From the Guidelines
If suspected air embolism occurs after coming off cardiopulmonary bypass (CPB), the patient should be immediately placed in the left lateral decubitus head-down position to prevent further air entry and reduce the volume of air entrained. This position is crucial in managing venous air embolism, as it helps to obstruct the right ventricular pulmonary outflow tract or obstruction of the pulmonary arterioles by a mixture of air bubbles and fibrin clots formed in the heart 1. The main goals of management include prevention of further air entry, reduction in the volume of air entrained, and hemodynamic support.
Some key considerations in managing suspected air embolism include:
- Preventing further air entry into the vascular system
- Reducing the volume of air entrained, if possible
- Providing hemodynamic support to the patient
- Considering intraoperative needle aspiration to relieve large air bubbles
- Using transesophageal echocardiography to confirm the diagnosis and monitor resolution
In terms of specific interventions, increasing the FiO2 to 100% can help maximize oxygen delivery and minimize ischemic damage. Maintaining adequate blood pressure with vasopressors like norepinephrine or phenylephrine can help ensure cerebral perfusion. If hemodynamic instability persists, considering returning to CPB to aspirate the air may be necessary. The anesthesiologist should attempt to aspirate air through the central venous catheter, and hyperbaric oxygen therapy may be considered if cerebral air embolism is suspected 1.
The importance of prompt action in managing air embolism cannot be overstated, as this complication can cause mechanical obstruction of blood flow and inflammatory responses leading to tissue ischemia. Careful de-airing procedures during the weaning process from CPB can help prevent this complication. By prioritizing the patient's morbidity, mortality, and quality of life, healthcare providers can take swift and effective action to address suspected air embolism after CPB.
From the Research
Suspected Air Embolism after Cardiopulmonary Bypass
If there is a suspected air embolism after coming off from cardiopulmonary bypass, the following steps can be taken:
- Immediate management includes placing the patient on high-flow oxygen and in the right lateral decubitus position for arterial air emboli 2
- For venous air emboli, the patient should be placed on high-flow oxygen and in the left lateral decubitus and/or Trendelenburg position 2
- Hyperbaric oxygen therapy is the definitive treatment, which may decrease the size of air emboli by facilitating gas reabsorption, while also improving tissue oxygenation and reducing ischemic reperfusion injury 3, 2, 4
- Multimodal neuroprotection strategies can be used to manage massive air embolism during cardiopulmonary bypass 5
Prevention and Management Strategies
Prevention is the best management strategy for air embolism, but if it occurs, a clear and concise management protocol should be in place 5
- Near-infrared spectroscopy monitoring can be used to rapidly detect air embolism 5
- A surgical team should determine and organize the strategies to be followed in case of an air embolism 5
- Hyperbaric oxygen treatment can be used for air or gas embolism, and it is similar to decompression sickness treatment 4
Important Considerations
- Air embolism is a life-threatening complication during cardiopulmonary bypass, and prompt diagnosis and management can result in significantly improved patient outcomes 2, 6
- The incidence of systemic air embolism during cardiopulmonary bypass is estimated to be 0.1%, but most instances are unreported and quietly ignored 3