More than 65,000 people develop empyema each year, and 25% of them are in the hospital a month or longer. Past randomized trials and a meta-analysis showed streptokinase didn't help, but case series suggested tissue plasminogen activator might.
Rahman et al randomized 210 people to a 2 x 2 table: double-placebo, DNAse and t-PA, DNAse alone, or t-PA alone. The combination of DNAse and t-PA improved radiographic clearance of the pleural space (primary endpoint). Combination therapy also reduced the rate of surgery consultation by an absolute 8% (4% vs. 16%). Mean hospital stay was 5 days shorter in the combination therapy group (12 vs. 17 days); these were all prespecified secondary endpoints. There was no difference in mortality. N Engl J Med 2011;365:518-526.