Research on the Application of Blood Collection Through Midline Catheters of Different Lengths

Therefore, in this study, the investigators propose to use a randomized controlled prospective open study on inpatients with difficult blood collection, by comparing the effects of the application of two types of peripheral venous catheters for blood collection via LPC and MC, with a view to improving the success rate of blood collection in difficult peripheral venous blood collection, and providing a theoretical basis for the later application of long peripheral venous catheters and midline catheters; and providing a basis for optimizing the experience of venous blood collection by nurses.