Parapneumonic Effusion

Light RW, MacGregor MI, Luchsinger PC, et al. Pleural effusions: the diagnostic separation of transudates and exudates. Ann Intern Med 1972;77:507-13. This paper is the basis for using pleural fluid LDH and protein to classify effusions as transudative or exudative. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=4642731

Light RW, Girard WM, Jenkinson SG, et al. Parapneumonic effusions. Amer J Med 1980;69:507-12. The notion that a parapneumonic effusion with pH less than 7.0 or glucose < 40mg/dl is "complicated" and requires drainage is derived from this study. Study included a total of 10 patients (7 with + cultures, 3 with pus). 6 of 10 met the pH criteria and 7 of 9 met the glucose criteria. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7424940

Berger HA, Morganroth ML. Immediate drainage is not required for all patients with complicated parapneumonic effusions. Chest 1990; 97:731-5. Oft-cited retrospective study found 13 of 16 patients with complicated effusions (defined as pH < 7.2 or positive GS or positive culture, but without pus present) had resolution of effusions with antibiotics alone. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2306975

Maskell NA, Davies CW, Nunn AJ et al. UK controlled trial of intrapleural streptokinase for pleural infection. N Engl J Med 2005;352:865-74. This study of 454 patients randomly assigned to streptokinase or placebo is noteworthy for contradicting previous small studies supporting the use of lytics in complicated parapneumonic effusion. The study found no difference in mortality, need for surgery, radiographic outcome, or length of hospital stay. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15745977 

Wait MA, Sharma S, Hohn J, Dal Nogare A. A randomized trial of empyema therapy. Chest 1997;111:1548-51. Only randomized trial comparing immediate VATS to tube thoracostomy plus 3 days of daily SK (only 20 patients total). The surgical group had better primary treatment success and earlier hospital discharge, but outcomes of patients randomized to chest tube/lytics was much worse than other reported series, suggesting suboptimal management of those patients. All medical failures were salvageable with VATS. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9187172

Davies CWH, Kearney SE, Gleeson FV, Davies RJO. Predictors of outcome and long-term survival in patients with pleural infection. Am J Respir Crit Care Med 1999; 160:1682-7. In the absence of frank empyema, tube thoracostomy plus lytics had a PPV of 93% for successful treatment (i.e. no need for surgery). The presence of pus had a PPV for failure of medical management of 26%. Fluid characteristics, effusion size, and degree of pleural thickening were not predictive of medical failure. Study didn't consider presence of loculations or assess long-term outcomes. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10556140

Ashbaugh DG. Empyema thoracis. Factors influencing morbidity and mortality. Chest 1991;99:1162-5. Study of 122 consecutive patients looked at the morbidity and mortality of delaying treatment of empyema. Waiting more than 3 days to place a chest tube, and more than 14 days to proceed to surgical drainage when chest tubes fail, was associated with increased morbidity and mortality. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2019172