Respiratory Practice Questions

Question 1

A 37-year-old man is presented to the emergency department by paramedics after being involved in a serious 3-car collision on an interstate highway while he was driving his motorcycle. On physical examination, he is responsive only to painful stimuli and his pupils are not reactive to light. His upper extremities are involuntarily flexed with hands clenched into fists. The vital signs include temperature 36.1°C (97.0°F), blood pressure 80/60 mm Hg, and pulse 102/min. A non-contrast computed tomography (CT) scan of the head shows a massive intracerebral hemorrhage with a midline shift. Arterial blood gas (ABG) analysis shows partial pressure of carbon dioxide in arterial blood (PaCO2) of 68 mm Hg, and the patient is put on mechanical ventilation. His condition continues to decline while in the emergency department and it is suspected that this patient is brain dead. Which of the following results can be used to confirm brain death and legally remove this patient from the ventilator?

Accepted Answer

Apnea test

Answer

Electrocardiogram

Answer

Lumbar puncture and CSF culture

Answer

Electromyography with nerve conduction studies

Answer

CT scan

Question 2

A 55-year-old man is brought to the emergency department by ambulance from a long term nursing facility complaining of severe shortness of breath. He suffers from amyotrophic lateral sclerosis and lives at the nursing home full time. He has had the disease for 2 years and it has been getting harder to breath over the last month. He is placed on a rebreather mask and responds to questions while gasping for air. He denies cough or any other upper respiratory symptoms and denies a history of cardiovascular or respiratory disease. The blood pressure is 132/70 mm Hg, the heart rate is 98/min, the respiratory rate is 40/min, and the temperature is 37.6°C (99.7°F). During the physical exam, he begs to be placed in a sitting position. After he is repositioned his breathing improves a great deal. On physical examination, his respiratory movements are shallow and labored with paradoxical inward movement of his abdomen during inspiration. Auscultation of the chest reveals a lack of breath sounds in the lower lung bilaterally. At present, which of the following muscles is most important for inspiration in the patient?

Accepted Answer

Sternocleidomastoid muscles

Answer

Muscles of anterior abdominal wall

Answer

Internal intercostal muscles

Answer

Trapezius muscle

Answer

External intercostal muscles

Question 3

Which of the following physiologic changes decreases pulmonary vascular resistance (PVR)?

Accepted Answer

Inhaling the entire vital capacity (VC)

Answer

Inhaling the inspiratory reserve volume (IRV)

Answer

Exhaling the entire vital capacity (VC)

Answer

Exhaling the expiratory reserve volume (ERV)

Answer

Breath holding maneuver at functional residual capacity (FRC)

Question 4

A 27-year-old woman is admitted to the emergency room with dyspnea which began after swimming and progressed gradually over the last 3 days. She denies cough, chest pain, or other respiratory symptoms. She reports that for the past 4 months, she has had several dyspneic episodes that occurred after the exercising and progressed at rest, but none of these were as long as the current one. Also, she notes that her tongue becomes ‘wadded’ when she speaks and she tires very quickly during the day. The patient’s vital signs are as follows: blood pressure 125/60 mm Hg, heart rate 92/min, respiratory rate 34/min, and body temperature 36.2℃ (97.2℉). Blood saturation on room air is initially 92% but falls to 90% as she speaks up. On physical examination, the patient is slightly lethargic. Her breathing is rapid and shallow. Lung auscultation, as well as cardiac, and abdominal examinations show no remarkable findings. Neurological examination reveals slight bilateral ptosis increased by repetitive blinking, and easy fatigability of muscles on repeated movement worse on the face and distal muscles of the upper and lower extremities. Which arterial blood gas parameters would you expect to see in this patient?

