Risk Factors of Air Embolism
- Positioning and Exposure: Hip replacement surgeries and other orthopedic procedures performed in the lateral or sitting position are associated with venous air embolism due to the large exposure of venous channels during joint manipulation or bone cutting.
- Use of Cement: Procedures involving the use of bone cement may contribute to gas embolism, particularly when the cement is pressurized into bones such as the femur, allowing air or nitrogen to enter the venous system.
- Long Bone Fractures: Surgeries involving long bone fractures, particularly those with significant venous exposure or manipulation, are also at risk for air embolism.
Prevention and Management of Air Embolism
- Positioning: Many orthopedic surgeries, such as total hip arthroplasty, are performed in the lateral or sitting position, which increases the risk of air embolism due to venous exposure. Proper padding and positioning are essential to avoid excessive pressure on venous structures and to maintain normovolemia to reduce negative venous pressure at the surgical site.
- Bone Cement Use: Bone cement, used in procedures like hip or knee replacement, can increase the risk of embolism due to the release of air or nitrogen bubbles into the venous system. To reduce the risk of air embolism, surgeons should use cement cautiously and minimize the pressure used to insert it.
- Hydration: Maintaining adequate hydration is critical in preventing air embolism in orthopedic surgeries, particularly those involving large venous structures or long bone fractures. Dehydration increases the risk of air entry due to lower venous pressures, especially during limb manipulation or bone cutting.
- Rapid Response to Air Embolism: If air embolism occurs during orthopedic surgery, immediate actions should be taken to stop further air entry. The surgical field should be flooded with saline, and the patient should be repositioned, if possible, to reduce the pressure gradient between the venous system and the surgical site.
- Air Aspiration: This may be particularly necessary in high-risk orthopedic procedures where large volumes of air may enter the circulation.
- Hemodynamic Stabilization: Hypotension and right heart failure resulting from air embolism should be managed aggressively with fluid resuscitation and inotropic support. Oxygen administration with 100% FiO₂ helps shrink air bubbles and optimize tissue oxygenation.
| Setting | Principal risk factors | Emphasis in prevention and management |
|---|---|---|
| Cesarean section | Placental removal, uterine exteriorization and uterine incision; placenta previa and abruptio placentae; Trendelenburg positioning; hypovolemia, preeclampsia and severe antepartum hemorrhage | Reverse Trendelenburg of 5° to 10° rather than Trendelenburg, flooding the field with saline, cautious PEEP, stopping nitrous oxide, and aspiration through a central or multi-orifice catheter |
| Posterior fossa neurosurgery | The sitting position, because of negative venous pressure at the surgical site | Precordial Doppler, which detects air as small as 0.015 mL/kg/min; repositioning to Trendelenburg or left lateral decubitus (Durant maneuver); aspiration through a central venous catheter; 100% oxygen to shrink bubbles |
| Cardiovascular surgery | Cannulation, decannulation and air in the perfusion circuit on cardiopulmonary bypass; intracardiac procedures with a PFO, risking paradoxical embolism; nitrous oxide | Correct circuit priming and de-airing, air-detection devices checked and calibrated beforehand, 100% oxygen instead of nitrous oxide, aspiration of air from the heart chambers, and hyperbaric oxygen for paradoxical embolism |
| Orthopedic surgery | Lateral or sitting positioning with wide venous exposure during joint manipulation or bone cutting; pressurized bone cement releasing air or nitrogen; long bone fracture surgery | Proper padding and positioning, normovolemia and adequate hydration, cautious low-pressure cement insertion, flooding the field and repositioning if embolism occurs, and 100% FiO2 with fluid and inotropic support |
