[Laboratories as predictors of length of hospital stay in patients with pneumonia].

Background: There are several factors that influence the length of hospital stay (LoHS) in patients with community-acquired pneumonia (CAP). There is currently no study in the literature that correlates laboratory parameters at hospital admittance with the LoHS.

Objective: To find the association of laboratory parameters with the LoHS in patients with community-acquired pneumonia.

Material and methods: An observational, prospective, longitudinal, and controlled study was conducted in the emergency room of a secondary level hospital.

Results: The mean time of LoHS in patients with CAP was 6.6 ± 3.0 days. The parameters of laboratory of monocytes, basophils and segmented neutrophils presented a correlation (Spearman rho) of 0.363, 0.364 and 0.331; p =0.02, 0.02 and 0.04, respectively, with LoHS. Systemic arterial hypertension (SAH) presented a relative risk (RR) of 2.8 (95% confidence interval [95% CI]: 1.41-5.56; p < 0.001), and the chronic obstructive pulmonary disease (COPD) a RR 1.94, (95%CI: 1.31-2.88; p = 0.03) associated with prolonged LoHS.

Conclusions: LoHS in patients with CAP is related to the counting of monocytes, basophils, and neutrophils at the time of the hospital admittance and it was increased in patients with SAH and patients with COPD.