SEE EXAM LATEST
1. A 55-year-old woman with a history of congenital long QT syndrome
is undergoing a hysteroscopy for abnormal uterine bleeding. She had
uneventful induction of general anesthesia but after paracervical block
with lidocaine develops ventricular tachycardia with morphological
appearance of torsades de pointe. Which of the following medications
should be AVOIDED in the treatment of her arrhythmia?
• Amiodarone
• Calcium chloride
• Esmolol
• Magnesium sulfate - ANSWERS-60. Amiodarone. Congenital long QT
syndrome may occur in conjunction with other hereditary syndromes,
such as Jervell, Lange-Nielsen or Romano-Ward syndrome, or acquired
as a result of pharmacologic or metabolic etiologies. It is an issue of
cellular repolarization which precipitates tachyarrhythmias, most
commonly polymorphic ventricular tachycardia or torsades de pointe.
There are multiple subtypes that affect both potassium and/or sodium
channels. The arrhythmias may be precipitated by sympathetic
activation, auditory stimuli or at rest. Family history may be positive for
sudden cardiac death and the ECG significant for prolonged corrected
QT interval > 430ms or bizarre odd-appearing T waves. Treatment
includes magnesium for arrhythmias, possible permanent pacemaker, or
beta blockers for subtypes 1 and 2, but amiodarone is considered
contraindicated as it prolongs the QT interval.
END OF
PAGE
1
, SEE EXAM LATEST
2. A 76-year-old man is scheduled for a hemicolectomy. His past
medical history is significant for third degree heart block treated with a
permanent pacemaker. Problems with electrocautery use in this patient
can be minimized by:
• placing the grounding pad near the pacemaker
• using infrequent bursts of longer duration
• the use of a bipolar cautery
• reducing the surface area of the return electrode - ANSWERS-59. the
use of a bipolar cautery. Electrical interference from the electrocautery
can be interpreted by the pacemaker as myocardial activity and suppress
pacemaker activity. These problems can be minimized by limiting use to
short bursts, placing the grounding pad as far from the pacemaker as
possible and using a bipolar cautery.
3. A 35-year-old woman who underwent orthotopic heart transplantation
2 years ago for nonischemic cardiomyopathy presents after a motor
vehicle accident for exploratory laparotomy under general anesthesia.
Intraoperatively, her blood pressure is 75/35 mmHg and heart rate is 90
bpm. After the administration of phenylephrine, which of the following
hemodynamic responses do you MOST expect?
• HR decreased, BP increased
• HR decreased, BP no change
END OF
PAGE
2
, SEE EXAM LATEST
• HR no change, BP increased
• HR no change, BP no change - ANSWERS-58. HR no change, BP
increased. After heart transplantation, the heart is completely
denervated. The normal resting heart rate is relatively tachycardic at 90-
100 bpm due to lack of vagal tone. Vagal bradycardic responses (to
laryngoscopy, hypertension, carotid sinus massage) will also be absent.
Over time, however, many patients require permanent pacemaker
placement for treatment of significant bradycardia. After heart
transplant, patients are not able to respond to demands for increased
cardiac output with increased heart rate. Thus in this situation of a
trauma with potentially significant blood loss, a normal patient would
have tachycardia but a heart transplant patient has no change in heart
rate, only hypotension. Instead for heart transplant patients, cardiac
output is augmented by increased stroke volume. For this reason it is
important to maintain adequate intravascular volume. The transplanted
heart is not able to respond to medications that block the
parasympathetic system. Bradycardia and hypotension have to be treated
with medications that have a direct effect such as epinephrine and
isoproterenol. Phenylephrine will result in increased blood pressure, but
no change in heart rate. Indirect and mixed indirect/direct-acting drugs
have minimal effect or have the effect of their direct components.
4. The postretrobulbar block apnea syndrome:
• is likely secondary to intravascular injection
• most commonly occurs during or immediately after injection
END OF
PAGE
3
, SEE EXAM LATEST
• is associated with unconsciousness
• carries a high morbidity and mortality - ANSWERS-57. is associated
with unconsciousness. The postretrobulbar block apnea syndrome is
probably due to injection of local anesthetic into the optic nerve sheath,
with spread into the CSF. The CNS is exposed to high concentrations of
local anesthetic leading to apprehension and unconsciousness. Apnea
occurs within 20 minutes and resolves within an hour. Treatment is
supportive.
5. A 75-year-old man is undergoing a mitral valve replacement via
cardiopulmonary bypass. The perfusionist is running bypass flows at >
2.5 liters/minute/m2. Which of the following is the MOST likely adverse
consequence of undergoing cardiopulmonary bypass at increased flow
rates?
• Increased trauma to blood elements
• Increased hypothermia
• Decreased blood flow to the brain
• Decreased myocardial blood flow - ANSWERS-56. A. Increased
trauma to blood component: Cardiopulmonary bypass (CPB) does the
work of the heart and lungs in order to isolate those organs from blood
flow such that surgery on the heart can occur in a relatively bloodless
fashion. Thus, the CPB circuit must oxygenate and ventilate the blood
and then deliver the oxygenated blood back to the body and end organs.
