Table 1: Pleural infections staging and recommended drainage [7].

CategoryPleural space anatomyPleural fluid chemistryRisk of poor outcomeDrainage

1Minimal free-flowing effusion (<10 mm on lateral decubitus)andGram stain and culture results unknownVery lowNo
2Small to moderate free-flowing effusion (≥10 mm and less than one half hemithorax)andNegative Gram stain and cultureLowNo
3Large, free-flowing effusion (≥ one half hemithorax), loculated effusion, or effusion with thickened parietal pleuraorPositive Gram stain and/or cultureModerateYes
4EmpyemapusHighYes