M-mode ultrasound for the detection of pneumothorax during helicopter transport.
BACKGROUND
The presence of the sonographic sliding lung sign (SLS) is a sensitive indicator for the absence of a pneumothorax. The addition of M-mode ultrasound (US) can be a useful adjunct in detecting the SLS.


OBJECTIVE
The objective of this study is to determine the feasibility of using M-mode US in evaluating the SLS during helicopter transport.


METHODS
A model simulating human lung was used during image acquisition. M-mode images of the SLS were obtained during 3 distinct phases of transport: without rotor rotation, with rotor rotation while on the ground, and at level flight. Four US-credentialed emergency physicians evaluated M-mode US tracings of the model along with examples from human lungs, both with and without pneumothorax, in random fashion.


RESULTS
A total of 104 images were reviewed (26 images per reviewer). All of the M-mode images were correctly identified. Motion artifact was noted on the M-mode tracings taken during rotor rotation, which was greatest during level flight. The rotor artifact was not felt to affect the diagnostic utility of the M-mode US tracing.


CONCLUSIONS
M-mode US may be used successfully to detect the SLS during helicopter transport.
Department of Emergency Medicine, Medical College of Georgia, AF 1006, Augusta, GA 30912-2800, USA.
Matthew
M
Lyon
Stephen A
SA
Shiver
Perry
P
Walton
D017732:Air Ambulances; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008953:Models, Anatomic; D011030:Pneumothorax / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D014463:Ultrasonography