Conjunctival oxygen tension monitoring during hemorrhage

Placement of an unheated, miniaturized oxygen electrode against the palpebral conjunctiva permits noninvasive measurement of tissue oxygen tension without the heating artifacts present with transcutaneous monitoring. In this study, the relationship between conjunctival oxygen tension (PcjO2) and standard cardiorespiratory variables was examined in a sequential hemorrhage model. PcjO2 was among the first set of physiologic variables that differed significantly from control values during hemorrhage. PcjO2 was the first noninvasively measured parameter to become abnormal. In particular, PcjO2 fell at an earlier point and more rapidly than did blood pressure. Conjunctival oxygen monitoring may have a useful clinical role in the early identification of blood loss.