TY - JOUR
T1 - Evaluation of multiple modes of oximetry monitoring as an index of splanchnic blood flow in a newborn lamb model of hypoxic, ischemic, and hemorrhagic stress.
AU - Applegate, Richard L.
AU - Ramsingh, Davinder S.
AU - Dorotta, Ihab
AU - Sanghvi, Chirag
AU - Blood, Arlin B.
N1 - Early and aggressive treatment of circulatory failure is associated with increased survival, highlighting the need for monitoring methods capable of early detection. Vasoconstriction and decreased oxygenation of the splanchnic circulation are a sentinel response of the cardiovasculature during circulatory distress.
PY - 2013/6
Y1 - 2013/6
N2 - Early and aggressive treatment of circulatory failure is associated with increased survival, highlighting the need for monitoring methods capable of early detection. Vasoconstriction and decreased oxygenation of the splanchnic circulation are a sentinel response of the cardiovasculature during circulatory distress. Thus, we measured esophageal oxygenation as an index of decreased tissue oxygen delivery caused by three types of ischemic insult, occlusive decreases in mesenteric blood flow, and hemodynamic adaptations to systemic hypoxia and simulated hemorrhagic stress. Five anesthetized lambs were instrumented for monitoring of mean arterial pressure, mesenteric artery blood flow, central venous hemoglobin oxygen saturation, and esophageal and buccal microvascular hemoglobin oxygen saturation (StO2). The sensitivities of oximetry monitoring to detect cardiovascular insult were assessed by observing responses to graded occlusion of the descending aorta, systemic hypoxia due to decreased FIO2, and acute hemorrhage. Decreases in mesenteric artery flow during aortic occlusions were correlated with decreased esophageal StO2 (R = 0.41). During hypoxia, esophageal StO2 decreased significantly within 1 min of initiation, whereas buccal StO2 decreased within 3 min, and central venous saturation did not change significantly. All modes of oximetry monitoring and arterial blood pressure were correlated with mesenteric artery flow during acute hemorrhage. Esophageal StO2 demonstrated a greater decrease from baseline levels as well as a more rapid return to baseline levels during reinfusion of the withdrawn blood. These experiments suggest that monitoring esophageal StO2 may be useful in the detection of decreased mesenteric oxygen delivery as may occur in conditions associated with hypoperfusion or hypoxia.
AB - Early and aggressive treatment of circulatory failure is associated with increased survival, highlighting the need for monitoring methods capable of early detection. Vasoconstriction and decreased oxygenation of the splanchnic circulation are a sentinel response of the cardiovasculature during circulatory distress. Thus, we measured esophageal oxygenation as an index of decreased tissue oxygen delivery caused by three types of ischemic insult, occlusive decreases in mesenteric blood flow, and hemodynamic adaptations to systemic hypoxia and simulated hemorrhagic stress. Five anesthetized lambs were instrumented for monitoring of mean arterial pressure, mesenteric artery blood flow, central venous hemoglobin oxygen saturation, and esophageal and buccal microvascular hemoglobin oxygen saturation (StO2). The sensitivities of oximetry monitoring to detect cardiovascular insult were assessed by observing responses to graded occlusion of the descending aorta, systemic hypoxia due to decreased FIO2, and acute hemorrhage. Decreases in mesenteric artery flow during aortic occlusions were correlated with decreased esophageal StO2 (R = 0.41). During hypoxia, esophageal StO2 decreased significantly within 1 min of initiation, whereas buccal StO2 decreased within 3 min, and central venous saturation did not change significantly. All modes of oximetry monitoring and arterial blood pressure were correlated with mesenteric artery flow during acute hemorrhage. Esophageal StO2 demonstrated a greater decrease from baseline levels as well as a more rapid return to baseline levels during reinfusion of the withdrawn blood. These experiments suggest that monitoring esophageal StO2 may be useful in the detection of decreased mesenteric oxygen delivery as may occur in conditions associated with hypoperfusion or hypoxia.
KW - Animals, Newborn
KW - Blood Pressure/physiology
KW - Sheep, Domestic
KW - Esophagus/blood supply
KW - Ischemia/diagnosis
KW - Hypoxia/diagnosis
KW - Oximetry/methods
KW - Regional Blood Flow/physiology
KW - Splanchnic Circulation/physiology
KW - Mesenteric Arteries/physiopathology
KW - Oxygen Consumption/physiology
KW - Animals
KW - Shock, Hemorrhagic/diagnosis
KW - Stress, Physiological/physiology
KW - Disease Models, Animal
UR - http://www.scopus.com/inward/record.url?scp=84891605145&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84891605145&partnerID=8YFLogxK
U2 - 10.1097/shk.0b013e3182934056
DO - 10.1097/shk.0b013e3182934056
M3 - Article
C2 - 23603766
SN - 1073-2322
VL - 39
SP - 501
EP - 506
JO - Shock
JF - Shock
IS - 6
ER -