Intrapleural Use of Tissue Plasminogen Activator and DNase in Pleural Infection

Background More than 30% of patients with pleural infection either die or require surgery. Drainage of infected fluid is key to successful treatment, but intrapleural fibrinolytic therapy did not improve outcomes in an earlier, large, randomized trial. Methods We conducted a blinded, 2-by-2 factorial trial in which 210 patients with pleural infection were randomly assigned to receive one of four study treatments for 3 days: double placebo, intrapleural tissue plasminogen activator (t-PA) and DNase, t-PA and placebo, or DNase and placebo. The primary outcome was the change in pleural opacity, measured as the percentage of the hemithorax occupied by effusion, on chest radiography on day 7 as compared with day 1. Secondary outcomes included referral for surgery, duration of hospital stay, and adverse events. Results The mean (+/- SD) change in pleural opacity was greater in the t-PA-DNase group than in the placebo group (-29.5 +/- 23.3% vs. -17.2 +/- 19.6%; difference, -7.9%; 95% confidence interval [CI], -13.4 to -2.4; P = 0.005); the change observed with t-PA alone and with DNase alone (-17.2 +/- 24.3 and -14.7 +/- 16.4%, respectively) was not significantly different from that observed with placebo. The frequency of surgical referral at 3 months was lower in the t-PA-DNase group than in the placebo group (2 of 48 patients [4%] vs. 8 of 51 patients [16%]; odds ratio for surgical referral, 0.17; 95% CI, 0.03 to 0.87; P = 0.03) but was greater in the DNase group (18 of 46 patients [39%]) than in the placebo group (odds ratio, 3.56; 95% CI, 1.30 to 9.75; P = 0.01). Combined t-PA-DNase therapy was associated with a reduction in the hospital stay, as compared with placebo (difference, -6.7 days; 95% CI, -12.0 to -1.9; P = 0.006); the hospital stay with either agent alone was not significantly different from that with placebo. The frequency of adverse events did not differ significantly among the groups. Conclusions Intrapleural t-PA-DNase therapy improved fluid drainage in patients with pleural infection and reduced the frequency of surgical referral and the duration of the hospital stay. Treatment with DNase alone or t-PA alone was ineffective.