END OF
PAGE
4
1. A 55-year-old woman with a history of congenital long QT syndrome
is undergoing a hysteroscopy for abnormal uterine bleeding. She had
uneventful induction of general anesthesia but after paracervical block
with lidocaine develops ventricular tachycardia with morphological
appearance of torsades de pointe. Which of the following medications
should be AVOIDED in the treatment of her arrhythmia?
• Amiodarone
• Calcium chloride
• Esmolol
• Magnesium sulfate - ANSWERS-60. Amiodarone. Congenital long QT
syndrome may occur in conjunction with other hereditary syndromes,
such as Jervell, Lange-Nielsen or Romano-Ward syndrome, or acquired
as a result of pharmacologic or metabolic etiologies. It is an issue of
cellular repolarization which precipitates tachyarrhythmias, most
commonly polymorphic ventricular tachycardia or torsades de pointe.
There are multiple subtypes that affect both potassium and/or sodium
channels. The arrhythmias may be precipitated by sympathetic
activation, auditory stimuli or at rest. Family history may be positive for
sudden cardiac death and the ECG significant for prolonged corrected
QT interval > 430ms or bizarre odd-appearing T waves. Treatment
includes magnesium for arrhythmias, possible permanent pacemaker, or
beta blockers for subtypes 1 and 2, but amiodarone is considered
contraindicated as it prolongs the QT interval.
END OF
PAGE
1
, SEE EXAM LATEST
2. A 76-year-old man is scheduled for a hemicolectomy. His past
medical history is significant for third degree heart block treated with a
permanent pacemaker. Problems with electrocautery use in this patient
can be minimized by:
• placing the grounding pad near the pacemaker
• using infrequent bursts of longer duration
• the use of a bipolar cautery
• reducing the surface area of the return electrode - ANSWERS-59. the
use of a bipolar cautery. Electrical interference from the electrocautery
can be interpreted by the pacemaker as myocardial activity and suppress
pacemaker activity. These problems can be minimized by limiting use to
short bursts, placing the grounding pad as far from the pacemaker as
possible and using a bipolar cautery.
3. A 35-year-old woman who underwent orthotopic heart transplantation
2 years ago for nonischemic cardiomyopathy presents after a motor
vehicle accident for exploratory laparotomy under general anesthesia.
Intraoperatively, her blood pressure is 75/35 mmHg and heart rate is 90
bpm. After the administration of phenylephrine, which of the following
hemodynamic responses do you MOST expect?
• HR decreased, BP increased
• HR decreased, BP no change
END OF
PAGE
2
, SEE EXAM LATEST
• HR no change, BP increased
• HR no change, BP no change - ANSWERS-58. HR no change, BP
increased. After heart transplantation, the heart is completely
denervated. The normal resting heart rate is relatively tachycardic at 90-
100 bpm due to lack of vagal tone. Vagal bradycardic responses (to
laryngoscopy, hypertension, carotid sinus massage) will also be absent.
Over time, however, many patients require permanent pacemaker
placement for treatment of significant bradycardia. After heart
transplant, patients are not able to respond to demands for increased
cardiac output with increased heart rate. Thus in this situation of a
trauma with potentially significant blood loss, a normal patient would
have tachycardia but a heart transplant patient has no change in heart
rate, only hypotension. Instead for heart transplant patients, cardiac
output is augmented by increased stroke volume. For this reason it is
important to maintain adequate intravascular volume. The transplanted
heart is not able to respond to medications that block the
parasympathetic system. Bradycardia and hypotension have to be treated
with medications that have a direct effect such as epinephrine and
isoproterenol. Phenylephrine will result in increased blood pressure, but
no change in heart rate. Indirect and mixed indirect/direct-acting drugs
have minimal effect or have the effect of their direct components.
4. The postretrobulbar block apnea syndrome:
• is likely secondary to intravascular injection
• most commonly occurs during or immediately after injection
END OF
PAGE
3
, SEE EXAM LATEST
• is associated with unconsciousness
• carries a high morbidity and mortality - ANSWERS-57. is associated
with unconsciousness. The postretrobulbar block apnea syndrome is
probably due to injection of local anesthetic into the optic nerve sheath,
with spread into the CSF. The CNS is exposed to high concentrations of
local anesthetic leading to apprehension and unconsciousness. Apnea
occurs within 20 minutes and resolves within an hour. Treatment is
supportive.
5. A 75-year-old man is undergoing a mitral valve replacement via
cardiopulmonary bypass. The perfusionist is running bypass flows at >
2.5 liters/minute/m2. Which of the following is the MOST likely adverse
consequence of undergoing cardiopulmonary bypass at increased flow
rates?
• Increased trauma to blood elements
• Increased hypothermia
• Decreased blood flow to the brain
• Decreased myocardial blood flow - ANSWERS-56. A. Increased
trauma to blood component: Cardiopulmonary bypass (CPB) does the
work of the heart and lungs in order to isolate those organs from blood
flow such that surgery on the heart can occur in a relatively bloodless
fashion. Thus, the CPB circuit must oxygenate and ventilate the blood
and then deliver the oxygenated blood back to the body and end organs.
END OF
PAGE
4
