ABSITE - Critical Care Exam
Questions and Answers37
The induction of general anesthesia in a patient with cardiac tamponade - ANSWERS -Can
interfere with a peripheral vasoconstriction and produce hypotension.
(General anesthesia causes peripheral vasodilatation instead of constriction and hypotension
may result. The slope will actually worsen if systemic vascular resistance is decreased.)
Measurement of cardiac output using the Fick principle requires - ANSWERS -- Arterial oxygen
content.
- Mixed venous oxygen content.
- Oxygen consumption.
All are potential causes of cardiogenic shock except:
- Myocardial infarction.
- Pericardial tamponade.
- Tension pneumothorax.
- Cardiac arrhythmias.
- Excessive preload. - ANSWERS -Excessive preload.
(Excessive preload is typically not a cause of cardiogenic shock, but is a result of cardiogenic
shock.)
A 60-year-old man has an arterial PO of 60 mm Hg when the calculated alveolar PO is 94 mm
Hg. This difference is most commonly due to - ANSWERS -a ventilation-perfusion mismatch
oxygen delivery and consumption - ANSWERS -- Under normal circumstances, approximately
20% to 30% of the oxygen delivered to the capillary bed is extracted by the tissues.
,- In conditions of decreased delivery of oxygen, tissues are capable of extracting up to 50% to
60% of the oxygen content in the capillary blood.
- When cellular oxygen supply does not meet demand, anaerobic respiration results.
(The variables in the equation for the delivery of oxygen are cardiac output, hemoglobin level,
oxygen saturation of hemoglobin, and the partial pressure of oxygen dissolved in blood.
Increases in the first three variables all yield significant increases in the total amount of oxygen
carried by blood. The partial pressure of oxygen is multiplied by a factor of 0.003, however, and
therefore has a miniscule contribution to the total oxygen content.)
Dopamine at doses of 5 to 10 μg/kg/min - ANSWERS -has a largely inotropic action profile
(Dopamine has a dose-dependent action profile. At 3 to 5 μg/kg/min, its actions are largely to
increase renal blood flow. At doses of 5 to 10 μg/kg/min, it largely acts to stimulate myocardial
β receptors and has an inotropic effect. At doses greater than 10 μg/kg/min, it stimulates α
receptors and has a chronotropic effect.)
As oxygen delivery increases on the flat horizontal portion of the oxygen consumption-delivery
curve - ANSWERS -Oxygen consumption remains the same
(On the flat horizontal portion of the oxygen consumption-delivery curve, oxygen delivery meets
cellular demand of oxygen; as oxygen delivery increases, oxygen consumption remains the
same.)
Most disorganized ventricular arrhythmias (frequent PVCs, ventricular fibrillation) are caused by
- ANSWERS -Metabolic derangements.
(Most disorganized ventricular arrhythmias are caused by some sort of metabolic derangement
such as ischemia or magnesium or potassium deficiencies. These abnormalities are not well
treated by antiarrhythmic medications.)
The best management for a patient with a posterior knee dislocation - ANSWERS -Arteriogram.
(The patient may have fairly normal pulses and still have an intimal injury of the popliteal artery
that is similar to the intimal disruption that can be seen in aortic isthmus injury.)
,the possible etiologies of multiorgan failure - ANSWERS -- Anticytokine antibodies have shown
therapeutic promise in animal studies.
- Evidence has shown that intestinal mucosa is made permeable by sepsis.
- The "two-hit" hypothesis postulates that after mounting an appropriate response to some
physiologic insult, the patient is left with a primed immune system which manifests an
exaggerated immune response to a second challenge.
- The early stages after injury actually appear to consist of an immediate proinflammatory state
as the organism tries to address the physiologic insult. When properly modulated, this is an
appropriate function. When overexpressed, this proinflammatory state leads to the systemic
inflammatory response syndrome. Later, anti-inflammatory and immunosuppressive
mechanisms are brought into play to bring the organism back to homeostasis. If
overmanifested, they can lead to a relative generalized immunosuppression and late incidents
of sepsis or multiorgan failure.
compensatory mechanisms in shock - ANSWERS -Antidiuretic hormone causes the reabsorption
of free water by the kidney and has vasoconstrictive properties.
(Antidiuretic hormone is released from the posterior pituitary where it stimulates free water
retention by the kidney and acts as a powerful vasoconstrictor.)
A 71-year-old man with colon cancer is in the intensive care unit following a left hemicolectomy.
