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Anastomotic leaks remain a dreaded complication after ileal pouch anal anastomosis (IPAA). Their impacts can be devastating, ranging from an acute leak leading to postoperative sepsis to chronic leaks and sinus tracts resulting in long-term pouch dysfunction and subsequent pouch failure. The management of acute leaks is intricate. Initial management is important to resolve acute sepsis, but the type of acute intervention impacts long-term pouch function. Aggressive management in the postoperative period, including the use of IV fluids, broad-spectrum antibiotics, and operative interventions may be necessary to preserve pouch structure and function. Early identification and knowledge of the most common areas of leak, such as at the IPAA anastomosis, are important for guiding management. Long-term complications, such as pouch sinuses, pouch-vaginal fistulas, and diminished IPAA function complicate the overall survival and functionality of the pouch. Knowledge and awareness of the identification and management of leaks is crucial for optimizing IPAA success.

Background Despite the initial diagnosis of ulcerative colitis (UC), approximately 10% to 20% of patients develop Crohn’s disease–like pouch inflammation (CDLPI) after restorative proctocolectomy (RPC) with ileal pouch anal anastomosis (IPAA). The aim of this study was to evaluate whether early pouchitis, defined as pouchitis within the first year after IPAA, is a predictor of CDLPI. Methods This was a retrospective cohort analysis of patients with UC or IBD unclassified (IBDU) who underwent RPC with IPAA at Mount Sinai Hospital between January 2008 and December 2017. The primary outcome was development of CDLPI. Predictors of CDLPI were analyzed via univariable and multivariable Cox regression models. Results The analytic cohort comprised 412 patients who underwent at least 1 pouchoscopy procedure between 2009 and 2018. Crohn’s disease–like pouch inflammation developed in 57 (13.8%) patients a median interval of 2.1 (interquartile range, 1.1-4.3) years after surgery. On univariable analysis, older age at colectomy (hazard ratio [HR], 0.97; 95% CI, 0.95-0.99) was associated with a reduced risk of CDLPI; although early pouchitis (HR, 2.43; 95% CI, 1.32-4.45) and a greater number of pouchitis episodes (HR, 1.38; 95% CI, 1.17-1.63) were associated with an increased risk. On multivariable analysis, early pouchitis (HR, 2.35; 95% CI, 1.27-4.34) was significantly associated with CDLPI. Time to CDLPI was significantly less in patients who developed early pouchitis compared with those who did not (P = .003). Conclusion Early pouchitis is significantly associated with subsequent CDLPI development and may be the first indication of enhanced mucosal immune activation in the pouch.

Background Pouchitis occurs in up to 80% of patients after total proctocolectomy (TPC) with ileal pouch–anal anastomosis (IPAA) and has been associated with microbial and host-related immunological factors. We hypothesized that a more robust immune response at the time of colectomy, manifested by acute severe ulcerative colitis (ASUC), may be associated with subsequent acute pouchitis. Methods This was a retrospective cohort analysis of all patients with UC or indeterminate colitis complicated by medically refractory disease or dysplasia who underwent TPC with IPAA at Mount Sinai Hospital between 2008 and 2017 and at least 1 subsequent pouchoscopy. Acute pouchitis was defined according to the Pouchitis Disease Activity Index. Cox regression was used to assess unadjusted relationships between hypothesized risk factors and acute pouchitis. Results A total of 416 patients met inclusion criteria. Of the 165 (39.7%) patients who underwent urgent colectomy, 77 (46.7%) were admitted with ASUC. Acute pouchitis occurred in 228 (54.8%) patients a median of 1.3 (interquartile range, 0.6-3.1) years after the final surgical stage. On multivariable analysis, ASUC (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.04-2.17) and a greater number of biologics precolectomy (HR, 1.57; 95% CI, 1.06-2.31) were associated with an increased probability of acute pouchitis, while older age at colectomy (HR, 0.98; 95% CI, 0.97-0.99) was associated with a decreased probability. Time to pouchitis was significantly less in patients admitted with ASUC compared with those not (P = .002). Conclusion A severe UC disease phenotype at the time of colectomy was associated with an increased probability of acute pouchitis.

