What is the preferred fibrinolytic agent, streptokinase or hyaluronidase, for managing retained hemothorax?

Streptokinase vs Hyaluronidase in Retained Hemothorax

Neither streptokinase nor hyaluronidase is the preferred agent for retained hemothorax—tissue plasminogen activator (alteplase) should be used instead, as it is the most effective fibrinolytic for this indication. However, if choosing between only streptokinase and hyaluronidase, streptokinase is the appropriate fibrinolytic agent, as hyaluronidase is not a fibrinolytic and has no role in managing retained hemothorax.

Critical Clarification

Hyaluronidase is not a fibrinolytic agent and should not be used for retained hemothorax. Hyaluronidase is an enzyme that breaks down hyaluronic acid in connective tissue and has no activity against fibrin clots. The question appears to contain a fundamental error in comparing these two agents for this indication.

Fibrinolytic Options for Retained Hemothorax

First-Line Recommendation: Tissue Plasminogen Activator (Alteplase)

• Alteplase is the preferred fibrinolytic for traumatic retained hemothorax with success rates exceeding 80% and bleeding complications less than 7% 1
• Dosing ranges from 6-100 mg in 50-120 mL normal saline, with higher doses and volumes recommended for hemothorax compared to empyema 1
• The number of doses typically ranges from 1-8 over the treatment course 1

Alternative: Streptokinase

If alteplase is unavailable, streptokinase can be used:

• Streptokinase at 250,000 IU diluted in 100 mL saline solution administered daily has demonstrated a 91.7% overall success rate in traumatic clotted hemothorax 2
• Mean doses administered: 5.0±1.8 doses (range 2-9) 2
• Complete response (resolution of symptoms with complete drainage) occurred in 62.5% of patients, with partial response in 29.2% 2
• Only 8.3% required surgical decortication 2

Important Caveats About Streptokinase

Streptokinase has significant limitations:

• It is a bacterial-derived protein that is highly antigenic, generating systemic antibody responses 3
• Fever after intrapleural injection is commonly reported 3
• The risk/benefit ratio is higher than for other fibrinolytics 3
• Notably, the BTS/MRC Multicentre Intrapleural Streptokinase Trial showed that streptokinase had no beneficial effect in adult empyema 3, though this finding was in empyema rather than hemothorax

Urokinase as Another Alternative

• Urokinase at 100,000 IU diluted in 100 mL saline has been used successfully 2
• Mean doses: 6.25±5.97 (range 2-15) 2
• Urokinase is non-antigenic (derived from human urine) with rare hypersensitivity reactions 3
• No longer available in North America 3

Timing Considerations

Early intervention is critical:

• The mean time between diagnosis and fibrinolytic treatment in successful cases was 11.65±6.38 days (range 4-25 days) 2
• Delayed treatment increases risk of complications including empyema and fibrothorax 4

Comparative Effectiveness

Videothoracoscopy remains superior to streptokinase when available:

• In a retrospective study of 65 cases, videothoracoscopy showed significantly shorter hospital stays (9.8±3.7 days vs 14.5±4.2 days) and fewer thoracotomies compared to streptokinase 5
• However, fibrinolytic therapy should be considered before proceeding to surgical intervention 2

Safety Profile

• No mortality occurred during fibrinolytic treatment in reported series 2
• Bleeding complications are rare but have been reported, particularly with traumatic drain insertion 3
• Minor side effects include discomfort during injection and transient blood staining of drainage fluid 3

Clinical Algorithm

1. First choice: Alteplase (tissue plasminogen activator) at higher doses than used for empyema 1
2. If alteplase unavailable: Streptokinase 250,000 IU in 100 mL saline daily for 5-6 doses 2
3. If fibrinolysis fails: Consider videothoracoscopy or surgical decortication 2, 5
4. Never use: Hyaluronidase (not a fibrinolytic agent)