The aetiology, management and outcome of severe community-acquired pneumonia on the intensive care unit

In a retrospective study of adults with severe community-acquired pneumonia (SCAP) admitted to the intensive care unit, 60 patients were identified from 25 hospitals within the 12-month study period. Thirty- two percent were aged < 44 years and 65% 7mmol 1 −1, were present in 72%. A pathogen was identified in 58% and five pathogens, Streptococcus pneumoniae, Haemophilus influenzae, Legionella pneumophila, Mycoplasma pneumoniae and Staphylococcus aureus accounted for 86% of these. Gram-negative enterobacteria were identified only once. Forty-eight percent reached the intensive care unit within 24 h of hospital admission, with respiratory failure or progressive exhaustion beingthe main reason for transfer. However, eight patients were only transferred following a cardio-respiratory arrest on the general ward. Eighty-eight percent received assisted ventilation which was given for a median of 8 days. A median of 4 (range 1–11) different antibiotics were given to each patient, with erythromycin and the penicillins prescribed most frequently. Aminoglycosides were given to 43% of patients, although Gram-negative enterobacteria were rarely found. Forty-eight percent died during the acute illness and a further 5% died shortly afterwards. Multi-organ failure was common with respiratory failure alone accounting for a minority of deaths. Forty-eight percent of deaths occurred within 1 week of hospital admission, but of 18 patients stillreceiving assisted ventilation at 14 days, 67% survived. No individual clinical or laboratory feature on admission was significantly associated with death. Only 27% of the total made a complete recovery. Based on the organisms identified in this study initial empirical antibiotic therapy in severely ill patients with community-acquired pneumonia should cover S. pneumoniae, H. influenzae, L. pneumophila, M. pneumoniae and Staph. aureus.