The prevalence of obesity has been increasing in Canada with obesity affecting an estimated 20% of Canadians [1]. Bariatric surgery continues to be the most effective treatment for obesity and obesity-related comorbidities for individuals with severe obesity or a body mass index (BMI) greater than 35 kg/m2 [2]. However, bariatric surgery has historically been underutilized in Canada, with only 0.1% of 1.5 million eligible patients receiving bariatric surgery per year [3]. As a result, Canadian bariatric programs began expanding to improve access to surgery and have achieved a four-times increase in volume between 2007 and 2013 [4]. Currently, the two main bariatric procedures offered across Canada are the Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

Although the rate of bariatric surgical complications have decreased over time, there are areas in the process of care that can be improved [5, 6]. Enhanced recovery after surgery (ERAS) pathways were initially developed for elective colorectal surgery to improve perioperative outcomes [7,8,9,10,11,12]. ERAS programs are multimodal approaches that involve evidence-based, perioperative interventions that maintain physiological function, enhance mobilization, reduce pain, and facilitate early oral nutrition [13]. Despite clear benefits in colorectal surgery, ERAS for bariatric surgery has not been widely implemented in Canada as there is a lack of consensus on ERAS guidelines.

This article is an initiative undertaken by expert bariatric surgeons across all major Canadian centers to develop consensus guidelines for optimal perioperative care in bariatric surgery based on the best available evidence.

Materials and methods

A literature search of the MEDLINE database was performed from database inception to August 2018 using search terms: “bariatric surgery,” “sleeve gastrectomy,” “gastric bypass,” “fast track,” and “enhanced recovery.” Search terms for specific ERAS elements were also included. Particular emphasis was placed on recently published articles of good quality with a focus on systematic reviews, meta-analyses, and randomized controlled trials (RCTs). Conference proceedings were excluded. Quality of evidence and recommendations were evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system [14]. Ethics approval and consent were not required for this type of study.

A group of Canadian bariatric surgeons from six different provinces and ten bariatric centers performed a review of the evidence surrounding ERAS in bariatric surgery and created consensus guidelines for 14 essential ERAS elements (Table 1).

Table 1 Enhanced recovery after surgery (ERAS) recommendations
Full size table

Results

Recommendations, evidence, and grade of recommendations are summarized in Table 1.

Preadmission information and counseling

Information and counseling should be provided well before the bariatric procedure. This can be done through one-on-one sessions with the patient or through group sessions with the patient and their relatives. Preparation for bariatric surgery and hospital admission creates realistic expectations about hospitalization, analgesia, mobilization, and discharge [15]. We also recommend offering patients prehabilitation and exercise counseling, although evidence specific to bariatric surgery is lacking. A meta-analysis of patients undergoing cardiac and abdominal surgery found that prehabilitation led to lower complications and a shorter length of stay [16], while another systematic review found no physiological improvement with prehabilitation and limited clinical benefit [17]. However, in both of these reviews, the majority of patients were older than 60 years, which is much older than the typical bariatric surgery patient [18]. Further research in prehabilitation specific to bariatric surgery is needed to support this recommendation.

Patients are also encouraged to participate in a presurgical weight loss program. A meta-analysis performed in 2011 [19] and an updated review in 2015 [20] both demonstrated that preoperative weight loss was associated with a reduction in postoperative complications. Furthermore, a study of the Scandinavian Obesity Registry also demonstrated a reduction in complications [21]. Whether patients should be required to achieve specific levels of mandatory weight loss remains unclear [20].

Patient optimization and bowel preparation

Tobacco cessation of at least 3 months is highly recommended prior to bariatric surgery. Although studies specific to bariatric surgery are lacking, tobacco smoking has consistently been demonstrated to increase the risk of pulmonary complications, wound infections, and thromboembolism after surgery [22]. Specific to bariatric surgery, there is evidence of increased risk of anastomotic ulceration after RYGB in tobacco users [23, 24]. Furthermore, a systematic review demonstrated that smoking cessation of 4 weeks or longer decreased the risk of postoperative complications [22]. To ensure compliance, tobacco testing with urine cotinine may be considered [25].

Patients are also advised to abstain from excessive alcohol intake, including binge drinking. Moderate alcohol consumption below Canada’s low-risk drinking guidelines is permissible [26]. In elective surgery, alcohol consumption is associated with increased perioperative risk [27]. There is also a higher risk of alcohol abuse after RYGB, and patients should be aware of this, especially those with a history of alcohol abuse [28].

With Canada’s planned legalization of cannabis, questions remain about the safety of cannabis in bariatric surgery. A review on this topic found little evidence on cannabis in bariatric surgery patients, although there is some evidence that chronic cannabis use has negative health effects [29]. Our recommendation is that patients with significant cannabis use should be carefully selected.

