Comparison of invasive and non-invasive measurement of spontaneous baroreflex during anesthesia

Many works have shown that beat-to-beat variations in systolic arterial pressure (SAP) could be used for the assessment of cardiac baroreflex function. The purpose of this study was to evaluate whether Finapres, a non-invasive device to measure systolic arterial pressure, could serve as an acceptable alternative to intra-arterial catheterization for assessing the spontaneous baroreflex during anesthesia.

Thirty ASA class I patients scheduled for surgical hepatic and gastric tumor excisions were enrolled in this study. Spontaneous baroreflex sensitivity (SBR) during anesthesia was calculated by sequence analysis of beat-to-beat variations in systolic arterial pressure and R-R intervals. Data obtained from Finapres were compared with those from standard intra-arterial catheterization technique.

SBR values determined by non-invasive and invasive blood pressure measurement technique were precisely correlated (r = 0.96) and the mean difference was about 0.22 ms/mmHg (12.5%). However, the individual data might differ by -0.52 to +0.96 ms/mmHg (-35% to +60%).

Finapres may trace the changes of SBR during anesthesia and provides similar results as does invasive method but individual variation exists.