UBP 2.5 (Short Form): Neuro – Cerebral Aneurysm

Question 1

Does this patient have elevated intracranial pressure (ICP)?

How would you know?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 1

Given the severe headache and a known aneurysm, I would certainly be concerned about the possibility of elevated ICP.

However, the lack of bleeding seen on MRA is reassuring since elevated ICP is less likely in the absence of intracranial bleeding.

Regardless, I would perform a thorough history and physical looking for signs of elevated ICP, such as headache, papilledema, N/V, altered mental status, and Cushing’s triad of HTN, bradycardia, and a change in respiratory pattern

(some sources substitute a widened pulse pressure - increased difference between systolic and diastolic blood pressure - as the third component of the triad, in place of an irregular respiratory pattern).

If I were still uncertain, I would order a CT, which would aid in identifying intracranial bleeding, small ventricles, or a midline shift.

Question 2

How would you evaluate this patient’s airway?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 2

I would perform a history and physical looking for specific findings that may suggest a difficult airway such as inability to open the mouth, poor cervical spine mobility, receding chin, large tongue, prominent incisors, short neck, reduced thyromental distance ( <6.5 cm), reduced sternomental distance ( <12.5 cm), and a Mallampati classification of III or IV.

I would also question the patient about weight change and evaluate the patency of his nares to determine whether nasal intubation would be an acceptable option in an emergent situation.

In addition, I would attempt to obtain the old anesthetic record to further delineate the difficulty encountered, whether ventilation was difficult, and what steps were taken to successfully secure the airway.

I would then discuss potential intubation plans with the patient, including the performance of an awake, fiberoptic intubation.

Question 3

What monitors would you require for this case?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 3

Given my concerns about providing adequate cerebral perfusion pressure while avoiding potentially damaging hypertension, I would place an arterial line prior to induction in addition to the standard ASA monitors.

This would allow me to more accurately monitor hemodynamic changes during induction and intubation.

I would also place a central venous line after induction to provide a route for the infusion of vasoactive agents, help assess fluid status, facilitate resuscitation in case of aneurysm rupture, and aid in the treatment of air embolism should one occur.

SSEP or EEG monitoring may prove helpful in identifying cerebral ischemia and guiding perioperative management, especially during temporary clip placement or in the event of vasospasm.

Finally, a Foley catheter would be useful to guide fluid management and assess renal function.

Question 4

Would a pulmonary artery (PA) catheter be useful?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 4

Given that this patient has a history of chronic hypertension, CAD, and an EKG showing LVH and non-specific ST changes, a PA catheter may be helpful.

If the preoperative workup demonstrated CHF, cardiomyopathy, or valvular disease, a PA catheter may be justified.

Additionally, in the event of cerebral vasospasm, it may be useful in guiding anesthetic management.

In any case, the placement of this catheter is a risk/benefit decision.

Question 5

Would you insert your lines prior to induction?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 5

As I mentioned before, I am concerned about providing adequate cerebral perfusion pressure while avoiding potentially damaging hypertension.

Two of the times when the patient is at highest risk of hemodynamic instability are during induction and intubation, especially when the patient has chronic hypertension, which predisposes him to hemodynamic instability.

Therefore, I would place an arterial line prior to induction to provide more accurate and timely information during these high-risk events.

Question 6

What would you do if you inadvertently cannulated the carotid artery on the right? Would you cancel the case? Can’t you just place a central line in the left internal jugular?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 6

If I inadvertently cannulated the right carotid artery, I would cancel the case and consult a vascular surgeon.

Pulling the cannula from the carotid artery would lead to bleeding and hematoma formation in the neck potentially leading to decreased cerebral venous return, decreased cerebral perfusion, and even airway compromise in this patient with possibly elevated ICP and a known difficult airway.

While I could place a central line in the left internal jugular, this may result in further impairment of cerebral venous return leading to increased intracranial hypertension which could further compromise cerebral perfusion.

Question 7

Is there any advantage to a subclavian approach?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 7

A subclavian approach theoretically avoids the risk of damaging the internal jugular vein or artery, with subsequent obstruction of cerebral venous return and/or cerebral perfusion.

However, placing a central line using the subclavian approach is technically more difficult and is associated with a higher risk of pneumothorax.

Question 8

What is this patient’s clinical neurologic grade according to the Hunt and Hess classification?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 8

The Hunt and Hess classification is used to grade the severity of non-traumatic subarachnoid hemorrhage.

Because the aneurysm is unruptured, this patient’s neurologic grade is 0, which corresponds to a 0-2% incidence of mortality or major morbidity.

Grades 1-5 are associated with ruptured aneurysms and are classified by associated signs and symptoms as follows:

1. Grade I represents an asymptomatic patient with a ruptured aneurysm and minimal headache and slight nuchal rigidity.
2. Grade II represents a patient with a moderate to severe headache, nuchal rigidity, and a neurologic deficit limited to cranial nerve palsy.
3. Grade III represents a patient who is drowsy, confused, or exhibits a mild focal deficit.
4. Grade IV represents a patient exhibiting stupor, hemiparesis, or vegetative disturbances.
5. Grade V represents a patient who is in deep coma, moribund, or exhibiting decerebrate rigidity.

• Don’t need to know all the Grades – if you at least know what the Hunt-Hess is used for… that’s sufficient, too.*
• If don’t know… say as such so you can move on to what you know.*

Question 9

What other labs would you order prior to induction?

(A 54-year-old, 73 kg man with severe headaches over the past 2 days, presents to the operating room for clipping of an anterior communicating artery (ACA) aneurysm. He has a 15-year history of hypertension and was told he was difficult to intubate during a previous laparoscopic procedure 5 years ago. P = 92, BP = 140/90 mmHg, RR = 16, T = 36ºC. EKG shows LVH and non-specific ST changes and the patient reports a history of myocardial infarction 2 years ago. Magnetic resonance angiography (MRA) shows a large ACA aneurysm, with no evidence of intracranial bleeding.)

Answer 9

Along with a CBC, I would type and cross this patient, due to the risk of aneurysm rupture.

Given the potential for electrolyte abnormalities and alterations in endocrine function, I would order a baseline blood sugar and electrolyte panel.

With the patient’s EKG exhibiting left ventricular hypertrophy and ST changes, combined with a history of myocardial infarction and chronic hypertension, I would consider an echocardiogram (to see if there are any myocardium at risk) to further evaluate cardiac function and identify signs of myocardial ischemia, such as wall motion abnormalities.