Comparison of Respiratory Rate Detection by Seven Sensor Signals in Clinically Challenging Conditions

Orbital ATK Conference Center

The underlying problem for two of the three most common patterns of unexpected hospital deaths (PUHD) is hypoventilation1. Concern over this opioid-induced respiratory depression has led many experts and consensus guidelines to recommend that all patients receiving opioids be monitored for respiratory rate. Currently, no clinically accepted “gold-standard” monitoring device exists for non-intubated, spontaneously breathing patients. We studied seven distinct respiratory sensors to compare their effectiveness in respiratory monitoring. Methods: With IRB approval, data were collected from 26 volunteers who were administered target controlled infusions of remifentanil and propofol in order to induce low respiratory rates. Data were collected from a suite of sensors which were analyzed using a single, custom breath detection algorithm. Breath rates derived from a capnometer, accelerometer, oro-nasal thermistor, nasal pressure transducer, microphone, photoplethysmogram, and impedance respiratory sensor were compared against breath rates derived from the reference standard of respiratory inductance plethysmography bands at both low and normal respiratory rate ranges. Results: Capnometry and acceleromtry reported respiratory rates closest to those reported by the respiratory inductance plethysmography bands. Conclusion: Detecting respiratory rate in the post-operative environment is a clinically challenging problem which likely requires further study.