Question Set 2 Flashcards
Pathophysiologic changes associated with liver disease include: (Select 2)
A: increased cardiac output
B: increased systemic vascular resistance
C: increased mean blood pressure
D: sodium-losing nephropathy
E: hyperkalemia
F: arterial hypoxemia
A: increased cardiac output, F: arterial hypoxemia
Arterio-venous shunting, resulting from advanced liver disease, results in a decrease in systemic vascular resistance, a decrease in blood pressure and an increase in cardiac output. Arterial hypoxemia is common in patients with advanced liver disease and appears to be the result of ascites, hepatic hydrothorax and widespread pulmonary vasodilation.
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In the graph of cerebral blood flow below, PaCO2 would best be represented by curve:
A
B
C
D
Curve B best represents the effects of changing carbon dioxide tensions on cerebral blood flow. Between the ranges of 20 to 80 mm Hg a linear relationship exists between PaCO2 and CBF, such that a change in PaCO2 from 30 to 60 mm Hg will double CBF.
Clinically significant histamine release has been associated with the use of:
A: vecuronium
B: rocuronium
C: cisatracurium
D: atracurium
D: atracurium
Atracurium has been associated with histamine release from mast cells and can result in bronchospasm, skin flushing and hypotension.
Pathophysiologic changes associated with metabolic alkalosis include: (Select 2)
A: compensatory hyperventilaton
B: hypokalemia
C: reduced tissue oxygen availability
D: ionized hypercalcemia
E: decreased digoxin effect
F: arterial hypoxemia
B: hypokalemia
C: reduced tissue oxygen availability
Metabolic alkalosis is associated with hypokalemia, ionized hypocalcemia, secondary ventricular arrhythmias, increased digoxin toxicity, and compensatory hypoventilation (hypercarbia). Alkalemia may reduce tissue oxygen availability by shifting the oxyhemoglobin dissociation curve to the left and by decreasing cardiac output.
The purpose of the ductus venosus in fetal circulation is to:
A: allow umbilical vein blood to bypass the liver
B: allow umbilical artery blood to bypass the liver
C: bypass the pulmonary circulation
D: divert portal vein blood to the placenta
B: allow umbilical vein blood to bypass the liver
Up to 50% of the umbilical vein blood can pass directly into the inferior vena cava, bypassing the liver, through the ductus venosus. The remainder mixes with blood from the portal vein and passes through the liver prior to returning to the heart.
Highly specific preoperative screening tests have a:
A: low incidence of false-positives results
B: low incidence of false-negative results
C: result that is specific for one pathologic process
D: low sensitivity
A: low incidence of false-positives results
The usefulness of a screening test depends on its sensitivity and specificity. Sensitive tests have a low rate of false-negative results, whereas specific tests have a low rate of false-positive results.
In the flow-volume loops below, chronic obstructive pulmonary disease is best represented by:
A
B
C
D
A:
Obstructive disease is best represented by flow-volume loop A, which demonstrates increased FRC and TLC with decreased expiratory flow.
Serotonin has vasodilatory properties in the: (Select 2)
renal vasculature
hepatic vasculature
skeletal muscle vasculature
pulmonary vasculature
coronary vasculature
skeletal muscle vasculature
coronary vasculature
Serotonin is a vasoconstrictor in most vascular beds, but has vasodilatory properties in the vasculature of the heart and skeletal muscle.
Drugs that bind to the proton pump of gastric parietal cell and inhibit hydrogen ion secretion include:
A: ranitidine
B: cimetadine
C: famotidine
D: omeprazole
D: omeprazole
Omeprazole (Prilosec) inhibits the proton pump of the parietal cells of the gastric mucosa, decreases hydrogen ion secretion and increase pH. Cimetidine, ranitidine and famotidine also increase gastric pH, however their mechanism is through blockade of the H2 receptor.
Drugs that inhibit coagulation through direct inhibition of thrombin include:
A: heparin
B: warfarin
C: bivalirudin
D: aprotonin
C: bivalirudin
Bivalirudin, hirudin, lepirudin and argatroban are anticoagulants that directly inhibit thrombin. These agents are most commonly used for cardiopulmonary bypass when heparin is contraindicated. No specific reversal agent is available and termination of effect occurs as a result of renal elimination of the drug.
Enoxaparin:
A: causes less platelet inhibition than heparin
B: is easily reversed with protamine
C: has a half-life that is 35% less than that of heparin
D: effects are monitored using the INR
A: causes less platelet inhibition than heparin
Low molecular weight heparins (LMWH), such as enoxaparin, have greater activity against factor Xa than thrombin. As a result, the INR is not a reliable monitoring tool. The LMWHs cause less platelet inhibition and are associated with a lesser incidence of heparin induced thrombocytopenia.
Termination of the effects of succinylcholine at the neuromuscular junction occurs as a result of:
A: succinylcholine hydrolysis by acetylcholinesterase
B: diffusion of succinylcholine away from the receptors
C: succinylcholine hydrolysis by hepatic esterases
D: the competition of succinylcholine with acetylcholine
B: diffusion of succinylcholine away from the receptors
Because depolarizing muscle relaxants are not metabolized by acetylcholinesterase, they diffuse away from the neuromuscular junction and are hydrolyzed in the plasma by pseudocholinesterase.
Signs of cardiac tamponade include: (Select 2)
A: distended neck veins
B: increased QRS voltage seen on ECG
C: decreased central venous pressure
D: bradycardia
E: systemic vasoconstriction
F: an increase in systolic blood pressure during inspiration
A: distended neck veins
E: systemic vasoconstriction
Cardiac tamponade is indicated by the presence of neck vein distention, hypotension, muffled heart sounds (Beck’s triad) and a greater than 10 mm Hg decline in blood pressure during spontaneous inspiration (pulsus paradoxus). Tachycardia and systemic vasoconstriction are present to maintain blood pressure with the associated decreased stroke volume.
Type I pneumocytes:
A: prevent the passage of albumin into the alveolus
B: are more numerous than Type II pneumocytes
C: produce surfactant
D: are capable of rapid cell division
A: prevent the passage of albumin into the alveolus
Type I pneumocytes are flat and form a tight junction with one another. This prevents the passage of oncotic molecules, such as albumin, into the alveolus. Type II pneumocytes are smaller, but more numerous, and produce surfactant. Unlike Type I pneumocytes, Type II pneumocytes are capable of cell division and can produce Type I pneumocytes when needed.
