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Retinal Venous Oxygen Saturation Correlates with Blood Volume
Author(s) -
Denninghoff Kurt R.,
Smith MatthewH.,
Hillman Lloyd W.,
Redden David,
Rue Loring W.
Publication year - 1998
Publication title -
academic emergency medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.221
H-Index - 124
eISSN - 1553-2712
pISSN - 1069-6563
DOI - 10.1111/j.1553-2712.1998.tb02464.x
Subject(s) - medicine , blood volume , venous blood , anesthesia , oxygen saturation , blood pressure , retinal , pulse rate , arterial blood , oxygen , ophthalmology , chemistry , organic chemistry
.Objectives : To evaluate the sensitivity of retinal venous O 2 saturation (SrvO 2 ) for early blood loss and reinfusion. A secondary objective was to measure the correlation between SrvO 2 and mixed venous O 2 saturation (SvO 2 ) during blood loss and reinfusion. Methods : Seven anesthetized swine were bled at 0.8 mL/kg/min to 16 mL/kg. Shed blood was re‐infused at the same rate and the swine were allowed to equilibrate. After equilibration, repeat hemorrhages were performed at 1.6 mL/kg/min and 2.4 mL/kg/min. SrvO 2 was measured using an eye oximeter (EOX) and SvO 2 was measured using a fiber‐optic catheter. Results : During blood loss, SrvO 2 correlated with blood removed ( r = ‐0.88, ‐0.97, ‐0.96) and SvO 2 ( r = 0.87, 0.98, 0.92). During reinfusion, SrvO 2 correlated with blood re‐infused ( r = 0.63, 0.76, 0.82) and SvO 2 ( r = 0.80, 0.93, 0.96). SrvO 2 decreased 1.22 ± 0.60%/mL/kg of blood removed. The rate of decrease in SrvO 2 per minute (ΔSrvO 2 ) when blood was removed at 2.4 mL/kg/min was significantly greater than ΔSrvO 2 when blood was removed at 0.8 mL/kg/ min (p < 0.007). The rates of change in blood pressure (BP) and pulse were not significantly different at any rate of blood removal. Conclusions : In this model, retinal venous O 2 saturation correlated with blood volume and central venous O 2 saturation. Unlike the rate of change in BP and heart rate, ΔSrvO 2 values were significantly different at different rates of blood removal. Use of an EOX to monitor for blood loss, estimate the rate of hemorrhage, and evaluate the response to therapy during resuscitation warrants further study.