The Diagnostic Value of Urinalysis in Hemodialysis Patients with Fever, Sepsis or Suspected Urinary Tract Infection

Introduction: The diagnostic validity of urinalysis in asymptomatic Hemodialysis (HD) patients is low and there is limited data on the diagnostic value of urinalysis in HD patients with fever, sepsis, or suspected Urinary Tract Infection (UTI). Aim: The aim of this study was to assess the sensitivity, specificity, positive and negative predictive value of pyuria, bacteriuria, Leukocyte Esterase (LE) and nitrite positivity in symptomatic, febrile or/and septic HD patients. Materials and Methods: A single-center, retrospective study was performed at New York University Lutheran Medical Center, Brooklyn, New York City, USA, in order to investigate the diagnostic validity of pyuria, bacteriuria, LE and nitrite positivity in HD patients with admitting diagnosis of fever, sepsis or UTI from September 2008 to August 2015. Results: A total of 275 HD patients were included in the study. There was significant association between pyuria of different cut-offs (>5,>10,>50 WBC/HPF) and urine culture positivity (p<0.001) and growth of >= 100,000 CFU/mL (p=0.039), but there was no association with fever or sepsis. The sensitivity and specificity of pyuria >10 WBC/HPF for positive urine culture with >100,000 CFU/mL was 86% and 35% respectively (p=0.025). Pyuria >50 WBC/HPF showed a sensitivity of 66% and a specificity of 58% (p=0.032). There was also association between bacteriuria, LE positivity and positive urine cultures but not with >= 100,000 CFU/mL. Conclusion: Our study results suggest that urinalysis is not a reliable diagnostic tool in febrile and/or septic HD patients and a urine culture is needed. In such patients, physicians should also maintain a high level of clinical suspicion for other potential sources of infection, which may not be initially evident.