Advanced pulse oximeter signal processing technology compared to simple averaging. I. Effect on frequency of alarms in the operating room

Study Objective: To determine the effect of a neu signal processing techniq ue (Oxismart(TM) Nellcor, Inc., Pleasanton, CA) on the incidence of false p ulse oximeter alarms in the operating room (OR). Design: Prospective observational study. Setting: Nonuniversity hospital Patients: 53 ASA physical status I, II, and III consecutive patients underg oing general anesthesia with tracheal intubation. Measurements and Main Results: In the OR we compared the number of alarms p roduced by a recently developed third generation pulse oximeter (Nellcor Sy mphony(TM) N-3000) with Oxismart(TM) signal processing technique and a conv entional pulse oximeter (Criticare(TM) 504). Three pulse oximeters were use d simultaneously in each patient: a Nellcor pulse oximeter, a. Criticare wi th the signal averaging time set at 3 seconds (Criticare(average3s)) and a similar unit with the signal averaging time set at 21 seconds (Criticare(av erage21s)). 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 Criticare(average21s) monitor (5 sec). The incid ence of false alarms was higher in Criticare(average3s) In eight patients, Criticare(average3s) produced 20 false alarms (p < 0.01). Conclusions: Our study did not show a beneficial effect in the OR on the in cidence of false alarms of the Nellcor monitor with Oxismart(TM) signal pro cessing compared with the Criticare monitor with the longer averaging time of 21 seconds. (C) 1999 by Elsevier Science Inc.