CENTRAL NERVOUS SYSTEM DISEASE Flashcards

Question

Answer 1

23. Dexmedetomidine and clonidine decrease cerebral blood flow through reductions in mean arterial pressure and cerebral perfusion pressure. They have minimal effect on cerebral metabolic rate and intracranial pressure. (478)

Answer 2

26. Succinylcholine may increase intracranial pressure through stimulation of muscle spindles, which then increases cerebral metabolic rate and cerebral blood flow. These effects are not consistent, and may be attenuated through a deep level of anesthesia during the administration of succinylcholine. Nondepolarizing neuromuscular blocking drugs do not generally affect intracranial pressure except through the potential release of histamine, leading to cerebral vasodilation.

Answer 3

27. Normal intracranial pressure is lower than 15 mm Hg. (478)

Answer 4

28. The intracranial pressure is determined by the intracranial contents occupying a fixed space. The intracranial compartment is composed of brain tissue, cerebrospinal fluid, and blood. Increases in brain tissue or fluid, such as by brain tumor and edema, are space occupying and could potentially increase the intracranial pressure. Initially, the displacement of cerebrospinal fluid from the cranium compensates for increases in the space-occupying mass, but as the mass enlarges an increase in intracranial pressure becomes apparent clinically. The relationship between the intracranial volume and intracranial pressure is such that after compensatory mechanisms are exhausted, minimal increases in the intracranial volume result in marked increases in the intracranial pressure. Increases in a patient’s intracranial pressure can interfere with cerebral perfusion and result in cerebral ischemia.

Answer 5

29. Although drug-induced increases in cerebral blood flow do not greatly affect the intracranial pressure of normal patients, patients with intracranial space- occupying lesions are not able to compensate for the changes in cerebral blood flow and are vulnerable to developing increased intracranial pressure.

Answer 6

30. Reductions in elevated intracranial pressure are achieved through reductions in cerebral spinal fluid, cerebral blood volume, and cerebral edema. Cerebral spinal fluid may be drained through an external ventricular or lumbar drain, or its production decreased by drugs such as furosemide and acetazolamide. Methods of reducing cerebral blood volume include positioning of the head to facilitate venous drainage, avoidance of high ventilatory pressures and PEEP, avoidance of hypertension, and hyperventilation. Finally, osmotic diuretics such as mannitol, as well as surgical resection of space-occupying lesions and decompressive craniectomy, may reduce intracranial pressure from cerebral edema

Answer 7

31. Signs and symptoms of an increased intracranial pressure include nausea and vomiting, hypertension, bradycardia, personality changes, altered levels of consciousness, altered patterns of breathing, papilledema, and seizures.

Answer 8

32. The use of induced hypothermia in neurosurgical procedures was widespread based on laboratory studies. An international multicenter study in 2005 of 1001 patients did not show any benefit in neurologic outcome, however. Because there has been no verifiable benefit ascribed to hypothermia for neuroprotection in humans, the routine use of hypothermia in neurosurgery is no longer recommended. Indeed, the routine use of hypothermia in neurosurgery is unlikely to continue.

Answer 9

33. Although intravenous anesthetics have been shown to decrease the cerebral metabolic rate and intracranial pressure, there has not been any evidence to prove that neurologic outcome is improved with their use. A concern with the use of intravenous anesthetics such as propofol or barbiturates for this purpose is that the moderate benefit they may provide for neuroprotection can be readily offset by alterations in the cardiovascular or hemodynamic status of the patient. When these drugs are being administered, vigilance is required to avoid exacerbation of cerebral injury, thus limiting their usefulness. Rather it is recommended that other physiologic parameters (cerebral perfusion pressure, oxygenation, normocapnia, temperature, and control of hyperglycemia) are attended to for maximal neuroprotection.

Answer 10

34. In addition to standard monitors, continuous monitoring of systemic blood pressure is commonly employed using a peripheral arterial catheter to monitor the hemodynamic changes that occur around induction of anesthesia, laryngoscopy, application of Mayfield head frame, surgery, and emergence from anesthesia. Abnormally low or high systemic blood pressure may compromise cerebral perfusion or increase cerebral swelling, respectively. In addition, these catheters permit blood sampling and accurate determination of PaCO2. Other monitors should include a peripheral nerve stimulator to monitor the level of paralysis and a bladder catheter, particularly if diuretics are used. Central venous catheters are not routinely employed but may be considered for patient or surgical indications.

