Diagnosis

Microbiology

In the hospital environment, the spectrum of pathogens that cause UTI is slightly different from those in the community. The most prevalent, just as in community acquired infections, is E. coli, making up 47 % of infections. The next most common pathogens are Enterococcus spp. (13 %), Klebsiella spp. (11 %), and Pseudomonas aeruginosa (8 %). Together, they make up almost 80 % of hospital-acquired UTI causes. The remaining 20 % are a variety of other species with very low incidences (Gordon and Jones 2003).

Causes and Prevention

Inappropriate use and extended length of urinary catheterization are the most frequent causes of CAUTI. Therefore, optimizing the use and monitoring of catheterization make these infections highly preventable and can significantly decrease the incidence and morbidity associated with them (Gould et al. 2010). Recent studies have found that a single episode of catheter-associated asymptomatic bacteria and a single episode of CAUTI cost an addition of $589 and $676, respectively. If CAUTI leads to bacteremia, this adds an additional cost of $2836 (Tambyah et al. 2002).

The National Institute of Health has approved guidelines concerning the appropriate indications for using an indwelling urinary catheter. Patients who require a urinary catheter include those with urinary retention, those who need close monitoring or intake and output and perioperatively in those who are undergoing long procedures. Other indications include use to assist in healing of perineal or sacral wounds in incontinent patients, but these are special circumstances where alternatives, such as condom catheters in males, should also be considered (Conway et al. 2012).

Even when urinary catheters are used for appropriate indications, best practice dictates expedient removal, when possible. Intraoperative catheters should be used only as necessary instead of routinely and discontinued within 24 h of the end time of operation.

When inserting a catheter, the smallest diameter possible should be used to avoid trauma to the urethra, which can serve as an entry point for infection. Sterile equipment and aseptic technique should be employed upon insertion, and only personnel trained in aseptic technique should participate in catheter insertion. Antiseptic lubricants have shown to be unnecessary for insertion, but the use of antiseptic agents versus sterile water to clean the urethral meatus prior to insertion remains a question that has yet to be answered. Lastly, catheters should be secured after insertion to prevent movement and trauma to the urethra from traction (Gould et al. 2010).

When maintaining a catheter, it is recommended to use a sterile drainage system and most guidelines recommend using a preconnected system with sealed junctions. If the drainage system becomes inadvertently disconnected, the entire apparatus, including the indwelling catheter, must be removed and replaced with a new one using aseptic technique. The drainage bag must be kept below the level of the bladder to prevent backflow, and routine irrigation, without indication, should be avoided (Conway et al. 2012).

Due to the preventable nature of CAUTI, many hospitals in the USA have put in place systems of quality assurance and close monitoring of catheter insertion and maintenance. These systems include urinary catheter removal prompts or reminders, nurse-initiated catheter discontinuation protocols, bedside ultrasound monitoring, and intermittent catheterization. With these methods in place, an annual decrease in CAUTI rates has been observed nationwide. There has been a 6 % decrease in CAUTI from 2009 to 2010, and some states report an even more substantial decrease, such as Michigan with a 25 % decrease (Saint et al. 2013).

Treatment

Two of the most pressing questions when it comes to treatment of CAUTI include duration of therapy and the use of prophylactic antibiotics immediately after catheter removal. In terms of duration, it has been shown that the appropriate course of antibiotics is somewhere between 3 and 10 days, depending on how long the catheter had been in place. More research needs to be done in the area of prophylaxis as no definitive evidence exists. What evidence does support is changing of a long-term catheter prior to beginning treatment for a CAUTI, as this will remove a possible nidus for infection (Traunter 2010).