Does End-tidal Carbon Dioxide Monitoring Detect Respiratory Events Prior to Current Sedation Monitoring Practices?
Version of Record online: 28 JUN 2008
© 2006 Society for Academic Emergency Medicine
Academic Emergency Medicine
Volume 13, Issue 5, pages 500–504, May 2006
How to Cite
Burton, J. H., Harrah, J. D., Germann, C. A. and Dillon, D. C. (2006), Does End-tidal Carbon Dioxide Monitoring Detect Respiratory Events Prior to Current Sedation Monitoring Practices?. Academic Emergency Medicine, 13: 500–504. doi: 10.1197/j.aem.2005.12.017
- Issue online: 28 JUN 2008
- Version of Record online: 28 JUN 2008
- Received October 5, 2005; revision received December 14, 2005; accepted December 28, 2005
- procedural sedation and analgesia;
- patient monitoring;
- end-tidal carbon dioxide;
Objectives: The value of ventilation monitoring with end-tidal carbon dioxide (ETCO2) to anticipate acute respiratory events during emergency department (ED) procedural sedation and analgesia (PSA) is unclear. The authors sought to determine if ETCO2 monitoring would reveal findings indicating an acute respiratory event earlier than indicated by current monitoring practices.
Methods: The study included a prospective convenience sample of ED patients undergoing PSA. Clinicians performed ED PSA procedures with generally accepted patient monitoring, including oxygen saturation (SpO2), and clinical ventilation assessment. A study investigator recorded ETCO2 levels and respiratory events during each PSA procedure, with clinical providers blinded to ETCO2 levels. Acute respiratory events were defined as SpO2≤92%, increases in the amount of supplemental oxygen provided, use of bag-valve mask or oral/nasal airway for ventilatory assistance, repositioning or airway alignment maneuvers, and use of physical or verbal means to stimulate patients with depressed ventilation or apnea, and reversal agent administration.
Results: Enrollment was stopped after independent review of 20 acute respiratory events in 60 patient sedation encounters (33%). Abnormal ETCO2 findings were documented in 36 patients (60%). Seventeen patients (85%) with acute respiratory events demonstrated ETCO2 findings indicative of hypoventilation or apnea during PSA. Abnormal ETCO2 findings were documented before changes in SpO2 or clinically observed hypoventilation in 14 patients (70%) with acute respiratory events.
Conclusions: Abnormal ETCO2 findings were observed with many acute respiratory events. A majority of patients with acute respiratory events had ETCO2 abnormalities that occurred before oxygen desaturation or observed hypoventilation.