[Show abstract][Hide abstract] ABSTRACT: IMPORTANCE Methemoglobinemia is a rare but serious disorder, defined as an increase in oxidized hemoglobin resulting in a reduction of oxygen-carrying capacity. Although methemoglobinemia is a known complication of topical anesthetic use, few data exist on the incidence of and risk factors for this potentially life-threatening disorder. OBJECTIVE To examine the incidence of and risk factors for procedure-related methemoglobinemia to identify patient populations at high risk for this complication. DESIGN AND SETTING Retrospective study in an academic research setting. PARTICIPANTS Medical records for all patients diagnosed as having methemoglobinemia during a 10-year period were reviewed. EXPOSURES All cases of methemoglobinemia that occurred after the following procedures were included in the analysis: bronchoscopy, nasogastric tube placement, esophagogastroduodenoscopy, transesophageal echocardiography, and endoscopic retrograde cholangiopancreatography. MAIN OUTCOMES AND MEASURES Comorbidities, demographics, concurrent laboratory values, and specific topical anesthetic used were recorded for all cases. Each case was compared with matched inpatient and outpatient cases. RESULTS In total, 33 cases of methemoglobinemia were identified during the 10-year period among 94 694 total procedures. The mean (SD) methemoglobin concentration was 32.0% (12.4%). The methemoglobinemia prevalence rates were 0.160% for bronchoscopy, 0.005% for esophagogastroduodenoscopy, 0.250% for transesophageal echocardiogram, and 0.030% for endoscopic retrograde cholangiopancreatography. Hospitalization at the time of the procedure was a major risk factor for the development of methemoglobinemia (0.14 cases per 10 000 outpatient procedures vs 13.7 cases per 10 000 inpatient procedures, P < .001). CONCLUSIONS AND RELEVANCE The overall prevalence of methemoglobinemia is low at 0.035%; however, an increased risk was seen in hospitalized patients and with benzocaine-based anesthetics. Given the potential severity of methemoglobinemia, the risks and benefits of the use of topical anesthetics should be carefully considered in inpatient populations.
JAMA Internal Medicine 04/2013; · 10.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adenoma detection rate is an important measure of colonoscopy quality; however, factors including procedure order that contribute to adenoma detection are incompletely understood.
The aim of this study was to prospectively evaluate factors associated with adenoma detection rate.
Prospective cohort study. Data were collected on patient and physician characteristics, trainee participation, time of day, and case rank.
Outpatient tertiary-care center.
This study involved consecutive patients presenting for first screening colonoscopies.
Adenoma and polyp detection rates (proportion of cases with one or more lesion detected) and ratios (mean number of lesions detected per case).
A total of 2139 colonoscopies were performed by 32 gastroenterologists. Detection rates were 42.7% for all polyps, 25.4% for adenomas, and 5.0% for advanced adenomas. Adenoma detection was associated with male sex and increasing age on multivariate analysis. In the overall study cohort, time of day and case rank were not significantly associated with detection rates. In post hoc analysis, polyp and adenoma detection rates appeared lower after the fifth case of the day for endoscopists with low volumes of cases and after the tenth case of the day for endoscopists with high volumes of cases.
Overall, time of day and case rank did not influence adenoma detection rate. We observed a small but significant decrease in detection rates in later procedures, which was dependent on physician typical procedure volume. These findings imply that colonoscopy quality in general is stable throughout the day; however, there may be a novel "stamina effect" for some endoscopists, and interventions aimed at improving colonoscopy quality need to take individual physician practice styles into consideration.
[Show abstract][Hide abstract] ABSTRACT: Duodenal villous atrophy (DVA) is a key diagnostic finding in coeliac disease (CD). However, the differential diagnosis for this finding is broad.
To identify conditions causing noncoeliac enteropathy (NCE) with villous atrophy and methods to differentiate between CD and NCE in clinical practice.
Through record review we identified patients with DVA due to conditions other than CD. Patient demographics, clinical features and relevant investigations were compared with CD patients. Rates of CD misdiagnosis, and response to treatments were recorded.
Thirty cases of NCE were identified with ten different aetiologies. Unspecified immune-mediated enteropathy was the most common aetiology; affecting 10 patients. Gastrointestinal symptoms were more common in NCE than those in CD patients (P < 0.01). Twenty of the 24 NCE patients tested were HLA-DQ2/DQ8 negative. Twenty-six NCE patients were negative for IgA tissue transglutaminase (tTG) (P = 0.0001). Intraepithelial lymphocytosis was absent in 10 (33.3%) patients. Twenty-one NCE patients initially misdiagnosed with CD and one with gluten intolerance were prescribed a gluten free diet (GFD). Fifteen of 22 had repeat biopsy and none showed histological improvement.
Although coeliac disease is the most common cause of DVA, noncoeliac enteropathy is not rare and may easily be mistaken for coeliac disease. Noncoeliac enteropathy is suggested by a normal initial tTG (87%), lack of intraepithelial lymphocytosis on biopsy, and lack of histological response to a gluten free diet. Subjective response to gluten free diet has poor predictive value for coeliac disease. Noncoeliac enteropathy can often be confirmed by negative HLA-DQ2/DQ8 testing and targeted investigations can ascertain a definitive aetiology in most cases.