Diagnostic performance of initial serum lactate for predicting bacteremia in female patients with acute pyelonephritis

Am J Emerg Med. 2016 Aug;34(8):1359-63. doi: 10.1016/j.ajem.2016.03.062. Epub 2016 Apr 3.

Abstract

Objectives: The purpose of the present study was to investigate the diagnostic value of lactate for predicting bacteremia in female patients with acute pyelonephritis (APN).

Methods: We conducted a retrospective study of female patients with APN who visited the study hospital emergency department. The demographics, comorbidities, physiologies, and laboratory variables including white blood cell count and segmented neutrophil count, C-reactive protein, and initial serum lactate levels were collected and analyzed to identify associations with the presence of bacteremia.

Results: During the study period, a total of 314 patients were enrolled. One hundred twenty-three patients (39.2%) had bacteremia. Escherichia coli was the most frequent pathogen. Logistic regression analysis demonstrated that the lactate level was independently associated with the presence of bacteremia (odds ratio, 1.39 [95% confidence interval, 1.08-1.78]). The C-statistic of the lactate level was 0.67 (95% CI, 0.60-0.73). At a cutoff value of 1.4mmol/L, the lactate level predicted bacteremia with a sensitivity (53.7%), specificity (72.3%), positive predictive value (55.5%), negative predictive value (70.8%), positive likelihood ratio (1.93), and negative likelihood ratio (0.64).

Conclusion: The initial serum lactate level showed poor discriminative performance for predicting bacteremia in female patients with APN.

MeSH terms

  • Acute Disease
  • Aged
  • Bacteremia / blood
  • Bacteremia / diagnosis*
  • Bacteremia / etiology
  • Biomarkers / blood
  • Female
  • Humans
  • Lactates / blood*
  • Male
  • Middle Aged
  • Odds Ratio
  • Predictive Value of Tests
  • Pyelonephritis / blood
  • Pyelonephritis / complications*
  • Pyelonephritis / diagnosis
  • Retrospective Studies

Substances

  • Biomarkers
  • Lactates