Lay Summary In a retrospective study of 412 patients with ulcerative colitis who underwent total proctocolectomy with ileal pouch anal anastomosis and had subsequent pouchoscopy, low 25-hydroxyvitamin D was common and was not significantly associated with age, sex, ethnicity, or precolectomy medication use.

BACKGROUND The risk of neoplasia of the pouch or residual rectum in patients with ulcerative colitis (UC) who undergo total proctocolectomy (TPC) with ileal pouch anal anastomosis (IPAA) is incompletely investigated. Thiopurine use is associated with a reduced risk of colorectal neoplasia in patients with UC. We tested the hypothesis that thiopurine use prior to TPC may be associated with a reduced risk of primary neoplasia after IPAA. METHODS We conducted a retrospective cohort analysis of patients from a tertiary referral center from January 2008 to December 2017. Eligible patients with UC or IC underwent TPC with IPAA and had at least two pouchoscopies with biopsies ≥ 6 months after surgery. Propensity score analysis was conducted to match thiopurine exposed vs unexposed groups based on clinical covariates. Multivariable Cox regression analysis estimated the risk of neoplasia. RESULTS A total of 284 patients with UC or IC (57.4% male, median age 35.6 years) were analyzed. Ninety-seven patients (34.2%) were confirmed to have thiopurine exposure ≥ 12 weeks immediately prior to TPC ("exposed") and 187 (65.8%) were confirmed to have no thiopurine exposure for at least 365 days prior to TPC ("non-exposed"). Compared to non-exposed patients, patients with thiopurine exposure less often had dysplasia (7.2% vs 23.0%, p = 0.001) and had lower grades of dysplasia before colectomy. After IPAA, patients with neoplasia were older (44.0 vs 34.8 years, p = 0.03), more likely to have had dysplasia as colectomy indication (44.4% vs 15.4%, p = 0.007), and more likely to require pouch excision (55.6% vs 10.2%, p

The purpose of this study is to shed light on a rare complication following ileostomy closure after 3-stage IPAA for further study and discussion. Our department IPAA database was queried for all patients who underwent 3-stage IPAA creation from 2011 through 2018. Data was reviewed and analyzed using the SPSS application. Chi-square test and Fisher’s exact test were used for categorical variables. t test or ANOVA was used for continuous variables. Significance was set at p < 0.05. Three hundred seventy-eight charts were queried. Sixty-eight complications (18.0%) were identified after ileostomy closure. Thirty-seven were small bowel obstruction or partial small bowel obstruction (SBO or pSBO, 9.79%), 5 cases of leak from ileoileostomy anastomosis (7.4%), and 4 cases of leak from pouch (5.9%). There was no significant difference in time between restorative proctocolectomy with IPAA and loop ileostomy closure with cases where a complication occurred and where one did not (p = 0.28). Eight patients developed a SIRS response in the first 5 days after surgery without an identified intraabdominal source after extensive work-up. Of these patients, 87.5% also had negative re-explorations (both open and laparoscopic). None required re-diversion, and all recovered well. While SBO remains the most common complication following ileostomy closure, a surprisingly large number of presents present with a SIRS response with no identifiable source. All of these patients recovered with supportive care, and none required further intervention or diversion. This is a poorly understood phenomenon which is unique to ileostomy closure after IPAA, and further study is required.

