As a matter of fact, a few reports have noted caveats in determining the need for draining PPEs on the basis of biochemical or microbiological criteria. For example, in a retrospective study3of 62 patients with PPEs, 26 nonpurulent CPPEs (defined as pleural fluid with a pH < 7.20, or a positive Gram stain or culture result) were identified. Thirteen of the 16 patients with CPPEs who were initially treated with antibiotics alone were cured uneventfully. Another retrospective analysis4 of 91 patients with PPEs found that 10 of 22 patients who met one or more criteria for tube thoracostomy (ie, frank purulence, pleural glucose level < 40 mg/dL, pleural pH < 7.00, or pleural lactate dehydrogenase level > 1,000 U/L) recovered without chest tube placement. Undoubtedly, there are some patients with PPEs and poor prognostic variables found in their pleural fluid who can be cured with antibiotic therapy alone. A retrospective update from our series, including 240 patients with PPEs (uncomplicated PPEs, 85 patients; CPPEs, 67 patients; and empyemas, 88 patients; defined as previously reported,1), showed that the American College of Chest Physicians guidelines5and the British Thoracic Society guidelines6 are associated with respective sensitivities of 97% and 98%, and respective specificities of 68% and 56% to discriminate nonpurulent CPPEs from uncomplicated PPEs (unpublished data). Specifically, the conditions of 12 patients with nonpurulent culture-positive pleural fluid samples and 2 patients with empyemas were resolved solely with antibiotic therapy.