Comparisons of Blood Pressure Control Ability Between HPI, ClearSight, and Conventional NIBP During Neuraxial Anesthesia in Cesarean Section

The Hypotension Prediction Index (HPI) is an algorithm based on the complex analysis of features in high-fidelity arterial pressure waveform recordings developed to observe subtle signs that could predict the onset of hypotension in surgical and intensive care unit patients. HPI is a unitless number that ranges from 1 to 100, and as the number increases, the likelihood of a hypotensive event (MAP \<65 mm Hg for more than 1 minute) occurring in the near future increases. In a validation study on HPI conducted in patients under general anesthesia, the algorithm, at its optimal value, predicted hypotension with both sensitivity and specificity of 86% 5 minutes before the event. Measurement of the arterial pressure waveforms using a finger cuff (ClearSight) is well established.

ClearSight is a non-invasive hemodynamic monitoring device using digital-cuff and volume-clamp technology to obtain a continuous arterial blood pressure waveform. Continuous finger blood pressure measurement is established by wrapping the cuff around the middle phalanx of a finger. The area under the waveform curve is analyzed using a unique algorithm that serves to calculate the arterial blood pressure, stroke volume (SV) and CO.