Hyperglycemia is likely to contribute to the negative outcomes associated with TPN in critically ill patients and other hospitalized patients. In surgical patients, hyperglycemia is linked to an increased risk of bloodstream infections (BSI) and sepsis. Patients who receive TPN often develop hyperglycemia because they cannot absorb enough glucose from their intestines to meet their body's needs. The resulting high levels of glucose in the blood stream can increase the risk of developing infections. In addition to causing hyperglycemia, TPN administration can lead to bacterial overgrowth due to loss of intestinal bacteria. This increases the risk of developing BSI and sepsis. TPN-related BSI are more likely to be caused by gram-negative organisms such as Escherichia coli and Klebsiella pneumoniae. These infections may spread hematogenously to various parts of the body including the lungs, brain, and heart. TPN use is also linked to an increased risk of developing catheter-associated urinary tract infections (CAUTI). The reason for this link has to do with how TPN tubes function. These tubes are not designed to filter urine; instead, they allow fluid to flow into and out of the patient's body while preventing particles larger than 7 microns from passing through.