Pulm Quizes 1rename
zwinthrop's version from 2015-04-19 13:57
Week 1 Quiz
|68 yo M presents to HMC with several days of increasing SOB. He is currently on 6 liters/min nasal cannula oxygen, and states he chronically is on 2 l/min. ABG: pH 7.210/ pCO2 80/p O2 146/bicarb 32. How would you interpret this gas (include both an assessment of oxygenation and acid-base status)? Assume that 6 l/min provides 40% FIO2.||Answer: Oxygenation: A-a gradient = [(Pb-PH2O) * FIO2 – PCO2/R] A-a gradient: [(760-47)*.4 – 80/.8] – 146 = 39 which is widened suggesting V/Q mismatch with shunting. This is consistent with COPD. Acid-Base: Acute on chronic respiratory acidosis. Low pH with elevated pCO2 and bicarb indicates a respiratory acidosis. If purely acute, pCO2 of 80 would imply pH of 7.02 and bicarb of 29 (25-31). Bicarb is higher and pH less severely depressed, implying some period of compensation. If this were purely chronic, bicarb should be higher, about 40. Alternatively, it is possible to argue that this is a chronic respiratory acidosis with a simultaneous metabolic acidosis. The numbers fit. But the clinical description fits better with the first explanation.|
|A man with normal lungs and an arterial PCO2 of 40 mm Hg takes an overdose of barbiturate that halves his alveolar ventilation but does not change his CO2 output. If his respiratory exchange ratio is 0.8, what will be his approximate arterial PO2 (in mm Hg)?||Answer: 50 mmHg|
|For each of the following, state whether obstructive lung disease would result in an increase, decrease, or no change from normal. (This is from the ventilation lecture and handout)||Answer: a. Functional residual capacity = Increase b. FEV1 = Decrease c. Forced vital capacity = Decrease d. Residual volume = Increase e. Total lung capacity = Increase f. FEV1/FVC = Decrease.|
|An otherwise healthy person has lost enough blood to decrease his body’s hemoglobin concentration from 15g/100ml blood to 12g/10ml blood. Which of the following would be expected to decrease (more than one answer may be correct).||a. Arterial PO2 (NO) b. Blood oxygen-carrying capacity (YES – will decrease) c. Arterial hemoglobin saturation (NO) d. Arterial oxygen content (YES – will decrease) The blood oxygen carrying capacity (excluding physically dissolved oxygen) will decrease from 20.1 to 16.1 ml O2/100 ml blood (it’s not important to know the specific number), and so the arterial oxygen content will also decrease because most of the blood’s oxygen is carried bound to hemoglobin. The arterial PO2 is not affected by the decreased hemoglobin concentration (assuming it equilibrates with alveolar PO2 at 100 mm Hg), and the oxygen saturation of the remaining hemoglobin is also unaffected. This is from the gas transport lecture and handout.|
|Describe how physical exertion (e.g. running) affects the diffusing capacity of the lungs||Answer: Exertion increases the diffusing capacity by increasing the cardiac output. This recruits previously unperfused capillaries, increasing the surface area available for diffusion. Oxygen transfer across the alveolar-capillary barrier will also increase because at high cardiac output the velocity of the blood moving through the pulmonary capillaries increases and there is less perfusion limitation of oxygen transfer. This is from the diffusion & blood flow lectures and handouts.|
|An otherwise healthy person is brought to the emergency department having aspirated a foreign body into the right main-stem bronchus, partially occluding it. Which of the following is likely to occur? a. The right lung PAO2 will be lower than the left lung b. The right lung PACO2 will be higher than the left lung c. The blood flow to the right lung will decrease d. The arterial PO2 will fall e. All of the above are correct.||Answer: The correct answer is E. With a partial obstruction of the airway the right lung will have a V/Q ratio lower than the left lung. Therefore, it will have lower alveolar PO2 and higher alveolar PCO2. The overperfusion may be somewhat attenuated if hypoxic pulmonary vasoconstriction diverts some blood flow away from hypoxic and hypercapnic alveoli to the better ventilated left lung, but this response would probably not function perfectly over such a large area. As a result, arterial PO2 will fall. This is from the V/Q matching lecture and handout.|
|Describe the three main changes in respiration occurring during non–REM sleep.||Answer: 1- Loss of wakefulness drive to breathing control: - Respiratory control system becomes very sensitive to changes in chemical stimuli. - Decrease in level of ventilation. PaCo2 typically increases by few mmHg and PaO2 decreases. 2- Reduction of upper airway muscle tone - Tone of Upper airway dilator muscles (Genioglossus) decreases - Snoring, increased upper airway resistance - Collapse of the upper airways leading to obstructive sleep apnea (OSA). 3- Reduced protective reflexes and compensatory mechanisms Reduction of Cough, Lower response to “load”|
|What are the specific components of the respiratory system’s protective mechanisms?||Answer: Branching of airways, cough, mucociliary clearance (physical/anatomic); lysozyme, lactoferrin, defensins, collectins (SP-A and SP-D), secretory IgA (antimicrobial peptides); pulmonary alveolar macrophages, dendritic cells, polymorphonuclear cells, NK cells (phagocytic and inflammatory cells); adaptive immunity.|
Review Q's COPD's
|1. Emphysema and chronic bronchitis; |
a. are mutually exclusive disorders
b. are pathologically defined disorders
c. produce restrictive functional abnormalities
d. are often referred to by the term “chronic obstructive pulmonary disease”
|2. The mechanism by which dilated air spaces of emphysema develop differs from that by which the dilated air spaces of "honeycomb lung" develop in that|
a. in honeycomb lung, air space walls are destroyed
b. in emphysema, air space walls are destroyed
c. in honeycomb lung, air trapping is the initiating event
d. in emphysema, air trapping is the initiating event
|3. Smoking is most closely associated with which type of emphysema? (choices below)|
4. Which type of emphysema develops in alpha-1-antitrypsin deficiency? (choices below)
|5. Which statement regarding the pathogenesis of emphysema is incorrect?|
a. In smokers, increased elastase activity contributes to the development of emphysema.
