More isn't always better: antibiotic duration after surgical decortication in pleural empyema

While ample high-level evidence supports the limited use of antibiotics post-source control in intraabdominal infections, there is a paucity of available data in guiding antibiotic duration for intrathoracic infections. This study aims to analyze patient outcomes among those who have undergone surgical decortication for parapneumonic pleural empyema, comparing cases managed with infectious disease (ID) specialists against those without, and to identify predictive factors influencing antibiotic duration post-source control. We hypothesized that antibiotic duration would vary depending on the involvement of ID specialists.

A retrospective chart review was completed on patients with parapneumonic pleural empyemas who underwent surgical decortication at a single tertiary center from January 2011 to March 2021. Differences in patient characteristics and outcomes for those whose antibiotics were managed by ID or not were compared with Wilcoxon two-sample tests and Fisher's exact tests. Linear regression was used to evaluate for significant factors predictive of antibiotic duration.

A total of 116 patients underwent surgical decortication for pleural empyema of parapneumonic etiology. ID specialists were involved with antibiotic management in 62 (53.4%) cases, while the remaining cases were not managed by ID. Demographics and patient comorbidities were similar between both groups. Growth of preoperative fluid cultures was higher in patients managed by ID (40.3% vs. 20.4%, P=0.03). Postoperatively, patients managed by ID had longer durations of antibiotics (28.7 vs. 20.9 days, P<0.001) and were more likely to be on IV antibiotics than patients not managed by ID (59.7% vs. 38.9%, P=0.04). However, postoperative outcomes were similar, including rates of disease recurrence, readmission, and 30-day mortality. Linear regression revealed length of antibiotics was significantly dependent on preoperative ventilator status [estimate: 16.346; 95% confidence interval (CI): 6.365-26.326; P=0.002], growth of preoperative pleural fluid cultures (estimate: 10.203; 95% CI: 2.502-17.904; P=0.01), and ID involvement (estimate: 8.097; 95% CI: 1.003-15.191; P=0.03).

Antibiotic duration for pleural empyema managed with surgical decortication is significantly dependent on ID involvement, preoperative growth of cultures, and preoperative ventilator status. However, outcomes, including disease recurrence and 30-day mortality, were similar between patients regardless of ID involvement and longer length of antibiotics, raising the question of what the adequate duration of antibiotics is for patients who receive appropriate source control for pleural empyema. Further study with randomized control trials should be conducted to provide high-level evidence regarding length of antibiotics in this patient population.