PURPOSE: The goal of this study was to quantify the acoustic changes in pneumothorax (PTX) and hemothorax (HTX).
METHODS: Sequential boluses of air were injected into 2 sedated, ventilated pigs to induce unilateral PTX. Similarly saline was used to simulate HTX. Lung sounds were recorded using a multichannel lung sound analyzer.
RESULTS: When no adventitious sounds were present lung sound amplitude was greater in the normal as compared to either PTX or HTX sides. This amplitude difference was proportional to the amount of air or saline injected. It was observed in both supine and prone positions. Statistically significant differences in sound amplitude were observed in PTXs as small as 100mL.
CONCLUSION: A quantifiable relationship between the amount of air and/ or saline injected was observed. To see this relationship, however, analysis of segments of the respiratory cycle free of adventitious sounds was required.
CLINICAL IMPLICATIONS: Automated acoustic analysis has a potential value in diagnosis of PTX and HTX.
DISCLOSURE: Raymond Murphy, No Product/Research Disclosure Information; Shareholder R. Murphy is shareholder of Stethographics, Inc.; Employee R. Murphy is an employee of Stethographics, Inc.