Venous gas embolism: detection with pulsed Doppler guided by two-dimensional echocardiography

Venous gas embolism is a rare but severe event in critically ill patients and the diagnosis should be obtained as soon as possible. Ultrasonography is a sensitive, non-invasive, and bedside means of detection.

We prospectively estimated the performance of two-dimensional (2D) echocardiography and pulsed Doppler guided by 2D echocardiography in the detection of venous embolism. We used, as a model of venous gas embolism, the decompression following a recreational dive. This activity is responsible for circulating bubbles related to nitrogen desaturation.

Venous gas emboli were detected following 44 of 68 dives in 20 of 24 divers. Gas emboli in 36 cases (16 divers) was shown by 2D echocardiography. Parasternal short-axis and right-cavity longitudinal views were the best views for positive detection. Pulsed Doppler confirmed the existence of venous gas emboli in all of the 36 cases with positive detection by 2D echocardiography. In 8 other cases, pulsed Doppler detected circulating bubbles, which were not observed by using 2D echocardiography. Discrepancies were observed in 4 divers with an echographic image of medium or poor quality.

Combined utilization of 2D echocardiography and pulsed Doppler provides a better method for the detection of venous gas embolism than 2D echocardiography alone. This protocol could be used for critically ill patients suspected of venous air embolism.