Use of Protected Specimen Brush for the Diagnosis of Pulmonary Infection

Lee, Jae Myung; Kim, Dong Kyu; Choi, Jeong Eun; Kim, Dong Hwan; Mo, Eun Kyung; Park, Myung Jae; Lee, Myung Goo; Hyun, In Gyu; Jung, Ki Suck

Abstract

OBJECTIVES
Culture of sputum is apt to be contaminated through oral cavity and proximal airway. Therefore, identification of true etiologic agents by sputum culture is not always reliable. In order to differentiate the pulmonary infection from non-infectious disease and to identify the true etiologic agent of acute pulmonary infection, we used PSB(Protected Specimen Brushing) and evaluated the efficacy of PSB.
METHODS
In 168 patients with acute febrile illness with pulmonary infiltrations(male 106, female: 61, mean age: 49.5+/-17.6), we performed PSB via a bronchoscope and compared the results along with blood culture and sputum culture. Protected specimen brush was introduced through biopsy channel of bronchoscope and was rotated within the purulent secretions. Tip of the brush was severed with aseptic technique and was immersed in 1cc of Ringer's lactate solution and vigorously mixed for 1 minute. The specimen was submitted for quantitative culture within 15 minutes and was regarded positive culture if colony forming units were above 10(3)/ml.
RESULTS
Using PSB for the diagnosis of pulmonary infection, sensitivity was 71.1% and specificity was 84.296. PSB was helpful in identifing true etiologic agent among several potentially pathogenic organisms. Using PSB for the diagnosis of UAP (ventilator associated pneumonia), sensitivity was 72.4% and specificity was 100%.
CONCLUSION
Use of PSB can be a helpful method for the diagnosis of pulmonary infection and identification of its etiologic agents.