Factors predicting the etiologic pathogens in intensive care patients with early-onset pneumonia
© Current Science Ltd 1999
Published: 16 March 2000
National surveillance data of nosocomial infections in Intensive Care Units (ICUs) in Belgium show that in early-onset pneumonia cases (i.e. within 48 h after ICU-admission) microbiology results are more likely to be lacking than in late-onset pneumonia cases. The aim was to examine whether the etiologic pathogen in ICU-patients with early-onset pneumonia could be predicted by specific patient characteristics.
Material and methods
Data provided by the ICUs participating in the national surveillance programme for nososcomial infections in ICUs between January 1996 and June 1998 were examined. For the most frequently isolated pathogens in early-onset pneumonia, associated patient characteristics at admission were identified. Independence of association was verified by multivariate analysis using logistic regression.
Seventy hospitals reported 472 cases of early-onset pneumonia, 366(77.5%) of which were microbiologically documented. The most frequently isolated pathogens were S. aureus (17.2%), E. coli (13.7%), P. aeruginosa (13.4%) and S. pneumoniae (12.8%). In univariate analysis, S. aureus infection was associated with a high Simplified Acute Physiology Score (SAPS II) (55 or more: OR 4.0, P < 0.001; P for trend =0.001), P. aeruginosa infection with prolonged prior hospital stay (1–7 days: OR 2.9, P=0.02; >7days: OR 4.3, P < 0.001; P for trend = 0.002). Factors associated with S. pneumoniae infection were younger age (<70 years: OR 2.2, P = 0.01), community origin (OR 4.8, P < 0.0001) no use of antibiotics in the last 48 h (OR 3.4, P < 0.001) and no prior surgery in the 30 days preceding diagnosis of pneumonia (OR 3.1, P = 0.002). No patient characteristics were found to he predictive for infection with E. coli. After multivariate analysis, S. aureus and P. aeruginose infection remained significantly associated with respectively a high SAPS II score and prolonged prior hospital stay. For S. pneumoniae infection, only community origin and no use of antibiotics in the last 48 h remained independently associated.
Empirical antimicrobial treatment for early-onset pneumonia in Belgian ICUs is common. Patient characteristic admission, such as duration of prior hospital stay, prior antibiotic use and patient severity score, are important factors in predicting the most probable etiologic pathogen and may be helpful in decision-making with regard to empirical antimicrobial therapy early-onset pneumonia in ICUs.