What question did this study set out to answer?

To determine whether waveform characteristics from ear or finger pulse oximeters can accurately estimate invasive arterial blood pressure during coronary artery bypass graft surgery.

December 1, 2001Anesthesia & Analgesia

How Does the Plethysmogram Derived from the Pulse Oximeter Relate to Arterial Blood Pressure in Coronary Artery Bypass Graft Patients?

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Why the study?

Can blood pressure be accurately derived from ear pulse oximeter waveforms compared to radial artery lines in CABG patients?

Population

20 patients scheduled for coronary artery bypass grafting (CABG)

Comparison

Calculated blood pressure derived from ear pulse… vs Measured blood pressure from radial artery line…

Design

Cohort

Authors

MGM. Ashraf M. GhobashyYale University RSRobert G. StoutCentral Michigan University DSDavid G. SilvermanRoche (United Kingdom)

Discussion

Member takes

Implication

May support calibrated ear oximetry BP monitoring in CABG; hypothesis-generating and should not yet change practice.

Key Points

To determine whether waveform characteristics from ear or finger pulse oximeters can accurately estimate invasive arterial blood pressure during coronary artery bypass graft surgery.
Collected ear oximeter, finger oximeter, and invasive radial artery blood pressure waveforms in 20 patients undergoing coronary artery bypass grafting.
Derived beat-to-beat amplitude, area, and width from oximeter waveforms in the first 10 patients to establish linear regression models against measured blood pressure.
Applied linear regression equations using a 50-beat patient-specific calibration period to calculate systolic, mean, and pulse pressures across 62,077 paired readings in the remaining 10 patients.
Ear pulse oximeter waveform width demonstrated the strongest correlation with measured arterial blood pressure (r = 0.80) in the derivation group.
Following calibration in the validation group, the bias was -2.60 mm Hg for systolic blood pressure, -1.88 mm Hg for mean blood pressure, and -1.28 mm Hg for pulse pressure.
Precision values achieved after calibration were 15.90 mm Hg for systolic blood pressure, 10.09 mm Hg for mean blood pressure, and 9.94 mm Hg for pulse pressure.

Structured PICO

Can blood pressure be accurately derived from ear pulse oximeter waveforms compared to radial artery lines in CABG patients?

Population

20 patients scheduled for coronary artery bypass grafting (CABG)

Intervention

Calculated blood pressure derived from ear pulse oximeter waveform (Width(Ear)) with an initial calibration period

Comparator

Measured blood pressure from radial artery line (Bp(meas))

Outcome

Bias and precision of calculated systolic BP, mean BP, and pulse pressure compared to measured arterial line BPsurrogate

Deriving blood pressure from an ear pulse oximeter waveform is feasible in CABG patients but requires an initial calibration period to achieve clinically acceptable bias.

Limitations

Initial bias was too large to be clinically useful without a calibration period

Cite This Study

Ghobashy et al. (2001) studied this question.

synapsesocial.com/papers/6a7cbd20076dbfca02ba63a1 https://doi.org/10.1097/00000539-200112000-00022

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How Does the Plethysmogram Derived from the Pulse Oximeter Relate to Arterial Blood Pressure in Coronary Artery Bypass Graft Patients?

Discussion

Member takes

Implication

Key Points

Structured PICO

Limitations

Cite This Study

How Does the Plethysmogram Derived from the Pulse Oximeter Relate to Arterial Blood Pressure in Coronary Artery Bypass Graft Patients?

Discussion

Member takes

Implication

Key Points

Structured PICO

Limitations

Cite This Study

Also Consider

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