Covidien INVOS 5100C, Operator'S Manual

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Pediatric Clinical Study
Operator's Manual B-3
B.3
Pediatric Clinical Study
A prospective clinical study was performed to validate the performance of the INVOS™ system in
the pediatric cath lab. The study compared the regional oxygen saturation index (rSO
2
) from the
INVOS™ system to estimates of actual cerebral oxygen saturation derived from blood sample anal-
ysis in 22 patients. No adverse events were reported during the study.
Regional cerebral oxygen saturation was estimated by field saturation (fSO
2
) calculated from arte-
rial and jugular venous blood oxygen saturation measurements combined in a 1:3 ratio. Based on
the assumption that cerebral tissue contains arterial and venous blood in a 1:3 ratio, fSO
2
was cal-
culated as:
fSO
2
= (0.25 X SarterialO
2
) + (0.75 X Sjugular veinO
2
)
Twenty-six patients with congenital malformations of the heart and great vessels were recruited
for the study. Data from 22 patients was successfully collected and used in the study. Of these sub-
jects, 14 were male and all had light skin. Mean age was 103 months, range 15 months to 34 years.
Methods : A minimum of five blood samples was obtained from the right internal jugular bulb
and femoral artery at random times at the discretion of the investigator. One or two samples were
drawn at times when inspired oxygen was augmented. INVOS™ data was recorded on disk and
compared to the fSO
2
at the time of the blood sample off line. Differences between estimated
actual and INVOS™ readings were determined and bias, standard deviation, and regression were
calculated.
Results : An initial 26-patient pilot study evaluated system performance. Modifications were made
to the hardware and software and an additional 22 patients were studied prospectively, as report-
ed here. Agreement between INVOS™ data and calculated field saturation was very good in indi-
viduals and when pooled. It was determined that the pediatric sensor worked optimally in
patients with weight between 4 kg and 40 kg. In this study, 7 of 22 patients weighed >40 kg and
used the adult sensor.