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.