BLOOD-PRESSURE RESPONSES AFTER CAROTID SURGERY - RELATIONSHIP TO POSTOPERATIVE BARORECEPTOR SENSITIVITY

BACKGROUND AND PURPOSE: Among hypertensive patients after carotid surg ery, a group of patients with increased baroreflex sensitivity was ide ntified. In the other group of hypertensive patients, blood pressure a nd reflex sensitivity were unchanged postoperatively. We hypothesized that a partial readjustment of baroreceptor sensitivity would produce more stable blood pressure profiles. METHODS: In order to test this hy pothesis, a prospective, long-term follow-up study was designed. Blood pressure was monitored in 18 hypertensive and 6 normotensive patients during 6 months using a self-measurement technique. In addition, cont inuous 24-hour blood pressure monitoring was performed 6 months after surgery. The mean values and the ranges (amplitudes) of systolic and d iastolic blood pressure were calculated as indicators for the stabilit y of the circulatory system. RESULTS: Hypertensive patients with uncha nged postoperative baroreceptor sensitivity showed significantly more pronounced instabilities of their blood pressure profiles (amplitudes of systolic and diastolic blood pressure p <0.05 to p <0.001). A relat ionship between baroreceptor function and antihypertensive therapy cou ld also be demonstrated, with adequate therapy being much more difficu lt in patients with reduced or unchanged baroreceptor sensitivity. CON CLUSIONS: In contrast to vascular surgery on the aorta or in the regio n of the low: er limbs, carotid surgery is frequently associated with blood pressure changes, demonstrating the essential role of the barore ceptors in the carotid sinus for the regulation of postoperative blood pressure. Since it seems to be the variability of blood pressure, and not the blood pressure level alone, that is critical, close blood pre ssure monitoring-allowing for an assessment of blood pressure variabil ity-appears to be of particular importance in such patients.