STOP-BANG: a Mandatory Tool for Targeted Respiratory Therapy in Bariatric Patients

Identification of patients with obstructive sleep apnea syndrome and high respiratory risk, optimization of the screening algorithm for these patients and administration of preventive non-invasive lung ventilation, makes it possible to prevent the development of perioperative complications, reduce duration of hospital stay and reduce mortality in patients undergoing surgery and bariatric surgery specifically.The objective: to evaluate the effectiveness of STOP-BANG questionnaire for preventive targeted respiratory therapy to reduce the risk of complications in bariatric patients. Subjects and Methods. We examined 60 patients with BMI above 30 kg/m2 referred to elective secondary surgery, the age made 44.2 ± 10.1 years, 23 men and 37 women. Before the operation, patients underwent STOP-BANG questionnaire survey, night respiratory monitoring with the calculation of the apnea/hypopnea index (AHI) and/or saturation during sleep. The standard preoperative examination included clinical and biochemical analyzes.Results. Based on results of STOP-BANG survey, a correlation was revealed between the score and AHI as well as the score and average saturation. The higher score the patients had according to the STOP-BANG questionnaire, the higher AHI was (r = 0.4748, p = 0.002), and the lower mean SpO2 was (r = -0.6958, p < 0.001). Using the ROC analysis, we chose the optimal threshold value - 4 points according to STOP-BANG questionnaire, where the sensitivity of the method was 93% for the AHI, the specificity was 56%, and for the average saturation it was 100% and 63%, respectively. Of the total number of bariatric patients included in the study, 30% required preventive ventilation. In the high respiratory risk group, no significant intraoperative incidents and deaths were reported by the surgical and anesthetic teams. All patients were discharged on time (5‒7 days). Based on the results, a screening procedure has been offered for bariatric patients with high respiratory risk associated with obstructive sleep apnea syndrome.Conclusion. The STOP-BANG questionnaire is a reliable screening tool for high respiratory risk in morbid obese patients. Early diagnosis of high respiratory risk and implementation of preventive ventilation reduces the incidence of perioperative respiratory and cardiovascular complications.

O-B01 Role of Ursodeoxycholic acid in prevention of gallstones formation in bariatric patients: need to amend recent BOMSS guidelines

Background During rapid weight-loss phase following bariatric procedures, biliary cholesterol homeostasis is altered leading to increased propensity to gallstone formation. Incidence of gallstone formation following bariatric procedures is shown to be 10-38%. There is no consensus regarding its prevention and current BOMSS guidelines do not address this issue. This meta-analysis aims to pool high level evidence (RCTs) to assess efficacy of Ursodeoxycholic acid (UDCA) in reducing risk of gallstone formation in this cohort of patients and the need for revision of current guidelines. Methods A systematic literature search was performed using electronic databases (Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, PROSPERO and Google Scholar) in line with PRISMA guidelines. Only randomised controlled trials were included without restrictions on study language, year, status of publication and patient’s age. Meta-analysis was performed using Review Manager Software to calculate pooled risk ratios (RR) using random-effects model. Results Fifteen trials were included (3952 patients analysed, 2487 in UDCA and 1465 in placebo group). The overall rate of gallstone formation was 16.0% (6.4% in UDCA vs 31.4% in placebo group). Trials included various bariatric procedures (SG/RYGB/OAGB/AGB/Gastroplasty). UDCA dose ranged from 300 to 1200mg per day. UDCA significantly reduced the risk of post-operative gallstone formation (3952 patients, RR 0.24, 95% CI 0.16-0.37, p &lt; 0.0001). The absolute risk reduction and number needed to treat (NNT) were 25% and 4 respectively. Conclusions Oral Ursodeoxycholic acid treatment following restrictive bariatric surgical procedures significantly reduces the risks of gallstone formation. As such, its regular use in first 6 months (rapid weight-loss phase) can significantly reduce the risk of complications associated with gallstones. Such treatment would be cost effective and benefit 1 in 4 patients. There is significant evidence available on benefits of using UDCA in post-operative bariatric patients and that this should be added to the recent BOMSS guidelines.

Gallstone Formation Follows a Different Trajectory in Bariatric Patients Compared to Nonbariatric Patients

Since obese patients form cholesterol gallstones very rapidly after bariatric surgery, in patients who did not form gallstones during preceding years, we hypothesized that gallstone formation follows a different trajectory in bariatric patients compared to nonbariatric patients. We therefore analyzed the lipid composition of gallbladder bile derived from 18 bariatric gallstone patients and 17 nonbariatric gallstone patients (median (IQR) age, 46.0 (28.0–54.0) years; 33 (94%) female) during laparoscopic cholecystectomy using an enzymatic and lipidomics approach. We observed a higher concentration of total lipids (9.9 vs. 5.8 g/dL), bile acids (157.7 vs. 81.5 mM), cholesterol (10.6 vs. 5.4 mM), and phospholipids (30.4 vs. 21.8 mM) in bariatric gallstone patients compared to nonbariatric gallstone patients. The cholesterol saturation index did not significantly differ between the two groups. Lipidomics analysis revealed an interesting pattern. Enhanced amounts of a number of lipid species were found in the gallbladder bile of nonbariatric gallstone patients. Most striking was a fivefold higher amount of triglyceride. A concomitant ninefold increase of apolipoprotein B was found, suggesting secretion of triglyceride-rich lipoproteins (TRLs) at the canalicular pole of the hepatocyte in livers from nonbariatric gallstone patients. These findings suggest that gallstone formation follows a different trajectory in bariatric patients compared to nonbariatric patients. Impaired gallbladder emptying might explain the rapid gallstone formation after bariatric surgery, while biliary TRL secretion might contribute to gallstone formation in nonbariatric patients.