Answer 11

35. An external ventricular device or a subdural bolt placed through a burr hole can be used to measure the intracranial pressure. The external ventricular device has the additional advantage of also allowing for drainage of cerebral spinal fluid

Answer 12

36. Before direct laryngoscopy and intubation of the trachea, there are several measures that can be taken to attenuate increases in arterial blood pressure and intracranial pressure. Neuromuscular blockade should be confirmed with a peripheral nerve stimulator. This ensures that dangerous rises in intracranial pressure due to coughing or bucking in response to direct laryngoscopy do not occur. The administration of an additional dose of propofol, thiopental, opioids, deeper levels of a volatile agent, a bolus of intravenous lidocaine, or a short-acting b-adrenergic antagonist (e.g., esmolol) prior to direct laryngoscopy are all methods that may be used to attenuate an increase in intracranial pressure. Finally, the duration of direct laryngoscopy should be minimized. (

Answer 13

Maintenance anesthesia in patients undergoing intracranial neurosurgery is often achieved with the administration of a low concentration of volatile anesthetic in conjunction with nitrous oxide and an opioid. The volatile anesthetic contributes to decreased awareness and the blunting of sympathetic nervous system responses. The disadvantage of volatile anesthetics during the resection of an intracranial tumor is its potential to increase cerebral blood flow. Alternatively, anesthesia may be maintained with a combination of intravenous anesthetic agents, most commonly propofol in conjunction with an opioid such as fentanyl or remifentanil. The use of intravenous anesthesia may be preferred in patients with elevated intracranial pressure due to a reduction of cerebral blood flow associated with these agents, as well as their compatibility with intraoperative neuromonitoring with evoked potentials.

Answer 14

38. To limit the degree of increase in cerebral blood flow associated with its administration, the MAC of volatile anesthetic administered should not exceed 0.5 MAC when administered for maintenance anesthesia in patients undergoing intracranial neurosurgery. It may be prudent to avoid the administration of volatile anesthetics altogether in patients with elevated intracranial pressure, since even slight increases in cerebral blood flow and intracranial pressure are potentially harmful. Likewise, the administration of a volatile anesthetic should be discontinued intraoperatively if cerebral swelling develops.

Answer 15

39. The PaCO2 should be maintained between 30 and 35 mm Hg to optimize cerebral blood flow intraoperatively. Below a PaCO2 of 30 mm Hg there is no evidence of any additional benefit.

Answer 16

40. Excessive use of PEEP during mechanical ventilation of the lungs in patients undergoing intracranial neurosurgery may lead to an increase in intracranial pressure by increasing the central venous pressure and impairing cerebral venous drainage.

Answer 17

41. Peripheral vasodilators may increase cerebral blood flow by causing cerebral vascular vasodilation while simultaneously decreasing mean arterial blood pressure and cerebral perfusion pressure. Examples include nitroglycerin, nitroprusside, adenosine, calcium channel blockers, and hydralazine. The use of these drugs is not recommended for use in neurosurgical patients, particularly before the dura is open in patients with elevated intracranial pressure.

Answer 18

42. Neuromuscular blockade is commonly maintained throughout intracranial surgical procedures to minimize the risk of patient movement, coughing, or bucking that may result in dangerous increases in intracranial pressure. Patient movement may also result in an increase in operative site bleeding and bulging of the brain into the operative site with difficult surgical exposure

Answer 19

43. Cerebral swelling occurring intraoperatively can be treated a number of ways. First, it should be confirmed that the maximal benefit is being derived from hyperventilation of the lungs with a PaCO2 between 30 and 35 mm Hg. Next, drugs that will cause cerebral dehydration may be administered. Mannitol at a dose of 0.25 to 1 g/kg or furosemide at a dose of 0.5 to 1 mg/kg is frequently used for this purpose. Intermittent injections of an intravenous anesthetic such as thiopental or propofol may also be administered. If surgically possible, placing the patient in a head-up position may improve venous drainage and reduce swelling. Discontinuing volatile anesthetic agents and using intravenous agents such as propofol should be considered to reduce cerebral blood flow.

