2008 Rapid diagnosis of pleural effusions by use of reagent strips
Dr Kwan Hoi Yee
Department of Medicine, North District Hospital
Background
Pleural effusion is a common clinical problem. Characterizing it timely into transudates or exudates, infectious or non-infectious, complicated or uncomplicated parapneumonic effusion allows prompt initiation of appropriate treatment, thus improving prognosis. Reagent strip has been proposed for use in other body fluids, while its role in pleural effusions is not yet confirmed.
Objectives
To evaluate the validity of glucostix and multistix in discriminating exudative pleural effusions, in predicting their infectivity, and in identifying complicated parapneumonic effusions.
Method
Patients admitted to the Medical Unit of North District Hospital and having pleural effusions requiring thoracocentesis were recruited. Laboratory investigations and bed-side rapid reagent tests were performed on the pleural fluids. Their validity scores in characterizing pleural effusions were compared with previous reported studies.
Main results
Seventy pleural fluid samples from 49 subjects were evaluated. Pleural fluid protein assessed by reagent strip was helpful in discriminating exudative pleural effusions. Glucometer-measured pleural fluid glucose could assist in the identification of complicated parapneumonic effusions. Pleural pH measured by reagent strip did not correlate with the laboratory measurement. Reagent strip-measured leucocyte esterase, although correlated with the laboratory total nucleated cell counts, was of no assistance in categorizing the pleural effusions. The findings were comparable with previous studies.
Conclusion
Reagent strip assisted timely etiologic diagnosis of pleural effusions. Further studies with a bigger sample size and using different brands of reagent strips are warranted to confirm their validity.
