Non-invasive venous waveform analysis and the IntraVAscular volume Number (IVAN) track acute hemorrhage and volume overload in a piglet model

<title>Abstract</title> <p>Purpose. Acute intravascular volume change is difficult to detect in children; most hemodynamic monitors were developed in adults. Non-invasive venous waveform analysis (NIVA) derives the IntraVAscular volume Number (IVAN) from the peripheral venous waveform. We evaluated whether NIVA tracks acute volume change across hypovolemia and hypervolemia in a pediatric-scale porcine model. Methods. Eight anesthetized, mechanically ventilated piglets underwent controlled hemorrhage (to 5%, 10%, 15%, 20%, and 25% of estimated blood volume, or until a 20% reduction in mean arterial pressure), then reinfusion and crystalloid-induced volume overload. NIVA was acquired simultaneously with invasive measurements, and IVAN was compared with volume change and invasive measures using correlation and concordance analyzes. Results. Data were analyzable for seven piglets (hemorrhage) and four piglets (overload). Across the combined range, IVAN tracked volume change with 92% concordance (r = 0.68; P &lt; 0.0001), comparable to right atrial pressure (98%, r = 0.69; P &lt; 0.0001) and pulmonary capillary wedge pressure (89%, r = 0.65; P &lt; 0.0001) and markedly superior to mean arterial pressure (67%, r = − 0.12; P = 0.32). Raw IVAN discriminated 15% and 25% blood loss (area under the ROC curve 0.87 and 0.89; paired reductions P = 0.016 and P = 0.047). Glucose, lactate, and creatinine also tracked volume change; most blood-gas and electrolyte indices did not. Conclusion. In this pediatric-scale porcine model, IVAN tracked intravascular volume change comparably to invasively measured filling pressures and substantially better than mean arterial pressure, supporting further development for pediatric volume monitoring.</p>