Answer 20

44. Mannitol is an osmotic diuretic whose onset of action is within 5 to 10 minutes, and whose maximum benefit lasts for 2 to 4 hours. There are some potential problems that can occur with the administration of mannitol, however. If given rapidly, hypotension through peripheral vasodilation combined with a short-term increase in intravascular fluid volume can lead to a decrease in the cerebral perfusion pressure. If large doses of mannitol are administered, there is a risk of acute mannitol toxicity, manifested by hyponatremia and a high measured serum osmolality.

Answer 21

45. Maintenance of euvolemia with isotonic intravenous fluids, such as normal saline or lactated Ringer solution, during intracranial neurosurgery is recommended. Hypotonic solutions are not recommended due to increases in free water and possible cerebral edema. Colloids such as 5% albumin are acceptable but no improvement in outcome has been demonstrated.

Answer 22

46. Glucose-containing solutions should be avoided as hyperglycemia augments ischemic neuronal cell damage in the brain.

Answer 23

47. Coughing and straining in patients awakening from anesthesia after intracranial surgery can result in dangerous increases in the intracranial pressure, increases in cerebral edema, and precipitate postoperative bleeding. A small dose of opioid, intravenous lidocaine, or both at the conclusion of the procedure may decrease the likelihood of coughing during extubation. The emergence from anesthesia is better timed to follow placement of the head dressings because movement of the head at the conclusion of surgery in the lightly anesthetized patient can stimulate coughing on the endotracheal tube.

Answer 24

48. Rapid awakening is desirable in neurosurgical procedures to allow for a timely assessment of neurologic status after surgery. (

Answer 25

49. Delayed recovery as well as worsening neurologic function after intracranial surgery without obvious cause warrant evaluation by computed tomography or magnetic resonance imaging. A tension pneumocephalus may be considered as a possible cause of postoperative delayed recovery when nitrous oxide was administered intraoperatively, particularly after posterior fossa surgeries in the sitting position. Tension pneumocephalus occurs as a result of air entering the subdural cavities and the treatment is burr hole removal of the gas

Answer 26

50. Labetalol is commonly used to treat hypertension on emergence from anesthesia for intracranial neurosurgery due to its ability to reduce mean arterial blood pressure without causing cerebral vasodilation and with rapid onset.

Answer 27

51. Patients undergoing neurosurgical procedures are at an increased risk for a venous air embolism due to positioning of the patient’s head above the level of the heart. In addition, veins that are opened intraoperatively in the cranial vault may remain tented open unlike in other body sites. Patients undergoing posterior fossa craniotomies in the sitting position are at particular risk of an intraoperative venous air embolism. For this reason, many neurosurgeons prefer to do posterior fossa craniotomies with the patient in the prone or park bench position.

Answer 28

52. A venous air embolism is characterized by entry of air into the venous circulation and the right heart. After entry into the heart, the air may take three paths. First, it may stay in the right ventricle, interfering with blood flow into the pulmonary artery. Second, it may enter the pulmonary circulation and precipitate acute pulmonary hypertension as well as traverse the pulmonary circulation and enter the arterial circulation. Finally, from the right atrium it could enter the left atrium through a patent foramen ovale, which is present in approximately 25% of adults. Arterial emboli in the cerebral and coronary circulation can lead to neurologic and coronary infarctions, respectively.

Answer 29

53. Methods by which a venous air embolism can be detected include transesophageal echocardiography, precordial Doppler ultrasound transducer, an acute decrease in the exhaled carbon dioxide concentration, increased end-tidal nitrogen concentration, and changes in pulmonary and systemic pressures. In response to a pulmonary embolus, patients may have bronchoconstriction, pulmonary edema, elevated right atrial or pulmonary artery pressure, and elevated peak inspiratory pressure. The most sensitive method to detect a venous air embolism is through the use of transesophageal echocardiography. It is also beneficial in that it allows for the identification of right-to-left air shunting. The drawbacks of routine transesophageal echocardiography monitoring for venous air embolism are its invasiveness, bulk, and cost. An acceptable alternative to transesophageal echocardiography for monitoring is through the combined use of a precordial Doppler transducer and monitoring exhaled concentrations of carbon dioxide. The transducer should be placed between the second or third intercostal spaces to the right of the sternum. The Doppler transducer is able to recognize small volumes of intracardiac air, but it is not able to distinguish between small volumes and large volumes of air. (

Answer 30

54. Signs and symptoms of a clinically significant venous air embolism include a decrease in end-tidal carbon dioxide, hypotension, hypoxemia, tachycardia, cardiac dysrhythmias, cyanosis, and a characteristic “mill wheel” murmur. The awake patient may experience anxiety, chest pain, and coughing

