Comparison of Hb-200 and 6% Hetastarch 450/0.7 During Initial Fluid Resuscitation of 20 Dogs with Gastric Dilatation-Volvulus

Original Study

Journal of Veterinary Emergency and Critical Care 22(2) 2012, pp 201-210 doi: 10.1111/j.1476-4431.2012.00726.x

Comparison of Hb-200 and 6% hetastarch 450/0.7 during initial fluid resuscitation of 20 dogs with gastric dilatation-volvulus

Carol E. Haak, DVM; Elke Rudloff, DVM, DACVECC and Rebecca Kirby, DVM, DACVIM, DACVECC

Abstract

Objective - To compare the use of polymerized stroma-free bovine hemoglobin (Hb-200) and 6% hetastarch 450/0.7 (HES 450/0.7) in 0.9% saline during fluid resuscitation of dogs with gastric dilatation-volvulus (GDV). Design - Prospective, randomized clinical case series.

Setting - Private specialty and referral clinic.

Animals - Twenty client-owned dogs presenting with GDV.

Interventions - Dogs presenting with GDV and abnormal perfusion parameters first received rapid IV infusion of a buffered isotonic replacement crystalloid (15 mL/kg) and IV opioids. Patients were then randomized to receive either Hb-200 (N = 10) or HES 450/0.7 (N = 10). Balanced isotonic replacement crystalloids (10- 20 mL/kg IV) were rapidly infused along with either Hb-200 or HES in 5 mL/kg IV aliquots to meet resuscitation end points.

Measurements and Main Results - Resuscitation was defined as meeting at least 2 of 3 criteria: (1) capillary refill time 1-2 seconds, pink mucous membrane color, strong femoral pulse quality; (2) heart rate (HR) ≤ 150/min; or (3) indirect arterial systolic blood pressure (SBP) > 90 mm Hg. HR, SBP , packed cell volume, hemoglobin, glucose, venous pH, bicarbonate, base excess, anion gap, and colloid osmotic pressure were compared at hospital entry and within 30 minutes post-resuscitation. Compared to the HES group, the Hb-200 group required significantly less colloid (4.2 versus 18.4 mL/kg) and crystalloid (31.3 versus 48.1 mL/kg) to reach resuscitation end points (P = 0.001). Time to resuscitation was significantly shorter in the Hb-200 group (12.5 versus 52.5 min). Conclusions - Dogs with GDV receiving Hb-200 during initial resuscitation required smaller volumes of both crystalloid and colloid fluids and reached resuscitation end points faster than dogs receiving HES 450/0.7 (P = 0.02).

(J Vet Emerg Crit Care 2012; 22(2): 201-210) doi: 10.1111/j.1476-4431.2012.00726.x

Keywords: canine, colloid, hemoglobin-based oxygen-carrying solution, GDV Introduction

Gastric dilatation-volvulus (GDV) in the dog is charac- terized by rapid accumulation of air inside the gastric lumen with malposition and rotation of the stomach. Circulatory shock is a hallmark of GDV, which may be at- tributable to hypovolemia, hemorrhage, maldistribution

From the Animal Emergency Center and Specialty Services, Silver Spring Drive, Glendale, WI 53209.

Presented in abstract form at International Veterinary Emergency and Critical Care Symposium, Orlando, FL, 2000.

The Oxyglobina used in this study was donated by Biopure Corporation, Cambridge, MA.

Address correspondence and reprint requests to Dr. Carol E. Haak, Ani- mal Emergency Center and Specialty Services, 2100 W. Silver Spring Drive, Glendale, WI 53209, USA. Email: caraol.haak@gmail.com

Submitted January 25, 2011; Accepted February 5, 2012.

Abbreviations

AG anion gap

COP colloid osmotic pressure

CRT capillary refill time

Hb-200 polymerized stroma-free bovine hemoglobin HBOC hemoglobin-based oxygen carriers

HES hetastarch

HR heart rate

GDV gastric dilatation-volvulus

MAP mean arterial pressure

MM mucous membranes

NO nitric oxide

PCV packed cell volume

SBP systolic blood pressure

⃝C Veterinary Emergency and Critical Care Society 2012

201

C.E. Haak et al.

of blood flow, cardiac dysfunction, and endotoxemia.1, 2 Hypotension at any point during hospitalization has been associated with increased mortality in dogs with GDV.3 Rapid intravascular fluid resuscitation to restore oxygen delivery to hypoxic tissues and correct or pre- vent hypotension is an essential component of presurgi- cal stabilization of dogs presenting with GDV and hypo- volemic shock. Surgical intervention to decompress and reposition the stomach should be performed as soon as the patient is stable for anesthesia and no later than 2- 3 hours after initiation of medical treatment to reduce the risk of gastric perforation.1, 3

Intravascular volume replacement promotes the de- livery of oxygen to peripheral tissues by improving flow through capillary beds. The rapid administration of large volumes of crystalloids alone can result in fluid extrava- sation due to increased intravascular hydrostatic pres- sure and a dilutional decrease in intravascular colloid osmotic pressure (COP).4 Combining a colloid such as hetastarch (HES), dextran, or hemoglobin-based oxygen carriers (HBOCs) with crystalloids may restore intravas- cular volume while maintaining or improving intravas- cular COP.4

Previous studies investigating the resuscitation of dogs with GDV using synthetic colloids focused on the use of dextran combined with hypertonic saline.5, 6 When compared to the administration of crystalloid solution alone, the administration of dextran 70 with hypertonic saline to dogs with GDV resulted in more rapid increases in systolic blood pressure (SBP), central venous pressure, and plasma volume with a significantly smaller fluid volume infused.5 In a study of 166 dogs with GDV, Beck et al3 found that the use of a synthetic colloid (ie dex- tran or HES) during resuscitation was associated with a decreased risk of hypotension. However, dextrans have been associated with more pronounced hemostatic ab- normalities and decreased platelet aggregation, and it is no longer readily available.7, 8

Hydroxyethyl starches are a family of synthetic col- loid plasma expanders made from a highly branched polysaccharide (98% amylopectin) plant starch of either maize or sorghum. There are a variety of hydroxythyl starches available for use, with 6% HES 450/0.7 in