CCRN QUESTIONS AND ANSWERS
A patient has had a large anterior myocardial infarction last month and developed a ventricular
aneurysm. He now has episodes of ventricular tachycardia that are not prevented or converted with
ant dysrhythmic agents. An implantable cardioverter-defibrillator (ICD) is implanted. Four days after
surgery he develops ventricular tachycardia. The ICD has delivered three shocks but has not
converted the rhythm. He is pulseless and apneic. Cardiopulmonary resuscitation is in progress.
What is the priority action now?
A.
Administer epinephrine IV.
B.
Administer amiodarone.
C.
Defibrillate.
D.
Reset the ICD. Correct Answers: Defibrillate
A 28-year-old woman is admitted to the critical care unit from the emergency department with a
diagnosis of asthma. Her initial arterial blood gases on a 28% Venturi mask are as follows:
pH 7.48
PaCO2 30 mm Hg
HCO3 24 mEq/L
PaO2 64 mm Hg
Which of the following repeat arterial blood gases on 40% oxygen indicate that the patient's condition
is worsening?
A.
pH 7.48, PaCO2 30 mm Hg, PaO2 68 mm Hg
B.
pH 7.46, PaCO2 32 mm Hg, PaO2 61 mm Hg
C.
pH 7.40, PaCO2 40 mm Hg, PaO2 62 mm Hg
D.
pH 7.39, PaCO2 30 mm Hg, PaO2 60 mm Hg Correct Answers: C.
pH 7.40, PaCO2 40 mm Hg, PaO2 62 mm Hg
The case study shows stage II asthma. Option c shows stage III asthma. The patient is still breathing
at a fast rate, but carbon dioxide is starting to be retained as evidenced by the increase of the PaCO2
into normal range. Options a and b are still stage II. Option d shows a respiratory alkalosis with a
,metabolic acidosis because you would have expected the pH to be in an alkalotic range with the
PaCO2 of 30.
A patient experiencing alcohol withdrawal syndrome describes the swirls in the wallpaper as being
worms. This is an example of which of the following?
A.
Delusion
B.
Hallucination
C.
Illusion
D.
Visual impairment Correct Answers: C.
Illusion
An illusion is a misperception or misinterpretation of an actual external stimulus. Illusions and
hallucinations (a perception that has no actual external stimulus) are common during alcohol
withdrawal syndrome.
A patient arrives in the emergency department with multiple gunshot wounds. He requires massive
transfusion for blood loss from chest and abdominal wounds. The electrocardiogram should be
observed closely for changes indicative of which of the following?
A.
Atrioventricular block
B.
Hyperkalemia
C.
Hypercalcemia
D.
Hypomagnesemia Correct Answers: Hyperkalemia
Banked blood is high in potassium because of hemolysis. Look for tall, peaked T waves and widening
of the QRS complex. Other considerations with massive transfusion of banked blood are
hypocalcemia, hypothermia, and decreased tissue oxygen delivery caused by decreased levels of
2,3-diphosphoglycerate.
A 65-year-old woman reports severe dyspnea 2 days after abdominal surgery. She is transferred to
the critical care unit. On 5 L of oxygen by nasal cannula, her arterial blood gases are as follows:
pH 7.39
PaCO2 35 mm Hg
HCO3 19 mEq/L
, PaO2 40 mm Hg
Arterial oxygen saturation 75%
Why does this patient have hypoxemia without hypercapnia?
A.
Because carbon dioxide is more diffusible than oxygen
B.
Because carbon dioxide has more driving pressure
C.
Because carbon dioxide is less diffusible than oxygen
D.
Because carbon dioxide excretion by the kidney is increased Correct Answers: Because carbon
dioxide is more diffusible than oxygen
Carbon dioxide is 20 times more diffusible than oxygen. In conditions that affect diffusion but do not
affect ventilation, expect the PaO2 to be decreased and the PaCO2 to be normal (or decreased in
hyperventilation, as in this patient). If ventilation were affected, such as if this patient were fatiguing,
the PaCO2 then would increase. Driving pressure is the fraction of the gas in inspired air multiplied by
the barometric pressure. Because carbon dioxide is ~0.5% of inspired air, the driving pressure would
be very low. The kidney eliminates bicarbonate and hydrogen ions, but the lungs eliminate carbon
dioxide.
A 55-year-old patient has headache, nuchal rigidity, photophobia, and positive Kernig's and
Brudzinski's signs. These are consistent with which of the following?
A.
Intracranial hemorrhage
B.
Subarachnoid hemorrhage
C.
Epidural hemorrhage
D.
Subdural hemorrhage Correct Answers: Subarachnoid hemorrhage
When there is bleeding from an aneurysm, that blood irritates the meninges. The clinical presentation
is very similar to meningitis. This clinical presentation is not consistent with intracranial, epidural, or
subdural bleeding because the blood is not in contact with the meninges in those situations.
An extra heart sound preceding S1 is most likely an S4 if the stethoscope's:
A.
diaphragm is over the apex.