Answer 31

55. The treatment for a venous air embolism includes the prompt administration of 100% oxygen and the discontinuation of nitrous oxide administration. The surgeons should be asked to irrigate the operative field with fluid and to occlude the bone edges to prevent the further entry of air. Lowering the operative field (Trendelenburg position) in conjunction with aggressive volume resuscitation may also prevent further entrainment of air and improve hemodynamics. Gentle compression of the jugular veins can be instituted. In addition, if a central venous catheter is in place, aspiration on the catheter to retrieve the air may be attempted to confirm the diagnosis. Other treatment methods of a venous air embolus are supportive as needed for hypotension, decreased cardiac output, bronchoconstriction, or other manifestations.

Answer 32

56. Nitrous oxide administration should be discontinued in the presence of a venous air embolism. The diffusion of nitrous oxide into the air embolus could potentially increase its size and worsen its clinical effects. Some clinicians choose to avoid the administration of nitrous oxide in patients at risk for a venous air embolus

Answer 33

57. Although a pulmonary artery catheter is not useful for aspirating air from the venous circulation because of its small catheter size, it may detect increases in pulmonary artery pressure caused by a pulmonary air embolus. In practice, pulmonary artery catheters are rarely used.

Answer 34

58. PEEP has not been shown to be efficacious in the prevention of a venous air embolism. (

Answer 35

59. Death occurring as a result of a venous air embolism is usually due to an obstruction of forward flow from the right side of the heart. Acute cor pulmonale, cardiovascular collapse, and arterial hypoxemia result.

Answer 36

60. Presenting signs and symptoms of patients with an intracranial tumor are typically reflective of an elevated intracranial pressure due to a space-occupying mass. Manifestations of elevated intracranial pressure include nausea and vomiting, hypertension, bradycardia, personality changes, altered levels of consciousness, altered patterns of breathing, and papilledema. Patients may also present with seizures depending on the location of the tumor. New-onset seizures in a previously asymptomatic adult are suggestive of an intracranial tumor.

Answer 37

61. The anesthetic goals in patients undergoing surgical resection of an intracranial tumor are to reduce intracranial pressure using medications, and avoid drugs or events (e.g., hypercarbia) that will cause undesirable changes in cerebral blood flow or intracranial pressure.

Answer 38

62. Preoperative sedative medications may result in depression of ventilation and increases in PaCO2 in patients with an intracranial tumor. This in turn could lead to an increase in cerebral blood flow and a corresponding increase in the intracranial pressure.

Answer 39

63. The induction of general anesthesia in patients scheduled to undergo surgical resection of an intracranial tumor can be achieved with the administration of thiopental or propofol to produce adequate anesthesia and minimize increases in intracranial pressure with direct laryngoscopy. Cerebral perfusion pressure must be maintained, however, to prevent cerebral ischemia in compromised patients. Etomidate may be useful in situations in which patients have a suspected elevated intracranial pressure but are also hemodynamically unstable or hypovolemic, such as trauma patients.

Answer 40

64. The sitting position facilitates surgical exposure of posterior fossa tumors and reduces retraction of brain structures, potentially preventing unwanted trauma. The high risk of venous air embolism (>25%), however, limits the use of the sitting position and many surgeons prefer the prone position instead. Other disadvantages of the sitting position include upper airway edema as a result of venous obstruction from cervical flexion and quadriplegia from spinal cord compression and ischemia.

Answer 41

65. There are some anesthetic considerations that are unique to posterior fossa tumors. Posterior fossa tumors place the patient at a higher risk for venous air embolism. In addition, resection of tumors in this area may injure vital brainstem structures and result in intraoperative hemodynamic fluctuations as well as respiratory depression in the postoperative period. Finally, injury to the cranial nerves may result in a loss of protective airway reflexes that necessitates postoperative ventilation.

Answer 42

66. Ruptured intracranial aneurysms have a mortality of 40% to 50%. Patients with ruptured intracranial aneurysms usually present with a sudden, severe headache, nausea, vomiting, focal neurologic signs, hypertension, and a depressed level of consciousness. Many of these symptoms are indications of an elevated intracranial pressure. The immediate management of patients with a ruptured intracranial aneurysm is to treat elevations in the intracranial pressure.

