Morphological changes in the arterial pressure waveform following hemodynamic therapies in critical care: A clinical proof-of-concept study in older adults.

Clinical management of hemodynamic instability remains challenging as underlying mechanisms are complex. A recent in-silico study showed that peripheral arterial waveform analysis can differentiate deficits in preload, afterload, and contractility. This study explores the clinical applicability of these findings. In this prospective observational study, continuous peripheral arterial blood pressure recordings were obtained from patients during and after cardiac surgery. Retrospectively, we identified isolated therapeutic events with expected physiological effects on preload (fluid bolus), afterload (norepinephrine), or contractility (dobutamine). Waveform morphology was characterized by 23 features. 132 patients were included; 92 fluid boluses, 91 norepinephrine, and 35 dobutamine administrations. Four waveform features differed significantly between the three types of events: augmented pressure (systolic peak minus anacrotic notch, p = 0.001), diastolic/systolic area ratio (p < 0.001), relative systolic downstroke time (p = 0.002), and relative diastolic time (p = 0.004). Fluid boluses increased the systolic component, norepinephrine increased the diastolic component, and dobutamine decreased augmented pressure by -3.0 (95% CI -4.5 to -1.6) mmHg (p < 0.001). Distinct morphological alterations of the peripheral arterial waveform were observed following a fluid bolus, norepinephrine, and dobutamine, providing a basis for future studies.