From invasive to non-invasive: point-of-care ultrasound parameters and a clinical decision algorithm for central venous pressure assessment in critically Ill neonates

Point-of-care ultrasound (POCUS) is increasingly used in neonatal intensive care units (NICUs) for hemodynamic assessment, but standardized protocols for central venous pressure (CVP) estimation remain lacking. This narrative review synthesizes current evidence on POCUS parameters—primarily the inferior vena cava collapsibility index (IVC-CI), maximum IVC diameter, the inferior vena cava-to-aortic ratio (IVC/Ao), and internal jugular vein (IJV) indices—for non-invasive CVP assessment in critically ill neonates. Key advances include demonstrating that ultrasound-measured IVC diameter correlates with invasively measured CVP in low birth weight infants and the emergence of multi-parameter models. However, major barriers persist: inconsistent neonatal-specific thresholds, operator dependence, limited training infrastructure, and insufficient validation in extremely low birth weight populations. We propose a practical clinical decision algorithm integrating IVC and IJV parameters with adjunctive lung and cardiac POCUS assessment, structured reassessment after every fluid bolus, and objective triggers for transitioning to invasive monitoring. Recent guidelines from the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) and the American Society of Echocardiography (ASE) provide foundational frameworks, but dedicated neonatal training and credentialing standards remain essential. Future directions include artificial intelligence-assisted measurement, multi-parameter scoring systems (e.g., Venous Excess Ultrasound score), and multicenter prospective validation. POCUS serves as a complementary tool to—not a replacement for—invasive monitoring in complex hemodynamic instability. Standardized thresholds, structured training, and quality assurance programs are critical for safe clinical translation, especially in resource-limited settings.