Clinical application of a digital thoracic drainage system for objectifying and quantifying air leak versus the traditional vacuum system: a retrospective observational study

BACKGROUND: Digital thoracic drainage systems have recently been introduced and widely used in clinical practices in developed countries. These systems can monitor intrathoracic pressure changes and air leaks in real time, and also allow for objective and quantitative analyses, which aid in managing patients with a prolonged persistent air leak into the pleural space. We investigated the feasibility and effectiveness of such a new device versus the traditional vacuum system for treating patients with pneumothorax. METHODS: Closed thoracostomy drainage was carried out on 100 adult patients with primary or secondary pneumothorax between January 2017 and December 2018. All the patients were aged ≥18 years and treated with a chest tube at a single medical center by the same cardiothoracic surgeons and intensivists. Patients who underwent closed thoracostomy drainage using an indwelling 24-French chest tube were divided into 2 groups immediately before closed thoracostomy: the digital thoracic drainage group (digital group, n=50) and the traditional analogue thoracic drainage group (analogue group, n=50). The detailed information about demographic data, treatment outcome, duration of indwelling catheterization., hospital days, cost-effectiveness and patient satisfaction was evaluated. We also evaluated whether digitally recorded intrapleural pressure changes and air leaks would predict chest tube removal timing and outcome. RESULTS: The baseline parameters of the 2 groups were comparable with no significant differences in sex, age, weight or body mass index. The mean hospital day was shorter in the digital group than in the analogue group (17.96±12.23 vs. 18.32±16.64, P=0.902), and there was no statistically significant difference in the hospital length of stay between the 2 groups. Air leaks through the chest tube and duration of chest tube indwelling hours showed no significant statistical differences between the digital and analogue groups (213.47±219.80 vs. 261.94±184.47, P=0.235 and 223.44±218.75 vs 275.29±186.06, P=0.205, respectively). Total drainage amount and ambulation time per day were significantly higher in the digital group than in the analogue group [209.62±139.63 vs. 162.48±80.42 (P=0.042) and 6.42±3.62 vs.3.94±1.74 (P<0.001), respectively]. Hours of full expansion were significantly shorter and sleep disturbance caused by the noise of chest tube drainage was less in the digital group than in the analogue group [25.64±14.55 vs. 46.52±25.53 (P<0.001) and 2.38±1.03 vs. 5.70±2.87 (P<0.001), respectively]. CONCLUSIONS: To date, there is no definite consensus and guidelines on the standardized digital suction system in pneumothorax. This study proposed the guidelines for the application of digital thoracic drainage systems in pneumothorax and also suggested that digital thoracic drainage systems might be a valuable tool to determine chest tube removal timing and reducing the length of hospital stay in patients with pneumothorax.