The urea transporters UT-A1 and UT-A3 mediate rapid transepithelial urea transport across the inner medullary collecting duct (IMCD). In a previous study, using a new mouse model in which both UT-A1 and UT-A3 were genetically deleted from the IMCD (UT-A1/3 Ϫ/Ϫ mice), we investigated the role of these transporters in the function of the renal inner medulla. Here

There has been a dramatic reduction in median DTB time and increased compliance with the related national guideline. Despite these improvements, in-hospital mortality was unchanged over the study period. Our results suggest that a successful implementation of efforts to reduce DTB time has not resulted in the expected survival benefit.