Effects of perfluorocarbon emulsions on microvascular blood flow and oxygen transport in a model of severe arterial gas embolism

Background

Arterial gas embolism (AGE) is a clinical problem that occurs directly in cardiopulmonary bypass machines in open-heart surgeries, or indirectly (through cardiac or pulmonary right to left shunts) in dive accidents, resulting in serious morbidity and even death. Perfluorocarbon (PFC) emulsions have been used for the treatment of AGE in an animal model. We hypothesized that PFC emulsions enhance microvascular blood flow, speed bubble resolution, and oxygenation in AGE compared with saline in a model of cremaster muscle from anesthetized rats.

Materials and methods

AGE was induced by direct air injection into the femoral artery ipsilateral to the studied cremaster muscle. Microhemodynamics, microvascular, and tissue oxygenation were determined before and after treatment with two different commercial PFC emulsions (C₁₀F₂₀, Oxycyte; Oxygen Biotherapeutics, Inc and C₁₀F₁₈, PHER-O₂; Sanguine Corporation, Inc) compared with saline in real time using brightfield and phosphorescence microscopy.

Results

Blood pressure and heart rate remained unchanged. Systemic PO₂, oxygen (O₂) content, and glucose were higher in PFC groups, whereas hematocrit dropped in all groups. Arteriolar blood flow went up 85% and 80% of baseline after C₁₀F₂₀ and C₁₀F₁₈ treatments, respectively, versus 11% after saline treatment. Arteriolar and tissue PO₂, and O₂ delivery were higher in PFC groups compared with the control group. There was an increase in arteriolar blood flow, reduction in diffusional resistance of O₂ in the plasma, and improved tissue oxygenation.

Conclusions

Administration of PFC emulsions in AGE is superior to saline primarily because of surfactant properties along with air bubble reabsorption.