MONTREAL — A dramatic increase in the incidence of postpneumonic empyema requiring decortication is an “alarming” phenomenon that may possibly signal a new crisis in the management of community-acquired pneumonia, according to Shona E. Smith, M.D., a third-year general surgery resident at the University of Western Ontario's London Health Sciences Centre.
In a review of all adult cases of postpneumonic empyema [defined as a pus-containing pleural effusion] requiring decortication at her center between April 1997 and December 2004, Dr. Smith discovered the annual numbers of cases of empyema were 44, 35, 36, 42, 75, 68, 72, and 55 in the final 9 months of the study period. The numbers of decortications required in each of those years were 0, 0, 6, 9, 20, 22, 30, and 24 in the final 9 months, she said.
When the first 4 years of the study period were compared with the last 3 years and 9 months, there was a 74% increase in the incidence of empyema and a 540% increase in empyema requiring decortication, she reported at the annual meeting of the Canadian Association of Thoracic Surgeons.
The etiology of this increase is not known, but it could be a reflection of changes in the treatment of community-acquired pneumonia, she suggested. “Empyema can be an indicator of delay in diagnosis and treatment of pneumonia, and this may be the case with more patients being treated at home.”
The mean age of the patients was 56 years, and 77% were male. There was a median of 2 days from the time of diagnosis until admission to hospital and a median of 14 days spent in the hospital. A total of 12 deaths were recorded.
At the time of admission, 22% of patients had been treated with antibiotics alone, and the type of antibiotic was known in 32% of these cases (51% macrolides, 32% quinolones, 30% combination, and 17% other). Another 20% of patients had received thoracentesis in addition to antibiotics, and 45% had received both treatments as well as a chest tube.
Pleural cultures (obtained in 98% of patients) were negative in 36%, gram negative in 26%, and gram positive in 38% (streptococcal species in 29%, staphylococcal species in 7%), Dr. Smith said. Among those patients requiring decortication, 77% of patients had this performed by thoracotomy, 9% had video-assisted thorascopic surgery, and 14% had an initial VATS procedure that was then converted to thoracotomy.