Effect of hemorrhage and resuscitation on subcutaneous, conjunctival, and transcutaneous oxygen tension in relation to hemodynamic variables

Subcutaneous (PscO2), conjunctival (PcjO2), and transcutaneous (PtcO2) oxygen tension values were measured in anesthetized dogs subjected sequentially to hemorrhage and reinfusion of the shed blood. Intravascular pressure, hemodynamic variables, and oxygen transport variables were measured simultaneously. During hemorrhage, PscO2 was the first of the PO2 measurements, and among the first set of hemodynamic variables that differed significantly from control values. During continuous bleeding, PscO2 and PcjO2 fell rapidly, the decline of PscO2 and PcjO2 was similar and significantly higher than that found for PtcO2. After reinfusion of shed blood, PscO2 was the last of PO2 measurements, and among the last set of hemodynamic variables, to return to control values. While PaO2 remained constant, PvO2 decreased significantly during hemorrhage and normalized during resuscitation. Unheated instruments for measuring PscO2 and PcjO2 are reliable indicators of peripheral perfusion during hemorrhage and resuscitation. Subcutaneous oxygen monitoring, in particular, seems capable of assessing early blood loss and adequacy of resuscitation after acute hemorrhage, and may be clinically useful.