Recent trends in empyema thoracis.
One hundred and twenty-three patients with empyema thoracis presenting between 1968 and 1978 were studied. The predominant cause was pneumonia, with thoracic and gastrooesophageal surgery as the other important predisposing factors. 99 patients had received antibiotics before hospital admission and organisms were isolated from the empyema of 62 of these (63%). Of the 62 patients with organisms 39 (63%) had previously received an antibiotic appropriate to the sensitivity of the pathogen. Staph. aureus, Str. pneumoniae and anaerobes were the organisms most frequently found in empyemata following pneumonia, whilst Gram-negative enteric bacilli, the most frequently isolated organisms, were the predominant pathogens in postoperative cases. Following treatment with antibiotics alone or with closed chest drainage 29% of empyemata resolved but another 64% required subsequent surgery. The former group had a mean duration of symptoms of 2.8 (SE +/- 0.8) weeks before hospital treatment whereas the surgically treated group had symptoms for a mean period of 8.3 (SE +/- 1.5) weeks. 83% of patients who required thoracotomy had a history of more than four weeks at the time of admission. Thirty-six deaths were recorded, 11 of which were attributable to the empyema, giving an empyema mortality-rate of 9%. We conclude that with widespread use of antibiotics the nature of empyemata has changed and that those now seen are more often refractory to closed chest drainage, particularly if the history prior to hospital admission is longer than four weeks.