Clinical and echocardiographic response to volume expansion in hypotensive preterm infants: a pilot observational study

Objective: To describe the short-term clinical and echocardiographic effects of a first volume expansion in hypotensive preterm infants during the first 24 h of life. Study design: Single-center retrospective observational pilot study including preterm infants ≤31 + 6 weeks of gestation, intubated and mechanically ventilated, presenting arterial hypotension within 24 h of life. All infants received a first volume expansion with modified fluid gelatin (20 mL/kg). Clinical and echocardiographic parameters were compared immediately before and after volume expansion. Results: Thirty-one infants were included. Volume expansion was associated with a significant increase in systolic, diastolic and mean arterial pressure (median MAP increase: +4 mmHg; +17%), and a significant decrease in heart rate and capillary refill time. Echocardiographic assessment showed a significant increase in left ventricular end-diastolic diameter and superior vena cava flow (median increase: +19%), suggesting improved preload and systemic blood flow. No immediate clinically apparent adverse events were recorded during the observation period. Conclusion: In this exploratory pilot study, a first volume expansion was associated with short-term improvements in clinical and echocardiographic hemodynamic parameters in hypotensive preterm infants. These findings are hypothesis-generating and cannot be generalized to current filling strategies or repeated fluid boluses.