Developing a Respiratory Depression Scorecard for Capnography Monitoring

Abstract

Pulse oximetry is the most common way to measure a patient’s respiratory status in the hospital setting; however, capnography monitoring is a more accurate and sensitive technique which can more comprehensively measure respiratory function. Due to the limited number of capnography monitoring equipment at the University of Minnesota Medical Center-Fairview (UMMC-Fairview), we analyzed which patients should preferentially be chosen for capnography monitoring over pulse oximetry based on risk of respiratory depression. We conducted a retrospective chart review of all serious opioid-induced over-sedation events that occurred at UMMCFairview between January 1, 2008 and June 30, 2012. Thirteen risk factors were identified which predispose patients to respiratory depression. The average patient demonstrated 3.75 risk factors. The most commonly occurring risk factor was the concomitant use of multiple opioids or an opioid and a CNS-active sedative, followed by an ASA score ≥ 3. Based on this data, we developed a scorecard for choosing patients at the most risk of developing respiratory depression; these patients are the best candidates for capnography. Although further studies are necessary to corroborate this research, at this time giving extra consideration to patients demonstrating the previously stated risk factors is prudent when assessing those patients most in need of capnography.