No abstract

Ultrasound technology has revolutionized the practice of safer vascular access, for both venous and arterial cannulation. The ability to visualize underlying structures of the chest, neck, and upper/lower extremities provides for greater success, speed, and safety with all vascular access procedures. Ultrasound not only yields superior procedural advantages but also provides a platform to perform a thorough assessment of the vascular structures to evaluate vessel health, viability, size, and patency, including the location of other important and best avoided anatomical structures-prior to performing any procedures. Such assessment is best performed using a systematic and standardized approach, as the Rapid Central Vein Assessment, described in this study.

Fluorescein angiograms from diabetics were digitised for analysis using digital image-processing techniques. Computer algorithms were written to detect and count microaneurysms present in the images. The accuracy, speed and reproducibility of the technique were assessed and compared with those of manual counts made by clinicians from both digitised and analogue images. Free-response ROC (receiver operating characteristic) curves were used to assess the performance of both the clinicians and the computer by comparing the results with "gold standards" compiled from prints of the original fluorescein angiograms. The computer performed as well as the clinicians when the latter were analysing the digitised images (512 x 512 pixel resolution), but only when one image was acquired at 4 times this resolution did the computer's performance match that of the clinicians analysing the analogue image. The automated technique was more reproducible than the manual method.

This report has demonstrated low complication rates for a hospital-wide service delivered by advance practice nurses. The results suggest that a centrally based service with specifically trained operators can be beneficial by potentially improving patient safety and promoting organizational efficiencies.