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

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 < 0.0001), comparable to right atrial pressure (98%, r = 0.69; P < 0.0001) and pulmonary capillary wedge pressure (89%, r = 0.65; P < 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.