PURPOSE: Monitoring respiration of spontaneously breathing patients with chronic obstructive lung disease (COPD) is a concern in a variety of clinical areas including the operating room, post anesthesia care unit (PACU), and on the general care wards. These patients require careful vigilance. We evaluated the accuracy of prototype bioacoustic sensor in adult patients with and without COPD in the PACU.
METHODS: Following IRB approval and informed consent, upon arrival to the PACU, 38 patients were enrolled. All patients received standard monitors; in addition, a nasal cannula was connected to a capnometer (SIMS, Waukesha WI). A prototype adhesive bioacoustic sensor connected to a breathing frequency monitor (Masimo Corp, Irvine CA) was applied to the neck lateral to the cricoid cartilage. The capnometer and bioacoustic monitor were connected to a computer for continuous recording and subsequent analysis. The accuracy of the new acoustic sensor and the capnometer were compared to a reference respiratory rate from a manual scoring system. Bias, precision and ARMS were calculated in the usual fashion, as either bioacoustic sensor-reference or capnometer-reference.
RESULTS: All data is expressed as mean ± standard deviation. 27 patients without COPD (age = 51.6 ± 22.5 years) and 11 patients with COPD (age = 51.1 ± 9.8 years) were enrolled. Duration of monitoring time was 69.4 ± 39.9 min. For the patients without COPD, the resultant bias, precision and ARMS for the capnometer was −0.74, 2.37, and 2.48 and bioacoustic sensor was −0.01, 2.38, and 2.38 respectively. For the patients with COPD, the resultant bias, precision and ARMS for the capnometer was −0.31, 2.46, and 2.48 and bioacoustic sensor was 0.01, 2.76, and 2.76 respectively.
CONCLUSION: The new prototype bioacoustic respiratory sensor demonstrates accuracy for respiratory rate monitoring as good as capnometry in PACU patients with and without COPD.
CLINICAL IMPLICATIONS: This data suggests the new bioacoustic sensor may provide an improved monitoring system for patients in a general care setting.
DISCLOSURE: Mark Macknet, Grant monies (from industry related sources) LLU Department of Anesthesiology has received industry support from Masimo, Irvine CA, covering expenses related to this ongoing clinical study; Consultant fee, speaker bureau, advisory committee, etc. I am a community member of the Scientific Advisory Board for Masimo, providing input into the development of the device discussed. As a member, I have received small amounts of money to cover expenses related to time and travel. Total received is less than $10,000; Product/procedure/technique that is considered research and is NOT yet approved for any purpose. The Masimo Acoustic Respiratory Sensor is an FDA approved device for acoustic respiratory monitoring. The device as configured in this study is not currently approved for clinical use.