North American Consensus Research Articles

Intestinal Methanogen Overgrowth (IMO) Is Associated with Delayed Small Bowel and Colonic Transit Time (TT) on the Wireless Motility Capsule (WMC).

Methanogens are associated with gut dysmotility in animal models but have not been robustly studied in humans. The WMC assesses regional transit time (TT) and pH in the GI tract. To study the segmental TT and pH among patients with SIBO or IMO utilizing WMC. We conducted a retrospective study of 207 patients who underwent a glucose or lactulose breath test (BT) and WMC from 2010 to 2022. Diagnosis of SIBO and IMO were based on the 2017 North American consensus criteria. TT and pH were extracted from WMC recordings. We tested for differences in means of continuous variables and frequencies of categorical variables using two-sample t tests, Wilcoxon Rank Sum test, Chi-square, and Fisher exact tests. We used R version 3.3.1 (2016-06-21) for all statistical analyses. A total of 196 patients met criteria, mean age 47.4years and 155 (79.1%) females. Of the 86 (43.9%) patients with a positive BT, 42 (58.3%) had IMO only (meeting only CH4 criteria) and 30 (34.9%) met both H2 and CH4 criteria. Colonic TT was longer in patients with a positive BT compared to negative patients (40h:29min vs 28h:51min, p = 0.028). Small bowel TT and colonic TT were longer in patients with IMO compared to negative patients (SBTT: 5h:15min vs 4h:32min, p = 0.021; CTT: 44h:23min vs 28h:51min, p = 0.030). There were no significant differences in segmental pH compared to negative patients. To our knowledge, this is the largest study of patients who have undergone both BT and WMC. A positive BT was associated with delayed CTT, while having IMO only was associated with both delayed CTT and SBTT, but neither with pH. Future investigation is needed to elucidate whether changes in intestinal microbiota affect gut transit.

Girth-based administered activity for pediatric 99m Tc-DMSA SPECT.

Pediatric molecular imaging requires a balance between administering an activity that will yield sufficient diagnostic image quality while maintaining patient radiation exposure at acceptable levels. In current clinical practice, this balance is arrived at by the current North American Consensus Guidelines in which patient weight is used to recommend the administered activity (AA). We have previously demonstrated that girth (waist circumference at the level of the kidneys) is better at equalizing image quality than patient weight for pediatric Tc-99m DMSA renal function imaging. However, the correlation between image quality (IQ), AA, and patient girth has not been rigorously and systematically developed. In this work, we generate a series of curves showing the tradeoff between AA and IQ as a function of patient girth, providing the data for standards bodies to develop the next generation of dosing guideline for pediatric DMSA SPECT. An anthropomorphic phantom series that included variations in age (5, 10, and 15 years), gender (M, F), local body morphometry (5, 10, 50, 90, and 95th girth percentiles), and kidney size (±15% standard size), was used to generate realistic SPECT projections. A fixed and clinically challenging defect-to-organ volume percentage (0.49% of renal cortex value) was used to model a focal defect with zero uptake (i.e., full local loss of renal function). Task-based IQ assessment methods were used to rigorously measure IQ in terms of renal perfusion defect detectability. This assessment was performed at multiple count levels (corresponding to various AAs) for groups of patients that had similar girths and defect sizes. Receiver-operating characteristics (ROC) analysis was applied; the area under the ROC curve (AUC) was used as a figure-of-merit for task performance. Curves showing the tradeoff between AUC and AA were generated for these groups of phantoms. Overall, the girth-based dosing method suggested different amounts of AA compared to weight-based dosing for the phantoms that had a relatively large body weight but a small girth or phantoms with relatively small bodyweight but large girth. Reductions of AA to 62.9% compared to weight-based dosing guidelines can potentially be realized while maintaining a baseline (AUC=0.80) IQ for certain 15-year-olds who have a relatively small girth and large defect size. Note that the task-based IQ results are heavily dependent on the simulated defect size for the defect detection task and the appropriate AUC value must be decided by the physicians for this diagnostic task. These results are based purely on simulation and are subject to future clinical validation. The study provides simulation-based IQ-AA data for a girth-based dosing method for pediatric renal SPECT, suggesting that patient waist circumference at the level of kidneys should be considered in selecting the AA needed to achieve an acceptable IQ. This data may be useful for standards bodies to develop girth-based dosing guidelines.

