Background: Pulse oximeters have been reported to fail to record data
in 1.12-2.50% of cases in which anesthesia records were handwritten. T
here is reason to believe that these may be underestimates. Computeriz
ed anesthesia records may provide insight into the true incidence of p
ulse oximetry data failures and factors that are associated with such
failures. Methods: The current study reviewed case files of 9,203 comp
uterized anesthesia records. Pulse oximetry data failure was defined a
s the presence of at least one continuous gap in data greater than or
equal to 10 min in duration in a case. A multivariate logistic regress
ion model was used to identify predictors of pulse oximetry data failu
re, and a modified case-control method was used to determine whether e
xtremes of blood pressure and hypothermia during the procedure were as
sociated with pulse oximetry data failure. Results: The overall incide
nce of cases that had at least one continuous gap of greater than or e
qual to 10 min in pulse oximetry data was 9.18%. The independent preop
erative predictors of pulse oximetry data failure were ASA physical st
atus 3, 4, or 5 and orthopedic, vascular, and cardiac surgery. Intraop
erative hypothermia, hypotension, hyper-tension, and duration of proce
dure were also independent risk factors for pulse oximetry data failur
e. Conclusions: Pulse oximetry data failure rates based on review of c
omputerized records were markedly greater than those previously report
ed. Physical status, type of surgery, and intraoperative variables wer
e risk factors for pulse oximetry data failure. Regulations and expect
ations regarding pulse oximetry monitoring should reflect the limitati
ons of the technology.