Time and Motion at the Endoscopy Unit-A University Hospital Experience.

Background/aims: An effective workflow at the endoscopy unit is important for optimal production. We conducted a time-and-motion study to identify the amount of time that patients spend during the different steps of a regular endoscopy procedure and compared propofol with midazolam sedation. Methods: Data from 376 patients were prospectively collected. Durations of the different procedure steps were measured. Correlations between recovery times, age, and dose of sedative were calculated. Multiple regression analysis was performed to evaluate how various factors affect recovery time. Results: The use of midazolam resulted in significantly shorter procedure duration for gastroscopy (5.1 vs 8.3 min), shorter endoscopist delay duration for either types of endoscopy (5.9 vs 8.3 min for gastroscopy and 6.7 vs 11.4 min for colonoscopy), shorter endoscopy room duration for gastroscopy (22.2 vs 30.0 min), shorter recovery time for colonoscopy (23.4 vs 27.4 min) and shorter Endoscopy Unit Duration for either type of endoscopy (77.1 vs 101.4 min for gastroscopy and 99.6 vs 123.2 min for colonoscopy). There was a weak correlation between dose of midazolam and recovery time. Conclusions: In contrast to other studies, propofol administration leads to more time spent at different steps in the workflow at our unit. Implementing propofol sedation will not improve efficacy if other steps in the workflow are not taken into account.

A single-step competitive binding assay for mapping of single DNA molecules.

Optical mapping of genomic DNA is of relevance for a plethora of applications such as scaffolding for sequencing and detection of structural variations as well as identification of pathogens like bacteria and viruses. For future clinical applications it is desirable to have a fast and robust mapping method based on as few steps as possible. We here demonstrate a single-step method to obtain a DNA barcode that is directly visualized using nanofluidic devices and fluorescence microscopy. Using a mixture of YOYO-1, a bright DNA dye, and netropsin, a natural antibiotic with very high AT specificity, we obtain a DNA map with a fluorescence intensity profile along the DNA that reflects the underlying sequence. The netropsin binds to AT-tetrads and blocks these binding sites from YOYO-1 binding which results in lower fluorescence intensity from AT-rich regions of the DNA. We thus obtain a DNA barcode that is dark in AT-rich regions and bright in GC-rich regions with kilobasepair resolution. We demonstrate the versatility of the method by obtaining a barcode on DNA from the phage T4 that captures its circular permutation and agrees well with its known sequence.