Chronic opioid use is common among bariatric surgery patients due to obesity-related symptoms. A retrospective cohort study found that after bariatric surgery in chronic opioid users, the majority continued to use opioids and at a higher dose [30], demonstrating that weight loss does not appear to reduce opioid usage. These patients should be assessed by a chronic pain specialist to optimize pain management prior to surgery. Treating postoperative pain in chronic opioid users is difficult and preoperative counseling may be necessary to ensure patients are properly educated.

Mechanical bowel preparations are not required prior to bariatric surgery. Although there is recent evidence supporting a combination of mechanical bowel preparation with antibiotics to reduce surgical site infection (SSI) in elective colorectal surgery [31], this does not apply to bariatric surgery. Combined mechanical bowel and oral antibiotic preparations prevent SSI by reducing fecal bacterial load and bacterial concentration within the colon [31]. However, bariatric surgery is performed only on the upper gastrointestinal tract, which has no fecal load and much lower bacterial counts [32].

Preoperative fasting and carbohydrate loading

A low-calorie diet (LCD, 1000–1200 kcal/day) or very low-calorie diet (VLCD, 400–800 kcal/day) is recommended for at least 2 weeks before surgery and up to 3–4 weeks for patients with a higher BMI. The main purpose of this preoperative diet is to reduce the size of the liver which reduces the technical difficulty of the bariatric procedure. This is supported by a systematic review that demonstrated an average reduction in liver volume of 14% with LCDs ranging from 2 to 12 weeks [33]. Another systematic review which only included VLCDs, ranging from 10 to 63 days, found that liver volume decreased by 5–20%. However, this meta-analysis found no difference in surgical complications [34]. Despite this, an RCT on two-week VLCD and RYGB found a reduction in 30-day complications (13.2% vs. 5.8%, p = 0.04) as well as the surgeon’s perceived difficulty of the procedure [35].

For preoperative fasting, our guidelines follow anesthesia society recommendations of 2 h for clear fluids and 6 h for solids before induction of anesthesia [36]. Carbohydrate loading prior to surgery has also been a part of the colorectal ERAS pathway; however, evidence in bariatric surgery is limited and not currently recommended, especially in patients with diabetes where evidence is lacking.

Preanesthetic medications

Currently, ERAS guidelines have been published for the practice of anesthesia in gastrointestinal surgery [37, 38]. Based on these guidelines, patients with higher-risk comorbidities should be seen at a preadmission clinic by anesthesia to optimize their perioperative care [37].

Preanesthetic administration of long-acting opioids increases the risk of postoperative respiratory depression and hypoventilation, especially in patients with obesity who have a higher incidence of obstructive sleep apnea and obesity hypoventilation syndrome [39]. Furthermore, anxiolytics such as benzodiazepines should be avoided as evidence does not support effectiveness in reducing preoperative anxiety [40]. Our consensus is to avoid long-acting sedatives and opioids as their effects can be unpredictable and delay postoperative recovery. Furthermore, a RCT comparing non-opioid to opioid-based anesthesia during LSG found comparable efficacy with regard to pain scores [41]. A preoperative dose of dexamethasone for postoperative nausea and vomiting is also recommended, although evidence specific to bariatric surgery is lacking [42].

Thromboprophylaxis

Patients with obesity have been shown to have an increased risk for venous thromboembolism [43]. Thromboembolic complications represent 50% of mortality associated with bariatric surgery [13, 44]. To prevent these events, thromboembolic prophylaxis is now a common practice in patients undergoing bariatric surgery. Currently, low-molecular-weight heparins have been shown to be just as effective, if not more effective than unfractionated heparin in preventing postoperative venous thromboembolism [45, 46]. Our group consensus recommends the use of unfractionated heparin of at least 5000 units or weight-adjusted low-molecular-weight heparin prior to surgery. However, the group did not reach consensus on the use of compression stockings or pneumatic compression devices in preventing vein thromboembolisms [47].

Preoperative skin preparation and antimicrobial prophylaxis

Removal of body hair is a preoperative procedure that improves adhesion of the dressing and decreases surgical site contamination [48]. However, the process and method of removing hair can cause micro-insults to the skin which increases the risk of SSIs. The current group consensus recommends removing hair by clipping rather than by shaving, to reduce the risk of infection as the preferred method. This is supported by a Cochrane systematic review which analyzed three RCTs (n = 3193) comparing shaving to clipping and found higher rates of SSI with shaving compared to clipping (RR 2.02, 95% CI, 1.21–3.36) [48].

For preoperative skin preparation, a RCT that included 849 participants showed that subjects assigned to the chlorhexidine–alcohol group had a lower SSI rate overall compared to the povidone–iodine group (9.5% vs. 16.1%; P = 0.004; RR 0.59; 95% CI, 0.41–0.85) [49]. Therefore, skin preparation with chlorhexidine–alcohol is our current recommendation.

