Digital versus analogue chest drainage system in patients with primary spontaneous pneumothorax: a randomized controlled trial

BACKGROUND: Patients with a primary spontaneous pneumothorax (PSP) who are treated with chest tube drainage are traditionally connected to an analogue chest drainage system, containing a water seal and using a visual method of monitoring air leakage. Electronic systems with continuous digital monitoring of air leakage provide better insight into actual air leakage and changes in leakage over time, which may lead to a shorter length of hospital stay. METHODS: We performed a randomized controlled trial comparing the digital with analogue system, with the aim of demonstrating that use of a digital drainage system in PSP leads to a shorter hospital stay. RESULTS: In 102 patients enrolled with PSP we found no differences in total duration of chest tube drainage and hospital stay between the groups. However, in a post-hoc analysis, excluding 19 patients needing surgery due to prolonged air leakage, hospital stay was significantly shorter in the digital group (median 1 days, IQR 1–5 days) compared to the analogue group (median 3 days, IQR 2–5 days) (p 0.014). Treatment failure occurred in 3 patients in both groups; the rate of recurrence within 12 weeks was not significantly different between groups (16% in the digital group versus 8% in the analogue group, p 0.339). CONCLUSION: Length of hospital stay was not shorter in patients with PSP when applying a digital drainage system compared to an analogue drainage system. However, in the large subgroup of uncomplicated PSP, a significant reduction in duration of drainage and hospital stay was demonstrated with digital drainage. These findings suggest that digital drainage may be a practical alternative to manual aspiration in the management of PSP. TRIAL REGISTRATION: Registered 22 September 2013 - Retrospectively registered, Trial NL4022 (NTR4195)