A patient has had a large anterior myocardial infarction last month and developed a ventricular
aneurysm. He now has episodes of ventricular tachycardia that are not prevented or converted with
ant dysrhythmic agents. An implantable cardioverter-defibrillator (ICD) is implanted. Four days after
surgery he develops ventricular tachycardia. The ICD has delivered three shocks but has not
converted the rhythm. He is pulseless and apneic. Cardiopulmonary resuscitation is in progress.
What is the priority action now?
A.
Administer epinephrine IV.
B.
Administer amiodarone.
C.
Defibrillate.
D.
Reset the ICD. Correct Answers: Defibrillate
A 28-year-old woman is admitted to the critical care unit from the emergency department with a
diagnosis of asthma. Her initial arterial blood gases on a 28% Venturi mask are as follows:
pH 7.48
PaCO2 30 mm Hg
HCO3 24 mEq/L
PaO2 64 mm Hg
Which of the following repeat arterial blood gases on 40% oxygen indicate that the patient's condition
is worsening?
A.
pH 7.48, PaCO2 30 mm Hg, PaO2 68 mm Hg
B.
pH 7.46, PaCO2 32 mm Hg, PaO2 61 mm Hg
C.
pH 7.40, PaCO2 40 mm Hg, PaO2 62 mm Hg
D.
pH 7.39, PaCO2 30 mm Hg, PaO2 60 mm Hg Correct Answers: C.
pH 7.40, PaCO2 40 mm Hg, PaO2 62 mm Hg
The case study shows stage II asthma. Option c shows stage III asthma. The patient is still breathing
at a fast rate, but carbon dioxide is starting to be retained as evidenced by the increase of the PaCO2
into normal range. Options a and b are still stage II. Option d shows a respiratory alkalosis with a
,metabolic acidosis because you would have expected the pH to be in an alkalotic range with the
PaCO2 of 30.
A patient experiencing alcohol withdrawal syndrome describes the swirls in the wallpaper as being
worms. This is an example of which of the following?
A.
Delusion
B.
Hallucination
C.
Illusion
D.
Visual impairment Correct Answers: C.
Illusion
An illusion is a misperception or misinterpretation of an actual external stimulus. Illusions and
hallucinations (a perception that has no actual external stimulus) are common during alcohol
withdrawal syndrome.
A patient arrives in the emergency department with multiple gunshot wounds. He requires massive
transfusion for blood loss from chest and abdominal wounds. The electrocardiogram should be
observed closely for changes indicative of which of the following?
A.
Atrioventricular block
B.
Hyperkalemia
C.
Hypercalcemia
D.
Hypomagnesemia Correct Answers: Hyperkalemia
Banked blood is high in potassium because of hemolysis. Look for tall, peaked T waves and widening
of the QRS complex. Other considerations with massive transfusion of banked blood are
hypocalcemia, hypothermia, and decreased tissue oxygen delivery caused by decreased levels of
2,3-diphosphoglycerate.
A 65-year-old woman reports severe dyspnea 2 days after abdominal surgery. She is transferred to
the critical care unit. On 5 L of oxygen by nasal cannula, her arterial blood gases are as follows:
pH 7.39
PaCO2 35 mm Hg
HCO3 19 mEq/L
, PaO2 40 mm Hg
Arterial oxygen saturation 75%
Why does this patient have hypoxemia without hypercapnia?
A.
Because carbon dioxide is more diffusible than oxygen
B.
Because carbon dioxide has more driving pressure
C.
Because carbon dioxide is less diffusible than oxygen
D.
Because carbon dioxide excretion by the kidney is increased Correct Answers: Because carbon
dioxide is more diffusible than oxygen
Carbon dioxide is 20 times more diffusible than oxygen. In conditions that affect diffusion but do not
affect ventilation, expect the PaO2 to be decreased and the PaCO2 to be normal (or decreased in
hyperventilation, as in this patient). If ventilation were affected, such as if this patient were fatiguing,
the PaCO2 then would increase. Driving pressure is the fraction of the gas in inspired air multiplied by
the barometric pressure. Because carbon dioxide is ~0.5% of inspired air, the driving pressure would
be very low. The kidney eliminates bicarbonate and hydrogen ions, but the lungs eliminate carbon
dioxide.
A 55-year-old patient has headache, nuchal rigidity, photophobia, and positive Kernig's and
Brudzinski's signs. These are consistent with which of the following?
A.
Intracranial hemorrhage
B.
Subarachnoid hemorrhage
C.
Epidural hemorrhage
D.
Subdural hemorrhage Correct Answers: Subarachnoid hemorrhage
When there is bleeding from an aneurysm, that blood irritates the meninges. The clinical presentation
is very similar to meningitis. This clinical presentation is not consistent with intracranial, epidural, or
subdural bleeding because the blood is not in contact with the meninges in those situations.
An extra heart sound preceding S1 is most likely an S4 if the stethoscope's:
A.
diaphragm is over the apex.