For antimicrobial prophylaxis, our recommendation is cefazolin which should be dosed pre-operatively [50] with metronidazole as an adjunct for patients undergoing RYGB [51]. A recent study demonstrated that cefazolin 2 g IV administered prior to skin incision achieves protective adipose tissue levels for the duration of the bariatric procedure [50]. Metronidazole is also recommended as an adjunct for patients undergoing RYGB due to increased enteric anaerobic contamination compared to SG; however, there is no evidence supporting this [52]. For patients with true penicillin allergies, vancomycin or clindamycin can be used as an alternative.

Anesthesia

Anesthetic considerations are detailed in ERAS guidelines designed for gastrointestinal surgeries [38]. However, the optimal anesthetic protocol should follow the mainstay principles of reduced opioid use which will help decrease patient recovery time. As well, the use of short-acting agents and the liberal use of antiemetics intraoperatively should decrease postoperative antiemetic therapy and the duration of stay in hospital [53].

Patients should receive a balanced volume of IV fluids intraoperatively. One study examined the outcomes of intraoperative fluid replacement in laparoscopic bariatric surgery and found that conservative (15 mL/kg) versus liberal (40 mL/kg) IV fluid administration did not change postoperative creatinine or creatine kinase [54]. Therefore, a conservative volume of IV fluids is recommended over a liberal approach to prevent fluid overload.

Although there has been some advocacy for combined epidural with general anesthesia for abdominal surgery, our consensus statement does not recommend epidural analgesia in primary laparoscopic bariatric surgery. Although there is no evidence in bariatric surgery, a RCT comparing epidural analgesics with patient-controlled analgesia in laparoscopic colorectal surgery found that epidural analgesia lead to no improvement in pain but longer hospital stays (3.7 vs. 2.8 days) and slower return of bowel function [55].

Hypothermia increases a patient’s risk for wound infection and delays healing; therefore, intraoperative normotherapy with preoperative warming in the holding area is recommended [56]. The use of heated insufflation during surgery is not recommended as a Cochrane systematic review demonstrated minimal increases in core temperatures with no reduction in adverse outcomes [57].

Intraoperative leak testing

There are currently no standard guidelines and requirements to perform intraoperative leak testing in bariatric surgery. However, early recognition and treatment of anastomotic or staple line leaks are important to reducing complications and length of stay. In a retrospective cohort study, routine intraoperative leak testing was performed in 1329 LSG cases but yielded zero positive results [58]. In another prospective series, 342 LRYGB cases underwent air leak testing with six positive cases, requiring reinforcement of the gastrojejunal anastomosis [59]. However, there is no evidence supporting that intraoperative leak testing reduces the incidence of postoperative leaks. Therefore, it is our recommendation that routine intraoperative leak testing is not required but is up to the surgeon’s preference. The method in which intraoperative leak testing is performed varies and can be performed by air or methylene blue during intraoperative endoscopy. The use of an orogastric tube to administer air or methylene blue is not recommended as a retrospective study demonstrated a lower rate of leak detection (8 vs. 4%) than with intraoperative endoscopy [60].

Nasogastric intubation

Historically, routine nasogastric intubation following abdominal surgery was the standard of care. However, research has shown that there is a limited role for nasogastric tubes in abdominal surgery or in bariatric surgery [61, 62]. A Cochrane systematic review, which included 37 studies (n = 5711), demonstrated that patients who were did not have nasogastric tubes had an earlier return of bowel function (p < 0.001), lower rates of respiratory complications (p = 0.09), and lower rates of ventral hernias (p = 0.09) [63]. Despite this, nasogastric intubation may be helpful to decompress the stomach during Veress needle insertion [64]. Our recommendation is that nasogastric intubation may be used during Veress needle access but has no role postoperatively.

Abdominal and urinary drainage

Routine abdominal drainage is not recommended [65]. This is supported by a Cochrane review of intra-abdominal drains for the prophylaxis of anastomotic leaks in colorectal surgery [66]. In this review, three RCTs with 908 participants showed no statistically significant difference in anastomotic dehiscence in patients with and without intra-abdominal drains [66]. However, drains may be considered for complicated or revisional cases as there are much higher leak rates in these cases [67].

Current group consensus is that Foley catheters are not necessary for routine bariatric surgery cases. Insertion of urinary catheters can prolong hospital stays due to issues with urinary retention [68]. One study demonstrated that early Foley catheter removal after bariatric surgery, as part of an ERAS clinical pathway, leads to shorter hospital stays [69]. Therefore, we do not recommend Foley catheters.

