Continuous Pulse Oximetry and Capnography Monitoring for Postoperative Respiratory Depression and Adverse Events: A Systematic Review and Meta-analysis

Abstract

The use of CPOX on the surgical ward is associated with significant improvement in the detection of oxygen desaturation versus intermittent nursing spot-checks. There is a trend toward less ICU transfers with CPOX versus standard monitoring. The evidence on whether the detection of oxygen desaturation leads to less rescue team activation and mortality is inconclusive. Capnography provides an early warning of PORD before oxygen desaturation, especially when supplemental oxygen is administered. Improved education regarding monitoring and further research with high-quality randomized controlled trials is needed.

Tracking tidal volume noninvasively in volunteers using a tightly controlled temperature‐based device: A proof of concept paper

“…Predicting postoperative respiratory depression using noninvasive technology is challenging. Pulse oximetry is an effective monitor to diagnose the hemoglobin‐oxygen saturation levels, although in the presence of supplemental oxygen, this monitor becomes a poor predictor of respiratory depression . Moreover, spot measurements of oximetry are less effective at detecting respiratory depression than continuous oximetry.…”

“…Moreover, spot measurements of oximetry are less effective at detecting respiratory depression than continuous oximetry. In contrast, capnography identifies respiratory depression more consistently than oxygen desaturation by diagnosing apnoeas, independent of the presence of supplemental oxygen . However, sidestream capnography is not widely used outside of critical care settings because of the complexity of the technology, expense, periodic re‐calibration, limited portability, inability to acutely track changes in V T and the need for a sampling line, which is subject to interruptions, sample dilution and disconnects.…”

“…Pulse oximetry is an effective monitor to diagnose the hemoglobin-oxygen saturation levels, although in the presence of supplemental oxygen, this monitor becomes a poor predictor of respiratory depression. 5,12 Moreover, spot measurements of oximetry are less effective at detecting respiratory depression than continuous oximetry. In contrast, capnography identifies respiratory depression more consistently than oxygen desaturation by diagnosing apnoeas, independent of the presence of supplemental oxygen.…”

“…Pulse oximetry, capnography, plethysmography and bioacoustics have been used to monitor respiration and to diagnose impending respiratory depression, although each suffers from limitations that include poor sensitivity to detect changes in respiration in the presence of supplemental oxygen, cost, bulkiness, external interference and the need for direct contact with the patient . Together, these limitations preclude their routine use in noncritical care settings such as in the emergency department, in the postanaesthesia care unit, on the ward, in dental and endoscopy clinics and offices and at home …”

“…[1][2][3] Together, these limitations preclude their routine use in noncritical care settings such as in the emergency department, in the postanaesthesia care unit, on the ward, in dental and endoscopy clinics and offices and at home. [4][5][6][7][8][9][10][11][12] To address this gap in monitoring, we investigated whether the Linshom Respiratory Monitoring Device, which measures the temperature profile of the breath throughout the respiratory cycle, tracked tidal volume (V T ) in volunteers. Previous studies demonstrated that the Linshom respiratory monitoring device (referred to as Linshom in the manuscript) measured respiratory rate as accurately as capnography in both volunteers and patients [13][14][15] ; however, thermistor technology has never been used to track V T in humans.…”