Detection and Hemodynamic Consequences of Venous Air Embolism

Anaesthesia for neurosurgery in the sitting position

“…While precordial Doppler is non-invasive and will detect very small amounts of air, TOE has the advantage of detecting air in the left heart, PFO and abnormalities in cardiac performance. 23 Lossaso et al 24 found a detection threshold of 0.05 ml/kg of air for Doppler, compared with 0.15 ml/kg for end-tidal CO 2 partial pressure (ETCO 2 ), with pulmonary artery pressure increases even less sensitive. Placement of an oesophageal stethoscope and listening for a mill-wheel murmur is the least sensitive method.…”

“…Placement of an oesophageal stethoscope and listening for a mill-wheel murmur is the least sensitive method. [24][25][26] Routine use of Doppler or TOE requires specific training by the neuroanaesthetist but will increase detection of small VAEs. Small VAEs may not be clinically relevant, but allow early management which may decrease the risk of larger VAEs occurring and subsequent morbidity.…”

Repeated attacks of venous air embolism during endoscopic sinus tumor surgery: A case report

“…The clinical picture may vary between an asymptomatic (even unnoticed) episode and severe pulmonary oedema [5] or cerebral embolism [6] that may result in death of the patient. Intraoperative detection of VAE is possible in various ways, namely Doppler ultrasound, trans-esophageal echocardiography (TEE), changes in P ET CO 2 and changes in pulmonary artery pressure, TEE being the most sensitive one and able to detect entrainment of air as slow as <0.1 ml kg À1 min À1 [7]. A sudden decrease in P ET CO 2 and SpO 2 is first noticed clinically.…”

Sitting Position in Neurosurgery

“…15 In another study by Losasso et al, the use of nitrous oxide helped reduce opioid and inhalational agent requirement, facilitating early recovery and neurologic assessment. 16 The use of PEEP (positive end-expiratory pressure) during neurosurgical procedures performed in the sitting position is another controversy. Physiological PEEP of 4 to 5 cm H 2 O helps decrease the venous gradient as the increase in the transthoracic pressure is transmitted to the central veins, which increases the CVP.…”