Catheterization is a process where a tube is inserted into a patient's urethra to drain urine from the bladder for collection or to inject liquids for treatment. It is commonly performed to manage incontinent patients, obtain urine samples, or carefully monitor urine output in intensive care situations. Acute renal failure occurs when the kidneys fail to remove waste from the blood, causing fluids and waste to build up. It can be caused by lack of blood flow to the kidneys due to injury, lack of fluids, or long-term medication use. Urine culture is a test to identify germs that may be causing a urinary tract infection by taking a urine sample and observing any bacteria growth.