Does End Tidal CO2 Monitoring During Emergency Department Procedural Sedation and Analgesia With Propofol Decrease the Incidence of Hypoxic Events? A Randomized, Controlled Trial
Received 24 April 2009; received in revised form 29 May 2009, 12 June 2009 and 8 July 2009; accepted 22 July 2009. published online 25 September 2009. Corrected Proof
Study objective
We determine whether the use of capnography is associated with a decreased incidence of hypoxic events than standard monitoring alone during emergency department (ED) sedation with propofol.
Methods
Adults underwent ED propofol sedation with standard monitoring (pulse oximetry, cardiac and blood pressure) and capnography and were randomized into a group in which treating physicians had access to the capnography and a blinded group in which they did not. All patients received supplemental oxygen (3 L/minute) and opioids greater than 30 minutes before. Propofol was dosed at 1.0 mg/kg, followed by 0.5 mg/kg as needed. Capnographic and SpO2 data were recorded electronically every 5 seconds. Hypoxia was defined as SpO2 less than 93%; respiratory depression, as end tidal CO2 (etco2) greater than 50 mm Hg, etco2 change from baseline of 10%, or loss of the waveform.
Results
One hundred thirty-two subjects were evaluated and included in the final analysis. We observed hypoxia in 17 of 68 (25%) subjects with capnography and 27 of 64 (42%) with blinded capnography (P=.035; difference 17%; 95% confidence interval 1.3% to 33%). Capnography identified all cases of hypoxia before onset (sensitivity 100%; specificity 64%), with the median time from capnographic evidence of respiratory depression to hypoxia 60 seconds (range 5 to 240 seconds).
Conclusion
In adults receiving ED propofol sedation, the addition of capnography to standard monitoring reduced hypoxia and provided advance warning for all hypoxic events.
Department of Emergency Medicine, Albert Einstein Medical Center, Philadelphia, PA (Deitch, Chudnofsky, Dominici, Latta); Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN (Miner)
Address for reprints: Ken Deitch, DO, Department of Emergency Medicine, Albert Einstein Medical Center, 5501 Old York Road, Korman Building, B-6, Philadelphia, PA 19141; 215-456-6679
Supervising editor: Steven M. Green, MD
Author contributions: KD, JM, and CRC conceived the study and designed the trial. KD, CRC, and PD supervised the conduct of the trial and data collection. KD, CRC, and PD managed the data, including quality control. PD and DL provided statistical advice on study design and analyzed the data. KD drafted the article. CRC and JM provided editorial support and contributed substantially to its revisions. KD takes responsibility for the paper as a whole.
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article that might create any potential conflict of interest. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement.The Capnostream 20 was donated for research purposes by Oridian Medical, Needham, MA.
ABSTRACT