Cardiorespiratory and conjunctival oxygen tension monitoring during resuscitation from hemorrhage.

Placement of an unheated miniaturized oxygen electrode against the palpebral conjunctiva permits noninvasive measurement of tissue oxygen tension. In this study, the relationship between conjunctival oxygen tension (PcjO2) and standard cardiorespiratory variables was examined during a sequential resuscitation protocol after acute hemorrhage. Anesthetized dogs were rapidly bled to a mean arterial pressure of 40 mm Hg and then retransfused with the shed blood in a stepwise fashion. PcjO2 fell to 2% of control values after hemorrhage and did not return to prehemorrhage values until more than 90% of the shed blood had been reinfused. PcjO2 was among the last set of cardiorespiratory variables to return to control values during resuscitation and was the last noninvasive variable to normalize. The ratio of PcjO2 to arterial oxygen tension decreased from a prehemorrhage value of 0.76 +/- 0.05 (SEM) to 0.02 +/- 0.003 after hemorrhage, and did not increase to values greater than 0.50 until resuscitation was more than 90% complete. Conjunctival oxygen monitoring may play an important role in assessing the adequacy of resuscitation after acute hemorrhage.