Clavicle tapping and auscultation as an alternative to chest percussion when performing thoracocentesis.

I read with interest the article “Limited Utility of Chest Radiograph After Thoracentesis” by Petersen and Zimmerman in a recent issue of CHEST (April 2000).1 Although I agree that performing a routine chest radiograph following a thoracentesis is needless in most patients, I was surprised by the number of pneumothoraces that occurred during the performance of thoracentesis, because, in my hands, pneumothorax occurs very rarely (, 0.025%). Upon review of the technique described in the article, I advise that during a thoracentesis procedure the tubing attached to the angiocatheter should be utilized in order to ascertain (using the tubing itself as a manometer) what the fluid pressure is in the chest. If the fluid pressure is 0 or even negative, then the removal of fluid will result almost certainly in a pneumothorax, or at worse shock, because one cannot have “a negative space.” However, if the fluid pressure is positive, it is very likely that the removal of fluid will not result in a pneumothorax. (In a patient who is borderline, I often recheck the pleural pressure of fluid intermittently during thoracentesis to make sure that I do not remove “too much.”) The patient at this point (when the fluid pressure is 0) usually complains of a dull chest pain, which is a reflection of a negative pressure in the chest. I also was concerned about the authors’ disparaging comment about the use of vacuum bottles in performing thoracentesis. I have found that the use of vacuum bottles is an excellent adjunct to the performance of thoracentesis. I have observed that if there is foam at the top of the fluid, then this means that the vacuum is still present; when there is no foam or little foam, there is no vacuum present, which can be indicative of a pneumothorax. Moreover, if a significant pneumothorax is found, I recommend a needle thoracostomy as opposed to chest tube insertion because often the pneumothorax is, at best, transient, when it is caused by such a small needle, as opposed to one induced by trauma. In closing, I wish to add that the evaluation of fremitus with the stethoscope is a much better test than listening to breath sounds in someone with a pneumothorax. The absence of fremitus is easier to ascertain, whereas the finding of “decreased breath sounds” is sometimes a very difficult physical finding to reproduce. Figures 1 and 2 illustrate a thoracentesis performed with the manometer technique.