Faculty Bibliography

OBJECTIVE:To assess the prevalence of delirium and coma in mechanically ventilated patients sedated with dexmedetomidine or propofol alone; to evaluate the hospital length of stay for both treatment groups; and to evaluate the level of sedation, adverse effects, and hospital outcomes. METHODS:Medical records were reviewed retrospectively for patients who were admitted to the medical or surgical intensive care units (ICUs) in a 591-bed teaching hospital and who received either dexmedetomidine or propofol alone for 24 hours or more for sedation. RESULTS:A total of 111 patients were included in the study, with 56 patients in the dexmedetomidine group and 55 patients in the propofol group. Results of the analysis showed that the propofol group had a higher prevalence of coma (43.6% versus 12.5%; P < 0.001). Dexmedetomidine patients had a longer median hospital length of stay of 23.5 days (interquartile range [IQR], 11.5-39.5 days) versus 15.0 days (IQR, 7.0-24.0 days; P = 0.01). The rates of delirium were similar in both groups, with 16% in dexmedetomidine-treated patients versus 20% in propofol-treated patients (P = 0.63). CONCLUSION/CONCLUSIONS:No difference in the prevalence of delirium was found when comparing the dexmedetomidine- and propofol-treated groups. Propofol was associated with more coma and oversedation; dexmedetomidine was associated with longer time to extubation, longer length of stay in the ICU, and longer hospital length of stay.

BACKGROUND:Vertical sleeve gastrectomy (VSG) ameliorates metabolic complications in obese and diabetic patients through unknown mechanisms. OBJECTIVE:synthase (L-PGDS) in glucose regulation in response to VSG using L-PGDS knock-out (KO), knock-in (KI), and C57BL/6 (wild type) mice. SETTING/METHODS:Winthrop University Hospital Research Institute. METHODS:Animals were divided into 6 groups: L-PGDS KO sham/VSG (n = 5), L-PGDS KI sham/VSG (n = 5), and C57BL/6 (wild type) sham/VSG (n = 5). Related parameters were measured in fasting animals after 10 weeks. RESULTS:Our intraperitoneal glucose tolerance tests and homeostatic model assessment insulin resistance results showed significant glycemic improvement 10 weeks post-VSG in both C57BL/6 and KI groups compared with the sham group. In contrast, the KO group developed glucose intolerance and insulin resistance similar to or greater than the sham group 10 weeks post-VSG. Interestingly, weight gain was insignificant 10 weeks post-VSG in all the groups and even trended higher in the KO group compared with sham. Peptide YY levels in the KO group post-VSG were slightly increased but significantly less than other groups. Similarly, the KO group showed significantly less leptin sensitivity in response to VSG compared with the KI group. Total cholesterol level remained unchanged in all groups irrespective of sham or surgery but interestingly, the KO group had significantly higher cholesterol levels. In parallel, adipocyte size was also found to be significantly increased in the KO group post-VSG compared with the sham group. CONCLUSION/CONCLUSIONS:Our findings propose that L-PGDS plays an important role in the beneficial metabolic effects observed after VSG.

BACKGROUND:Glucagon-like peptide-1 (GLP-1) level was significantly increased post Vertical Sleeve Gastrectomy (VSG), an effect believed to contribute to its beneficial cardiometabolic effects. OBJECTIVE:To validate the beneficial GLP-1 mediated cardiometabolic effects post VSG using GLP-1 antagonist (exendin 9-39) in Zucker diabetic fatty rats. METHODS:Animals were divided into three (n = 5) groups: (i) sham, (ii) VSG, and (iii) VSG received exendin 9-39 (GLP-1 receptor antagonist). The study was performed over 12 weeks and parameters were measured 12 weeks post-surgery. RESULTS AND DISCUSSION/CONCLUSIONS:As expected, fasting blood glucose and insulin levels were improved post VSG due to enhanced GLP-1 secretion. However, both fasting glucose and insulin levels were impaired in the presence of GLP-1 antagonist. Baseline total cholesterol level pre-surgery was 100±1 mg/dl which remained unchanged in the VSG group but significantly increased to 140±8 mg/dl in the presence of antagonist. Interestingly, post-surgery there was a nearly 70% reduction in triglyceride level in the VSG group compared to sham which was overcome in the presence of antagonist. Myographic studies using aortic rings showed no significant change between groups. Additionally, blood pressure and heart rate also remained unchanged in all groups. Serum bile acid and L-PGDS levels increased post VSG but significantly decreased in the presence of antagonist, suggesting a strong association with GLP-1 and a novel mechanism of action. CONCLUSION/CONCLUSIONS:Enhanced GLP-1 secretion post VSG imparted beneficial cardiometabolic effects on blood glucose, insulin, total cholesterol, triglyceride, bile acids and L-PGDS levels which were abated in the presence of GLP-1 antagonist.

