What is the role of BiPAP (Bilevel Positive Airway Pressure) in managing hemothorax?

BiPAP and Hemothorax

BiPAP should be discontinued in patients with hemothorax, particularly if the hemothorax is large or the patient has massive hemoptysis, as positive pressure ventilation may worsen bleeding and hemothorax accumulation. 1

Evidence-Based Recommendations by Severity

For Patients with Hemoptysis (Bleeding into Airways)

The American Journal of Respiratory and Critical Care Medicine guidelines provide clear stratification based on bleeding severity:

Scant Hemoptysis (<5 ml):

• BiPAP should NOT be discontinued - the risks of withholding respiratory support outweigh concerns about worsening bleeding 1
• Panel consensus rated discontinuation as inappropriate (median score 2, IQR 0-2) 1

Mild-to-Moderate Hemoptysis (5-240 ml):

• BiPAP discontinuation is not strongly recommended - evidence is equivocal with median score of 3 (IQR 2-4.75) 1
• Clinical judgment should weigh the patient's respiratory dependence on BiPAP against bleeding risk 1

Massive Hemoptysis (>240 ml or life-threatening):

• BiPAP should be discontinued during active bleeding - rated as acceptable management in many circumstances (median score 8, IQR 4.25-9) 1
• The concern is that positive pressure may prevent clot formation and worsen hemorrhage 1
• ICU observation may be necessary when withholding BiPAP from patients who are chronically dependent on it 1

For Patients with Pneumothorax

BiPAP should be withheld from all patients with pneumothorax, regardless of size, as long as the pneumothorax is present:

• Small pneumothorax: median score 8 (IQR 5-9) - acceptable management in many circumstances 1
• Large pneumothorax: median score 8 (IQR 6-9) - acceptable management in many circumstances 1
• The rationale is that positive pressure ventilation may cause progression or enlargement of the pneumothorax 1

Clinical Context for Hemothorax

While the provided guidelines focus on hemoptysis (blood in airways) and pneumothorax rather than hemothorax (blood in pleural space) specifically, the principles are relevant:

For traumatic hemothorax:

• Hemothorax >300 mL should be drained with tube thoracostomy 2
• Pigtail catheters are conditionally recommended for hemodynamically stable patients 3
• Early VATS (≤4 days) is recommended for retained hemothorax 3

Case report evidence suggests positive pressure may be therapeutic:

• One case report described successful use of positive end-expiratory pressure (PEEP 5 cmH₂O) to stop bleeding from a massive hemothorax after scoliosis surgery 4
• However, this was in a controlled post-surgical setting with concurrent chest tube drainage 4

Key Clinical Pitfalls

Common errors to avoid:

• Do not assume all intrathoracic bleeding requires BiPAP discontinuation - scant hemoptysis patients should continue BiPAP 1
• Do not continue BiPAP in any patient with pneumothorax, as this may cause tension physiology 1
• For massive hemoptysis patients on chronic BiPAP, plan for ICU-level monitoring when discontinuing support 1
• Hemothorax requires drainage as primary management, not simply BiPAP adjustment 3, 2

The decision algorithm:

1. Identify if bleeding is hemoptysis (airway) vs hemothorax (pleural space)
2. For hemoptysis: quantify volume and discontinue BiPAP only if massive (>240 ml)
3. For pneumothorax: always discontinue BiPAP regardless of size
4. For hemothorax: prioritize drainage with tube thoracostomy; BiPAP decisions should be made cautiously with recognition that positive pressure could theoretically worsen accumulation, though limited direct evidence exists 3, 2, 4