Published online by Cambridge University Press: 02 January 2015
Infection of the urinary tract is acknowledged to be the most common hospital infection, associated closely with the presence of an indwelling catheter. Patients are catheterized for a variety of reasons and for different periods of time, ranging from postoperative catheterization of a few days following urological surgery to the long-term catheterization over many months or years of patients who are unfit for operation, with spinal injuries or neuropathic bladders. The extent of the problem includes patients returning home infected, requiring catheterization before readmission to the hospital or needing nursing at home with a long-term catheter. The risks of infection and its complications as well as methods of control may differ between each group.
It is of fundamental importance to distinguish between patients who came to surgery with an existing infection and those with sterile preoperative urine. Other factors include recent previous catheterization and, importantly, the length of time the catheter is inserted. For the patient with sterile preoperative urine, postoperative bacteriuria seldom causes severe symptoms and can be treated with antibiotics or left to clear spontaneously after removal of the catheter. A minority of patients suffer consequences of their infection especially when bacteriuria starts before the catheter is removed postoperatively. Catheter removal often causes transient bacteremia, also induced by instrumentation or operation on infected urine, which may lead to serious complications, particularly of septicemia. In our experience in Bristol, about 1 in 4 patients admitted for urological surgery already has infected urine as defined by the presence of ≥105 bacteria/ml midstream urine or ≥=104 bacteria/ml catheter urine. Of those admitted with infected urine, 3 in 4 have a catheter already inserted compared with only 1 catheterized patient in 4 admitted to operation with sterile urine.