Accepted Answer

PaCO2 = 51 mm Hg, PaO2 = 58 mm Hg

Answer

PaCO2 = 37 mm Hg, PaO2 = 46 mm Hg

Answer

PaCO2 = 34 mm Hg, PaO2 = 61 mm Hg

Answer

PaCO2 = 31 mm Hg, PaO2 = 67 mm Hg

Answer

PaCO2 = 43 mm Hg, PaO2 = 55 mm Hg

Question 5

A 24-year-old woman presents to the emergency department after she was found agitated and screaming for help in the middle of the street. She says she also has dizziness and tingling in the lips and hands. Her past medical history is relevant for general anxiety disorder, managed medically with paroxetine. At admission, her pulse is 125/min, respiratory rate is 25/min, and body temperature is 36.5°C (97.7°F). Physical examination is unremarkable. An arterial blood gas sample is taken. Which of the following results would you most likely expect to see in this patient?

Accepted Answer

pH: increased, HCO3-: decreased, Pco2: decreased

Answer

pH: increased, HCO3-: increased, Pco2: increased

Answer

pH: decreased, HCO3-: decreased, Pco2: decreased

Answer

pH: decreased, HCO3-: increased, Pco2: increased

Answer

pH: normal, HCO3-: increased, Pco2: increased

Question 6

A 32-year-old woman comes to the physician for a screening health examination that is required for scuba diving certification. The physician asks her to perform a breathing technique: following deep inspiration, she is instructed to forcefully exhale against a closed airway and contract her abdominal muscles while different cardiovascular parameters are evaluated. Which of the following effects is most likely after 10 seconds in this position?

Accepted Answer

Decreased left ventricular stroke volume

Answer

Decreased intra-abdominal pressure

Answer

Decreased pulse rate

Answer

Decreased systemic vascular resistance

Answer

Increased venous return to left atrium

Question 7

A student health coordinator plans on leading a campus-wide HIV screening program that will be free for the entire undergraduate student body. The goal is to capture as many correct HIV diagnoses as possible with the fewest false positives. The coordinator consults with the hospital to see which tests are available to use for this program. Test A has a sensitivity of 0.92 and a specificity of 0.99. Test B has a sensitivity of 0.95 and a specificity of 0.96. Test C has a sensitivity of 0.98 and a specificity of 0.93. Which of the following testing schemes should the coordinator pursue?

Accepted Answer

Test C on the entire student body followed by Test A on those who are positive

Answer

Test A on the entire student body followed by Test B on those who are positive

Answer

Test A on the entire student body followed by Test C on those who are positive

Answer

Test C on the entire student body followed by Test B on those who are positive

Answer

Test B on the entire student body followed by Test A on those who are positive

Question 8

During heavy exercise, what is the primary mechanism for maintaining arterial pH despite increased lactic acid production?

Accepted Answer

Hyperventilation

Answer

Increased bicarbonate reabsorption

Answer

Phosphate buffering

Answer

Increased hydrogen secretion

Question 9

A 35-year-old man presents to pulmonary function clinic for preoperative evaluation for a right pneumonectomy. His arterial blood gas at room air is as follows:

pH: 7.34
PaCO2: 68 mmHg
PaO2: 56 mmHg
Base excess: +1
O2 saturation: 89%

What underlying condition most likely explains these findings?

Accepted Answer

Chronic obstructive pulmonary disease

Answer

Cystic fibrosis

Answer

Bronchiectasis

Answer

Obesity

Answer

Acute respiratory distress syndrome

Question 10

A 56-year-old male comes to the physician because of a 2-month history of excessive sleepiness. He reports that he has been sleeping for an average of 10 to 12 hours at night and needs to take multiple naps during the day. Six months ago, he was diagnosed with small cell lung carcinoma and underwent prophylactic cranial irradiation. This patient's symptoms are most likely caused by damage to which of the following structures?

Accepted Answer

Suprachiasmatic nucleus

Answer

Subthalamic nucleus

Answer

Ventromedial nucleus

Answer

Preoptic nucleus

Answer

Supraoptic nucleus

Respiratory

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Respiratory mechanics and work of breathing

Pulmonary volumes and capacities

Spirometry interpretation

Flow-volume loops

Airway resistance determinants

Control of breathing

Central and peripheral chemoreceptors

Respiratory centers in the brainstem

Exercise respiratory physiology

Sleep effects on respiration

High altitude adaptation

Dyspnea mechanisms

Integrated respiratory responses

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