Lower neutrophil-to-lymphocyte ratio predicts high risk of multidrug-resistant Pseudomonas aeruginosa infection in patients with hospital-acquired pneumonia

Abstract

Background and purpose

Hospital-acquired pneumonia (HAP) remains an important cause of morbidity and mortality despite advances in antimicrobial therapy. The emergence of multidrug resistant (MDR) Pseudomonas aeruginosa (PA) is of major concern. Our aim was to evaluate the risk factors and prognosis of HAP due to MDR-PA infection.

Patients and methods

In a retrospective observational study, we collected data on all episodes of HAP caused by PA (PA-HAP) occurring from January 2013 to December 2016. Characteristics of patients with drug-sensitive PA were compared with those with MDR-PA. Data of demographic, underlying conditions, peripheral neutrophil-to-lymphocyte ratio (NLR), and clinical outcomes were collected and analyzed.

Results

One hundred fifty-seven patients with PA-HAP were included, of which 69 (43.9%) patients were diagnosed with MDR-PA infection. There were significant differences between MDR-PA group and non-MDR-PA group on the following variables: initial inappropriate antibiotic therapy (P<0.001, OR 0.103, 95% CI 0.044–0.244), admission in more than two departments in previous 30 days (P<0.001, OR 0.186, 95% CI 0.072–0.476), and NLR level (P=0.020, OR 0.911, 95% CI 0.843–0.985). The effect of antibiotic treatment was significantly different (P<0.001, OR 4.263, 95% CI 2.142–8.483). The 30-day mortality was higher in MDR-PA group than that in non-MDR-PA group (P<0.001).

Conclusion

We have shown that lower NLR level was identified as a clinical predictor of MDR-PA infection in HAP patients. Even with goal-directed therapy, MDR-PA infection implicates poor outcomes in patients with HPA.

Keywords:

• risk factors
• prognosis
• multidrug-resistant Pseudomonas aeruginosa
• hospital-acquired pneumonia

View correction statement:

Lower neutrophil-to-lymphocyte ratio predicts high risk of multidrug-resistant Pseudomonas aeruginosa infection in patients with hospital-acquired pneumonia [Corrigendum]

Acknowledgments

We appreciate Dr Anthony Yii Chau Ang for his helpful suggestions on the design of this study and we thank Dr Yan Yan for carefully proofing our manuscript.

This study was supported by Science and Technology Projects Foundation of Guangzhou City (Number 201709010040).

Author contributions

Y-QZ and D-YF designed the study and participated in the drafting of manuscript. W-JL and H-LY participated in the data collection. Z-NW participated in revisions of the draft. T-TZ designed the study and participated in the critical revision of the draft. Z-GC drafted the manuscript and participated in the critical revisions of the draft. All authors contributed to data analysis, drafting and revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.