Introduction: The true incidence of Clostridioides difficile infection (CDI) in patients with an ileal pouch is unknown, and there is little published on its associated risk factors. Objective: We aimed to evaluate the rate and risk factors of CDI in pouch patients. Methods: This was a retrospective review conducted at a single tertiary care inflammatory bowel disease (IBD) center. All ulcerative colitis or IBD-unspecified (IBD-U) patients who underwent total proctocolectomy with ileal pouch anal anastomosis for medically refractory disease or dysplasia between 2008 and 2017 were identified. Symptomatic patients tested for CDI were included. Demographic, disease, and surgical characteristics were collected. Nonparametric methods were used to compare continuous outcomes, and χ2 and Fisher’s exact tests were used to compare patients with and without CDI as appropriate. Results: A total of 154 pouch patients had postoperative C. difficilestool testing for symptoms of fever, urgency, increased stool frequency, hematochezia, incontinence, and abdominal and/or pelvic pain. CDI was diagnosed in 11 (7.1%) patients a median of 139 days (IQR 34–1,170) after the final surgical stage. Ten patients (90.9%) received oral vancomycin for 10 days and 1 patient (9.1%) received oral metronidazole for 2 weeks. Ten patients (90.9%) reported improvement in symptoms at completion of therapy. Nine patients (81.8%) were retested for CDI for recurrent symptoms and found to be negative. No patient had CDI recurrence. There was no significant difference in demographic and surgical characteristics, previous antibiotic or proton pump inhibitor use, or previous hospital admission among the patients with and without CDI. Conclusions: CDI is a rare cause of infectious pouchitis and treatment with oral vancomycin improves symptoms.

BACKGROUND Approximately 10% to 20% of patients with ulcerative colitis require surgery during their disease course, of which the most common is the staged restorative proctocolectomy with IPAA. OBJECTIVE The aim was to compare the rates of anastomotic leaks among all staged restorative proctocolectomy with IPAA procedures. DESIGN This was a retrospective cohort study. SETTINGS This study was conducted at a single tertiary care IBD center. PATIENTS All patients with ulcerative colitis or IBD-unspecified who underwent a primary total proctocolectomy with IPAA for medically refractory disease or dysplasia between 2008 and 2017 were identified. MAIN OUTCOME MEASURES The primary outcome was anastomotic leak within a 6-month postoperative period. Univariate and multivariate logistic regression were used to compare patients with and without anastomotic leaks. RESULTS The sample was composed of 584 nonemergent patients, of whom 50 (8.6%) underwent 1-stage, 162 (27.7%) underwent 2-stage, 58 (9.9%) underwent modified 2-stage, and 314 (53.7%) underwent a 3-stage total proctocolectomy with IPAA. The primary indication was medically refractory disease in 488 patients and dysplasia/cancer in 101 patients. Anastomotic leak occurred in 10 patients (3.2%) after 3-stage, 14 patients (8.6%) after 2-stage, 6 patients (10.3%) after modified 2-stage, and 10 patients (20.0%) after a 1-stage procedure. A 3-stage procedure had fewer leaks and additional procedures for leaks compared with 1- and modified 2-stage procedures (p < 0.03). The 3-stage procedure had fewer combined anastomotic leaks and pelvic abscesses than all of the other staged procedures (p < 0.05). LIMITATIONS This study was limited by its retrospective design and evolving electronic medical charts system. CONCLUSIONS The 3-stage total proctocolectomy with IPAA is the optimal staged method in ulcerative colitis to reduce leaks and related complications. See Video Abstract at http://links.lww.com/DCR/B693. LENTO Y CONSTANTE GANA LA CARRERA UN CASO SLIDO PARA UN ENFOQUE DE TRES ETAPAS EN LA COLITIS ULCEROSA ANTECEDENTES:Aproximadamente el 10-20% de los pacientes con colitis ulcerosa requieren cirugia durante el curso de su enfermedad, de los cuales la mas comun es la proctocolectomia restauradora escalonada con anastomosis con bolsa ileo-anal.OBJETIVO:El objetivo fue comparar las tasas de fugas anastomoticas entre todos los procedimientos de proctocolectomia restauradora por etapas con procedimiento de anastomosis con bolsa ileo-anal.DISENO:Este fue un estudio de cohorte retrospectivo.ENTORNO CLINICO:Este estudio se llevo a cabo en un unico centro de atencion terciaria de tercer nivel para enfermedades inflamatorias del intestino.PACIENTES:Se identificaron todos los pacientes con colitis ulcerosa o enfermedad inflamatoria intestinal inespecifica que se sometieron a una proctocolectomia total primaria mas anastomosis con bolsa ileo-anal por enfermedad medicamente refractaria o displasia entre 2008 y 2017.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la fuga anastomotica dentro de un periodo posoperatorio de seis meses. Se utilizo regresion logistica univariante y multivariante para comparar pacientes con y sin fugas anastomoticas.RESULTADOS:La muestra estuvo compuesta por 584 pacientes no emergentes, de los cuales 50 (8,6%) se sometieron a una etapa, 162 (27,7%) se sometieron a dos etapas, 58 (9,9%) se sometieron a modificacion en dos etapas y 314 (53,7%) se sometieron a una proctocolectomia total en tres tiempos mas anastomosis con bolsa ileo-anal. La indicacion principal fue enfermedad medicamente refractaria en 488 pacientes y displasia / cancer en 101 pacientes. Se produjo una fuga anastomotica en 10 (3,2%) pacientes despues de tres etapas, 14 (8,6%) pacientes despues de dos etapas, 6 (10,3%) pacientes despues de dos etapas modificadas y 10 (20,0%) pacientes despues de una etapa procedimiento. Un procedimiento de tres etapas tuvo menos fugas y procedimientos adicionales para las fugas en comparacion con los procedimientos de una y dos etapas modificadas (p

