Enhanced oxygen transport by perfluorocarbon emulsion mixed with flowing human blood studied in vitro

Abstract

Perfluorocarbons (PFC) are compounds with high gas solubility that mixed with sickle cell disease (SCD) blood could potentially help deliver O2 to tissues, possibly compensating for SCD red blood cell's lower O2 affinity. PFC have also been suggested as adjunct therapy in certain ischemic conditions. Therefore, an in vitro system was developed for studying O2 transport using blood from 9 SCD patients and 5 healthy donors. The system included a pump, gas mixers, oxygenation and deoxygenation chambers that allowed the flowing blood to reach various levels of hemoglobin O2 saturation (SO2) and O2 partial pressures (PO2) that were measured using a CO‐oximeter and a blood gas analyzer. After addition of PFC emulsion (Oxycyte) (hematocrit = 31%, fluorocrit = 4%), the measurements suggested an increase in the transport of O2 and CO. Addition of PFC resulted in a larger PO2 gradient: from 15 ± 2 mmHg to 23 ± 2 mmHg. Using normal blood, the average O2 extraction ratio (O2ER) after PFC (0.13 ± 0.01) was significantly higher than baseline (0.10 ± 0.01, p<0.004). Using blood from SCD patients, the average O2ER after PFC (0.16 ± 0.01) was also significantly higher than baseline (0.12 ± 0.01, p<0.001). Addition of saline did not cause statistically significant changes. The data suggest increased O2 transport by this PFC emulsion in both normal and SCD blood.Support: Virginia Commonwealth University and Oxygen Biotherapeutics, Inc.