Is manipulation of mediastinal chest drains useful or harmful after cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients who have undergone cardiothoracic surgery does manipulation of drainage tubes affect drainage volumes or post-surgical outcome? Altogether 681 papers were found using the reported search, of which four represented the best evidence to answer the clinical question. Duncan and Erickson in 1982 found that chest tube stripping can lead to very low negative intrathoracic pressures. The authors report that this has the potential to cause tissue injury. Issacson et al. in 1986 compared two different methods of drain manipulation. They found no significant differences in the milking and stripping methods, suggesting that they are of similar efficacy in enhancing drainage. Lim-Levy et al. in 1986 also compared milking vs. stripping, with a control group that received no manipulation. They found no significant differences between the three groups in drainage volume. Furthermore, they recorded no incidences of tube occlusion in any of the three groups, implying that leaving the drains free of manipulation is acceptable in terms of clot clearance in the majority of patients. The milking and stripping methods were also compared by Pierce et al. in 1991. They also found no significant differences between the two manipulation methods. The studies by Issacson et al., Lim-Levy et al., and Pierce et al. were included in a Cochrane systematic review by Wallen et al. in 2002. No other relevant studies other than the three mentioned above were found after an extensive search of the literature. Overall, the authors concluded that there was insufficient evidence to recommend one type of drain manipulation technique over another, or to support or refute the need for drain manipulation at all. In our paper the authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that due to possible tissue damage and lack of demonstrable benefit, in most patients drainage tube manipulation should not be performed. No differences in either safety or efficacy have been demonstrated between the milking and stripping methods of manipulation.