Ulcerative colitis frequently requires surgery as a definitive management strategy. The colonic specimen can be extracted from various sites including a midline incision, the stoma site, or a Pfannenstiel incision. It is unclear if one extraction site offers improved outcomes and fewer complications. A retrospective review of charts obtained of colorectal surgery patients was conducted for all patients with ulcerative colitis who underwent a subtotal colectomy between 2008 and 2016 at a single tertiary care institution. Demographic data and outcomes data including parastomal and incisional hernias, advanced wound/ostomy certified nurse referrals, surgical site infections, reoperations, and readmissions were collected. Univariate and multivariate analyses were completed to detect any significant differences in outcomes between groups based on extraction site (midline incision, stoma site, or Pfannenstiel incision). Univariate analysis did not show any statistical differences between groups in regard to outcomes. Stoma site extraction did not statistically differ from midline extraction in regard to hernias, advanced ostomy referrals, infections, or reoperations, but midline incision extraction did have a lower risk of readmission (OR = 0.56, p = 0.0066). Pfannenstiel extraction had lower risk of incisional hernias (OR = 0.25, p = 0.0002), advanced ostomy referrals (OR = 0.45, p = 0.0164) and readmission (OR = 0.26, p < 0.0001) as compared to stoma site extraction. While stoma site extraction can be successfully performed for most patients requiring subtotal colectomy for ulcerative colitis, Pfannenstiel extraction leads to the fewest number of complications and provides the most consistent results.

Despite improvements in medical management, 10%-15% of patients with ulcerative colitis (UC) require total proctocolectomy (TPC) with ileal pouch anal anastomosis (IPAA) for refractory disease.1 Acute pouchitis is the most common post-IPAA inflammatory condition, with cumulative incidence of 45% at 5 years.2 Up to 20%-30% of patients develop chronic pouch inflammation (CPI), categorized as antibiotic responsive, antibiotic refractory, or Crohn's disease-like (CDL).3.

