Advanced pulse oximeter signal processing technology compared to simple averaging. I. Effect on frequency of alarms in the operating room.
OBJECTIVE
To determine the effect of a new signal processing technique (Oxismart, Nellcor, Inc., Pleasanton, CA) on the incidence of false pulse oximeter alarms in the operating room (OR).


METHODS
Prospective observational study.


METHODS
Nonuniversity hospital.


METHODS
53 ASA physical status I, II, and III consecutive patients undergoing general anesthesia with tracheal intubation.


RESULTS
In the OR we compared the number of alarms produced by a recently developed third generation pulse oximeter (Nellcor Symphony N-3000) with Oxismart signal processing technique and a conventional pulse oximeter (Criticare 504). Three pulse oximeters were used simultaneously in each patient: a Nellcor pulse oximeter, a Criticare with the signal averaging time set at 3 seconds (Criticareaverage3s) and a similar unit with the signal averaging time set at 21 seconds (Criticareaverage21s). For each pulse oximeter, the number of false (artifact) alarms was counted. One false alarm was produced by the Nellcor (duration 55 sec) and one false alarm by the Criticareaverage21s monitor (5 sec). The incidence of false alarms was higher in Criticareaverage3s. In eight patients, Criticareaverage3s produced 20 false alarms (p < 0.01).


CONCLUSIONS
Our study did not show a beneficial effect in the OR on the incidence of false alarms of the Nellcor monitor with Oxismart signal processing compared with the Criticare monitor with the longer averaging time of 21 seconds.
Rheineck-Leyssius
A T
AT
Department of Anesthesiology, Twenteborg Hospital, Almelo, The Netherlands.
Kalkman
C J
CJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D016477:Artifacts; D005189:False Positive Reactions; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis / Q000628:therapy*; D007442:Intubation, Intratracheal; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009873:Operating Rooms; D010092:Oximetry / Q000379:methods*; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted