Controlled Trial of Intrapleural Streptokinase in the Treatment of Pleural Empyema and Complicated Parapneumonic Effusions (Results)

1 Jan

Controlled Trial of Intrapleural Streptokinase in the Treatment of Pleural Empyema and Complicated Parapneumonic Effusions (Results)There were 52 patients (41 men and 11 women) with a mean (SD) age of 57 years, range between 16 and 18 years. Most patients (75%) had some underlying disease, with diabetes in 41% and chronic lung diseases in 31%. There were no significant differences in age, sex ratio, frequency of underlying disease, and degrees of peripheral blood leukocytosis between patients on the SK and Drain treatment protocols (Table 1). Forty patients (77%) had frank empyema and the rest had complicated parapneumonic effusions. Twenty-eight (54%) patients had positive pleural fluid cultures, of which 32% were anaerobic and 21% were polymicrobial. The most common aerobic isolates were Klebsiella pneumoniae and Staphylococcus aureus while the most frequently isolated anaerobe was Bacillus fragilis. There was no significance difference between the two treatment groups in the frequency of gross empyema, bacterial isolates, pleural fluid loculations, and biochemical abnormalities (Table 2).

The mean (SD) duration of tube drainage on the Drain protocol was 12 (SD=8) days (n=29) with five patients requiring more than one tube insertion (Table 3). Four patients (14%) did not respond to the treatment and required surgical decortication. Two patients in this group stayed more than 60 days in hospital. They developed complications (end-stage renal failure in one and postanoxic encephalopathy in another) not related to the pleural sepsis that had resolved after 12 and 15 days of tube drainage. If these two patients were excluded, the mean (SD) duration of stay in hospital for this group was 21 days (n=27). One patient who stayed 21 days in hospital developed a persistent fistula following chest tube removal which resolved after 18 months of ambulatory care. Seven patients (24%) in this group died, six from septicemia (one of these patients died following open drainage and decortication) and one after an acute myocardial infarct.

The patients on the SK protocol received between 1 to 10 daily administrations of SK (mean [SD] 5.3 [2.7]). No adverse effect of SK was noted. Figure 1 shows the marked increase in pleural fluid drainage after SK instillation. The mean (SD) total cumulative volume of fluid drained in the SK group was 1,982 mL. This was significantly higher than the cumulative volume of pleural fluid in the Drain group mL; p=0.007). Nine patients had more than one chest tube inserted. One patient who needed five tubes inserted into three locules over a 2-week period made a complete recovery. Five patients (22%) underwent thoracoscopic evacuation and pleurodesis; all survived. Two patients in the SK group died, one from myocardial infarction and the other from septicemia.

There were no significant differences in clinical outcomes between the two groups (Table 3). The duration of hospital stay was 22 days for the SK group and 21 for the Drain group (n=27, excluding the two patients described above who had long stays in hospital from complications not related to pleural sepsis); the duration from the day of hospital admission to defervescence was 10.6 days for the SK protocol and 7.7 days for the Drain protocol. The percentage of patients who eventually required surgical intervention was 22% for the SK group and 14% for the Drain group, and there was also no significant difference in the mortality, which was 9% in the SK group and 24% in the Drain group. The overall failure rate (defined as either surgical intervention or death) was 30% (7/23) in the SK group and 34% (10/29) in the Drain group.

Table 1—Clinical and Demographic Information

SK GroupDrain Group
Age, yr50 63
Sex ratio, M/F18/523/6
Underlying disease, %4859
Blood TWBC, X106/L18,200 16,210

Table 2—Pleural Fluid Characteristics: Mean (SD)

SK GroupDrain Group
Empyema, %7479
Positive cultures, %4859
Multiloculation, %227
pH7.2 (0.2)6.96 (0.6)
LDH, U/L14,850 16,700

Table 3—Clinical Outcomes: Mean (SD)

SK GroupDrain Group
Duration of hospitalization, d22 (11)21 (12)’
Days before defervescence, d10.6 7.7
Total volume of fluid drained, L2.0 (1.5)1.0(1.01)’
Days with chest tube12 12 (8)
Surgical procedures, %2214
Mortality, %924
Failure rate, %3034


Figure 1. The cumulative volumes of pleural fluid drained before (Pre SK) and after (Post SK) institution of intrapleural streptokinase.

Mean (SD)