BACKGROUND: The significance of endoscopic activity in asymptomatic ulcerative colitis (UC) patients with an ileal pouch is unknown. AIM: We aimed to understand the association of endoscopic pouch activity in asymptomatic patients with the development of pouchitis. METHODS: We analyzed a retrospective cohort of patients with UC or IBD-Unspecified (IBD-U) who underwent a total proctocolectomy with ileal pouch anal anastomosis (IPAA). Asymptomatic patients with a Pouchitis Disease Activity Index (PDAI) symptom sub-score of zero who underwent an index surveillance pouchoscopy were included. Endoscopic pouch body activity was graded as 0: normal, 1: mucosal inflammation, or 2: mucosal breaks (ulcers and/or erosions). The primary outcome was primary acute idiopathic pouchitis defined as PDAI score ≥ 7 with symptoms lasting less than four weeks and responsive to standard antibiotics, not otherwise meeting criteria for secondary pouchitis. The secondary outcome was chronic idiopathic pouchitis defined as PDAI score ≥ 7 with symptoms lasting greater than four weeks despite standard antibiotics. Predictors of pouchitis were analyzed using Kaplan-Meier and Cox regression methods with hazard ratios (HR) and 95% confidence intervals (CI) reported. RESULTS: A total of 143 asymptomatic pouch patients were included. Index endoscopic pouch body activity was graded as 0 in 86 (60.1%) patients, 1 in 26 (18.2%) patients and 2 in 31 (21.7%) patients. The median length of follow-up after index surveillance pouchoscopy was 3.03 [IQR 1.24–4.60] years. Primary acute idiopathic pouchitis occurred in 44 (31%) patients and chronic idiopathic pouchitis in 12 (8.4%) patients. Grade 2 endoscopic pouch activity was associated with the development of acute pouchitis (HR 2.39, 95% CI 1.23–4.67), however not chronic pouchitis (HR 1.76, 95% CI 0.53–5.87). Histologic inflammation in endoscopically normal pouch mucosa was not associated with acute or chronic pouchitis. CONCLUSIONS: Mucosal breaks are present in nearly a quarter of asymptomatic pouch patients and are associated with an increased risk of acute pouchitis.

Surgical treatment of ileosigmoid fistulas in Crohn's disease is poorly characterized.The purpose of this study was to identify differences in patient postoperative outcomes for isolated ileosigmoid fistulas by surgical approach (laparoscopic versus open) and sigmoid colon repair type (sigmoid resection versus primary repair).Using a prospectively collected database, we gathered perioperative data from chart reviews to calculate differences and associations between treatment groups.The study was conducted at a single tertiary care center.Patients with Crohn's disease who underwent surgery for isolated ileosigmoid fistulas between July 1, 2010, and June 30, 2016 were included.We identified 84 patients, with an average age of 37 years. A total of 51 were men and 33 were women; 34 underwent a sigmoid resection, whereas 50 had a primary repair of the sigmoid. All of the patients underwent an ileocolic resection. A total of 67 surgeries were initially attempted laparoscopically, of which 17 (25.4%) were converted to open, with 50 (59.5%) completed laparoscopically. There were no significant differences in length of stay or incidence of postoperative complications by surgical approach (laparoscopic versus open). For patients who underwent a primary sigmoid repair versus a sigmoid resection, there were no significant differences in postoperative complications, but there was a significant difference in the length of stay (6.36 vs 9.56 d for primary repair versus resection; multivariate p value of 0.022).Postoperative complications and length of stay were measured.The study was limited by its small sample size, cross-sectional nature of the data, and limited information about preoperative outpatient medical treatment.Laparoscopic surgery for isolated ileosigmoid fistulas in Crohn's disease is safe and does not result in a different length of stay or incidence of postoperative complications. Primary repair (rather than resection) of the sigmoid colon in these cases, when feasible, appears to be safe and is likely to be cost-effective given the reduced length of stay. See Video Abstract at http://links.lww.com/DCR/A993. TÉCNICAS QUIRÚRGICAS Y DIFERENCIAS EN LOS RESULTADOS POSTOPERATORIOS PARA LOS PACIENTES CON ENFERMEDAD DE CROHN CON FÍSTULAS ILEO-SIGMOIDEAS: UNA EXPERIENCIA EN UNA SOLA INSTITUCIÓN, 2010-2016: El tratamiento quirúrgico de las fístulas ileo-sigmoideas en la enfermedad de Crohn está mal caracterizado.Identificar las diferencias en los resultados postoperatorios de los pacientes para las fístulas ileo-sigmoideas aisladas por abordaje quirúrgico (laparoscópica versus abierta) y tipo de reparación de colon sigmoide (resección sigmoidea versus reparación primaria). DISEÑO:: Utilizando una base de datos recopilada de forma prospectiva, se recopilaron datos perioperatorios de las revisiones de los gráficos para calcular las diferencias y las asociaciones entre los grupos de tratamiento.Un solo centro de atención terciaria.Pacientes con enfermedad de Crohn que se sometieron a una cirugía para fístulas ileo-sigmoideas aisladas entre el 1 de julio de 2010 y el 30 de junio de 2016.Se identificaron 84 pacientes, con una edad promedio de 37 años. Un total de 51 eran hombres y 33 mujeres; 34 se sometieron a una resección sigmoidea, mientras que 50 tuvieron una reparación primaria del sigmoide. Todos los pacientes fueron sometidos a resección ileocólica. Inicialmente, un total de 67 círugias se intentaron por vía laparoscópica, de las cuales 17 (25,4%) se convirtieron en cirugías abiertas, y 50 (59,5%) se completaron por vía laparoscópica. No hubo diferencias significativas en la duración de la estancia o la incidencia de complicaciones postoperatorias por abordaje quirúrgico (laparoscópica versus abierta). Para los pacientes que se sometieron a una reparación sigmoidea primaria versus una resección sigmoidea, no hubo diferencias significativas en las complicaciones postoperatorias, pero sí hubo una diferencia significativa en la duración de la estancia hospitalaria (6,36 versus a 9,56 días para la reparación primaria frente a la resección; p multivariable -valor de 0.022).Complicaciones postoperatorias y duración de la estancia.Tamaño de muestra pequeño, naturaleza transversal de los datos e información limitada sobre el tratamiento médico ambulatorio preoperatorio del paciente.La cirugía laparoscópica para fístulas ileo-sigmoideas aisladas en la enfermedad de Crohn es segura y no ocasiona una duración diferente de la estancia hospitalaria ni una incidencia diferente de complicaciones postoperatorias. La reparación primaria (en lugar de la resección) del colon sigmoide en estos casos, cuando es posible, parece ser segura y es probable que sea rentable, dada la duración reducida de la estancia. Vea el Resumen del Video en http://links.lww.com/DCR/A993.

