MKSAP 17 Pulmonary and Critical Care
Medicine UPDATED ACTUAL Exam
Questions and CORRECT Answers
What FEV1/FVC ratio on spirometry is consistent with airflow obstruction? - CORRECT
ANSWER - 70%
What is used to characterize the degree of obstruction? - CORRECT ANSWER - the
degree of reduction in FEV1
What is considered moderately reduced FEV1? - CORRECT ANSWER - 50-80%
What is considered severely reduced FEV1? - CORRECT ANSWER - 34-49%
What is considered very severely reduced FEV1? - CORRECT ANSWER - less than 34%
In patients with obstruction, what additional test on spirometry should be performed? -
CORRECT ANSWER - bronchodilator challenge (2-4 puffs of a short acting B2 agonist)
which helps differentiate between asthma and COPD
What is considered a positive bronchodilator response? - CORRECT ANSWER - an
increase in FEV1 of 12% or 200ml
What does a normal FEV1/FVC ratio reflex? - CORRECT ANSWER - normal lung
function or may indicate a restrictive lung defect
however, if the FEV1 and FVC are reduced proportionately with each other and are below the
predicted normal values, the spirometry results are consistent with a restrictive defect, which
may be confirmed by further testing demonstrating low lung volumes
,In patients with clinical symptoms suggestive of bronchospastic disease (such as cough or
unexplained dyspnea) but with normal spirometry, what test may be diagnostically helpful? -
CORRECT ANSWER - bronchial challenge testing (methacholine)
uses a controlled inhaled stimulus to induce bronchospasm in association with spirometry; a
positive test is indicated by a drop in the measured FEV1
PD20 (provocative dose 20%) is the dose of methacholine that causes a significant drop in the
FEV1 of 20% or greater; the ability to achieve a PD20 at low concentrations of methacholine
indicates more easily induced obstruction and is sensitive for detecting asthma
similar principles apply to other forms of bronchial challenge testing, such as exposure to cold
air or exercise, in which case a 10% drop in FEV1 from baseline in the context of a supporting
clinical picture is diagnostic
What measurement on spirmoetry can determine whether restriction is due to a primary
parenchymal process or chest cage restriction from factors such as obesity, muscle weakness, or
scoliosis? - CORRECT ANSWER - TLC
What will TLC and RV be in obstructive lung diseases? - CORRECT ANSWER - elevated
TLC is suggestive of hyperinflation and high compliance
increased RV is suggestive of air trapping
What will the flow volume loop look like in asthma? - CORRECT ANSWER - reduction
in peak expiratory flow and concave curvature for the expiratory limb while the inspiratory limb
remain normal; significant change is seen after bronchodilator response
What does the flow volume loop look like in COPD? - CORRECT ANSWER - significant
reduction in peak expiratory flow and concave appearance of the expiratory limb; no significant
change is seen after bronchodilator response
,What does the flow volume loop look like in fixed obstruction/tracheal stenosis? - CORRECT
ANSWER - flattening of the peak inspiratory and expiratory flows
How is the diffusing capacity for carbon monoxide performed? - CORRECT ANSWER -
having the patient take a single, deep breath containing a very low percentage of carbon
monoxide and measuring the amount of subsequently exhaled carbon monoxide following a
short period of breath holding
carbon monoxide is rapidly and efficiently taken up by hemoglobin, and the amount absorbed is
determined by the amount of blood recruited to the pulmonary alveolar capillary bed and the
surface area available for diffusion
What is DLCO useful for measuring? - CORRECT ANSWER - the capacity for gas
transfer through the alveolar-capillary membrane
What clinical disorders can elevate DLCO levels? - CORRECT ANSWER - clinical
disorders that recruit blood to the alveoli (cardiac shunt, asthma, erythrocytosis, alveolar
hemorrhage)
What clinical disorders can reduce DLCO? - CORRECT ANSWER - conditions that
decrease permeability across the alveolar-capillary membrane, or otherwise interfere with gas
transfer
for example: a reduced DLCO in a patient with a low TLC or restriction on spirometry is
suggestive of a parenchymal or interstitial process
DLCO may also be diminisehd in COPD (from parenchymal destruction) or in conditions that
affect the pulmonary vasculature such as pulmonary HTN or chronic pulmonary thromboembolic
disease
What test is useful to assess diability and prognosis in chronic lung conditions? - CORRECT
ANSWER - 6 minute walk test (6MWT)
, simple pulse ox and oxygen desaturation studies performed at rest and with exertion assess the
need for oxygen supplementation
O2 sat, HR, dyspnea and fatigue level, and distance walked at a normal pace in 6 minutes are
recorded; this relatively simple maneuver quantifies exercise tolerance, determines effective
interventions, and helps predict morbidity and mortality
this test is commonly used before, during, and after pulmonary rehab programs
What is pulse oximetry? - CORRECT ANSWER - noninvasive measurement of arterial
hemoglobin saturation
2 light emitting diodes and a photodetector that measures the pulsatile fraction of hemoglobin
and algorithmically estimates the arterial hemoglobin saturation
in general, resting oxygen saturation less than or equal to 95% or a desaturation with exercise
greater than or equal to 5% is considered abnormal
What can falsely elevated pulse ox levels? - CORRECT ANSWER - carboxyhemoglobin
(the pulse ox cannot distinguish oxygen bound or cabon monoxide)
if the presence of carboxyhemoglobin is suspected, co-oximetry is the preferred test to measure
oxyhemoglobin
***also painted nails***
What is the equivalent daytime radiation of a PA/lateral radiograph? - CORRECT
ANSWER - 10 days
What is the equivalent daytime radiation of a routine CT? Equivalent number of chest
radiographs? - CORRECT ANSWER - 3 years
