title: The relationship of early hypertension following carotid endarterectomy to intraoperative cerebral ischemia.
abstract: The relationship between early hypertension following carotid endarterectomy, and intraoperative cerebral ischemia was investigated. Two measures of the adequacy of collateral cerebral circulation during carotid clamping were used: collateral cerebral perfusion pressure (delta P), and the ratio of collateral to ipsilateral cerebral vascular resistance (R/R). Change in blood pressure was measured by the ratio of mean early post to preendarterectomy pressure (P/P). Nitroprusside or nitroglycerin (NN) was used after endarterectomy to maintain systolic blood pressure less than 160 mmHg. The mean values for NN (n = 26) and no NN (n = 81) groups were: delta P = 30.0 and 40.2 mmHg (p less than 0.001); R/R = 1.93 and 1.24 (p less than 0.005); and P/P = 1.03 and 0.857 (p less than 0.001 p by unpaired t test). Linear regression analysis of the two measures of cerebral perfusion with the ratio of post-to preoperative blood pressure gave correlation coefficients between 0.629 and 0.841 with a probability that the slope of the regression line greater than 0 of less than 0.01. Low delta P and high R/R correlate with early postcarotid endarterectomy hypertension. These results support the hypothesis that one determinant of early post endarterectomy hypertension is inadequate collateral cerebral circulation during carotid clamping.
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D002545:Brain Ischemia / Q000209:etiology*; D002340:Carotid Artery Diseases / Q000601:surgery*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003097:Collateral Circulation / Q000187:drug effects; D004691:Endarterectomy; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000209:etiology*; D007431:Intraoperative Complications / Q000209:etiology*; D002546:Ischemic Attack, Transient / Q000601:surgery; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000627:therapeutic use; D009599:Nitroprusside / Q000627:therapeutic use; D011183:Postoperative Complications / Q000188:drug therapy / Q000209:etiology*; D012307:Risk Factors
chemical_list: D009599:Nitroprusside; D005996:Nitroglycerin