Neuroanaesthesia

‘Gasp reflex’Classic ‘mill wheel’ murmurPulmonary oedema

CVP = central venous pressure; PAP = pulmonary artery pressure.

What other clinical situations are associated with VAE?

For a VAE to occur there must be a gas source, a communication with the venous circulation and a pressure gradient favouring transfer of gas into the circulation.

Table 16.3 Causes of venous air embolism

Surgery	Neurosurgery Head and neck Orthopaedics Laparoscopic Obstetrics	Where surgical site is above the heart, creating a pressure gradient favouring the passage of air into the circulation Including LASER procedures Arthroscopy, arthroplasty (Release pneumoperitoneum immediately) C-section, termination of pregnancy
Trauma	Penetrating trauma to head, neck, thorax, abdomen
Intravascular catheterization	Air in IV giving sets During central venous access, disconnection or removal
Barotrauma	Positive-pressure ventilation