Conscious sedation in the emergency department: the value of capnography and pulse oximetry.
OBJECTIVE
The purpose of this observational study was to describe the use of nasal capnography and pulse oximetry in monitoring heavily sedated emergency department patients.


METHODS
Prospective, nonblinded, nonrandomized, noncontrolled clinical trial.


METHODS
The study was conducted in a tertiary-care hospital with 36,000 annual ED visits.


METHODS
Twenty-seven patients requiring sedation with benzodiazepines and/or narcotics for painful procedures.


METHODS
The ventilatory status of each patient was monitored with a capnometer by nasal cannula as well as a pulse oximeter before, during, and after administration of the sedative agents.


METHODS
Vital signs, nasal end-tidal CO2 (PETCO2) measurements, and oxygen saturation were measured at baseline, during the procedure, and for a two-hour observation period after the procedure.


RESULTS
The average PETCO2 increased from 35.9 to 42.1 mm Hg during the procedure while the oxygen saturation dropped from an average of 98% to 94.3%. One patient developed clinically significant apnea after the procedure that was picked up by the apnea alarm, and eight additional patients developed clinically silent hypoxemia and increased PETCO2 during the procedure.


CONCLUSIONS
The use of pulse oximetry is recommended for the detection of unrecognized hypoxemia during conscious sedation. Capnography by nasal cannula appears to be a useful modality in monitoring during conscious sedation, but further research and clinical experience are required before routine use can be recommended.
Wright
S W
SW
Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee.
D000293:Adolescent; D000328:Adult; D001569:Benzodiazepines / Q000627:therapeutic use; D002245:Carbon Dioxide / Q000032:analysis*; D016292:Procedural Sedation; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D013511:Minor Surgical Procedures; D008991:Monitoring, Physiologic / Q000379:methods; D009294:Narcotics / Q000627:therapeutic use; D010092:Oximetry; D011446:Prospective Studies; D012119:Respiration
D009294:Narcotics; D001569:Benzodiazepines; D002245:Carbon Dioxide