In noncritically-ill patients, quantification of pleural fluid is usually done in an upright sitting position. It is the objective of this paper to formulate an estimate equation of projected amount of pleural fluid which can be drained using the volume of pleural fluid determined by ultrasound prior to thoracentesis.
Demographics of patients and characteristic of pleural fluid were noted and recorded using a database. Quantification of the pleural effusion was done using an ultrasound with dimensions of length, width and depth and computation of the volume recorded while patient is in an upright sitting position before and after thoracentesis. The actual amount drained was likewise noted.
30 patients were included with mean age of 61 years old, 26 of which were in- patients and majority were nonsmokers. Etiology of pleural effusion showed 11 (30%) was most likely malignancy, 9 (30%) TB, 8 (27%) parapneumonic, 1 (3%) uremia, 1 (3%) congestion. Co-morbid illnesses include hypertension (n = 20), diabetes mellitus (n = 6), chronic obstructive pulmonary disease (COPD, n = 4), breast cancer (n = 3), chronic kidney disease (n = 2).
Using simple linear regression analysis two estimate equations were formulated. The first equation, y = 0.75674x + 212.73538 , where x is the difference of the prevolume and postvolume in cc, may predict the value of y, which is the actual volume drained with the prevolume and postvolume difference having a significant contribution to the actual volume drained (p < 0.0001). The second equation, y = 0.52361x + 173.71958, where x is the prevolume in cubic centimeters, may predict the value of y, which is the predicted actual volume to be drained. The prevolume has a significant contribution to the actual volume drained with p < 0.0001.
The equation may be used to guide the clinician in the amount of fluid which is expected to be drained. This can be applicable when the prevolume (second equation) measurement of pleural fluid via ultrasound is available as well as the prevolme and postvolume difference for the first equation.
Julie Christie Visperas, No Financial Disclosure Information; No Product/Research Disclosure Information