In pleural infection, medical treatment failure (chest-tube drainage and an
tibiotics) requires surgery and increases mortality. It would be helpful to
predict which patients will fail this approach. We examined clinical predi
ctors in 85 consecutive patients with pleural infection receiving chest dra
inage and intrapleural fibrinolytics, and recorded age, length of history,
antibiotic delay and choice, time to drainage, blood/pleural fluid (PF) bac
teriology, PF pH, lactate dehydrogenase (LDH), glucose and appearance, effu
sion size, pleural thickness on computed tomographic (CT) scan, and surviva
l from time of drainage. Failures (surgery/death) were compared with succes
ses. There were 13 (15%) medical failures. PF purulence was more frequent i
n medical failures (10 of 13 versus 29 of 72 successes, p < 0.02 chi-square
). Absence of purulence was a useful predictor of success (positive predict
ive value [PPV] 93%). Purulence was not useful in predicting medical failur
e (PPV 26%). There was a trend for positive blood culture to predict failur
e (5 of 13 failures versus 11 of 72 successes, p = 0.05 chi-square), but no
significant differences in other endpoints. Twelve (14%) patients died in
followup, all with comorbidity within 400 d after drainage. Probability of
survival at 4 yr was 86%. Of endpoints considered in this study, PF purulen
ce was the only useful predictor of outcome with medical therapy in pleural
infection. There is good long-term survival from pleural infection.