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

Abstract

Objectives: to study the effects of three types of fluids on hemodynamic and perfusion parameters in an infant animal model of hemorrhagic hypovolemic shock. Methods: Prospective, randomized study of 34 two month-old piglets (9.9+/-2kg). Following anaesthesia (fentanyl, propofol), paralysis (atracurium) and mechanical ventilation (TV 15 ml/kg, PEEP 3cm, and Rate 20/min), hypovolemia was induced by controlled 30 ml/kg bleed. After 30 min, pigs were randomized to receive: 1) Normal Saline (NS) 30 ml/kg, n=11 vs. 2) Hypertonic 3% Saline (HS) 15 ml/kg, n=12 vs. 3) Albumin 5% plus 3% Hypertonic Saline (AHS) 15 ml/kg, n=11. Hemodynamic (HR, MAP, CI), brain tissue oxygenation by near infrared spectroscopy (bTOI) and tissue perfusion (arterial lactate and gastric pHi) parameters were compared by rmANOVA. Results: 30 min. after bleeding, high baseline HR: 191+/-7, and low MAP 73+/-3 mmHg, CI 2.8+/-0.6 L/min/m2, bTOI: 44+/-2%, gastric pHi 7.1+/-0.2 and lactate 3.4+/-0.4 mmol/L were recorded with non significant differences between groups. 30 min after infusion there were no significant differences between groups for HR (NS: 188+/-14, HS: 184+/-14, AHS: 151+/- 14 bpm); MAP (NS: 80+/- 7, HS: 86+/- 7, AHS: 87+/- 7 mmHg); CI (NS 4.1+/- 0.4, HS 3.9+/- 0.4, AHS 5.1+/- 0.4 ml/min/m2); lactate (NS 2.8+/- 0.7, HS 2.3+/- 0.6, AHS: 2.4+/- 0.6 mmol/l); bTOI (NS: 43.9+/-2.2, HS 40.1+/-2.5, AHS: 46.1+/-2.3 %); and pHi (NS: 7.07+/-0.6, HS: 7.25+/- 0.5, AHS 7.21+/- 0.5). Conclusion: In this model of hypovolemic shock, both hypertonic crystalloid (HS) and hypertonic colloid (AHS) fluids achieved similar hemodynamic endpoints, requiring half of the volume compared to normal saline (NS).