|Anesthesia type||GETA vs. regional anesthesia|
|Lines and access||PIV x 2 18 ga or larger is adequate|
|Monitors||Standard monitors, arterial line|
|Primary anesthetic considerations|
Carotid endarterectomy (CEA) is a surgical procedure for treating occlusive atherosclerotic disease involving the common and internal carotid arteries. The procedure is more effective than medical management for patients with high grade stenosis (70–99%), symptomatic moderate stenosis (50-69%), or asymptomatic high-grade stenosis (≥ 60%). CEA involves making a longitudinal incision along the anterior border of the sternocleidomastoid muscle to expose the common, internal, and external carotid arteries as well as the carotid sinus. The carotid artery is then opened and the atherosclerotic plaque is removed. Opening of the carotid artery requires occlusion of the proximal common carotid and distal internal and external carotid arteries, which requires adequate collateral flow from the contralateral common carotid artery or placement of an internal shunt between the proximal common carotid and the distal internal carotid arteries. On removal of the atherosclerotic plaque, the media and adventitia of the arteries may be re-approximated or a graft may be used. These grafts are typically synthetic, but vein grafts are occasionally used.
|Neurologic||Evaluate plaque location and adequacy of collateral flow with carotid angiograms prior to surgery|
|Cardiovascular||Preoperative ECG is useful as perioperative MI is the most common major postoperative complication. Uncontrolled hypertension or diabetes, as well as recent MI are reasons to delay the case.|
|Respiratory||ABGs, Spirometry, and CXRs are useful only if otherwise indicated from the H&P|
|Hematologic||Anti-platelet agents (typically aspirin) are typically initiated preoperatively and continued until the day of surgery to prevent perioperative thromboembolic complications.|
Labs and studies
Operating room setup
Patient preparation and premedication
Premedication in CEA may complicate the immediate postoperative evaluation for stroke or TIA. Use of preoperative benzodiazepines and opioids should be limited. If a discussion of the operation and safety steps is inadequate to alleviate the patient's fear, a small dose of midazolam is preferred to opioid premedication.
Regional and neuraxial techniques
CEA may be performed under regional anesthesia be performing both superficial and deep cervical plexus blocks with supplemental field blocks by the surgeon. Patients receiving regional anesthesia for CEA have decreased ICU times and may have decreased need for surgical shunts. Regional anesthesia for CEA, however, does not provide cerebral protection afforded by general anesthesia and it makes conversion to GETA more challenging should the need arise.
Monitoring and access
All patients require standard ASA monitors including pulse oximetry, ECG (5-lead is preferred over 3), non-invasive blood pressure, capnography, and temperature. Invasive blood pressure monitoring with an arterial line allows prompt vasopressor titration in response to changes in blood pressure, particularly if induced-hypertension is being used during carotid clamping. Invasive blood pressure monitoring is particularly useful during the immediate postoperative period to monitor for cerebral hyperperfusion syndrome.
Neurologic monitoring including EEG, somatosensory evoked potentials (SSEPs), and motor evoked potentials (MEPs) may be used to assess cerebral perfusion.
Induction and airway management
If general anesthesia is chosen, endotracheal intubation is preferred over placing an LMA. Choice of induction medications is dependent on patient comorbidies, but caution should be used with ketamine as it increases CMRO2 at a time when cerebral blood flow is limited.
For patients undergoing regional anesthesia light sedation with midazolam, fentanyl, propofol, or dexmedetomidine is reasonable. Avoid heavy sedation as patient cooperation may be required for neurologic exam.
Patients are positioned supine with the head turned away from operative site. Beach chair may be used for comfort in awake patients
Maintenance and surgical considerations
Volatile anesthetics supplemented with opioids for analgesia and neuromuscular blockade is adequate for CEA without electrophysiologic monitoring (EP). For patients receiving EP monitoring, a total IV anesthetic with propofol and remifentanil provides excellent sedation and operating conditions.
Heparin is required prior to carotid cross-clamping. The ACT goal is 200-250 seconds.
Carotid cross clamping may induce a severe vagal response with bradycardia and hypotension. Local anesthetic infiltration by the surgeon prior to cross clamping may improve this response.
Unclamping can produce a reflex bradycardia and vasodilation effect
Blood Pressure Maintenance
MAPs should be kept at or above the patient's awake MAP. A phenylephrine drip is a good choice because it's pure α-1 activity decreases the risk of arrhythmias. Wide swings in blood pressure should be expected during CEA. Sudden bradycardia may occur with associated hemodynamic instability, so atropine of glycopyrrolate should be available.
Many surgeons prefer to verify neurologic status prior to extubation, but this must be weighed against the risk of surgical bleeding caused by coughing and bucking.
Neurologic deficits may surface after emboli from plaque or shunts or from hypoperfusion during the procedure
Plaque removal during surgery may cause baroreceptor changes causing either hypotension or hypertension requiring vasoactive medications in the recovery unit
|Variant 1||Variant 2|