It is admittedly desirable that the guess methods relating to the incidence of both serofibrinous pleurisy and empyema as complications and sequelæ of pneumonia should give way at the earliest possible moment to exact knowledge. It has been the current professional impression that pleurisy is the most common complication of the pneumonic process, but it must be confessed that there is no available statistical evidence to confirm it fully. Again, the precise definition of the term empyema is free from difficulty, it being applicable to a collection of pus in the pleura, however small, while that of serofibrinous pleurisy secondary to pneumonia is distinctly difficult.
In our view, pleurisy in the clinical sense should be regarded as a complication when it co-exists, either as a severe form of the dry plastic variety with marked friction to auscultation or accompanied by sufficient effusion to be demonstrable by means of the physical
ANDERS JM, MORGAN AC. THE INCIDENCE OF SEROFIBRINOUS PLEURISY AND EMPYEMA AS COMPLICATIONS AND SEQUELÆ OF PNEUMONIA, WITH REMARKS ON THEIR MEDICAL TREATMENT. JAMA. 1911;LVII(15):1204-1207. doi:10.1001/jama.1911.04260100030008