Advanced | Vascular and Endovascular Anesthesia Flashcards
This is the most important risk factor for future stroke
TIA (transient ischemic attack) and symptoms
It has been estimated that up to 15% of strokes are heralded by TIA, and the most important risk factor for future stroke is the presence of recent TIA symptoms. The risk of stroke following TIA is elevated in the initial days to weeks following the initial event.
In the context of cerebral blood flow and its correlation with neuromonitoring, EEG deterioration usually begins below a threshold of approximately _____ brain tissue.
A. 30 mL/min/100g
B. 15 mL/min/100g
C. 50 mL/min/100g
D. 10 mL/min/100g
B. 15 mL/min/100g
Normal cerebral blood flow is approximately 50 mL/min/100 g brain tissue. In the perioperative period, decreases in cerebral
blood flow as low as approximately 22 mL/min/100 g brain tissue may be well tolerated with no EEG changes.
EEG deterioration usually begins below a threshold of approximately 15 to 18 mL/min/100 g brain tissue, and frank cellular failure appears to occur below 10 to 12 mL/min/100 g brain tissue.
TRUE or FALSE
EEG is a global monitor of cerebral activity.
TRUE
it is important to recognize that EEG is a global monitor of cerebral activity. It is unable to reliably detect strokes related to smaller thromboembolic phenomena, which is the most likely etiology of perioperative stroke.
During CEA surgery, the _______ measures the maximum velocity of blood flow through the middle cerebral artery as a surrogate for cerebral blood flow.
A. Electroencephalography (EEG)
B. Somatosensory-evoked potentials (SSEP)
C. Motor-evoked potentials (MEP)
D. Transcranial Doppler (TCD)
E. Carotid stump pressure
D. Transcranial Doppler (TCD)
Confirming that cerebral blood flow remains at an acceptable level after carotid cross-clamping will most likely be accurately detected through which of the following intraoperative monitoring device?
A. Electroencephalography (EEG)
B. Somatosensory-evoked potentials (SSEP)
C. Motor-evoked potentials (MEP)
D. Transcranial Doppler (TCD)
E. Carotid stump pressure
D. Transcranial Doppler (TCD)
Carotid stump pressure estimates ipsilateral hemispheric blood flow by directly measuring the pressure in the carotid stump distal to the clamp. What value is generally considered adequate to avoid
temporary shunt placement during CEA surgery?
A. greater than 40 to 50 mmHg
B. greater than 50 to 75 mmHg
C. greater than 10 to 15 mmHg
D.greater than 20 to 30 mmHg
A. greater than 40 to 50 mmHg
Stump pressures greater than 40 to 50 mmHg are generally considered adequate to avoid temporary shunt placement, although a critical value for stump pressure is not known.
Some patients may have adequate perfusion below values of 40 to 50
mmHg, whereas others may not have sufficient collateral flow despite maintaining stump pressure above this range.
A 60 year old male is scheduled for CEA surgery. Which of the following is INACCURATE pertaining to the perioperative anesthetic management?
A. Premedication with sedatives is generally avoided
B. Maintain hemodynamics within 20% of the patient’s baseline
C. Painful arthritis is a relative
contraindication
D. General anesthesia is maintained at a “deep” level that ensures amnesia and analgesia
E. Etomidate is contraindicated in these cases
D. General anesthesia is maintained at a “deep” level that ensures amnesia and analgesia - WRONG statement!
- General anesthesia is maintained at a “light” level that ensures amnesia but minimally interferes
with neurophysiologic monitoring. Typically, a balanced technique is favored and a variety of agents have been successfully employed. - Premedication is generally avoided if possible.
- Patient cooperation is vital
as the patient will have to lie still for the duration of the operation (inability to communicate, orthopnea, and painful arthritis are relative contraindications) and patients cannot be claustrophobic as the surgical drapes will be in close proximity to the patient’s face. - Etomidate is indicated for those patients with limited cardiac reserve.
In addition, Muscle relaxation is not mandated for this surgery.
Barash | 9th edit
Intraoperatively, which is more beneficial in CEA surgery? Hypercapnia strategy or hypocapnia strategy?
The answer is NORMOCAPNIA.
Normocapnia should be maintained during CEA. Hyperventilation may lead to cerebral vasoconstriction and decreased cerebral blood flow during critical periods of carotid cross-clamping. Hypercapnia may be equally detrimental if it leads to dilation of the cerebral vasculature in normal areas of the brain, whereas vessels in ischemic areas are already maximally dilated and are unable to further respond.
- The net effect is a “steal”
phenomenon with diversion of blood flow from hypoperfused to normal areas of the brain.
An aneurysm is defined as a greater than 50% dilation of normal expected arterial diameter; for most patients, this corresponds to an abdominal aortic diameter greater than ____
A. 3 cm
B. 1.5 cm
C. 2 cm
D. 5 cm
A. 3 cm
A 63-year-old man with a history of congestive heart failure and left ventricular dilation is scheduled for carotid endarterectomy. During carotid cross-clamping, the surgeon requests that systolic blood pressure be increased from 100 to 160 mmHg. Compared with an identical patient with normal left ventricular size, what is the effect of this change in blood pressure on this patient’s myocardial oxygen consumption?