BACKGROUND:Per oral endoscopic myotomy (POEM) represents a natural orifice transluminal endoscopic surgery approach to Heller myotomy. Our center was the first to offer POEM outside of Japan, allowing us to accumulate what is likely the highest single-operator POEM volume in the United States. OBJECTIVE:To define the POEM learning curve of a gastroenterologist by using a larger data set and more detailed statistical analysis than used in 2 other reports of POEM performed by surgeons. DESIGN/METHODS:Prospective cohort study. SETTING/METHODS:Tertiary-care academic medical center. PATIENTS/METHODS:We analyzed the first 93 consecutive POEMs on patients with achalasia aged >18 years without contraindications to POEM performed by a single operator from October 2009 to November 2013. INTERVENTIONS/METHODS:(1) Efficiency estimation via cumulative sum (CUSUM) analysis, (2) mastery estimation via penalized basis-spline regression and CUSUM analysis, (3) correlation of operator experience with clinical outcomes (Eckardt score improvement, lower esophageal sphincter pressure reduction) and technical errors (accidental mucosotomy rate), and (4) unadjusted and adjusted regression analysis to assess how patient characteristics affected procedure time by using a generalized linear model. MAIN OUTCOME MEASUREMENTS/METHODS:Clinical outcomes, procedure time, technical errors. RESULTS:Efficiency was attained after 40 POEMs and mastery after 60 POEMs. When we used the adjusted regression analysis, only case number (operator experience) significantly affected procedure time (P < .0001). Improvements in clinical outcomes were excellent but not significantly affected by operator experience, as was the case with accidental mucosotomies. Procedure time was not significantly affected by age, sex, achalasia stage, baseline lower esophageal sphincter pressure, baseline Eckardt score, prior treatment of achalasia, prior botulinum toxin injection, incidence of accidental mucosotomies, length of myotomy, or type of knife used (all P > .05). LIMITATIONS/CONCLUSIONS:Our analysis may underestimate the number of POEMs required to achieve mastery for operators with limited or no endoscopic submucosal dissection experience. CONCLUSION/CONCLUSIONS:These results offer thresholds for efficiency and mastery of a single gastroenterologist operator that may guide the efforts of novice POEM operators.

BACKGROUND:While surgical exploration remains the gold standard for diagnosing internal hernia (IH) after certain bariatric surgeries, decisions for operative intervention are often based on computed tomography (CT) findings. OBJECTIVES/OBJECTIVE:The aim of this study is to review our institutional experience and create an algorithm to approach patients presenting with abdominal pain and/or emesis after certain bariatric procedures. SETTINGS/METHODS:University Hospital METHODS:Following institutional review board approval, a retrospective chart review of all patients presenting with obstruction symptoms after laparoscopic Roux-en-Y gastric bypass (LRYGB) was performed at 2 institutions from 2008 to 2013. Patients without CT scans or with incidental hernia defect findings were excluded. CT and intraoperative findings were compared via univariate statistical analysis. RESULTS:Fifty-two patients who underwent an operation for a suspected IH were identified. Of the 50 patients, 25 (50%) had IH at operation. Twenty-nine patients (58%) had positive CT scans read for IH and/or obstruction. Of these 29, 19 (66%) were found to have IH at operation and 10 (34%) underwent negative diagnostic laparoscopy. Of the 21 patients with negative CT scans, 6 (29%) had IH at operation versus 15 (71%) who were negative. The sensitivity of CT scan to detect an internal hernia is 76% with 95% confidence interval (CI) [53% to 90%] and specificity is 60% with 95% CI [39% to 78%]. Sensitivity increased to 96% with 95% CI [78% to 99.8%] when combining CT scans with neutrophilia findings. CONCLUSION/CONCLUSIONS:Positive CT scans are sensitive for IH but not specific. CT scans will not detect IH in 1:4 patients; despite negative findings, surgical exploration should remain the gold standard for patients with acute abdominal pain after LRYGB or biliopancreatic diversion when IH is a consideration.

