A novel bedside technique for differentiation of exudative from transudative pleural effusion

 Abstract  Background: At present, differentiation between exudative and transudative pleural  effusion is based solely on laboratory measures and is time-consuming. Asimple  bedside method would be of great help to differentiate between these two types of effusions.  We present a new method for this purpose assessed in 46 patients.  Methods: Standard laboratory tests and our method were tested using the same fluid  samples in 46 patients with pleural effusion. Aprincipal in physics called the capillary  tube law (h=2a/rpg) was used to compare the samples. The imbibition of the fluid  level less than 15mm signified exudate and greater than 15mm signified transudate.  Results: Our data shows that this method is 74% sensitive and 89.4% specific compared  to the standard method when analyzed statistically by the chi-square and Kappa  agreement (Cronbach’s K) tests.  Conclusion: The capillary tube test has an acceptable validity for bedside diagnosis  of exudative or transudative effusions.