Background Total proctocolectomy (TPC) with ileal pouch anal anastomosis (IPAA) is the gold standard surgery for ulcerative colitis (UC) patients with medically refractory disease. The aim of this study was to report the rates and risk factors of inflammatory pouch conditions. Methods This was a retrospective review of UC or IBD unspecified (IBDU) patients who underwent TPC with IPAA for refractory disease or dysplasia between 2008 and 2017. Pouchoscopy data were used to calculate rates of inflammatory pouch conditions. Factors associated with outcomes in univariable analysis were investigated in multivariable analysis. Results Of the 621 patients more than 18 years of age who underwent TPC with IPAA between January 2008 and December 2017, pouchoscopy data were available for 386 patients during a median follow-up period of 4 years. Acute pouchitis occurred in 205 patients (53%), 60 of whom (30%) progressed to chronic pouchitis. Cuffitis and Crohn's disease–like condition (CDLC) of the pouch occurred in 119 (30%) patients and 46 (12%) patients, respectively. In multivariable analysis, female sex was associated with a decreased risk of acute pouchitis, and pre-operative steroid use and medically refractory disease were associated with an increased risk; IBDU was associated with chronic pouchitis; rectal cuff length ≥2 cm and medically refractory disease were associated with cuffitis; age 45–54 at colectomy was associated with CDLC. Rates of pouch failure were similar in chronic pouchitis and CDLC patients treated with biologics and those who were not. Conclusions Inflammatory pouch conditions are common. Biologic use for chronic pouchitis and CDLC does not impact the rate of pouch failure.

