MKSAP 17 Pulmonary and Critical Care
Medicine 2026 Exam Questions and
Correct Answers | New Update
What FEV1/FVC ratio on spirometry is consistent with airflow obstruction? -
🧠ANSWER ✔✔70%
What is used to characterize the degree of obstruction? - 🧠ANSWER
✔✔the degree of reduction in FEV1
What is considered moderately reduced FEV1? - 🧠ANSWER ✔✔50-80%
What is considered severely reduced FEV1? - 🧠ANSWER ✔✔34-49%
,What is considered very severely reduced FEV1? - 🧠ANSWER ✔✔less
than 34%
In patients with obstruction, what additional test on spirometry should be
performed? - 🧠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? - 🧠ANSWER ✔✔an
increase in FEV1 of 12% or 200ml
What does a normal FEV1/FVC ratio reflex? - 🧠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? - 🧠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? - 🧠ANSWER ✔✔TLC
What will TLC and RV be in obstructive lung diseases? - 🧠ANSWER
✔✔elevated TLC is suggestive of hyperinflation and high compliance
3
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
, increased RV is suggestive of air trapping
What will the flow volume loop look like in asthma? - 🧠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? - 🧠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? - 🧠ANSWER ✔✔flattening of the peak inspiratory and expiratory
flows
How is the diffusing capacity for carbon monoxide performed? - 🧠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
Medicine 2026 Exam Questions and
Correct Answers | New Update
What FEV1/FVC ratio on spirometry is consistent with airflow obstruction? -
🧠ANSWER ✔✔70%
What is used to characterize the degree of obstruction? - 🧠ANSWER
✔✔the degree of reduction in FEV1
What is considered moderately reduced FEV1? - 🧠ANSWER ✔✔50-80%
What is considered severely reduced FEV1? - 🧠ANSWER ✔✔34-49%
,What is considered very severely reduced FEV1? - 🧠ANSWER ✔✔less
than 34%
In patients with obstruction, what additional test on spirometry should be
performed? - 🧠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? - 🧠ANSWER ✔✔an
increase in FEV1 of 12% or 200ml
What does a normal FEV1/FVC ratio reflex? - 🧠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? - 🧠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? - 🧠ANSWER ✔✔TLC
What will TLC and RV be in obstructive lung diseases? - 🧠ANSWER
✔✔elevated TLC is suggestive of hyperinflation and high compliance
3
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
, increased RV is suggestive of air trapping
What will the flow volume loop look like in asthma? - 🧠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? - 🧠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? - 🧠ANSWER ✔✔flattening of the peak inspiratory and expiratory
flows
How is the diffusing capacity for carbon monoxide performed? - 🧠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
