The influence of hemorrhagic shock on ocular microcirculation by obtained by laser speckle flowgraphy in a white rabbit model. (29th May 2021) - Watanabe, Kento
Abstract: Purpose: To clarify the continuous changes in the retinal vessels' and choroid's microcirculation during hemorrhagic shock and resuscitation in a rabbit model. Methods: Hemorrhagic shock by the removal of blood (30 mL) and resuscitation by a blood‐return technique was induced in anesthetized male New Zealand White rabbits ( n = 10). We evaluated the retinal vessel blood flow (relative flow volume: RFV) and choroidal blood flow (mean blur rate in the choroid area: MBR‐CH) by laser speckle flowgraphy (LSFG), with simultaneous measurements of systemic hemodynamics and laboratory parameters. Results: RFV and MBR‐CH showed significant decreases immediately after the initiation of blood removal and recovered by blood return. The lactate concentration tended to increase from baseline by the blood‐removal operation, and it was significantly higher at the end of observation period. The %RFV and %MBR‐CH each showed a significant positive correlation with mean arterial blood pressure, cardiac output, carotid blood flow, and central venous pressure. %RFV showed a significant positive correlation with %central venous oxygen saturation and negatively correlated with %lactate. The %hemoglobin did not show a significant correlation with %RFV or %MBR‐CH. Conclusion: This rabbit hemorrhagic shock model confirmed that ocular microcirculation measurements by LSFG feasibly reflect variations in systemic hemodynamics during hemorrhagic shock and recovery.