Sensitivity of End-tidal Nitrogen in Venous Air Embolism Detection in Dogs

Venous Air Embolism during Surgery, Especially Cesarean Delivery

“…The time to maximal change in ETN 2 (32±8 sec) was 30-60 sec earlier than that of pulmonary artery catheters and ETCO 2 (53). The mass spectrometer used in the study by Matjasko et al (53) had a nitrogen sensitivity of 0.01%, in contrast to the 0.1% in clinically used mass spectrometers. Emission spectrometry can also be used to detect increased ETN 2 levels indicative of venous air embolism as an alternative to mass spectrometers, and may be a more sensitive detector (0.1 mL/kg) (54).…”

“…The pulmonary artery catheter is capable of detecting as little as 0.5 mL/kg of air in 80% of bolus injections when pulmonary artery pressure exceeding baseline by 25% is defined as a positive sign of VAE (53). Although the pulmonary artery pressure is less sensitive than ETCO 2 , it changes earlier than ETCO 2 , when air embolism occurs as much as volumes of 1.5 mL/kg (53). The pulmonary artery catheter has limitations in detecting VAE in normal patients undergoing elective cesarean section due to its invasiveness.…”

“…The pulmonary artery catheter has limitations in detecting VAE in normal patients undergoing elective cesarean section due to its invasiveness. However, in patients with other complicated indications requiring its use, the pulmonary artery catheter can provide useful information such as pulmonary artery hypertension, low cardiac output and low mixed venous saturation that manifests in severe or fatal VAE (53). …”

“…Increased ETN 2 in a patient ventilated with denitrogenated gas has been considered as a specific sign of venous air embolism (54). ETN 2 monitor is capable of detecting as little as 0.25±0.5 mL/kg of air (53, 55) and increases rapidly after an experimental VAE is large enough to cause minimal changes in blood pressure (56). The time to maximal change in ETN 2 (32±8 sec) was 30-60 sec earlier than that of pulmonary artery catheters and ETCO 2 (53).…”

“…ETN 2 monitor is capable of detecting as little as 0.25±0.5 mL/kg of air (53, 55) and increases rapidly after an experimental VAE is large enough to cause minimal changes in blood pressure (56). The time to maximal change in ETN 2 (32±8 sec) was 30-60 sec earlier than that of pulmonary artery catheters and ETCO 2 (53). The mass spectrometer used in the study by Matjasko et al (53) had a nitrogen sensitivity of 0.01%, in contrast to the 0.1% in clinically used mass spectrometers.…”