Abstract
Purpose :
Shock is defined as the progression of organ disorder ; however, the evaluation method has not been established. We tested the hypothesis that ocular blood flow reflects the systemic organ blood flow, such as that in the kidneys and intestines, using an experimental rabbit model of hemorrhagic shock.
Methods :
We used ten New Zealand white rabbis and administered general anesthesia. A catheter was placed in the brachial artery to measure their mean arterial blood pressure (MAP). Blood flow in the intestines and kidneys was measured using an ultrasonic blood flow meter at the mesenteric artery and the renal artery exposed on laparotomy. For the measurement of ocular blood flow, laser speckle flowgraphy that can evaluate the ocular blood flow non-invasively, was used. The mean blur rate (MBR) that is a blood flow index specific to laser speckle flowgraphy, was measured in the retinal vessels (RV) and choroid (CH). To create a shock state, blood was removed at a rate of 1 mL/min for 30 min. After an observation time of 20 min, blood was returned over a period of 15 min. Each parameter was evaluated as per the rate of change from the reference value before blood removal.
Results :
MBR in RV and CH, intestinal and renal blood flow, and MAP were significantly decreased by the blood removal operation and recovered nearly to the reference value by the blood return operation. The rate of change at the end of blood removal was MAP, 69.4%; kidney, 43.5%; intestine, 54.8%; MBR-RV, 42.3%; and MBR-CH, 55.5%. The rates of change between MBR-RV and kidney and between MBR-CH and intestine were similar, and no significant difference was observed. MBR-RV and MBR-CH showed a significant positive correlation with MAP (r = 0.87, 0.73), with renal blood flow(r = 0.66, 0.59) and with intestinal blood flow(r = 0.84, 0.61).
Conclusions :
Ocular blood flow reflected the renal and intestinal blood flow during the progression and recovery of hemorrhagic shock in white rabbits.
This is a 2021 ARVO Annual Meeting abstract.