Methods: A single-center, retrospective chart review of adult patients with positive blood cultures for Escherichia coli, Klebsiella pneumoniae or Pseudomonas aeruginosa was conducted to compare clinical outcomes between those who received ≥ 48 hours of AZT or CEP therapy (cefepime or ceftriaxone). The following clinical outcomes were assessed: clinical cure, in-hospital mortality, post-infection length of stay (LOS), post-infection intensive care unit LOS, microbiologic cure and leukocytosis resolution.
Results: One-hundred and twenty-nine patients met criteria for evaluation: 41 received AZT and 88 received CEP therapy. At baseline, patients who received AZT were more likely to have renal dysfunction (34.1% vs. 18.2%, p= 0.046), receive synergistic antimicrobials (61% vs. 28.4%, p < 0.001) and had a longer pre-infection LOS (1 day [0-2] vs. 0 [0-1], p=0.032) compared to those who received CEP. Although in-hospital mortality rates were similar between both groups (2.4% vs. 3.4%, p=1.000), there was a statistically significant difference in clinical cure rates (70.7% vs. 90.9%, p=0.003), post-infection length of stay (7 days [5-10] vs. 5 [4-8], p=0.007), and time to clinical cure (2.8 days (1.6-5.8) vs. 2.0 (1.2-2.9), p=0.018) in the AZT and CEP groups respectively. In a multivariate logistic regression model, patients who received AZT were significantly less likely to achieve clinical cure (OR=0.187, 95% CI (0.058-0.597). In a pre-determined subgroup analysis, clinical cure rates varied in E. coli (72% vs. 94.4%, p=0.009), K. pneumoniae (70% vs. 90.5%, p=0.296) and P. aeruginosa (66.7% vs. 76.9%, p=1.000) in the AZT and CEP group respectively.
Conclusion: Patients who receive aztreonam for gram-negative bacteremia may be more likely to experience clinical failure. Larger, prospective studies are warranted to confirm these findings.
T. Bias, None