Research

Recombinant human activated protein C ameliorates oleic acid-induced lung injury in awake sheep

Kristine Waerhaug¹ , Mikhail Y Kirov^1,2 , Vsevolod V Kuzkov^1,2 , Vladimir N Kuklin¹ and Lars J Bjertnaes¹

¹Department of Anesthesiology, Institute of Clinical Medicine, Faculty of Medicine, University of Tromsø, 9037 Tromsø, Norway

²Department of Anesthesiology, Northern State Medical University, Troitzky avenue 51, 163000 Arkhangelsk, Russian Federation

author email corresponding author email

Critical Care 2008, 12:R146doi:10.1186/cc7128

Published:	20 November 2008

See related commentary by Maybauer et al., http://ccforum.com/content/13/1/112

Abstract

Introduction

Acute lung injury (ALI) may arise both after sepsis and non-septic inflammatory conditions and is often associated with the release of fatty acids, including oleic acid (OA). Infusion of OA has been used extensively to mimic ALI. Recent research has revealed that intravenously administered recombinant human activated protein C (rhAPC) is able to counteract ALI. Our aim was to find out whether rhAPC dampens OA-induced ALI in sheep.

Methods

Twenty-two yearling sheep underwent instrumentation. After 2 days of recovery, animals were randomly assigned to one of three groups: (a) an OA+rhAPC group (n = 8) receiving OA 0.06 mL/kg infused over the course of 30 minutes in parallel with an intravenous infusion of rhAPC 24 mg/kg per hour over the course of 2 hours, (b) an OA group (n = 8) receiving OA as above, or (c) a sham-operated group (n = 6). After 2 hours, sheep were sacrificed. Hemodynamics was assessed by catheters in the pulmonary artery and the aorta, and extravascular lung water index (EVLWI) was determined with the single transpulmonary thermodilution technique. Gas exchange was evaluated at baseline and at cessation of the experiment. Data were analyzed by analysis of variance; a P value of less than 0.05 was regarded as statistically significant.

Results

OA induced profound hypoxemia, increased right atrial and pulmonary artery pressures and EVLWI markedly, and decreased cardiac index. rhAPC counteracted the OA-induced changes in EVLWI and arterial oxygenation and reduced the OA-induced increments in right atrial and pulmonary artery pressures.

Conclusions

In ovine OA-induced lung injury, rhAPC dampens the increase in pulmonary artery pressure and counteracts the development of lung edema and the derangement of arterial oxygenation.