Final answer:
An umbilical catheter in a vein is used to administer medications, fluids, and for blood tests in newborns, as well as for hemodynamic monitoring and emergency transfusions, while ensuring strict hygiene to prevent infections.
Step-by-step explanation:
An umbilical catheter placed in a vein is predominantly used for the administration of medications, fluids, and for obtaining blood samples in newborn infants. The umbilical vein is a crucial component during fetal development, as it carries oxygen- and nutrient-rich blood from the placenta to the fetal heart. However, after clamping the umbilical cord at birth, the umbilical vessels close and become fibrotic remnants. In medicine, venous catheters, including umbilical ones, may save lives by providing long-term administration of medication or fluids and also allowing for blood extraction necessary for various tests. These catheters can also support hemodynamic monitoring and transfusions. Moreover, they are used in emergency situations when other access routes are not viable. It is imperative, though, to maintain stringent hygiene protocols due to the risk of catheter-related bloodstream infections, which have significant morbidity and mortality rates.