How should ventilation be managed during a carotid endarterectomy?

A. Both hypercapnea and hypocapnea can potentially result in alterations in cerebral blood flow. Hypercapnea can dilate vessels and potentially result in a steal phenomenon in which areas of decreased perfusion suffer increased ischemia at the expense of increased perfusion to normal vessels. Hypocapnea can theoretically constrict cerebral blood vessels and potentially reduce blood flow causing a reverse steal effect. There is little clinical data to demonstrate that this occurs, however. In fact, a mild degree of hypocapnea has been shown to reduce the size of the region at risk for ischemia. The common practice is to maintain normocapnea to mild hypocapnea during a carotid endarterectomy.

B. Adjust randomly

C. Only use hypocapnea

D. Use normocapnea only