Comparison of Blood Pressure Measurement by Pulse Oximetry and Oscillometry Techniques in Neonates

BACKGROUNDBlood pressure (BP) measurement is a very important aspect in the management and evaluation of sick and unstable neonates.The aim and objective of this study is to investigate the reliability of the plethysmographic waveform of the pulse oximeter to measure the systolic blood pressure by comparing it with the blood pressure measured by oscillometry method in healthy neonates. MATERIALS AND METHODSNon-invasive BP measurements were made using two techniques (pulse oximetry and oscillometry) in 188 neonates.The limit of agreement of statistical method by Bland-Altman was applied, considering oscillometry as the reference method. RESULTSBlood pressures obtained by reappearance of pulse oximetry waveform showed a significantly better correlation (Pearson's correlation coefficient of 0.970) with oscillometric measurements in comparison with those obtained by pulse oximetry with disappearance of waveform or by the average of BP values obtained by reappearance and disappearance of pulse oximetry waveform method (Pearson's correlation coefficient of 0.761 and 0.912, respectively).Additionally, the limits of agreement (mean difference ±2 SD) between BP values obtained by oscillometry measurements and those obtained by pulse oximetry (reappearance of waveform) were within a clinically acceptable range as opposed to those obtained by the comparison of oscillometric method and pulse oximetry (disappearance of waveform or average of BP obtained by reappearance and disappearance of pulse oximetry waveform method).In case of BP measurement by pulse oximetry method (reappearance of waveform) the average bias was 1.22 mmHg, which was less than the priori criteria of 5 mmHg.The confidence limit was 4.0 mmHg, which was less than a priori criterion of 5 mmHg. CONCLUSIONReappearance of the pulse oximeter plethysmographic waveform is an accurate and reliable way to measure systolic BP noninvasively in stable neonates.