Medicine UPDATED ACTUAL Exam
Questions and CORRECT Answers
What FEV1/FVC ratio on spirometry is consistent with airflow obstruction? - CORRECT
ANSWER - 70%
What is used to characterize the degree of obstruction? - CORRECT ANSWER - the
degree of reduction in FEV1
What is considered moderately reduced FEV1? - CORRECT ANSWER - 50-80%
What is considered severely reduced FEV1? - CORRECT ANSWER - 34-49%
What is considered very severely reduced FEV1? - CORRECT ANSWER - less than 34%
In patients with obstruction, what additional test on spirometry should be performed? -
CORRECT ANSWER - bronchodilator challenge (2-4 puffs of a short acting B2 agonist)
which helps differentiate between asthma and COPD
What is considered a positive bronchodilator response? - CORRECT ANSWER - an
increase in FEV1 of 12% or 200ml
What does a normal FEV1/FVC ratio reflex? - CORRECT ANSWER - normal lung
function or may indicate a restrictive lung defect
however, if the FEV1 and FVC are reduced proportionately with each other and are below the
predicted normal values, the spirometry results are consistent with a restrictive defect, which
may be confirmed by further testing demonstrating low lung volumes
,In patients with clinical symptoms suggestive of bronchospastic disease (such as cough or
unexplained dyspnea) but with normal spirometry, what test may be diagnostically helpful? -
CORRECT ANSWER - bronchial challenge testing (methacholine)
uses a controlled inhaled stimulus to induce bronchospasm in association with spirometry; a
positive test is indicated by a drop in the measured FEV1
PD20 (provocative dose 20%) is the dose of methacholine that causes a significant drop in the
FEV1 of 20% or greater; the ability to achieve a PD20 at low concentrations of methacholine
indicates more easily induced obstruction and is sensitive for detecting asthma
similar principles apply to other forms of bronchial challenge testing, such as exposure to cold
air or exercise, in which case a 10% drop in FEV1 from baseline in the context of a supporting
clinical picture is diagnostic
What measurement on spirmoetry can determine whether restriction is due to a primary
parenchymal process or chest cage restriction from factors such as obesity, muscle weakness, or
scoliosis? - CORRECT ANSWER - TLC
What will TLC and RV be in obstructive lung diseases? - CORRECT ANSWER - elevated
TLC is suggestive of hyperinflation and high compliance
increased RV is suggestive of air trapping
What will the flow volume loop look like in asthma? - CORRECT ANSWER - reduction
in peak expiratory flow and concave curvature for the expiratory limb while the inspiratory limb
remain normal; significant change is seen after bronchodilator response
What does the flow volume loop look like in COPD? - CORRECT ANSWER - significant
reduction in peak expiratory flow and concave appearance of the expiratory limb; no significant
change is seen after bronchodilator response
,What does the flow volume loop look like in fixed obstruction/tracheal stenosis? - CORRECT
ANSWER - flattening of the peak inspiratory and expiratory flows
How is the diffusing capacity for carbon monoxide performed? - CORRECT ANSWER -
having the patient take a single, deep breath containing a very low percentage of carbon
monoxide and measuring the amount of subsequently exhaled carbon monoxide following a
short period of breath holding
carbon monoxide is rapidly and efficiently taken up by hemoglobin, and the amount absorbed is
determined by the amount of blood recruited to the pulmonary alveolar capillary bed and the
surface area available for diffusion
What is DLCO useful for measuring? - CORRECT ANSWER - the capacity for gas
transfer through the alveolar-capillary membrane
What clinical disorders can elevate DLCO levels? - CORRECT ANSWER - clinical
disorders that recruit blood to the alveoli (cardiac shunt, asthma, erythrocytosis, alveolar
hemorrhage)
What clinical disorders can reduce DLCO? - CORRECT ANSWER - conditions that
decrease permeability across the alveolar-capillary membrane, or otherwise interfere with gas
transfer
for example: a reduced DLCO in a patient with a low TLC or restriction on spirometry is
suggestive of a parenchymal or interstitial process
DLCO may also be diminisehd in COPD (from parenchymal destruction) or in conditions that
affect the pulmonary vasculature such as pulmonary HTN or chronic pulmonary thromboembolic
disease
What test is useful to assess diability and prognosis in chronic lung conditions? - CORRECT
ANSWER - 6 minute walk test (6MWT)
, simple pulse ox and oxygen desaturation studies performed at rest and with exertion assess the
need for oxygen supplementation
O2 sat, HR, dyspnea and fatigue level, and distance walked at a normal pace in 6 minutes are
recorded; this relatively simple maneuver quantifies exercise tolerance, determines effective
interventions, and helps predict morbidity and mortality
this test is commonly used before, during, and after pulmonary rehab programs
What is pulse oximetry? - CORRECT ANSWER - noninvasive measurement of arterial
hemoglobin saturation
2 light emitting diodes and a photodetector that measures the pulsatile fraction of hemoglobin
and algorithmically estimates the arterial hemoglobin saturation
in general, resting oxygen saturation less than or equal to 95% or a desaturation with exercise
greater than or equal to 5% is considered abnormal
What can falsely elevated pulse ox levels? - CORRECT ANSWER - carboxyhemoglobin
(the pulse ox cannot distinguish oxygen bound or cabon monoxide)
if the presence of carboxyhemoglobin is suspected, co-oximetry is the preferred test to measure
oxyhemoglobin
***also painted nails***
What is the equivalent daytime radiation of a PA/lateral radiograph? - CORRECT
ANSWER - 10 days
What is the equivalent daytime radiation of a routine CT? Equivalent number of chest
radiographs? - CORRECT ANSWER - 3 years