His blood pressure is 72/38 mm Hg, pulse rate is 114/min, respiratory rate is 23/min, and
oxygen saturation is 94% on 2 L of oxygen by nasal cannulae. A pulmonary artery catheter
shows a central venous pressure of 8 cm H O, a pulmonary artery pressure of 22/8 mm Hg, a
pulmonary artery wedge pressure of 6 mm Hg, and a cardiac output of 3.4 L/min. The next step
in management should be the intravenous administration of - ANSWERS -a fluid bolus
pulmonary artery catheters - ANSWERS -Allow accurate approximation of left atrial pressure.
The magnitude of a left-to-right shunt in the presence of an ASD is determined by - ANSWERS -
Difference in compliance between left and right ventricles.
(The blood will tend to fill the more compliant ventricle which will usually be the right, until
chronic pulmonary hypertension yields right ventricular hypertrophy.)
, Compared to conventional ventilation (endotracheal intubation), noninvasive ventilation (mask,
continuous positive airway pressure) is - ANSWERS -contraindicated in hemodynamically
unstable patients
According to the American College of Chest Physicians/Society of Critical Care Medicine
Consensus Conference, which of the following are not part of the diagnostic criteria for sepsis? -
ANSWERS -Hypotension defined as a systolic blood pressure less than 90 mm Hg.
(Sepsis is defined as bacteriologic evidence of infection superimposed on a clinical picture of
SIRS. According to the ACCP/SCCM, by definition these patients are hemodynamically stable. If
they should become hemodynamically unstable (defined as a systolic blood pressure <90 mm
Hg), the name for the condition changes to "severe sepsis.")
SIRS - ANSWERS -- Temperature greater than 38°C or less than 36°C.
- Heart rate greater than 90 bpm.
- Respiratory rate greater than 22 bpm
- White blood cell count greater than 12,000 or less than 4,000 and greater than 10% bands.
abdominal compartment syndrome - ANSWERS -Once diagnosed, treatment consists of
reopening the abdomen including doing so at the bedside if necessary.
(The presence of an abdominal compartment syndrome requires decompression of the
abdomen. If the patient is too unstable to be transported to the operating room, the abdomen
should be promptly reopened at the bedside.)
carotid bruit - ANSWERS -a marker for generalized atherosclerosis
(In fact, studies have shown that a carotid bruit is a risk factor for coronary artery disease and
future myocardial infarction.)
alveolar ventilation - ANSWERS -The alveolar gas equation characterizes the potential for oxygen
uptake and carbon dioxide removal.
Questions and Answers37
The induction of general anesthesia in a patient with cardiac tamponade - ANSWERS -Can
interfere with a peripheral vasoconstriction and produce hypotension.
(General anesthesia causes peripheral vasodilatation instead of constriction and hypotension
may result. The slope will actually worsen if systemic vascular resistance is decreased.)
Measurement of cardiac output using the Fick principle requires - ANSWERS -- Arterial oxygen
content.
- Mixed venous oxygen content.
- Oxygen consumption.
All are potential causes of cardiogenic shock except:
- Myocardial infarction.
- Pericardial tamponade.
- Tension pneumothorax.
- Cardiac arrhythmias.
- Excessive preload. - ANSWERS -Excessive preload.
(Excessive preload is typically not a cause of cardiogenic shock, but is a result of cardiogenic
shock.)
A 60-year-old man has an arterial PO of 60 mm Hg when the calculated alveolar PO is 94 mm
Hg. This difference is most commonly due to - ANSWERS -a ventilation-perfusion mismatch
oxygen delivery and consumption - ANSWERS -- Under normal circumstances, approximately
20% to 30% of the oxygen delivered to the capillary bed is extracted by the tissues.
,- In conditions of decreased delivery of oxygen, tissues are capable of extracting up to 50% to
60% of the oxygen content in the capillary blood.
- When cellular oxygen supply does not meet demand, anaerobic respiration results.
(The variables in the equation for the delivery of oxygen are cardiac output, hemoglobin level,
oxygen saturation of hemoglobin, and the partial pressure of oxygen dissolved in blood.
Increases in the first three variables all yield significant increases in the total amount of oxygen
carried by blood. The partial pressure of oxygen is multiplied by a factor of 0.003, however, and
therefore has a miniscule contribution to the total oxygen content.)
Dopamine at doses of 5 to 10 μg/kg/min - ANSWERS -has a largely inotropic action profile
(Dopamine has a dose-dependent action profile. At 3 to 5 μg/kg/min, its actions are largely to
increase renal blood flow. At doses of 5 to 10 μg/kg/min, it largely acts to stimulate myocardial
β receptors and has an inotropic effect. At doses greater than 10 μg/kg/min, it stimulates α
receptors and has a chronotropic effect.)