Answer 43

67. The goals of the anesthetic management of a patient undergoing resection of an intracranial aneurysm are (1) avoidance of sudden increases in systemic arterial blood pressure, and therefore transmural pressure of the aneurysm, which could result in rupture; and (2) facilitate surgical exposure and access to the aneurysm. Exaggerated increases in arterial blood pressure during direct laryngoscopy and surgical frame pinning must be attenuated. The anesthetic goals for resection or embolization of arteriovenous malformations are similar to those of aneurysms with a few distinct considerations. These vascular abnormalities are low pressure and high flow, and therefore increases in systemic blood pressure are less likely to result in rupture of the lesion. Hypertension should still be avoided, however, due to the high incidence of aneurysms associated with arteriovenous malformations. In addition, prolonged arteriovenous malformation resection has been associated with massive blood loss and severe cerebral swelling.

Answer 44

68. Major complications of intracranial aneurysm rupture include death, rebleeding, and vasospasm. Early treatment has been shown to reduce the incidence of rebleeding but may be technically more difficult due to swelling and inflammation. Other complications of aneurysm rupture include seizures, acute and chronic hydrocephalus, and systemic complications, such as neurogenic pulmonary edema and hyponatremia. (

Answer 45

69. The electrocardiogram of patients with a ruptured intracranial aneurysm often appears abnormal and may mimic myocardial ischemia. These changes are usually due to a neurologic mechanism and are not usually related to underlying coronary artery disease. Changes frequently seen on the electrocardiogram of these patients include arrhythmias, Q waves, U waves, T wave inversion, prolonged QT intervals, and ST segment depression or elevation. Mild elevations in cardiac enzymes are common but usually do not correlate with significant myocardial dysfunction.

Answer 46

70. A major cause of mortality and morbidity after rupture of an intracranial aneurysm is vasospasm of the cerebral arteries. Vasospasm occurs in about 70% of these patients and typically has onset 3 to 5 days after rupture of an intracranial aneurysm, but may occur as late as 12 days after rupture. Drowsiness is the most common clinical sign of vasospasm, and transcranial Doppler ultrasound or radiologic studies can confirm its presence

Answer 47

71. Vasospasm that occurs after cerebral aneurysm rupture is treated with “Triple H” therapy (hypertension, hypervolemia, and hemodilution) through an increase in cardiac output and the administration of intravenous fluids. Administration of the calcium channel blocker nimodipine has been shown to decrease the morbidity and mortality from vasospasm. Finally, cerebral vasospasm may be treated using the selective injection of vasodilators into the cerebral circulation or angioplasty in the interventional radiology suite.

Answer 48

72. Intracranial aneurysms may be treated using endovascular coiling or surgical resection. Outcomes are similar between patients treated surgically and with endovascular insertion of coils. Certain patients may be unsuitable candidates for endovascular coiling due to the anatomy and location of their aneurysms; these patients require surgery

Answer 49

73. Arteriovenous malformations may be treated expectantly, with open resection, endovascular embolization, or with stereotactic radiosurgery (gamma knife). Preoperative embolization is often used prior to open resection to reduce blood loss and facilitate surgical resection.

Answer 50

74. Temporary clips are often applied to a major feeding artery of an aneurysm to facilitate resection and permanent clip placement. These clips may create regional hypoperfusion to the areas perfused by these vessels. Anesthetic management during temporary clip placement should involve maintenance of normal or slightly increased systemic arterial blood pressure to maintain perfusion through the collateral circulation. Drugs such as thiopental or propofol may be used to achieve burst suppression on the electroencephalogram in the hope that this provides some protection from ischemia. Rarely, hypothermic circulatory arrest may be required for very large or complex aneurysms

Answer 51

75. Carotid endarterectomy is indicated in symptomatic patients with 70% to 99% stenosis of the carotid artery. Carotid endarterectomy may be beneficial in asymptomatic patients. However, the perioperative risk of stroke and death (approximately 4% to 7%) must be taken into account given a reduced benefit. Data suggest carotid endarterectomy should be optimally performed within 2 weeks of symptom onset.

