SandboxAB

Overview

About 15-25% of hospitalized patients have got a urinary catheter during in-patient management. Catheter associated bacteriuria is the most common infection during hospitalization. however,less than quarter of hospitalized patient develop symptomatic urinary tract infection.

Definition

Catheter associated urinary tract infection is defined by the presence of urinary tract infection symptoms or signs in patients with or indwelling or suprapubic catheters with isolation of one or more bacterial strains≥10³cfu/ml from catheter assembled urine specimen or midstream voided urine specimen in patients who had a catheter removed in the last 48 hours. And this is applied after exclusion of other possible sources of infection.

Catheter associated UTI signs and symptoms

General signs and symptoms
Non specific presentations are the most common. The new onset or worsening of any of the following :

• Fever
• Rigors
• Altered mental status
• Malaise or lethargy

After exclusion of alternative diagnosis with thorough evaluation.

Urinary tract specific signs and symptom

• Flank pain
• Costovertebral angel tenderness
• Acute hematuria
• Pelvic discomfort

After catheter removal

• Urgency
• Frequency
• Dysuria
• Suprapubic pain or tenderness

Patients with spinal cord injury

• Increased spasticity
• Autonomic dysreflexia
• Sence of unease

Pathogenesis and Microbiology

Urinary catheterization disturbs the normal uroepithelial barrier, allowing uropathgenes to access through the lamina.

Microbiology

Short-term catheterization

E.Coli is the most common isolated organism with about third of all isolates, other isolates include Klebsiella spp, Serratia spp, Citrobacter spp, P.aeruginosa and gram positive cocci(coagulase negative)like staphylococci and Enterococci.

Long-term catheterization

It is usually polymicrobial, and in addition to the previous organisms, P.mirabilis, Morganella morganii and P.stuartii are also common.

CA-UTI risk reduction

Avoidance of Unnecessary Catheterization

• Indications for indwelling catheters are:30-120-121

1-Significant urinary retention. 2-Urinary incontinence if other less invasive measures fail or contraindicated. 3-Monitoring output for critically ill patients. 4-Anesthetized patients undergoing certain surgical procedures(urological or gynecological).

• It's not an indication to use urinary catheters for patients with pressure sacral ulcers.
• Using educational methods through hospital or institution guidelines and spreadsheets for indication and contraindication has reduced the inappropriate use of catheters and thereby the rate of CA-UTI. 128
• For post-operation patients, a portable ultrasound for bladder has proven to be accurate assessment for bladder volumes, thus reducing unnecessary catheterization. 131-130

Discontinuation of Catheter

• Catheter removal should be as soon as possible when it's no longer indicated. Early removal of catheters reduced the risk135-136 and the rate137-138 of catheter associated urinary infections.

Prevention Before Catheter Insertion

Infection prevention

Health institutions should consider providing screening and preventive programs, which include guidelines and recommendations for catheterization placement procedure, replacement and discontinuation requirements, in addition to feedback of UTI rate to the medical staff. These measurements had significant risk reduction of catheter associated UTIs. 146-151-152

Alternatives to Indwelling Catheterization

• Condom catheter:an alternative option to short-term and long-term indwelling catheters, to reduce risk of infection for patients with normal post-voiding volume.190-193-195
• Intermittent catheterization:also used as alternative for both short-term and long-term indwelling catheters to reduce CA-UTI risk and its complications 22-24-157-158.It's commonly used with neurogenic bladder and spinal cord injuries.16
• Suprapubic cathterization:an alternative to short-term indwelling catherterization to reduce CA-bacteriuria161. It's preferable more than long-term indwelling catheterization for reduction of catheter associated bacteriuria and infections.It's more comfortable than indwelling catheter with no effect on sexual function, but knowing that it is invasive procedure needs specially trained caregiver has limited its use

Indwelling Catheter Insertion Technique

Aseptic technique should be used with sterile equipment, although it's there is no significant difference in rates of infection with clean(non-aseptic)technique199, but it is preferable approach know the multi-drug resistant organism that can cause infection in hospitalized patients.199