Air Embolism

Etiology

  • Can be venous or less commonly, arterial
  • Three vulnerable areas of air entry in dialysis patients:
    • Between patient and blood pump, due to high negative pressure and leaks in the circuit in this segment
    • Air in the dialysate fluid (uncommon, mostly gets trapped in venous chamber)
    • During central venous catheter insertion or removal
  • Upright body position and hypovolemia, both by reducing venous pressure, are significant contributing factors

Treatment

  • Prevent further air entry by clamping and disconnecting the circuit
  • Flat supine position may be better over traditionally advocated left lateral (Duran’s position) and Trendelenburg position1,2
  • Oxygen with FiO2 100%
  • Hyperbaric oxygen3 (prevents cerebral edema)
  • Use of Luer-lock syringes for blood draw from catheters

Prevention

  • Test machine prior to use to ensure that the air detector alarm system is working effectively
  • Catheter insertion or removal should be in a head low position (insertion site 5 cm below right atrium).  Patient can assist by holding their breath or doing a Valsalva maneuver that will increase central venous pressure4.

References:

  1. Vesely TM. Air embolism during insertion of central venous catheters. J Vasc Interv Radiol 12:1291-1295, 2001
  2. Muth CM, Shank ES. Gas embolism. N Engl J Med  342:476-482, 2000
  3. Baskin SF, Woznizk RF. Hyperbaric oxygenation in the treatment of hemodialysis-associated air embolism. N Engl J Med 293:184-185, 1975
  4. Palmon SC, Moore LE, Lundberg J, Toung T. Venous air embolism: A review. J Clin Anesth 9:251-257, 1997