TY - JOUR
T1 - Effects of hyperventilation on conjunctival oxygen tension in humans
AU - Nisam, M.
AU - Albertson, Timothy E
AU - Panacek, Edward A
AU - Rutherford, W.
AU - Fisher, C. J.
PY - 1986
Y1 - 1986
N2 - A polarographic conjunctival oxygen sensor was used to measure oxygen tension in a tissue bed supplied by the internal carotid artery. The shared vascular source of the conjunctiva and brain suggests that conjunctival PO2 monitoring may provide an index of cerebral perfusion. We studied the effects of hyperventilation, a known stimulus of cerebral vasconstriction, on conjunctival oxygen tension (P(cj)O2) in six normal, healthy adults; arterial blood gases were simultaneously measured in four of these subjects. A 5-min period of hyperventilation to a PaCO2 near 20 torr resulted in a rapid and significant (p<.01) increase in systemic oxygen tension as measured by arterial blood gases and a transcutaneous oxygen monitor. These values gradually returned to baseline upon cessation of hyperventilation. P(cj)O2, however, decreased significantly (p<.01) during hyperventilation, suggesting vasoconstriction of the conjunctival vascular supply. Because these changes temporally correlate with the cerebral vasoconstriction during hyperventilation, the conjunctival index of tissue oxygen tension may correlate with cerebral perfusion.
AB - A polarographic conjunctival oxygen sensor was used to measure oxygen tension in a tissue bed supplied by the internal carotid artery. The shared vascular source of the conjunctiva and brain suggests that conjunctival PO2 monitoring may provide an index of cerebral perfusion. We studied the effects of hyperventilation, a known stimulus of cerebral vasconstriction, on conjunctival oxygen tension (P(cj)O2) in six normal, healthy adults; arterial blood gases were simultaneously measured in four of these subjects. A 5-min period of hyperventilation to a PaCO2 near 20 torr resulted in a rapid and significant (p<.01) increase in systemic oxygen tension as measured by arterial blood gases and a transcutaneous oxygen monitor. These values gradually returned to baseline upon cessation of hyperventilation. P(cj)O2, however, decreased significantly (p<.01) during hyperventilation, suggesting vasoconstriction of the conjunctival vascular supply. Because these changes temporally correlate with the cerebral vasoconstriction during hyperventilation, the conjunctival index of tissue oxygen tension may correlate with cerebral perfusion.
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M3 - Article
C2 - 3940750
AN - SCOPUS:0022656550
VL - 14
SP - 12
EP - 15
JO - Critical Care Medicine
JF - Critical Care Medicine
SN - 0090-3493
IS - 1
ER -