Contribution of Hyperbaric Oxygen Therapy in the Management of Gas Gangrene, Necrotizing Fasciitis and Suppuration of the Limbs

Hyperbaric oxygen therapy (HBOT) is defined as a method of administering inhaled oxygen (O2) for therapeutic purposes under a pressure greater than atmospheric pressure. The therapeutic benefits of HBO result, on the one hand, from the physical effects linked to the increase in barometric pressure and the partial pressure of O2 in the tissues and, on the other hand, from the biological effects linked to the production reactive species of O2 and nitrogen. These are likely to interact with many molecular processes responsible for the main anti-ischemic, pro-healing and anti-infective effects. Its indications are regularly evaluated within the framework of international consensus conferences. The references in terms of indications for HBO are, on the one hand, the North American consensus of the Undersea and Hyperbaric Medical Society (UHMS) and, on the other hand, the European consensus of the European Committee of Hyperbaric Medicine (ECHM). HBOT is applied through an hyperbaric chamber. It is a complex technique, which requires a strong human and material investment. It includes some contreindications to respect and well-identified risks to take into account.

S1582 Abnormal Glucose Breath Test Does Not Correlate With Patient’s Self-Reported Symptoms and Their Severity

Introduction: Glucose Hydrogen Breath Testing (GBT) is commonly used for diagnosing Small Intestinal Bacterial Overgrowth (SIBO). However, patients present with clinical symptoms (sx) and their predictive value for a positive (pos) GBT remains unclear. AIM: To assess the prevalence of self-reported GI sx profiles in adults with unexplained upper GI symptoms and correlate this with GBT. Methods: We retrospectively analyzed all adult patients presenting to a single medical center from 6/20 –12/21 for GBT. A pos GBT for SIBO was defined by the North American Consensus (≥20 ppm H2 increase over basal within 90 minutes (mins) and/or ≥10 ppm CH4 at any time). Pts completed a GI questionnaire assessing 17 key sxs: regurgitation (RG), chest pain (CP), heartburn (HB), belch (BH), abdominal pain (AP), bloating (BT), gas (GS), nausea (NA), vomit (VT), abdominal cramps (AC), indigestion (ID), distension (DN), fullness (FL), early satiety (ES), diarrhea (DR), constipation (CN), and fatigue (FT). Sxs measured by frequency (None, < 1/week (wk), 1/wk, ≥ 1/wk), intensity (None, Mild, Moderate, Severe), and duration (None, < 10 mins, 10 – 30 mins, ≥ 30 mins). Sub-groups, GERD, Dyspeptic, and IBS were constructed assessing the mean summation scores for Frequency, Intensity, and Duration between negative (neg) and pos GBTs. Univariate analysis and logistic regression analysis was performed. A P-value of < 0.05 was considered statistically significant. Results: We evaluated 184 pts, mean age of 51.7 (18 – 85), 78.3% female, 82.8% Caucasian, and mean BMI of 27.2. No significant differences were seen between GI sx frequency and intensity categories for pts with GBT neg and pos groups. A trend for a higher percentage of pos GBT pts reporting FL (P=0.09) and DR (P=0.07) in sx duration categories of 10 -30 mins (FL: 30.8% vs 27.5%; DR: 31.8% vs 23.4%) and ≥ 30 mins (FL: 51.3% vs 41.3%; DR: 37.2% vs 22.1%) was noted. Regression analysis showed a trend toward a pos GBT for VT frequency of Less than 1/wk: (P = 0.07; OR = 2.99; 95% CI: 0.91, 9.83) and NA intensity of Severe: (P = 0.09; OR = 2.24; 95% CI: 0.86, 5.84). No differences were seen between the GERD, Dyspeptic, and IBS sub-groups (Figure). Conclusion: The pre-test predictability of GI symptoms as it relates to a pos or neg GBT is poor. The yield for a pos GBT varies between 31%-55% and depends on age. In routine practice, when the index of clinical suspicion is high for SIBO, clinicians should consider objective testing with GBT rather than empiric antibiotic treatment.Figure 1.: (Left) Mean Summation Scores for Self-Reported Frequency, Intensity, and Duration Responses to GI Symptoms Relative to the Gastroesophageal Reflux Disease (GERD), Dyspeptic, and irritable bowel syndrome (IBS) Groups. (Right) Prevalence of Positive Glucose Breath Test (GBT) Among Age Cohorts and Glucose Breath Test Measurements

