Stratifying fibrinolytic dosing in pediatric parapneumonic effusion based on ultrasound grade correlation

Abstract

Background: Complicated pleural effusion prolongs the hospital course of pneumonia. Chest tube placement with instillation of fibrinolytic medication allows efficient drain output and decreases hospital stay. Objective: To evaluate experience with lower fibrinolytic dose for parapneumonic effusions and to assess potential dose stratification based on a simple ultrasound grading system. Materials and methods: We retrospectively reviewed the medical record to identify children and young adults who received fibrinolytic therapy for parapneumonic effusion and had chest tube placement by an interventional radiology service at a single children’s hospital. We assessed tissue plasminogen activator (tPA) dosing and treatment duration, as well as the need for a second pleural procedure or surgical drainage. Diagnostic US images were classified as showing less than 50% pleural echogenicity (grade 1) or greater than 50% pleural echogenicity (grade 2) and were correlated with clinical parameters. Results: Of 32 patients with parapneumonic effusion, all except one received at least some 1-mg tPA doses. Dosing was solely 1-mg tPA in 81% of subjects; 19% of subjects also received 2-mg tPA doses. Mean fibrinolytic duration was 3.1 days for grade 1 effusions compared to 5.4 days for grade 2 effusions. A second pleural procedure was required in 15.6% of children. Pleural drainage with fibrinolytic therapy was successful in 97%; only one child required surgical drainage. Grade 2 US differed significantly from grade 1 US, with grade 2 occurring in younger patients (P < 0.0001), smaller patients (P < 0.0001), those needing a second procedure (P = 0.001), those with positive pleural culture or polymerase chain reaction test (P = 0.006), and those with longer treatment duration (P = 0.03). Conclusion: A lower 1-mg dosing regimen of tissue plasminogen activator was effective in all children with less complex (grade 1 US imaging) parapneumonic effusions. Grade 2 US images correlated with younger and smaller children, presence of a pleural organism, and longer or more complicated chest tube duration.