[Diagnosing pneumothorax by using transthoracic lung ultrasonography during one lung ventilation].

BACKGROUND: Ultrasound guided neuraxial block or central venous puncture is now becoming popular in our anesthesia practice to reduce the risk of complications. Pneumothorax is a rare, but possible complication related to these interventions even if the ultrasound is used. However, the pneumothorax itself can also be diagnosed by the ultrasound. We therefore examined the efficacy of ultrasound for diagnosing pneumothorax during lung surgery requiring one lung ventilation.

METHODS: In 20 elective surgery patients, transthoracic lung ultrasonography was performed. The lung sliding, comet-tail artifact, M-mode, lung pulse, and power sliding were used to eliminate pneumothorax, and the reverberation artifact was used as a sign of the pneumothorax. Ultrasound procedure was videotaped for postprocedure analysis. Both sensitivity and specificity were calculated in each case.

RESULTS: Lung sliding and M-mode procedure showed high sensitivity and specificity in diagnosing pneumothorax. Reverberation artifact also showed high sensitivity, but its specificity was too low to determine pneumothorax.

CONCLUSIONS: Among six ultrasonic lung findings, lung sliding and M-mode procedure are most useful as screening methods of differentiating a pneumothorax.