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

Abstract

Study 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).Design: Prospective observational study.Setting: Nonuniversity hospital.Patients: 53 ASA physical status I, II, and III consecutive patients undergoing general anesthesia with tracheal intubation.Measurements and Main 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.