24 Comparison of Normal Saline, Hypertonic Saline and Hypertonic Colloid Resuscitation Fluids in An Infant Animal Model of Hemorrhagic Hypovolemic Shock

Abstract

Background: Few studies have analyzed the effect of resuscitation fluid composition in infant animal models of hemorrhagic-hypovolemic shock. Our hypothesis was that hypertonic and hyperoncotic fluid will achieve goal-directed hemodynamic endpoints with less volume infusion than normal saline. Methods: Prospective, randomized study in 34 two month-old piglets (9.9±2kg). Following anaesthesia, paralysis and mechanical ventilation, hypovolemia was induced by controlled 30 ml/kg bleed. After 30 min, pigs were randomized to receive: Normal Saline (S0.9%) 30 ml/kg, n=11, Hypertonic 3% Saline (S3%) 15 ml/kg n=12, or Albumin 5% plus Hypertonic 3% Saline (A5%-S3%) 15 ml/kg, n=11. Hemodynamic (heart rate (HR), mean arterial pressure (MAP), cardiac index (CI)), brain tissue oxygenation by near infrared spectroscopy (bStO2) and tissue perfusion (arterial lactate and gastric pHi) parameters were compared by ANOVA. Results: 30 min. after bleeding, high baseline HR: 192±37, and low MAP 72±19 mmHg, CI 2.8±1L/min/m2, bStO2: 44±8%, gastric pHi 7.1±0.2 and lactate 3.4 ±2.3 mmol/L were recorded with non significant differences between groups. 30 min after infusion there were non significant differences between groups for HR (S0.9%: 188±14, S3%: 184±14, A5%-S3%: 151±14 bpm); MAP (S0.9%: 80±7, S3%: 86±7, A5%-S3%: 87±7 mmHg); CI (S0.9%: 4.9±0.5, S3%: 5.1±0.4, A5%-S3%: 5.3±0.4 ml/min/m2); lactate (S0.9%: 2.8±0.7, S3%: 2.3±0.6, A5%-S3%: 2.5±0.6mmol/l); bStO2 (S0.9%: 43.9±2.2, S3%: 40.1±2.5, A5%-S3%: 45.7±2.3 %); and pHi (S0.9%: 7.07±0.6, S3%: 7.25±0.5, A5%-S3%: 7.23±0.5). Conclusion: In this model of pediatric hypovolemic shock, both hypertonic (S3%) and hyperoncotic (A5%- S3%) fluids achieved similar hemodynamic endpoints, requiring half of the volume compared to normal saline.