Non-bacteremic pneumococcal pneumonia: general characteristics and early predictive factors for poor outcome

Abstract

Purpose: Nowadays, most cases of pneumococcal community-acquired pneumonia (PCAP) are diagnosed by positive urinary antigen. Our aims were to analyse process of care in patients hospitalised with non-bacteremic PCAP (NB-PCAP) and identify factors associated with poor outcome (PO) in this population.

Methods: We conducted a prospective study, including patients hospitalised for NB-PCAP (positive urinary antigen and negative blood culture) over a 15 year period. We performed multivariate analysis of predisposing factors for PO, defined as need for mechanical ventilation and/or shock and/or in-hospital death.

Results: Of the 638 patients included, 4.1% died in hospital and 12.8% had PO. Host-related factors were similar in patients with and without PO, but patients with PO had higher illness severity on admission. Adjusted analysis revealed the following independent factors associated with PO: being a nursing home resident (OR: 6.156; 95% CI: 1.827–20.750; p = .003), respiratory rate ≥30 breaths/min (OR: 3.030; 95% CI: 1.554–5.910; p = .001), systolic blood pressure <90 mmHg (OR: 4.789; 95% CI: 1.967–11.660; p = .001), diastolic blood pressure <60 mmHg (OR: 2.820; 95% CI: 1.329–5.986; p = .007), pulse rate ≥125 beats/min (OR: 3.476; 95% CI: 1.607–7.518; p = .002), pH <7.35 (OR: 9.323; 95% CI: 3.680–23.622; p < .001), leukocytes <4000/µL (OR: 10.007; 95% CI: 2.960–33.835; p < .001), and severe inflammation (OR: 2.364; 95% CI 1.234–4.526; p = .009). The area under the curve for predicting PO was 0.890 (95% CI: 0.851–0.929).

Conclusions: Since patients with PO seem different and had worse in-hospital course, we identified eight independent risk factors for PO measurable on admission.

Keywords:

• Community acquired pneumonia
• Streptococcus pneumoniae
• non-bacteraemia
• poor outcome
• predictive factors

This article refers to:

Of coccus, Rocco and scores: pneumococcal disease, Rocky Graziano and pneumonia severity scoring systems

Acknowledgements

We wish to thank the team of Ideas Need Communicating Language Services for help with improving the use of English in the manuscript.

Disclosure statement

All authors wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.

Authors’ contributions

LS, LAR, RZ, PPE, AG and AU conceived and designed the study. AA, MG, LS, LAR, and RZ enrolled patients and collected and compiled data. LM and BS performed the statistical analysis. LS, RZ, LAR, AG, AU, PPE, and MG analysed and interpreted the data. LS, RZ, and LAR wrote the manuscript. AG, AU, AA, MG and PPE commented and revised the report. All authors read and approved the final manuscript.