Performance and Interpretation of Hydrogen and Methane Breath Testing Impact of North American Consensus Guidelines

BackgroundHydrogen and methane breath tests (HMBT) are widely used clinical investigations but lack standardization. To address this, the North American Consensus (NAC) group published evidence-based recommendations for HMBT.AimsTo evaluate results obtained using NAC recommendations for HMBT, compared to retrospective data that utilized guidelines previously recommended.MethodsHMBT data from 725 patients referred for small intestinal bacterial overgrowth (SIBO) and/or carbohydrate malabsorption (CM) testing were analyzed. Data were compared regarding dose of substrate for SIBO testing (16 vs. 10 g lactulose, and 50 vs. 75 g glucose) and the effect of post-ingestion sampling period for malabsorption testing. The effect of different recommended cut-off values for SIBO were examined.ResultsSubstrate dose did not affect methane production. 10 g lactulose significantly reduced positive SIBO results compared to 16 g lactulose (42 vs. 53%, p = 0.04). 75 g glucose significantly increased positive results compared to 50 g glucose (36 vs. 22%, p = 0.04). Provoked symptoms were significantly more prevalent in patients testing positive by both North American Consensus and Ledochowski cut-off values.34.5% of patients tested positive for CM at 180-min compared to 28% at 120-min (not significant, p = 0.19).Conclusions and Inferences10 g lactulose substrate produces fewer positive SIBO results than 16 g lactulose, while 75 g glucose dose produces more positive SIBO results than 50 g. Performing CM breath tests for 180 min increases number of positive results when compared to 120 min. SIBO cut-off timings require further investigation, but our findings broadly support the NAC recommendations for SIBO and CM testing.

Eradication of small intestinal bacterial overgrowth in irritable bowel syndrome using herbal therapy: A case report

Small intestinal bacterial overgrowth (SIBO) is a common pathology in irritable bowel syndrome (IBS). Symptoms include bloating, excessive belching, flatulence, epigastric and abdominal pain, nausea, early satiety, fatigue and altered bowel habits. Given the high incidence of IBS globally, SIBO needs to be investigated in IBS using hydrogen and methane breath testing. Adherence to the North American Consensus 2017 or the updated guidelines from the Association of Gastrointestinal Physiology (AGIP) committee of the British Society of Gastroenterology 2019 is necessary to ensure that testing and diagnosis are standardised. The treatment of SIBO with antibiotics, most commonly rifaximin, may restore gastrointestinal function and reduce the symptoms of IBS. A number of herbal and nutraceutical supplements are known to exert antimicrobial effects. There is increasing awareness amongst the public regarding these herbal and nutraceutical supplements, and there is an increased demand for their use. The present study describes the case of a patient with severe IBS symptoms, scoring in the extreme category on a quality of life questionnaire validated for IBS and functional digestive disorders. The patient tested positive for SIBO, which was then eradicated using a herbal formulation containing garlic, berberine, oregano, grapefruit seed extract and caprylic acid, while following a diet low in fermentable oligo‑, di‑, mono‑saccharides and polyols (FODMAP). The patient's quality of life assessment markedly improved following treatment and the remaining symptoms improved at the 3‑month follow‑up performed by verbal confirmation.

Sobrecrecimiento bacteriano del intestino delgado en pacientes con lesión medular

AimSpinal cord injury (SCI) patients may have intestinal dysmotility and digestive symptoms that are associated with small intestinal bacterial overgrowth (SIBO). The aim of this study is to describe the prevalence of SIBO in SCI patients and the risk factors of its development. MethodsTwenty-nine consecutive SCI patients were studied (10 women/19 men; mean age 47 years), 16 with subacute injuries (<9 months) and 13 with chronic injuries (>1 year). Nine patients were affected by tetraplegia and 15 by paraplegia. Each patient underwent a glucose breath test according to the North American Consensus and the presence of abdominal symptoms was evaluated during the test.The results were compared with 15 non-neurological patients with SIBO. ResultsSix patients tested positive for SIBO (21%), all of them affected by SCI in the subacute phase, 6/16 vs. 0/13 in the chronic phase (P<.05) and the majority with tetraplegia, 5/9 vs. 1/19 with paraplegia (P<.05). No statistically significant relationship was found with other clinical characteristics. All the tests were positive for methane or mixed (methane and hydrogen), while only 67% of the controls had methane-predominant production (P>.05). ConclusionSCI patients can develop SIBO, more frequently in the subacute phase and in tetraplegic patients, highlighting a high production of methane. This complication should be considered in neurogenic bowel management.