Background Portomesenteric venous thrombosis (PMVT) is an under-recognized complication of colorectal surgery. The aim of this study was to describe the rate and risk factors for PMVT in patients undergoing surgery for medically refractory ulcerative colitis (UC). Methods A retrospective review of medically refractory UC patients who underwent surgery between January 2010 and December 2016 at a single tertiary care center was conducted. PMVT was defined as thrombus within the portal, splenic, superior, or inferior mesenteric vein on postoperative abdominal computed tomography scans. Factors associated with PMVT on univariable analysis were tested in multivariable analysis. Clinical relevance of risk factors was examined with receiver operating characteristic curves and Kaplan-Meier curves. Results A total of 434 patients were identified. Postoperative venous thromboembolism (VTE) prophylaxis was administered to 428 (98.5%) inpatients for a mean duration of 7.7 ± 0.17 days. PMVT developed in 36 (8.3%) patients a mean interval of 55.3 ± 10.8 days after index surgery. The majority of PMVT occurred after subtotal colectomy, and the most common initial symptom was abdominal pain. Preoperative C-reactive protein (CRP) was associated with PMVT (odds ratio, 1.01; 95% confidence interval, 1.00-1.02; P = 0.01), and the optimal predictive CRP threshold was 45 mg/L. The rate of PMVT development was greater for patients with CRP >45 mg/L (P = 0.01). Conclusions PMVT can present as abdominal pain and occur multiple weeks after discharge. Further studies are needed to identify the appropriate postoperative outpatient thrombosis prophylaxis regimen for at-risk patients.

Rationale: Obstructive sleep apnea (OSA) is associated with recurrent obstruction, subepithelial edema, and airway inflammation. The resultant inflammation may influence or be influenced by the nasal microbiome. Objectives: To evaluate whether the composition of the nasal microbiota is associated with obstructive sleep apnea and inflammatory biomarkers. Methods: Two large cohorts were used: 1) a discovery cohort of 472 subjects from the WTCSNORE (Seated, Supine and Post-Decongestion Nasal Resistance in World Trade Center Rescue and Recovery Workers) cohort, and 2) a validation cohort of 93 subjects rom the Zaragoza Sleep cohort. Sleep apnea was diagnosed using home sleep tests. Nasal lavages were obtained from cohort subjects to measure: 1) microbiome composition (based on 16S rRNA gene sequencing), and 2) biomarkers for inflammation (inflammatory cells, IL-8, and IL-6). Longitudinal 3-month samples were obtained in the validation cohort, including after continuous positive airway pressure treatment when indicated. Measurements and Main Results: In both cohorts, we identified that: 1) severity of OSA correlated with differences in microbiome diversity and composition; 2) the nasal microbiome of subjects with severe OSA were enriched with Streptococcus, Prevotella, and Veillonella; and 3) the nasal microbiome differences were associated with inflammatory biomarkers. Network analysis identified clusters of cooccurring microbes that defined communities. Several common oral commensals (e.g., Streptococcus, Rothia, Veillonella, and Fusobacterium) correlated with apnea–hypopnea index. Three months of treatment with continuous positive airway pressure did not change the composition of the nasal microbiota. Conclusions: We demonstrate that the presence of an altered microbiome in severe OSA is associated with inflammatory markers. Further experimental approaches to explore causal links are needed.