Prevention of postoperative ileus

To prevent postoperative ileus, it is important to avoid excessive intravenous fluids through early discontinuation of intravenous infusions and early return to oral fluid intake [70]. According to one RCT in major abdominal surgery, optimal postoperative fluid management should be individualized and goal-directed [71]. Regarding prokinetic agents, a Cochrane systematic review of 39 RCTs (n = 4615) demonstrated insufficient evidence to recommend prokinetic agents for the treatment of postoperative ileus [72]. However, alvimopan, a gamma-opioid receptor antagonist, has been shown to improve recovery times in patients postoperatively compared to placebo [72,73,74]. Other agents such as bisacodyl have been found to be effective in accelerating gastrointestinal motility following elective colorectal surgery and is an option to treat postoperative ileus [75]. Oral magnesium oxide is another intervention that has demonstrated benefit in preventing postoperative ileus [76, 77]. Our current recommendation is to avoid fluid overload by initiating early enteral feeds and discontinuation of intravenous infusions when possible. Overall, no current prokinetic agent has been shown to be effective in the treatment of postoperative ileus; however, alvimopan, bisacodyl, or magnesium oxide may be considered.

Another method to prevent postoperative ileus is to encourage early ambulation and the current group consensus is to ambulate within 4 h of surgery. A RCT in patients undergoing laparotomy and intestinal resection demonstrated that patients randomized to rehabilitation with early ambulation spent fewer days in hospital compared to traditional care (5.4 vs. 7.1 days, p = 0.01) [78]. Another prospective study showed that early ambulation, as part of a fast-track care package after bariatric surgery, leads to a shorter length of stay [69].

Postoperative analgesia

Initiating and providing effective postoperative pain management is crucial in a patient’s recovery process and important in achieving a reasonable discharge date. Following surgery with moderate to severe pain, opioids are frequently prescribed; however, it is recommended to minimize the use of opioids to decrease the associated side effects including nausea, vomiting, respiratory depression, and ileus [79]. A multimodal analgesic approach should be employed, including acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), as studies have shown evidence of clinically superior outcomes when used in combinations [80]. However, for patients undergoing bariatric surgery, it is recommended that NSAIDs be used sparingly and for short durations, as NSAIDs increase the risk of marginal ulcers and may lead to poor anastomotic healing [81].

Early pain control can be achieved using subcutaneous or intravenous narcotics [82]; however, patients should be transitioned to oral medications as soon as possible. At the time of discharge, patients are frequently prescribed a short course of oral hydromorphone, Percocet, or tramadol [83]. Prescribed medications can be taken orally and liquid formulations or crushed pills may be required. Furthermore, the liberal use of antiemetics is important to reduce postoperative nausea and vomiting. The combination of ondansetron and dexamethasone has been shown to decrease the risk of postoperative nausea and vomiting [84]. In summary, postoperative pain control can be achieved through a multimodal pain approach and postoperative nausea and vomiting can be managed through the use of various antiemetics.

Postoperative nutrition

Postoperatively, patients may begin to sip on clear fluids the evening following the surgery once they are fully awake. A systematic review and meta-analysis of 13 trials (n = 1173 participants) showed no benefit in keeping a patient NPO following gastrointestinal surgery [85]. Moreover, providing a patient a full diet does not confer increased morbidity compared to NPO [86]; therefore, a full fluid diet should be initiated on postoperative day one [85, 86].

Discharge and follow-up

Following surgery, most patients will undergo a recovery process, as an inpatient, that culminates to their discharge. Criteria for discharge vary for different services, but on a whole is based on the main principles of meeting normal hemodynamics, establishing good pain control, tolerating diet, ambulating well, and being agreeable to leave. Our recommendation is to perform bloodwork as needed on postoperative day one if there are concerns about electrolyte abnormalities, blood loss, or early infection.

Upon discharge, a patient navigator should follow up with a phone call within 24–48 h to determine how the patient is managing at home. A follow-up clinic appointment is normally arranged 3–4 weeks after discharge and once again in 3 months.

Discussion

There are currently few published studies on enhanced recovery after surgery in bariatric surgery. The purpose of an ERAS protocol is to improve postoperative outcomes by reducing complications and morbidities associated with the procedure [87]. By addressing these 14 essential ERAS elements, it will help to develop guidelines that can be implemented and practiced clinically.

Compared to traditional care in bariatric surgery, the benefits of ERAS are to reduce variability in clinical practice, cost, and postoperative complications; ultimately improving the quality of care provided to patients. There has been keen interest for a Canadian protocol for a fast-track concept to improve surgical efficiency and create a common perioperative pathway.

The most recently published bariatric ERAS guidelines by Thorell et al. in 2016 [13] highlight recommendations and collaboration between different developed countries with the exception of North America [13]. Overall, ERAS is an excellent model that improves surgical efficiency and perioperative complications. In the interim, this bariatric perioperative guideline serves as a common consensus point for Canadian bariatric surgeons.