Abstract 178: Deep Muscle Oxygen Saturation Tracks Success of Resuscitation During Uncontrolled Hemorrhage in Swine
The goal of resuscitation from hemorrhagic shock is to restore adequate oxygen to meet the metabolic demands of the tissue. Near infrared spectroscopy can be used noninvasively and continuously to assess deep muscle oxygen saturation (SmO2). Hypovolemia results in lower SmO2 through increased oxygen extraction. HYPOTHESIS: SmO2 at the end of resuscitation will be higher for pigs who survive for 4 hours compared to those that die early. METHODS: Hemorrhage was conducted with a computerized pump until 24 mL/kg of blood was removed (Shock). This was followed by transection of the spleen causing uncontrolled hemorrhage throughout the remainder of the protocol. After 15min resuscitation was begun until 15.25mg/kg of fluid was given over a period of 30min. Resuscitation fluids included either hextend, fresh frozen plasma or platelets. SmO2 was measured continuously on the posterior thigh muscle using a prototype of the CareGuide 1100 Oximeter (Reflectance Medical Inc.). Differences between survivors and non-survivors were assessed with two-way repeated measures ANOVA followed by a Tukey test for pairwise comparisons. Mean ± se are reported. RESULTS: Thirteen of the 26 swine did not survive for the full 4 hours. SmO2 at the end of each period is shown in the table; * p< 0.05 compared to baseline. Controlled hemorrhage resulted in significantly lower SmO2 for all animals (Shock). Surviving animals were marked by a return to baseline SmO2 by the end of resuscitation, while animals which later died did not have significant increases in SmO2 during resuscitation. CONCLUSIONS: Noninvasively determined SmO2 provided real-time feedback on the efficacy of resuscitation.
- © 2012 by American Heart Association, Inc.