Does end tidal CO2 monitoring during emergency department procedural sedation and analgesia with propofol decrease the incidence of hypoxic events? A randomized, controlled trial.
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).


CONCLUSIONS
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, 5501 Old York Road, Philadelphia, PA 19141, USA. deitchk@einstein.edu
Kenneth
K
Deitch
Jim
J
Miner
Carl R
CR
Chudnofsky
Paul
P
Dominici
Daniel
D
Latta
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D019296:Capnography; D002245:Carbon Dioxide / Q000032:analysis; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives; D000860:Hypoxia / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D010092:Oximetry; D015742:Propofol; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000175:diagnosis / Q000503:physiopathology; D012680:Sensitivity and Specificity; D055815:Young Adult
D006993:Hypnotics and Sedatives; D002245:Carbon Dioxide; D015742:Propofol