Antithrombotic Therapy in Patients With Atrial Fibrillation Treated With Oral Anticoagulation Undergoing Percutaneous Coronary Intervention

A growing number of patients undergoing percutaneous coronary intervention (PCI) with stent implantation also have atrial fibrillation. This poses challenges for their optimal antithrombotic management because patients with atrial fibrillation undergoing PCI require oral anticoagulation for the prevention of cardiac thromboembolism and dual antiplatelet therapy for the prevention of coronary thrombotic complications. The combination of oral anticoagulation and dual antiplatelet therapy substantially increases the risk of bleeding. Over the last decade, a series of North American Consensus Statements on the Management of Antithrombotic Therapy in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention have been reported. Since the last update in 2018, several pivotal clinical trials in the field have been published. This document provides a focused updated of the 2018 recommendations. The group recommends that in patients with atrial fibrillation undergoing PCI, a non-vitamin K antagonist oral anticoagulant is the oral anticoagulation of choice. Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor should be given to all patients during the peri-PCI period (during inpatient stay, until time of discharge, up to 1 week after PCI, at the discretion of the treating physician), after which the default strategy is to stop aspirin and continue treatment with a P2Y12 inhibitor, preferably clopidogrel, in combination with a non-vitamin K antagonist oral anticoagulant (ie, double therapy). In patients at increased thrombotic risk who have an acceptable risk of bleeding, it is reasonable to continue aspirin (ie, triple therapy) for up to 1 month. Double therapy should be given for 6 to 12 months with the actual duration depending on the ischemic and bleeding risk profile of the patient, after which patients should discontinue antiplatelet therapy and receive oral anticoagulation alone.

How the North American Consensus Protocol Affects the Performance of Glucose Breath Testing for Bacterial Overgrowth Versus a Traditional Method

The North American Consensus guidelines for glucose breath testing (GBT) for small intestinal bacterial overgrowth (SIBO) incorporated changes in glucose dosing and diagnostic cutoffs. We compared GBT positivity based on hydrogen and methane excretion and quantified symptoms during performance of the North American vs older modified Rome Consensus protocols. GBT was performed using the North American protocol (75 g glucose, cutoffs >20 parts per million [ppm] hydrogen increase after glucose and >10 ppm methane anytime) in 3,102 patients vs modified Rome protocol (50 g glucose, >12 ppm hydrogen and methane increases after glucose) in 3,193 patients with suspected SIBO. Positive GBT were more common with the North American vs modified Rome protocol (39.5% vs 29.7%, P < 0.001). Overall percentages with GBT positivity using methane criteria were greater and hydrogen criteria lower with the North American protocol (P < 0.001). Peak methane levels were higher for the North American protocol (P < 0.001). Times to peak hydrogen and methane production were not different between protocols. With the North American protocol, gastrointestinal and extraintestinal symptoms were more prevalent after glucose with both positive and negative GBT (P < 0.04) and greater numbers of symptoms (P < 0.001) were reported. GBT performed using the North American Consensus protocol was more often positive for SIBO vs the modified Rome protocol because of more prevalent positive methane excretion. Symptoms during testing were greater with the North American protocol. Implications of these observations on determining breath test positivity and antibiotic decisions for SIBO await future prospective testing.

Small-bowel aspiration during upper esophagogastroduodenoscopy: Rao technique.

Small-bowel aspiration during upper esophagogastroduodenoscopy: Rao technique.

Body morphometry appropriate computational phantoms for dose and risk optimization in pediatric renal imaging with Tc-99m DMSA and Tc-99m MAG3

