Comparison of Blood Pressure Measured by Oscillometry from the Supraorbital Artery and Invasively from the Radial Artery

In previous studies, oscillometric blood pressure measured from the supraorbital artery has been shown to agree quite well with pressure measured from the brachial artery in normal subjects. In this study, surgical patients whose conditions warranted the use of invasive blood pressure monitoring during the surgery were chosen. We compared systolic and diastolic blood pressure measured oscillometrically from the supraorbital artery with intraarterial blood pressures, measured invasively from the radial artery. A pressure bladder was attached to the forehead of each patient. The bladder was connected to a forehead blood pressure monitor. A catheter was inserted in a radial artery, and connected to a pressure monitor. Forehead blood pressure was measured every 5 min. Radial arterial pressure was averaged over the same period during which the forehead measurement was made. Blood pressures measured with the two methods were compared. For the systolic pressure, the difference between the two methods was –9.9 ± 17.9 mm Hg (mean ± SD). For diastolic pressure, the difference was –8.0 ± 10.9 mm Hg. There was a significant difference between the two methods in the patient population chosen in this study.