Comparison of a urine chemistry analyser and microscopy, culture and sensitivity results to detect the presence of urinary tract infections in an elective orthopaedic population.

Currently elective orthopaedic patients require a microscopy and culture of urine (MSU) to be performed on admission. Between 70-80% of urine cultures are found to be negative for infection, making this practice costly and time consuming. The purpose of this study was to compare the accuracy of a dip stick urine chemistry analyser (Clinitek 50 machine) with a MSU, to detect the presence of nitrites and/or leukocytes in a group of elective orthopaedic surgical patients. methodology: Using a prospective cohort study design all elective orthopaedic patients who met the study criteria were invited to participate. In total 102 patients undergoing total hip or total knee replacement surgery participated. results: Results showed that the prevalence of urinary tract infections in patients undergoing total knee or hip surgery, was 14%. High specificity and negative predictive values for the detection of bacterial growth by dip stick urine chemical analysis were found, especially when either the presence of nitrites or leukocytes was used as an indicator. conclusion: This study has provided valuable baseline data on the accuracy of using photometry techniques as a screening measure, in the detection of UTI, in a sample of orthopaedic patients. While the Clinitek 50 dip stick urine chemistry analyser did not have high sensitivity in identifying those patients with a UTI, it was specific in identifying those patients who did not have an infection. Given the enormous cost in routine screening of these patients and the impact on nursing resources, use of this analyser could have potential nursing resource and financial benefits.