[Studies on risk factors influencing delayed resolution of pneumonia]

Among 61 patients admitted to our hospital because of bacterial pneumonia during the last six years, we investigated several risk factors influencing delayed resolution of pneumonia shadows, such as age, extent of the lesion, period of fever and sputum production after antibiotic therapy, WBC, CRP and PaO2 values on admission, the period of increased values of WBC and CRP, the presence or absence of etiological pathogens, the period from the appearance of symptoms to admission, and the period of drug therapy. In our series, the period from appearance of symptoms to admission (r = 0.62) and that of increased WBC (r = 0.35) significantly correlated with the period of pneumonia shadows to the time of their resolution. Similar results were obtained from the multiple variate analysis of various factors. These results suggest that the duration period (nontherapy period) of inflammation closely associated with leukocytosis plays a crucial role in the delayed resolution of pneumonia shadows.