as it is associated with a lower incidence of PONV [112].
Opioids with rapid elimination kinetics, such as remifentanil, have demonstrated faster postoperative awakening and recovery of respiratory functions in general surgical populations compared to other opiods [114]. In obese patients, remifentanil has demonstrated reduced recovery time from general anesthesia, respiratory complications, and LOS [115]. Patient-controlled analgesia has also been successfully used in obese surgical patients [116] and should be preferred over continuous infusion in the postoperative period [3,20].

Neuromuscular blockade
Neuromuscular blockade (NMB) is suggested at the induction of general anesthesia to facilitate airway management and subsequent pulmonary ventilation [20,33,82]. Deep compared to moderate NMB optimizes the surgical field view, reduces procedural complications in laparoscopic surgery [140], and is associated with less postoperative pain [140,141]. Sugammadex compared to cholinesterase inhibitors provides a more rapid and predictable recovery of rocuronium-induced NMB [142,143] and is associated with less pain and PONV in the postoperative period [141,144] and faster discharge to the surgical ward [143,144]. Quantitative monitoring and complete recovery of the neuromuscular function at the end of surgery are highly recommended [4,20,33].

Protective ventilation
Protective mechanical lung ventilation should be preferred for obese patients undergoing general anesthesia for bariatric surgery [20] because it is associated with reduced postoperative respiratory complications, LOS, and mortality in both non-obese and obese surgical patients [145][146][147].
Slow abdominal insufflation with a maximum intraabdominal pressure of less than 15 mmHg is advised, when possible, during laparoscopy [20] to favor mechanical lung ventilation [20,148]. This strategy, combined with limiting surgical time, is associated with a reduction in the risk of postoperative respiratory complications [148][149][150].

Goal-directed fluid therapy
Proper perioperative fluid management avoiding overhydration helps to minimize the risk of PONV, postoperative complications, and prolonged LOS [151][152][153]. A goal-directed fluid therapy (GDFT) has been suggested as an adequate strategy to reduce these risks [154], even in bariatric surgery [155][156][157]. In bariatric surgery, excessive fluid should be avoided, and GDFT should be considered a useful strategy [155][156][157]. A GDFT guided by noninvasive indices, such as the Pleth Variability Index, may be a more acceptable monitoring option to GDFT based on invasive methods [155] and, consequently, more widely used in bariatric surgery, even in the ERABS context [155][156][157]. Postoperative fluid infusions should be discontinued as soon as possible, with preference given to the enteral route [60,153,158]. Intraoperative hypotension (mean arterial pressure of ≤ 65 mmHg), even for a few minutes, is a predictor of renal and myocardial damage [159]. It should thus be avoided or promptly treated in the perioperative period [154,159].

Protected extubation
The extubation should be performed on an awake patient in the ramped position and/or reverse Trendelenburg position, which improves lung volume, oxygenation, and respiratory mechanics [20,33,160,161]. Oxygen therapy with nasal goggles or HFNC was associated with a reduced risk of postextubation desaturation [160] and reintubation [162]. CPAP or NIV was recommended for awakening moderate-severe OSA patients or those suffering from the obese hypoventilation syndrome who are already receiving home treatment or who will require opioid therapy postoperatively [20,32,163]. CPAP and NIV do not appear to negatively affect the outcome of the surgical procedure [32].

Nasogastric tube
In abdominal surgery, avoiding the routine use of nasogastric tubes (NGTs) results in a faster recovery of the bowel function, a decrease in pulmonary complications, and a shorter LOS without any associated increase in anastomotic dehiscence [164]. In ERABS, compared to the conventional approach, avoiding NGT use demonstrated better postoperative recovery without an increase in complications [11][12][13]41], reducing postoperative pain and PONV, promoting early mobilization and resumption of liquid diet, and resulting in better compliance at discharge [38,39,55]. Society positions in favor of abandoning, when possible, the routine use of postoperative NGT are already available [3,54].

Abdominal drainage
Many gastrointestinal surgeries can be performed safely without prophylactic drainage [165]. In bariatric surgery, the evidence is limited [166]. A retrospective study of a gastric bypass population reported no difference in anastomotic dehiscence and reintervention rates in patients receiving abdominal drainage compared to those who are not [167]. Avoiding abdominal drainage was found to be a key item in the ERABS [3,11,12,14,17,19,59,67,168]. Society positions in favor of abandoning the routine use of abdominal drainage, when possible, are available [3,54].

Bladder catheter
Avoidance or early removal of bladder catheters resulted in early mobilization and prevented urinary tract infection [169][170][171]. In ERABS, compared to the conventional approach, avoiding bladder catheters was associated with early mobilization and reduced LOS, readmission rate, and minor complications, such as urinary tract infection [3,10,14,18,50,67,168,172]. Society positions in favor of abandoning the routine use of bladder catheter, when possible, are available [54].

Early refeeding
The advantage of early oral refeeding has been reported in both ERAS [3] and ERABS [39-41, 173] and seems particularly associated with an earlier restoration of bowel function, faster wound healing, less infection, and lower risk of postoperative complications [36,37,174]. Early oral refeeding was associated with a reduced LOS and mortality [44,60]. Conversely, prolonged postoperative fasting was associated with thirst, emotional fixation on food, and a phobia about the reintroduction of food [36,37,174].

Discharge
Discharge on postoperative day 1 or 2 was not associated with an increase in the complication rate, readmission, or telephone consultations in both ERAS [3,18] and ERABS [11,12,175], particularly in the absence of significant comorbidities [176,177]. Caution should be taken in the presence of suspected clinical conditions (e.g., tachycardia) and/or abnormal level of serological markers (e.g., C-reactive protein, procalcitonin) as predictors of risk of postoperative complications [178][179][180][181]. However, there is no consensus on which serological markers should be assessed and at which postoperative time point [182][183][184][185]. Routine postoperative contrast imaging examination increased costs and LOS [186,187] and was not considered to be a reliable assessment of postoperative complications [188][189][190].
Discharge on the day of surgery was reported as feasible in selected patients [190][191][192]. However, there was some disagreement around the safety of same-day discharge [193,194]. The adoption and verification of a discharge checklist may be a useful tool for a safe discharge [57]. The minimum criteria for a discharge included vital parameters within the normal range, adequate pain control by nonopioid analgesics, adequate water intake, ability to tolerate liquid diet, and no evidence of sepsis or signs of postoperative complication. Finally, predischarge education concerning signs and symptoms of possible postoperative complications and procedures for contacting the staff were also identified as a key component of a successful discharge [11,12,39,55].

Discussion
Literature review supports ERABS in reducing LOS without increasing complications and costs [8][9][10]. Producing a statement on ERABS standardizes the ERABS approach across bariatric surgery centers, benefiting both patients and hospitals [195]. The standardization of the approach may also allow the evaluation of ERABS's effective impact on the postoperative complications and total costs compared to the standard approach [196]. Notably, it became clear from this statement that the more items in the protocol that are adopted, the more efficient the ERABS approach will be [13].
Perioperative management involves a multidisciplinary team, where a full collaboration among anesthesiologists, surgeons, and staff members may lead to the best results [73]. The ERABS statement, drafted thanks to this collaboration, is, therefore, addressed not only to anesthesiologists or surgeons, but also to everyone involved in the perioperative care of obese patients in bariatric surgery centers.
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