Introduction Current practice for diagnostic only thoracoscopy varies from day-case procedures to routine overnight stays. Radiographic evidence of lung re-expansion and underwater seal evidence of lack of on-going air leak are required before patient discharge. Use of a digital suction device which accurately measures air leak may allow earlier identification of lung re-expansion and hence earlier discharge.

Patients pleurodesed at thoracoscopy are admitted for 3–4 days, however the presence of trapped lung preventing re-expansion after thoracoscopy reduces the chance of successful pleurodesis, and measurement of air leak with a digital device may allow prediction of trapped lung.

Aim To determine whether initial air leak measurement can predict trapped lung and whether use of digital device can reduce time to chest radiograph post thoracoscopy.

Methods Data was prospectively collected (November 2012 to May 2013), on patients undergoing thoracoscopy in a specialist respiratory centre. Post-procedure, the “air leak” was measured using a digital suction device (Thopaz, Medela UK), and time to chest radiograph (CXR) was compared to LAT in the preceding three months.

Results 32 patients were investigated. Results were non-normally distributed so non-parametric analysis was undertaken. Median initial flow rate post-thoracoscopy was 108ml/min. Nine (28%) had trapped lung: median air flow rate was significantly lower in this group 45ml/min (IQR 39–118ml/min) vs 118ml/min (IQR 75–179ml/min), using Mann-Whitney U Test (p = 0.01). Those with trapped lung had larger effusions drained during procedure: 1739ml vs 1332ml (p = 0.48).

Fourteen (44%) patients were successfully managed as day-cases with the digital suction device: mean time to CXR was 2.1 hours (SD 1.1); less than the 8 preceding day-case thoracoscopies (mean 2.9, SD 1.6 hours) (p = 0.2).

Conclusion This pilot data suggests that digital air flow measurement has the potential to predict which patients are likely to have trapped lung and lack of air leak, and may potentially identify the group of patients in which to use indwelling pleural catheters. Use of the device may also allow earlier identification of full re-expansion, earlier CXR and hence more rapid discharge home.