Assessment of Intraoperative Microbiological Culture in Patients with Empyema: Comparison with Preoperative Microbiological Culture

Purpose: Assessing microbiological culture results is essential in the diagnosis of empyema and appropriate antibiotic selection; however, the guidelines for the management of empyema do not mention assessing microbiological culture intraoperatively. Therefore, we tested the hypothesis that intraoperative microbiological culture may improve the management of empyema.Methods: We performed a retrospective analysis of 47 patients who underwent surgery for stage II/III empyema from January 2011 to May 2019. We compared the positivity of microbiological culture assessed preoperatively at empyema diagnosis versus intraoperatively. We further investigated the clinical characteristics and postoperative outcomes of patients whose intraoperative microbiological culture results were positive.Results: The positive rates of preoperative and intraoperative microbiological cultures were 27.7% (13/47) and 36.2% (17/47), respectively. Among 34 patients who were culture-negative preoperatively, eight patients (23.5%) were culture-positive intraoperatively. Intraoperative positive culture was significantly associated with a shorter duration of preoperative antibiotic treatment (p = 0.002). There was no significant difference between intraoperative culture-positive and -negative results regarding postoperative complications.Conclusions: Intraoperative microbiological culture may help detect bacteria in patients whose microbiological culture results were negative at empyema diagnosis. Assessing microbiological culture should be recommended intraoperatively as well as preoperatively, for the appropriate management of empyema.