Show me the evidence. Do larger size indwelling urinary catheters really increase the risk of catheter associated urinary tract infection?

Purpose:  

Catheter associated urinary tract infection (CAUTI) affects approximately 8% of the home care population.  Although a vast amount of research is available in prevention of CAUTI, limited evidence is available specific to the relationship of CAUTI and size of catheter. Clinical guidelines recommend that clinicians choose the smallest bore urinary catheter possible to increase comfort, reduce risk of trauma to urethra, and to allow proper drainage of periurethral glands.  However, these recommendations are based only on expert opinion. Large bore catheters are ordered frequently in the home care environment and CAUTI is also widely prevalent. The purpose of this study was to examine the relationship between size of catheter and CAUTI prevalence.

Method:  

A large home health agency performed a retrospective chart review to include a convenience sample of all patients with reported urinary tract infections(UTI) over a one year period. UTI was defined as reportable based on symptomatic bacteriuria of 10⁵. Inclusion criteria were limited to patients with indwelling Foley catheters. Exclusion criteria included suprapubic catheters. Data extracted included: age, sex, size of catheter, balloon size, short term/ long term, change frequency, primary and secondary ICD-9 codes, silver catheter use, and if patients utilized irrigation. Each UTI occurrence was counted as one event.

Results:  

Preliminary SPSS software results of one way ANOVA show a significance between size of catheter and CAUTI, F(7,67) =1.931, p. <.001.  Further exploration of data extracted using multiple regression analysis is pending and will be presented.

Conclusion:

Preliminary results of this study show that there is a significant relationship between size of catheter and risk of CAUTI. In this sample, large bore catheters may be erroneously overutilized. Final study results, along with clinical guidelines, can be used to present to practitioners requesting use of small bore catheters in an effort to facilitate cultural change.