(A) Equal decrease
(B) Greater decrease
(C) Lesser increase
(D) Equal increase
(E) Greater increase
(E) Greater increase
Intraoperative hemodynamic goals during CEA include:
- Maintain mean arterial pressure (MAP) close to baseline;
- Increase MAP during cross-clamp placement to promote contralateral cerebral blood flow through the circle of Willis;
- Decrease MAP prior to cross-clamp release to avoid hyperperfusion and intimal tear;
maintain MAP at baseline when the shunt is in place to maintain adequate perfusion.
During protamine administration following separation from cardiopulmonary bypass, blood pressure decreases from 100/70 to 60/30 mmHg and peak inspiratory pressure increases from 26 to 60 cm H2O. The most appropriate next step in management is administration of:
(A) diphenhydramine
(B) dopamine
(C) epinephrine
(D) methylprednisolone
(E) terbutaline
(C) epinephrine
- seems like allergic reaction to Protamine sulfate leading to broncospasm.
Normal PIP is 22 - 26 cmH2O. High PIP may mean broncospasm. Broncospasm increases intrathoracic pressure – > worsens the hypotension.
Which of the following results in the greatest increase in right-to-left shunting in an infant with cyanotic heart disease?
(A) Decreased pulmonary vascular resistance
(B) Decreased systemic vascular resistance
(C) Hemodilution
(D) Increased heart rate
(E) Myocardial depression
(B) Decreased systemic vascular resistance
This decrease in SVR increases right-to-left shunting, causing acidosis, worsened hypoxia, hypercarbia, and spasm of the right ventricular outflow tract.
Which of the following is ACCURATELY describing Aneurysm in terms of pathology and incidence?
A. 15% of Abdominal Aortic Aneurysms are infrarenal
B. In men, AAA exceeding 5.5 cm is a candidate for surgery
C. Acute dissections are those symptomatic patients with symptoms lasting between 5 - 7 days
D. Generally, descending aortic aneurysm is a surgical emergency
B. In men, AAA exceeding 5.5 cm is a candidate for surgery
- 85% are infrarenal
- Acute dissections are those symptomatic that is lasting less than 14 days
*ASCENDING aortic aneurysm is a SURGICAL EMERGENCY.
During repair for coarctation of the aorta in a healthy 13-year-old patient, right radial artery pressure increases from 100/60 to 105/70 mmHg after the aorta/ is CROSS CLAMPED. This most likely indicates that:
(A) collateral blood flow has decreased the hemodynamic consequences of cross-clamping
(B) left ventricular hypertrophy has decreased left ventricular compliance
(C) spinal cord blood flow is impaired
(D) the coarctation has decreased aortic diameter less than 50%
(E) the coarctation involves the origin of the right subclavian artery
(A) collateral blood flow has decreased the hemodynamic consequences of cross-clamping
A 5-month-old infant with tetralogy of Fallot is scheduled for elective inguinal herniorrhaphy. Which of the following would require the operation to be postponed?
(A) Current propranolol therapy
(B) Hematocrit of 65%
(C) History of “tet spells”
(D) Patent ductus arteriosus
(E) Room air oxygen saturation of 82%
(B) Hematocrit of 65%
ABA question | cardiac anesthesia
A 14-month-old child has tetralogy of Fallot with dynamic obstruction to right ventricular outflow. Which of the following is most likely to decrease cyanosis in this child?
(A) Calcium
(B) Epinephrine
(C) Nitroglycerin
(D) Nitroprusside
(E) Propranolol
(E) Propranolol
Which of the following physiologic changes is NOT true with aortic cross clamping?
A. Increased Arterial blood pressure above the clamp
B. Decreased Arterial blood pressure below the clamp
C. Decrease Mixed venous oxygen saturation
D. Metabolic Acidosis
C. Decrease Mixed venous oxygen saturation
THERAPEUTIC STRATEGIES (During cross clamping)
- reduce afterload and maintain a normal preload and cardiac output. Vasodilators, positive and negative
inotropic drugs, and controlled intravascular volume depletion
(i.e., phlebotomy) may be used selectively.
Which of the following hemodynamic changes is ACCURATE with aortic cross “UNCLAMPING”?
A. ↓ Myocardial contractility
B. ↓ Arterial blood pressure
C. ↓ Pulmonary artery pressure
D. ↓ Central venous pressure
E. ↓ Venous return
C. ↓ Pulmonary artery pressure - It’s the opposite
In the absence of coronary artery disease, isoflurane-induced vasodilation and tachycardia are beneficial hemodynamic goals for which of the following cardiac diseases?
(A) Aortic regurgitation
(B) Aortic stenosis
(C) Asymmetric septal hypertrophy (IHSS)
(D) Mitral stenosis
(E) Pulmonary regurgitation
(A) Aortic regurgitation
Patients with impaired ventricular function requiring supraceliac aortic cross-clamping are the most challenging. Which of the following maneuver or strategy is MOST correct to avoid abrupt and extreme stress on the heart?
A. Start Clevidipine
B. Start Sodium Nitroprusside
C. Avoid Hypercarbia and Hypoxia
D. All of the above
D. All of the above
Both afterload and preload
reduction are often required. Afterload reduction, most commonly accomplished with the use of sodium nitroprusside
or clevidipine (predominantly arteriolar dilators), is necessary
to unload the heart and reduce ventricular wall tension.