Current guidelines for administered activity (AA) in pediatric nuclear medicine imaging studies are based on a 2016 harmonization of the 2010 North American Consensus guidelines and the 2007 European Association of Nuclear Medicine pediatric dosage card. These guidelines assign AA scaled to patient body mass, with further constraints on maximum and minimum values of radiopharmaceutical activity. These guidelines, however, are not formulated based upon a rigor-ous evaluation of diagnostic image quality. In a recent study of the renal cortex imaging agent 99mTc-DMSA (Li Y et al 2019), body mass-based dosing guidelines were shown to not give the same level of image quality for patients of differing body mass. Their data suggest that patient girth at the level of the kidneys may be a better morphometric parameter to consider when selecting AA for renal nuclear medicine imaging. The objective of the present work was thus to develop a dedicated series of computational phantoms to support image quality and organ dose studies in pediatric renal imaging using 99mTc-DMSA or 99mTc-MAG3. The final library consists of 50 male and female phantoms of ages 0 to 15 years, with percentile variations (5th to 95th) in waist circumference (WC) at each age. For each phantom, nominal values of kidney volume, length, and depth were incorporated into the phantom design. Organ absorbed doses, detriment-weighted doses, and stochastic risks were assessed using ICRP reference biokinetic models for both agents. In Monte Carlo radiation transport simulations, organ doses for these agents yielded detriment-weighted dose coefficients (mSv/MBq) that were in general larger than current ICRP values of the effective dose coefficients (age and WC-averaged ratios of eDW/e were 1.40 for the male phantoms and 1.49 for the female phantoms). Values of risk index (ratio of radiation-induced to natural background cancer incidence risk x 100) varied between 0.062 (newborns) to 0.108 (15-year-olds) for 99mTc-DMSA and between 0.026 (newborns) to 0.122 (15-year-olds) for 99mTc-MAG3. Using tallies of photon exit fluence as a rough surrogate for uniform image quality, our study demonstrated that through body region-of-interest optimization of AA, there is the potential for further dose and risk reductions of between factors of 1.5 to 3.0 beyond simple weight-based dosing guidance.

Antithrombotic Therapy in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention.

Patients with atrial fibrillation who undergo percutaneous coronary intervention with drug-eluting stent implantation often require oral anticoagulation (OAC) and antiplatelet therapies. Triple antithrombotic therapy (OAC, a P2Y12-receptor inhibitor, and aspirin) has been the default antithrombotic strategy. Evidence from randomized trials indicates, however, that a dual antithrombotic therapy strategy (OAC plus a P2Y12-receptor inhibitor) reduces bleeding risk without increasing the risk of ischemic events. This review provides an overview of advancements in this field as well as European and North American guidelines and consensus documents to inform clinical decision making around antithrombotic therapies for patients with atrial fibrillation who undergo percutaneous coronary intervention.

Optimal Antithrombotic Treatment of Patients with Atrial Fibrillation Early after an Acute Coronary Syndrome-Triple Therapy, Dual Antithrombotic Therapy with an Anticoagulant… Or, Rather, Temporary Dual Antiplatelet Therapy?

The combination of atrial fibrillation (AF) and acute coronary syndrome (ACS) is a complex situation in which a three-dimensional risk—cardioembolic, coronary, and hemorrhagic—has to be carefully managed. Triple antithrombotic therapy (TAT) is burdened with a high risk of serious bleeding, while dual antithrombotic therapy with an anticoagulant (DAT) likely provides only suboptimal coronary protection early after stent implantation. Moreover, TAT precludes the advantages provided by the use of the latest and more potent P2Y12 inhibitors in ACS patients. Here, we aimed to simulate and compare the expected coronary, cardioembolic, and hemorrhagic outcomes offered by DAT, TAT, or modern dual antiplatelet therapy (DAPT) with aspirin plus one of the latest P2Y12 inhibitors in AF patients early after an ACS. The comparison of numbers needed to treat to prevent major adverse events with the various antithrombotic regimens suggests that AF–ACS patients at high ischemic and hemorrhagic risk and at moderately low embolic risk (CHA2DS2VASc score 2–4) might safely withhold anticoagulation after revascularization for one month taking advantage of a modern DAPT, with a favorable risk-to-benefit ratio. In conclusion, this strategy, not sufficiently addressed in recent European and North American guidelines or consensus documents, adds to the spectrum of treatment options in these difficult patients; it might be the best choice in a substantial number of patients; and should be prospectively tested in a randomized controlled trial.

Core principles for fracture prevention: North American Consensus from the National Osteoporosis Foundation, Osteoporosis Canada, and Academia Nacional de Medicina de Mexico.

