Arterial gas embolism

Background

• Due to negative intrathoracic pressure from spontaneous breathing
• May be fatal when air entry reaches 200-300 mL (pressure gradient of 5 mmHg across 14 ga catheter entrains air at 100 mL/sec)
• Prevention is most important
  • Positive pressure mechanical ventilation reduces positive pressure gradient
  • Trendelenburg for insertion/removal of IJV and subclav lines
  • Reverse Trendelenburg for femoral

Clinical Features

• Acute dyspnea, chest tightness, LOC, cardiac arrest
• Decompression syndrome - see SCUBA Diving Emergencies

Differential Diagnosis

Dialysis Complications

• Dialysis-associated hypotension
• Dialysis disequilibrium syndrome
• Air embolism
• Missed dialysis (pulmonary edema)

Workup

• Low ETCO2 in significant venous air embolism

Management

• Prevent any further air entry
• Immediately cover puncture site with saline soaked gauze
• Treat w/ 100% NRB
• Hemodynamic support with positive inotropes
• Rapid CPR in large air embolus

See Also

• Dialysis complications

Sources

• The ICU book, 4th edition
• Shaikh N., Ummunisa F. Acute management of vascular air embolism. J Emerg Trauma Shock. 2009 Sep-Dec; 2(3): 180–185.