Pleural drainage: an evolving area – authors' response

We would like to thank Dr Kelly [1] for his interest in our recent article [2] on the use of central venous catheters for pleural drainage. His comments add to those recently highlighted by MacDuff and Grant [3].

We would like to comment on the use of ultrasound (USS)-guided drainage of the pleural cavity. The technique we have described is a cheaper and less traumatic alternative to the use of bigger bore chest tubes. It is, however, not meant as an alternative for situations where USS guidance is needed, such as in difficult patient anatomy or in the drainage of loculated effusions. As Kelly has pointed out correctly, it is a luxury and in our context also expensive, and it involves logistical arrangements that delay the performance of the procedure. We have also encountered situations of failure despite the 'X marks the spot' methodology.

To avoid this, in situations where we seek the aid of the radiologist, we either perform the insertion with the radiologist present or get them to insert their fine bore catheters at the first attempt. This avoids the double cost and logistical arrangements needed should we fail. In our experience there have been occasions where chest radiograph diagnosis of significant pleural effusions was not confirmed by USS, and we invite caution in performing this procedure without USS information.

As we have highlighted in our paper and in our recent reply [4], our reported group is small and selective. We recognize that we cannot accurately predict the rate of infection as well as catheter blockage with our sample size, although thus far we have not encountered these problems.

We agree that a 'real world' study is needed to answer a number of issues. MacDuff and Grant have highlighted potential medicolegal pitfalls with the use of the central venous catheters that we have described. We believe, however, that cost issues should be taken into account when designing this study.