The large number of clinical practice guidelines for osteoporosis and discordance of recommendations has led to confusion among clinicians and patients, and likely contributes to the large osteoporosis treatment gap. We propose that stakeholder organizations reach agreement on fundamental principles in the management of osteoporosis and prevention of fracture as a first step toward a goal of guideline harmonization. The best available evidence, as interpreted by an ad hoc working group of expert representatives from major osteoporosis societies in North America, was considered in the development of core principles for skeletal healthcare. These principles were subsequently endorsed by the USA National Osteoporosis Foundation, Osteoporosis Canada, and Academia Nacional de Medicina de Mexico (National Academy of Medicine of Mexico). Core principles are summarized here in bullet format. Categories include evaluation, lifestyle and nutrition, pharmacological therapy, and monitoring. A pathway forward to achieve guideline harmonization, at least in part, is proposed. Greater concordance of recommendations for the care of patients at risk for fracture are expected to lead to improved patient care across jurisdictions, with a narrowing of the osteoporosis treatment gap and reduced burden of fractures.

Use of breath testing in gastrointestinal disorders

The article presents the data and review of the North American Consensus (2017) recommendations on the use of hydrogenmethane breathing test in diagnosing gastrointestinal disorders accompanied by excessive bacterial growth in the small intestine. On May 16, 2015, 17 leading scientists specializing in breathing tests took part in a consensus meeting in Washington (DC, USA). By a voting method, 28 consensus statements were identified and recommendations were given on the following issues regarding the use of the hydrogen-methane the procedure itself test in gastroenterological practice: 1) preparation for a breathing test; 2) indications for a breathing test; 3) the procedure itself; 4) interpretation of results; 5) gaps in the knowledge and unresolved issues.

Correction to: Characterization of Proximal Small Intestinal Microbiota in Patients With Suspected Small Intestinal Bacterial Overgrowth: A Cross-Sectional Study.

Small intestinal bacterial overgrowth (SIBO) has historically been described in the context of maldigestion and malabsorption in patients with anatomic abnormalities (e.g., fistulae, strictures, bowel reconstruction, bowel obstruction), underlying dysmotility secondary to diabetes or scleroderma, and hypochlorhydria (1). This syndrome has also been implicated in the pathophysiology of numerous gastrointestinal and hepatobiliary diseases including common conditions such as irritable bowel syndrome (IBS) (2) and functional dyspepsia (3). Typical SIBO-associated symptoms include bloating, diarrhea, abdominal pain, and gas. SIBO symptoms may overlap with those of functional gastrointestinal disorders. However, the role of SIBO in the pathogenesis of functional gastrointestinal disorders remains controversial given that its definition relies on tests, including breath test and culture of small bowel aspirates, which have not been appropriately validated (4). Indirect techniques such as breath testing have important limitations related to heterogeneous testing methods and lack of standardization in interpretation. To address these limitations, guidelines for breath testing indications, performance, and interpretation were recently published in a North American consensus document (5). Yet, there remain important knowledge gaps in how these tests reflect the microbial landscape of the human small intestine. Small bowel aspirates and culture were previously considered the gold standard for the diagnosis of SIBO. SIBO has traditionally been defined by abnormally high amounts of bacteria in the small intestine and more precisely by >105 colony-forming units (CFU)/mL of colonic-type bacteria from jejunal aspirates (6). However, the validity of this approach has been questioned as the proposed cutoff of 105 seemed more predictive of postsurgical patients in a previous systematic review (7). Others have suggested that lower cutoff values of 103 CFU/mL be considered as diagnostic of SIBO (5), especially if coliforms are present (8). Standard culture-based techniques are limited in their ability to characterize fully the complex diversity of the small intestinal microbiome, particularly as a large proportion of bacterial species remain uncultured (9). In light of increasing evidence supporting the hypothesis that the intestinal microbiome serves a key role in host physiology and gastrointestinal disease, better characterization of the small intestinal microbiome will be a critical step in developing novel diagnostic and therapeutic strategies in a number of human diseases and disorders. In the recent years, the introduction of culture-independent techniques has dramatically expanded our ability to characterize the complexity of the intestinal microbiota. It also has increased our knowledge of the culture conditions needed to detect and identify previously difficult to culture organisms (10). Integration of rapid molecular approaches (11) for the assessment of SIBO in conditions such as IBS has yielded promising data including evidence for decreased microbial diversity from duodenal aspirates in patients with IBS compared with control subjects (12). However, these findings are preliminary. Overall, there are limited data reporting detailed characterizations of the human small intestinal microbiome. It may be hypothesized that alterations in the small intestinal microbiome are associated with culture-proven SIBO, which in turn could suggest that although imperfect, culture-proven SIBO is at least a useful surrogate marker of small intestinal dysbiosis. However, further investigation is needed to (i) explore the role of microbial diversity in SIBO using culture-independent approaches and (ii) describe the interactions between the host and small intestinal microbiome in the context of gastrointestinal disease. This study characterizes small intestinal microbial composition of small bowel aspirates and mucosal specimens in patients with and without a diagnosis of SIBO defined by qualitative and quantitative culture of proximal small bowel aspirates.

