Ph. Pan et N. Gravenstein, INTRAOPERATIVE PULSE OXIMETRY - FREQUENCY AND DISTRIBUTION OF DISCREPANT DATA, Journal of clinical anesthesia, 6(6), 1994, pp. 491-495
Study Objective: To determine the types of discrepant data during intr
aoperative pulse oximetry and their frequency and duration. Design: Pr
ospective study. Setting: University medical center. Patients: 46 cons
ecutive ASA physical status I-III patients undergoing general anesthes
ia fm elective surgical operations. Measurements and Main Results: Wit
h an integrated computer algorithm on the pulse oximeter and another c
omputer linked to it, data were screened and the frequency and distrib
ution of the following oximeter signals recorded: absent; low quality
or interrupted, as detected by the pulse oximeter algorithm; nonphysio
logic, identified by the personal computer as a heart rate change grea
ter than 10 beats per minute within 2 consecutive 2-second samples, wi
th no similar abrupt change reported simultaneously on ECG. The number
of episodes per hour of discrepant oximeter data and the duration of
the episodes were recorded by phase of anesthesia: induction, maintena
nce, and emergence Discrepant data occurred most frequently and lasted
longest during emergence (p < 0.05); the majority of episodes of disc
repant data during emergence fasted less than 12 seconds. Excluding di
screpant data that lasted less than 12 seconds decreased the frequency
of discrepant data by 63% and excluding those that fasted less than 3
0 seconds decreased the frequency of discrepant data by 93%. Conclusio
ns: Pulse oximeters frequently report discrepant data intraoperatively
, most frequently during emergence from anesthesia. An alarm delay tri
ggered by discrepant data and lasting 12 to 30 seconds would keep most
discrepant data from becoming faire alarms and, thus, may reduce dist
racting sound pollution in the operating room.