Colonoscopy Trainers Experience Greater Stress During Insertion than Withdrawal: Implications for Endoscopic Curricula.

BACKGROUND: Optimal colonoscopy training curricula should minimize stress and cognitive load. This study aimed to determine whether withdrawal or insertion colonoscopy skills training is associated with less stress or cognitive load for trainees or trainers. METHODS: In Phase I, participants were randomized to train on either insertion or withdrawal in a simulated environment. In Phase II, participants were randomized to begin with either insertion or withdrawal in patient encounters. Salivary cortisol levels, heart rate, and State-Trait Anxiety Inventory (STAI) surveys were used to assess stress in trainees and trainers. NASA Task Load Index (TLX) survey was used to assess cognitive workload in trainees. RESULTS: In Phase I, trainee stress increased during the simulation training during both withdrawal and insertion compared to baseline, while trainer stress changed minimally. Cognitive load was higher for trainees during withdrawal (P = 0.005). In Phase II, trainers' STAI scores were greater during insertion training (P = 0.013). Trainees' stress was highest prior to beginning patient training and decreased during training, while trainer's stress increased during training. Trainees reported insertion training being of greater value (70.0%), while trainers reported withdrawal was preferred (77.8%). CONCLUSION: Trainees and trainers exhibit important differences in stress during colonoscopy skills training. Trainees reported more stress during simulation training and greatest cognitive load during simulation withdrawal, whereas trainers reported greatest stress during patient encounters, particularly training of insertion techniques. Attention to the effect of stress on trainees and trainers and the drivers of stress is warranted and could be incorporated in competency based medical education.

Lack of benefit of active preparation compared with a clear fluid-only diet in small-bowel visualization for video capsule endoscopy: results of a randomized, blinded, controlled trial.

BACKGROUND AND AIMS: Controversy remains regarding the type and amount of precapsule bowel cleansing required for small-bowel video capsule endoscopy (VCE). This study aims to assess the efficacy and tolerance of 2 active preparations and a control group of clear fluids only. METHODS: Patients with clinical indications for VCE were randomized to (1) clear fluids only the evening before VCE, (2) 2 sachets of sodium picosulfate plus magnesium sulfate (P/MC) the evening before, or (3) 2 L of polyethylene glycol (PEG) the evening before. Diet instructions were the same for all 3 groups. Small-bowel cleansing was assessed in 3 ways: a 5-point ordinal scale (primary outcome), the percentage of time the small-bowel view was clear, and a validated computerized assessment of cleansing. RESULTS: In total, 198 patients were randomized and 175 patients completed the trial with a mean age of 49.2 years. There was no clear benefit of active preparation with either P/MC or PEG over clear fluids only in the overall 5-point rating scale or in the distal fourth of each examination. There was no difference in diagnostic yield between groups. Significant differences were seen concerning tolerance of the preparations, with a higher proportion rating it as easy or very easy in the clear fluids-only group (93%) and the P/MC group (67%) than in the PEG group (13%) (P < .0001). CONCLUSIONS: Small-bowel cleansing for VCE remains a controversial topic. This randomized control trial demonstrates no benefit in overall or distal small-bowel visualization with active preparation using either PEG or P/MC compared with clear fluids only. (Clinical trial registration number: NCT00677794.).

Novel role of the serine protease inhibitor elafin in gluten-related disorders.

OBJECTIVES: Elafin, an endogenous serine protease inhibitor, modulates colonic inflammation. We investigated the role of elafin in celiac disease (CD) using human small intestinal tissues and in vitro assays of gliadin deamidation. We also investigated the potential beneficial effects of elafin in a mouse model of gluten sensitivity. METHODS: Epithelial elafin expression in the small intestine of patients with active CD, treated CD, and controls without CD was determined by immunofluorescence. Interaction of elafin with human tissue transglutaminase-2 (TG-2) was investigated in vitro. The 33-mer peptide, a highly immunogenic gliadin peptide, was incubated with TG-2 and elafin at different concentrations. The degree of deamidation of the 33-mer peptide was analyzed by liquid chromatography-mass spectrometry. Elafin was delivered to the intestine of gluten-sensitive mice using a recombinant Lactococcus lactis vector. Small intestinal barrier function, inflammation, proteolytic activity, and zonula occludens-1 (ZO-1) expression were assessed. RESULTS: Elafin expression in the small intestinal epithelium was lower in patients with active CD compared with control patients. In vitro, elafin significantly slowed the kinetics of the deamidation of the 33-mer peptide to its more immunogenic form. Treatment of gluten-sensitive mice with elafin delivered by the L. lactis vector normalized inflammation, improved permeability, and maintained ZO-1 expression. CONCLUSIONS: The decreased elafin expression in the small intestine of patients with active CD, the reduction of 33-mer peptide deamidation by elafin, coupled to the barrier enhancing and anti-inflammatory effects observed in gluten-sensitive mice, suggest that this molecule may have pathophysiological and therapeutic importance in gluten-related disorders.

Increased bacterial translocation in gluten-sensitive mice is independent of small intestinal paracellular permeability defect.

AIM: We investigated whether treatment with gliadin induces a paracellular permeability defect that enhances bacterial translocation to mesenteric lymph nodes (MLN) via resident dendritic cells (DC) expressing TLR-2 or 4 in HCD4/HLA-DQ8 transgenic mice. METHODS: HLA-DQ8 transgenic mice were sensitized and subsequently gavaged with gliadin, in the presence or absence of AT1001 (paracellular permeability inhibitor). Non-sensitized mice were gavaged with indomethacin (permeability inducer) or rice cereal. CD11c and CD103 (DC markers) and TLR-2 and 4 were investigated by immunostaining. Intestinal permeability was assessed by paracellular flux of (51)Cr-EDTA in Ussing chambers. Bacterial translocation to MLN was performed by plate counting on aerobic and anaerobic conditions. RESULTS: In gliadin-treated mice, both (51)Cr-EDTA flux in jejunal mucosa and aerobic and anaerobic bacterial counts in MLN were increased (p < 0.05) compared to indomethacin-treated mice and controls. The inhibitor AT1001 normalized (51)Cr-EDTA flux, but had no effect on bacterial translocation in gliadin-treated mice. In addition, changes in mucosal DC marker distribution such as increased (p < 0.05) trans-epithelial CD103(+) cells and reduction (p < 0.05) of CD11c immunostaining were detected in gliadin-treated mice. Moreover, changes in DC markers and TLR-2 or 4 immunophenotypes were not associated. CONCLUSIONS: Pharmacological restoration of paracellular permeability was not sufficient to prevent bacterial translocation in gluten-sensitive mice. We hypothesize that transcellular mechanisms involving CD103(+)DC and CD11c(+)DC may explain in gluten-sensitive HCD4/HLA-DQ8 transgenic mice the sustained increased bacterial translocation observed in the absence of a significant inflammatory response.