Abstract 3170 Background: The Prothrombin time (PT) can be performed in laboratories by instruments such as BCS (Siemens), and at the Point of Care using devices such as the Protime 3 (ITC) and the Coaguchek XS (Roche). Laboratory based instruments such as the BCS have been regarded as the Gold Standard for PT/INR assuming results can be obtained in under 24 hours from blood drawn in an uncentrifuged sample. A previous study performed in the Netherlands recommends that INR testing be completed within 6 hours of blood draw. This recommendation has not been universally adopted. In order to assess this effect, a study comparing the laboratory instrument (BCS) to POC instruments was performed while simultaneously comparing lab based results at or greater than 6 hours. Methods: The INR values of the BCS in two separate laboratories, Coaguchek XS, and Protime 3 were compared to each other. The INR values and turnaround times for each were recorded. The results were compared using paired observation T-tests and regression analysis including all data and within sub-therapeutic (3.0). Additionally, point of care results were compared to BCS test results before and after 6 hours. Results: 60 patients had 3 INR test methods performed. All samples were tested in two different reference laboratories, both using BCS testing method. Reference lab A performed the tests under optimal conditions including a turnaround times of less than 2 hours, while Reference lab B performed the tests under usual workflow conditions. While the total Protime 3 results were significantly different from Reference lab A, the Coaguchek XS results were not. In the therapeutic range, the Coaguchek XS and Reference lab B had significant correlation (r = .556 and .634 respectively) to reference lab A while the Protime 3 did not (r = .281). Reference lab B results were significantly different from Reference lab A when testing was performed after 6 hours (P-value = .0252), but had similar results to Reference lab A when performed within 6 hours (P-value = .402). The Coaguchek XS showed no significant differences when compared to Reference lab A results (p-value = .1262). Another indicator of lack of concordance between Reference lab A and B, when testing is performed greater than 6 hours, was the change in directionality of the bias (p-value = .0396). Additionally, Protime 3 results in the therapeutic range correlated significantly better with Reference lab B results when they were resulted within 6 hours (r= .191 and r= .782). Conclusions: Based on these findings, the BCS method appears to lose reliability when the test is performed on uncentrifuged blood greater than 6 hours after blood draw. Interestingly, the Coaguchek XS correlated best with Reference lab A, BCS testing under optimal conditions. The Protime 3, on the other hand, was less well correlated with Reference lab A. The change in directionality of the bias also suggests that the BCS results were flawed when testing was performed after 6 hours. Although additional preanalytic factors (i.e. temperature) may have had an effect on these results, these data suggest that laboratory based INR testing should be performed within six hours of sample collection. Disclosures: No relevant conflicts of interest to declare.

Abstract 4256 Background: Activated clotting time (ACT) is determined during cardiac procedures in order to assess the level of anti-coagulation. There are three main anticoagulants used during cardiac procedures:heparin, angiomax and Plavix. Heparin is often used in the cardiac OR for major procedures and is neutralized, over time, by platelet factor 4(PF4). Angiomax, bivalirudin, has a quick onset of action, but a much shorter half-life when compared to Heparin. Plavix, clopidogrel, irreversibly inhibits platelets from clotting and is used on patients in need of anticoagulation for an extended period of time. The purpose of this study was to evaluate the stability of ACT results over time utilizing different coagulation regimens. If the ACT value remains stable over time, this would enable us to remove the device from the OR and place it in a stat laboratory. Methods: ACTs were determined by the ISTAT (Abbott), a hand held point of care device, using kaolin activated cartridges. A single blood sample was obtained and was evaluated at intervals of 0, 5, 10, 15, and 20 minutes. In addition, temperature, age, body surface area and platelet count of patient were recorded. The time 0 specimen was used to determine the patients ACT and interval testing was performed on the remnant. Results: 36 samples representing 22 patients had ACT tests performed using the ISTAT. There was no significant change from 0 to 20 minutes over the entire dada set. However, when divided into different anti-clotting agents there were significant changes. Patients who had only taken Angiomax had a significant difference within the first 5 minutes (p value=.0094). Patients taking Angiomax and Plavix together had no change in ACT values at 20 minutes. Patients on Heparin alone demonstrated a loss of ACT stability at 10 minutes with values both increasing and decreasing. Conclusions: Patients on Angiomax alone demonstrated a significant difference in ACT value within the first 5 minutes and all intervals thereafter. Based on Angiomax short half-life the ACT should be performed as soon as possible. The ACT values in patients taking both Angiomax and Plavix achieved steady state throughout the 20 minutes and had little if any decrease in value. The results for the Heparin group were unreliable at 10 minutes. As a result of these findings, performing an ACT outside the OR is feasible assuming the test can be performed by 10 minutes. Disclosures: No relevant conflicts of interest to declare.