Paediatric nuclear medicine practice: an international survey by the IAEA

PurposeThe International Atomic Energy Agency (IAEA) decided to initiate a survey to evaluate the current status of the practice of paediatric nuclear medicine worldwide, with the focus mainly on low and middle-income countries specifically in Latin America, Eastern Europe, Africa and Asia. This investigation sought to determine if the practice in paediatric nuclear medicine in these countries differed from that indicated by the survey of the Nuclear Medicine Global Initiative (NMGI) and if nuclear medicine practitioners were following established paediatric nuclear medicine guidelines.MethodsA total of 133 institutes took part in the survey from 62 different IAEA member states within Africa (29), Asia (39), Europe (29) and Latin America (36). The four most frequent conventional (single-photon) nuclear medicine procedures were 99mTc labelled MDP, DSMA, MAG3 and pertechnetate thyroid scans. In addition, 46 centres provided data on FDG PET/CT, including exposure data for the CT component. Nearly half of the sites (48%) perform less than 200 paediatric nuclear medicine studies per year, while 11% perform more than 1000 such studies per year.ResultsAdministered activities largely exceeded the recommendations for most of the sites for DMSA, MAG3 and pertechnetate, while compliance with international standards was somehow better for MDP studies. For FDG PET, the results were more uniform than for conventional nuclear medicine procedures. However, the use of CT in PET/CT for paediatric nuclear medicine revealed a high variability and, in some cases, high, dose-length product (DLP) values. This observation indicates that further attention is warranted for optimizing clinical practice in FDG PET/CT.ConclusionsOverall, in most parts of the world, efforts have been undertaken to comply either with the EANM dosage card or with the North American Consensus Guidelines. However, variability in the practice of paediatric nuclear medicine still exists. The results of this survey provide valuable recommendations for a path towards global standardization of determining the amount of activity to be administered to children undergoing nuclear medicine procedures.

An Australian local diagnostic reference level for paediatric whole-body 18F-FDG PET/CT.

The aim of this study is to report a local diagnostic reference level (DRL) for paediatric whole-body (WB) fludeoxyglucose (18F-FDG) positron emission tomography (PET) CT examinations. The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) national DRL (NDRL) age category (0-4 years and 5-14 years), the International Commission on Radiological Protection age category (ICRP age) (<1, >1-5, >5-10, and >10-15 years), and European guideline weight category ( EG weight) (<5, 5-<15, 15-<30, 30-<50, and 50-<80 kg) were used to determine a local DRL for WB 18F FDG PET/CT studies. Two-structured questionnaires were designed to collect dose data, patient demographics, equipment details, and acquisition protocols for WB 18F-FDG PET/CT procedures. The local DRL was based on the median 18F-FDG administered activity (MBq), dose-length product (DLP), and the CT dose index volume (CTDIvol), values. The effective dose (E) was also calculated and reported. The local DRLs for 18F-FDG administered activity, CTDIvol and DLP values based on ARPANSA age and ICRP age were increased from lower to higher age categories. For the EG weight category, the local DRL for 18F-FDG administered activity, CTDIvol and DLP values were increased from the low EG weight category to the high EG weight category. The mean administered activity in our study based on ICRP age category >1-5, >5-10, and >10-15 years is 79.97, 119.40, and 176.04 MBq, which is lower than the mean administered activity reported in the North American Consensus guideline published in 2010 (99, 166, and 286 MBq) and European Association of Nuclear Medicine and Dosage Card (version 1.5.2008) (120, 189, and 302 MBq). However, the mean administered activity in our study based on ICRP age category <1 year was 55 MBq compared to the EANM Dosage card (version 1.5.2008) (70 MBq) and the NACG 2010 (51 MBq). Our study shows that the finding for ICRP age category <1 year was similar to the NACG 2010 value. The determined local DRL values for the radiation doses associated with WB 18F FDG PET/CT examinations are differed considerably between the ARPANSA and ICRP age category and EG weight category. Although, the determined 18F-FDG value for ICRP < 1 year is in good agreement with available publish data, it is preferable to optimise the 18F-FDG administered activity while preserving the diagnostic image quality. The local DRL value determined from WB 18F-FDG PET/CT examinations may help to establish the ARPANSA NDRL for WB FDG 18F-PET/CT examinations.

