Intravenous perfluorocarbons increased oxygen delivery/ consumption in ARDS in swine

Introduction

Emulsified perfluorocarbons (PFC) are synthetic hydrocarbons that can carry 50 times more oxygen than human plasma. Their properties may be advantageous in applications requiring preservation of tissue viability in oxygen-deprived states, which makes them a potential candidate for combat and civilian prehospital resuscitation. Our hypothesis was that an intravenous dose of PFC increases vital organ tissue oxygenation, improves survival and reduces or prevents the development of ventilator-associated ARDS. Here we report data from the second part (ARDS only) of a multiphase swine study to investigate the benefits of PFC in treating hemorrhagic shock and preventing ARDS.

Methods

Anesthetized Yorkshire swine were randomized (n = 6/ group) to receive a bolus of the PFC Oxycyte™ either 45 minutes before (PFC-B) or after (PFC-A) induction of ARDS or nothing as a control (NON). ARDS was induced via intravenous oleic acid infusion (time 0 (T0)) over 30 minutes. Animals were monitored for physiological and hematological parameters. They were euthanized at T180 minutes and a full necropsy and histopathological analysis was performed.

Results

Survival was 100% in the NON group, 80% in the PFC-A group and 20% in the PFC-B group. Mean arterial pressure (MAP) and mean pulmonary artery pressure (MPAP) were significantly increased during infusion of PFC and during ARDS in the PFC-B group, while cardiac output (CO) was significantly reduced. In the PFC-A group it was observed that MAP and MPAP increased and CO decreased during ARDS induction, but not during PFC infusion. Those changes were significant in comparison with the NON group. Oxygen delivery and consumption in the PFC-A group were significantly increased. Histopathological analysis is currently being performed. Interim analysis showed a trend to reduced alveolar damage in PFC-A animals.

Conclusion

Administration of PFC before induction of ARDS was detrimental, while giving PFC after ARDS improved oxygen delivery and increased oxygen consumption. Although survival in this group was lower than in the NON control group (80% vs. 100%, not significant), a reduction in alveolar damage was observed. This might improve longterm outcome after ARDS. Based on these data we will continue to the final phase of this project and evaluate the capacity of PFC to prevent ARDS in combination with HS.