Adjusting the RAPID score with 3 additional variables significantly increases its predictive value in patients with empyema

Abstract

Abstract BackgroundPleural empyema is a serious condition leading to a significant burden on health care systems due to protracted hospitalisations. Treatment ranges from non-surgical interventions such as antibiotic therapy and chest tube placement to thoracoscopic or open surgery. Various risk factors which impact outcomes have been investigated. The RAPID (renal, age, purulence, infection source, and dietary factors) score is a clinical risk score which identifies patients at risk of death and may be used to formulate individual treatment strategies accordingly. All patients undergoing surgical interventions for empyema at a major tertiary medical center in Germany from 2017-2020 were analysed. The aim was to identify perioperative risk factors which significantly impact treatment outcomes but are currently not included in the RAPID score. Methods245 patients with pleural empyema treated at the Department of General, Visceral and Thoracic Surgery at the University Medical Center, Hamburg, Germany (admitted from January 2017 to April 2020) were retrospectively analysed. All patients which received either minimally invasive or open thoracic surgery were included. Epidemiological as well as perioperative data was analysed to identify risk factors which impact long-term overall outcomes. 90-day mortality rate was the primary endpoint. Postoperative morbidity and length of hospital stay (LOS) were also investigated.ResultsThe mean age was 59.4 years with a bimodal distribution. There was a male predominance across the cohort (71.4% compared to 28.6%), with no significant differences across ages below or above 60 years. 53 (21.6%) patients died within the first 90 days. Diabetes type 1 and 2, renal insufficiency, immunosuppression, postoperative bleeding, intraoperative transfusion as well as microbiologically confirmed bacterial invasion of the pleura all led to higher mortality rates. Higher RAPID scores accurately predicted higher 90-day mortality rates. Modifying the RAPID score by adding the comorbidities diabetes, renal insufficiency and immunosuppression significantly increased the predictive value.ConclusionsWe demonstrated various perioperative and intraoperative risk-factors not included in the RAPID score which negatively impact postoperative outcome in patients receiving surgical treatment for pleural empyema. These should be taken into consideration when deciding on the best course of treatment. If confirmed in a prospective study with a significantly larger cohort, it may be worth considering expanding the RAPID score to include these.