Lactulose Breath Testing Predicts Response to Rifaximin for Cardinal Irritable Bowel Syndrome With Diarrhea (IBS-D)

Introduction: Rifaximin is a nonsystemic antibiotic indicated for IBS-D treatment in adults. We have previously shown that baseline lactulose breath testing (LBT) predicts higher likelihood (OR=4.3) of FDA-defined response to therapy (≥50% decrease from baseline in diarrhea and ≥30% decrease in abdominal pain). This analysis assessed use of LBT results before and after rifaximin to determine response to cardinal IBS-D symptoms. Methods: The TARGET 3 trial included adults with IBS-D (Rome III criteria). Eligible patients received open-label rifaximin 550 mg 3 times daily for 2 weeks, followed by a 4-week post-treatment period to assess response. Patients used at-home kits with 10 g of lactulose for LBT. LBT was conducted before (day 1) and after (day 14+5) therapy (sampled q 15 min; up to 240 min) in a subgroup of patients from 13 centers. Breath test results were categorized as positive or negative (H2 rise <20 ppm within 90 min of test and methane <10 ppm), based on the 2017 North American Consensus publication. After therapy, 4-week average daily scores and average daily score changes from baseline were compared based on LBT results. Results: Of 98 patients (mean age, 49.4 y; 67.3% female) with LBT data, 93 had interpretable results and no missing data at baseline; 62 (66.7%) had positive baseline LBT. Forty-five of 93 patients (48.4%) responded to rifaximin. There were no significant differences in demographics or IBS-D symptom profile according to LBT result, and none predicted therapy response. Compared with patients with a baseline negative LBT, patients with positive LBT had 70.6% and 70.7% more improvement in bloating and loose/watery bowel movements, respectively (P<0.001;Table 1). Patients with a positive LBT had significantly larger improvement in stool frequency, stool consistency, and abdominal pain compared with patients with negative breath test (Table 1). LBT results after rifaximin therapy did not predict response independently (P>0.05); however, patients whose LBT normalized after therapy reported the highest symptomatic improvement in bloating, urgency, diarrhea, stool consistency, and abdominal pain (Table 2). Conclusion: Currently, breath testing is the only biomarker available to independently predict higher response to rifaximin therapy for IBS-D symptoms, including bloating, abdominal pain, stool frequency, and stool consistency. The results are consistent with theories that there is an important role for the gut microbiota in IBS.468_A Figure 1 No Caption available.468_B Figure 2 No Caption available.

Antithrombotic Therapy in Patients With Atrial Fibrillation Treated With Oral Anticoagulation Undergoing Percutaneous Coronary Intervention: A North American Perspective-2018 Update.

The optimal antithrombotic treatment regimen for patients with atrial fibrillation undergoing percutaneous coronary intervention with stent implantation represents a challenge in clinical practice. In 2016, an updated opinion of selected experts from the United States and Canada on the treatment of patients with atrial fibrillation undergoing percutaneous coronary intervention was reported. After the 2016 North American consensus statement on the management of antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention, results of pivotal clinical trials assessing the type of oral anticoagulant agent and the duration of antiplatelet treatment have been published. On the basis of these results, this focused update on the antithrombotic management of patients with atrial fibrillation undergoing percutaneous coronary intervention recommends that a non-vitamin K antagonist oral anticoagulant be preferred over a vitamin K antagonist as the oral anticoagulant of choice. Moreover, a double-therapy regimen (oral anticoagulant plus single antiplatelet therapy with a P2Y12 inhibitor) by the time of hospital discharge should be considered for most patients, whereas extending the use of aspirin beyond hospital discharge (ie, triple therapy) should be considered only for selected patients at high ischemic/thrombotic and low bleeding risks and for a limited period of time. The present document provides a focused updated on the rationale for the new expert consensus-derived recommendations on the antithrombotic management of patients with atrial fibrillation treated with oral anticoagulation undergoing percutaneous coronary intervention.