Over the last 20 years, a significant liberalization has taken place in regards to the amount of fluid which should prevent a chest drain from being removed. In the 1970s, chest drainage of less than 100 ml/24 h was required for removal of a chest drain. There have been numerous studies in more recent decades including one from Brunelli et al. [1] that showed that a chest drain in standard thoracic procedures (resections, biopsies, etc) could safely be removed with up to 400 ml/24 h. One study by Bjerregaard et al. [2] demonstrated that a drain could safely be removed with up to 500 ml/24 h of drainage without significant effusion or clinical relevant issue afterward.

After (talc) pleurodesis, different considerations have to be made. Chest drain outputs below 100 ml/24 h are felt to be sufficiently low to safely remove the drain. It has to be emphasised though that there is no clear evidence for doing so.

The second criterion that determines the timing of chest drain removal is the presence of an air leak. If there is no air leak detected and the fluid production is within a tolerable range (see above), the drain(s) can be removed. Experience with electronic drainage systems over many years has shown that small air leaks (20–40 ml/min), which are stable over 6–8 h, are also amenable to safe removal of the chest drain(s) ([3], own experience).

Very small “air leaks” seen with electronic systems can be attributed to their sensitive measurement capabilities. These very small air leaks are clinically irrelevant leaks due to the smallest of leakages in the system (patient – tubing – aggregate).

In such a situation, the observation of a very small stable air leak over a 6–8 h period is crucial before removing the drain.

With the above criteria, a chest drain can be safely removed regardless of how much time has passed since the initial procedure. Unfortunately, there is little information in the literature concerning the correct timing for chest tube removal. Neither the ACCP [4] nor the BTS [5] give any clear recommendations regarding chest tube removal in their very precise and detailed guidelines concerning all other aspects of pneumothorax treatment.