Answer 52

76. Patients undergoing a carotid endarterectomy often have coexisting coronary artery and other atherosclerotic disease. The perioperative risk of myocardial ischemia should be evaluated preoperatively and medically optimized. The range of normal blood pressures for the patient should be determined. Neurologic symptoms and deficits should be documented preoperatively to prevent any dysfunction noted postoperatively from being incorrectly attributed to the surgical procedure or intraoperative events

Answer 53

77. The goals of the anesthetic management for patients undergoing a carotid endarterectomy include (1) prevention of cerebral ischemia through maintenance of adequate cerebral perfusion pressure and (2) prevention of myocardial ischemia through avoidance of acute peaks in blood pressure and heart rate. The critical period of the procedure occurs intraoperatively while the carotid artery is clamped. Mean arterial pressure should be maintained above the patient’s baseline blood pressure (within 20%) to ensure adequate blood flow through the circle of Willis. Finally, rapid emergence from anesthesia is recommended to facilitate early neurologic assessment.

Answer 54

78. During a carotid endarterectomy procedure, the arterial blood pressure should be maintained in a normal or slightly elevated range specific to that patient. It may be helpful to blunt sympathetic nervous system responses to direct laryngoscopy to avoid acute hypertension. A high-normal range of mean arterial pressures should be maintained during carotid artery clamping to increase collateral blood flow and prevent cerebral ischemia, particularly when there is no intraluminal shunt in place. Intraoperative hypotension is often treated with phenylephrine

Answer 55

79. During a carotid endarterectomy the PaCO2 should be maintained near normal, between 35 and 40 mm Hg. Hypocarbia should be avoided given the risk of cerebral vasoconstriction and ischemia.

Answer 56

80. The purpose of intraoperative neurologic monitoring during a carotid endarterectomy is to identify cerebral ischemia and the potential need for an intraluminal shunt placed for perfusion to the ipsilateral brain while the diseased carotid artery is clamped. Several methods of monitoring for cerebral ischemia have been used, including stump pressure measurement (blood pressure in the carotid artery distal to the placement of the surgical clamp as an indication of adequate collateral flow), electroencephalogram, and somatosensory evoked potentials, direct measurement of cerebral blood flow, and transcranial Doppler ultrasonography. Alternatively, an intraluminal shunt is routinely placed regardless of whether cerebral ischemia is detected.

Answer 57

81. The administration of either local or general anesthesia for carotid endarterectomy is acceptable. Neither has been shown to have better outcomes or reduced morbidity or mortality

Answer 58

82. Local anesthesia for a carotid endarterectomy is achieved with the administration of a deep and superficial cervical plexus block. A deep cervical plexus block provides anesthesia to the C1-C4 nerve roots and blocks the greater auricular, lesser occipital, transverse cervical, and supraclavicular peripheral nerves. The superficial cervical plexus block anesthetizes the cutaneous nerves. The advantages of local anesthesia for this procedure include a more accurate assessment of the patient’s neurologic status intraoperatively and improved hemodynamic stability. Neurologic status is typically monitored using the patient’s contralateral grip strength, level of consciousness, and quality of prompted speech. Disadvantages of this technique include the need for a cooperative and motionless patient.

Answer 59

83. The induction of general anesthesia for a carotid endarterectomy is usually achieved with the administration of an opioid, an intravenous induction agent, and a neuromuscular blocking drug. The maintenance of anesthesia is typically achieved by the administration of a volatile anesthetic in conjunction with nitrous oxide and an opioid. Neuromuscular blockade is usually maintained throughout the course of the procedure to minimize the risk of intraoperative movement. Advantages of general anesthesia include the ability to manipulate cerebral blood flow and the cerebral metabolic oxygen requirement, as well as the security of a protected airway. General anesthesia may also be advantageous when patients are unable to communicate or when their neck anatomy appears difficult for the administration of local anesthesia. Disadvantages include reliance on surrogate indicators to monitor neurologic status and greater hemodynamic instability

Answer 60

84. Potential postoperative complications after a carotid endarterectomy include recurrent laryngeal nerve injury, hemodynamic instability, airway compression secondary to neck hematoma, loss of carotid body function, myocardial infarction, and neurologic dysfunction. Neurologic dysfunction after carotid endarterectomy is usually due to intraoperative embolization or hypoperfusion during carotid artery clamping.

Answer 61

85. Postoperative hypertension is common after a carotid endarterectomy as the majority of patients undergoing carotid endarterectomy have chronic hypertension. Hypertension may also occur secondary to the loss of function of the carotid sinus or the loss of innervation to the carotid sinus during surgery. Hypertension may result in an increased incidence of postoperative complications such as neck hematoma, myocardial ischemia, and hyperperfusion syndrome, and should be strenuously avoided.