As oxygen delivery increases on the flat horizontal portion of the oxygen consumption-delivery
curve - ANSWERS -Oxygen consumption remains the same
(On the flat horizontal portion of the oxygen consumption-delivery curve, oxygen delivery meets
cellular demand of oxygen; as oxygen delivery increases, oxygen consumption remains the
same.)
Most disorganized ventricular arrhythmias (frequent PVCs, ventricular fibrillation) are caused by
- ANSWERS -Metabolic derangements.
(Most disorganized ventricular arrhythmias are caused by some sort of metabolic derangement
such as ischemia or magnesium or potassium deficiencies. These abnormalities are not well
treated by antiarrhythmic medications.)
The best management for a patient with a posterior knee dislocation - ANSWERS -Arteriogram.
(The patient may have fairly normal pulses and still have an intimal injury of the popliteal artery
that is similar to the intimal disruption that can be seen in aortic isthmus injury.)
,the possible etiologies of multiorgan failure - ANSWERS -- Anticytokine antibodies have shown
therapeutic promise in animal studies.
- Evidence has shown that intestinal mucosa is made permeable by sepsis.
- The "two-hit" hypothesis postulates that after mounting an appropriate response to some
physiologic insult, the patient is left with a primed immune system which manifests an
exaggerated immune response to a second challenge.
- The early stages after injury actually appear to consist of an immediate proinflammatory state
as the organism tries to address the physiologic insult. When properly modulated, this is an
appropriate function. When overexpressed, this proinflammatory state leads to the systemic
inflammatory response syndrome. Later, anti-inflammatory and immunosuppressive
mechanisms are brought into play to bring the organism back to homeostasis. If
overmanifested, they can lead to a relative generalized immunosuppression and late incidents
of sepsis or multiorgan failure.
compensatory mechanisms in shock - ANSWERS -Antidiuretic hormone causes the reabsorption
of free water by the kidney and has vasoconstrictive properties.
(Antidiuretic hormone is released from the posterior pituitary where it stimulates free water
retention by the kidney and acts as a powerful vasoconstrictor.)
A 71-year-old man with colon cancer is in the intensive care unit following a left hemicolectomy.
His blood pressure is 72/38 mm Hg, pulse rate is 114/min, respiratory rate is 23/min, and
oxygen saturation is 94% on 2 L of oxygen by nasal cannulae. A pulmonary artery catheter
shows a central venous pressure of 8 cm H O, a pulmonary artery pressure of 22/8 mm Hg, a
pulmonary artery wedge pressure of 6 mm Hg, and a cardiac output of 3.4 L/min. The next step
in management should be the intravenous administration of - ANSWERS -a fluid bolus
pulmonary artery catheters - ANSWERS -Allow accurate approximation of left atrial pressure.
The magnitude of a left-to-right shunt in the presence of an ASD is determined by - ANSWERS -
Difference in compliance between left and right ventricles.
(The blood will tend to fill the more compliant ventricle which will usually be the right, until
chronic pulmonary hypertension yields right ventricular hypertrophy.)
, Compared to conventional ventilation (endotracheal intubation), noninvasive ventilation (mask,
continuous positive airway pressure) is - ANSWERS -contraindicated in hemodynamically
unstable patients
According to the American College of Chest Physicians/Society of Critical Care Medicine
Consensus Conference, which of the following are not part of the diagnostic criteria for sepsis? -
ANSWERS -Hypotension defined as a systolic blood pressure less than 90 mm Hg.
(Sepsis is defined as bacteriologic evidence of infection superimposed on a clinical picture of
SIRS. According to the ACCP/SCCM, by definition these patients are hemodynamically stable. If
they should become hemodynamically unstable (defined as a systolic blood pressure <90 mm
Hg), the name for the condition changes to "severe sepsis.")
SIRS - ANSWERS -- Temperature greater than 38°C or less than 36°C.
- Heart rate greater than 90 bpm.
- Respiratory rate greater than 22 bpm
- White blood cell count greater than 12,000 or less than 4,000 and greater than 10% bands.
abdominal compartment syndrome - ANSWERS -Once diagnosed, treatment consists of
reopening the abdomen including doing so at the bedside if necessary.
(The presence of an abdominal compartment syndrome requires decompression of the
abdomen. If the patient is too unstable to be transported to the operating room, the abdomen
should be promptly reopened at the bedside.)
carotid bruit - ANSWERS -a marker for generalized atherosclerosis
(In fact, studies have shown that a carotid bruit is a risk factor for coronary artery disease and
future myocardial infarction.)
alveolar ventilation - ANSWERS -The alveolar gas equation characterizes the potential for oxygen
uptake and carbon dioxide removal.