BACKGROUND:Roux-en-Y gastric bypass (RYGB) ameliorates type 2 diabetes (T2DM) and obesity through alteration in gastrointestinal (GI) hormones. OBJECTIVE:The objective of this study was to investigate the effect of RYGB on GI hormones and cardiometabolic parameters in Zucker diabetic fatty (ZDF) rodents. SETTING/METHODS:Winthrop University Hospital, Research and Academic Center METHODS:Animals were divided into 3 groups, pair-fed (n = 4), ad lib (n = 4), and RYGB (n = 5). This study was carried out for 4 weeks and all related parameters were measured pre- and postsurgery in fasted obese diabetic Zucker rodents. RESULTS:Postoperatively, RYGB significantly decreased fasting blood glucose by 32% compared with ad lib. Plasma insulin and leptin levels were also found to be significantly decreased, by 66% and 38%, respectively, after surgery. Moreover, both glucose-dependent insulinotropic polypeptide (GIP) and peptide tyrosine-tyrosine (PYY) were significantly increased after RYGB-by 300% and 51%, respectively. Glucagon-like peptide-1 (GLP-1) levels were also increased, but the increase was not statistically significant. Total cholesterol levels of the RYGB group remained unchanged for 4 weeks. However, total cholesterol in the ad lib and pair-fed groups increased by 25% and 34%, respectively, compared with initial levels. The cholesterol/high-density lipoprotein (HDL) ratio was decreased in the RYGB group by 14% and 30% compared with the ad lib and pair-fed group, respectively. The RYGB group had a significant decrease in aortic wall thickness of 25% compared with the ad lib and pair-fed groups. Similarly, the RYGB group had a 20-unit (mm Hg) decrease in systolic blood pressure compared with the presurgical value. CONCLUSION/CONCLUSIONS:RYGB has beneficial cardiometabolic effects through alterations in GI hormones in a severely obese and diabetic rodent model.

BACKGROUND:Roux-en-Y gastric bypass (RYGB) may improve cardiometabolic risk through alteration of bile acids and L-PGDS levels. OBJECTIVE:The objective of this study was to investigate the effect of RYGB on aortic wall thickness, in relation to bile acid and L-PGDS metabolism. METHODS:Zucker diabetic fatty (ZDF) rats were divided into two groups, ad lib (n = 4), and RYGB (n = 6). Bile acid and L-PGDS were measured presurgery and fourteen weeks post-surgery. RESULTS:Elevation of bile acid levels following RYGB in Zucker Diabetic Fatty (ZDF) rodents was observed, as compared to ad lib. RYGB in ZDF rodents led to a significantly decreased aortic wall thickness (25%) as compared to ad lib control. Although bile acid metabolism is implicated in these alterations, other mediators are likely involved. Our laboratory has demonstrated lipocalin prostaglandin D2 synthase (L-PGDS) is a kno n cardiometabolic modulator that also functions as a bile acid binding protein. Therefore, L-PGDS levels were measured and a significant elevation was observed with RYGB compared to ad lib control. CONCLUSION/CONCLUSIONS:Based on these findings, RYGB showed beneficial effect on aortic wall thickness, possibly through bile acids and L-PGDS elevation in a severely obese and diabetic rodent model.