b. In smokers, neutrophil and macrophage accumulation in alveoli is important.
c. A1AT function is inhibited by oxidants in smoke.
d. Ciliary dysfunction is an important factor in the development of emphysema.
|6. Which statement regarding chronic bronchitis is incorrect?|
a. Chronic bronchitis is defined as a persistent cough with sputum production for at least 3 mos. in at least two consecutive years.
b. Cigarette smoking predisposes to chronic bronchitis by impairing ciliary function.
c. In patients with chronic bronchitis, pigmented macrophages are often seen in bronchioles.
d. Chronic bronchitis only develops in smokers.
|7. Pathologic findings characteristic of chronic bronchitis include|
a. eosinophil infiltrates in bronchial walls
b. increased size of the bronchial submucosal glands
c. enlarged distal air spaces
d. intraalveolar neutrophilic infiltrates.
|8. Which of the following statements about asthma is incorrect?|
a. Antigens triggering attacks of atopic asthma cause wheal-and-flare reactions.
b. A Th2 response is important in the pathogenesis of asthma.
c. Viral and fungal infections are involved in the pathogenesis of some types of asthma.
d. Reflex bronchodilation in asthma is initiated by release of inflammatory mediators.
e. Airway fibrosis can result if asthma is not treated.
|9. A 30-year-old patient with an obstructed bronchus due to a tumor is most likely to develop which of the following diseases?|
b. chronic bronchitis
|10. Factors predisposing to development of bronchiectasis include all of the following except: |
a. dysfunctional cilia
b. necrotizing pneumonia
d. cystic fibrosis.
|11. An asthmatic patient has peripheral eosinophilia (15% of WBC), neuropathy, and pulmonary infiltrates. A lung biopsy is most likely to show|
a. fungi colonizing bronchi
b. honeycomb changes
c. hyaline membranes
d. necrotizing vasculitis.
Review Q's Vascular Diseases
|1. Hemodynamic causes of pulmonary edema include all of the following except:|
a. increased hydrostatic pressure
b. lymphatic obstruction
c. decreased oncotic pressure
d. microvascular injury.
|2. Which of the above categories of mechanisms (a-d) are responsible for the development of pulmonary edema in |
a. congestive heart failure?
b. nephrotic syndrome?
c. lymphangitic carcinomatosis?
|a-a, b-c, c-b,d-d.|
|3. Which statement is true about pulmonary embolism?|
a. The physiologic consequences are unrelated to the extent of pulmonary vascular obstruction.
b. Large pelvic veins are the most common source of pulmonary emboli.
c. The status of collateral (bronchial) circulation is a major determinant of the significance of an embolus.
d. Pulmonary emboli frequently lead to compromise of left heart function.
|4. Disorders associated with an increased incidence of pulmonary emboli include all of the following except:|
b. factor V Leiden
c. chronic immobilization
|Which of the following clinical consequences of emboli is |
5. Most common?
6. Least common?
a. sudden death
c. pulmonary infarction
d. pulmonary hemorrhage.
|5. b, 6. a.|
|7. A radiodense area appears on a patient's chest X ray. Physical examination reveals a tender area in the calf, with a rope-like consistency. Two days later, the patient dies suddenly. Which histologic findings might you expect to see in the lungs?|
a. ischemic necrosis of the lung parenchyma with hemosiderin-laden macrophages
b. intraalveolar neutrophils
c. interstitial and intraalveolar fibrosis
d. small arteries with intimal proliferation and fibrosis.
|8. A 20 year old intravenous drug abuser develops a new cardiac murmur. Several days later, he complains of shortness of breath and dyspnea. A chest X ray will most likely show/pathologic examination of the lungs may show (best answer):|
a. central nodular infiltrate/fibrin thromboembolus with fungal hyphae and neutrophils
b. central nodular infiltrate/intimal fibrosis in small arteries
c. wedge-shaped peripheral infiltrate/fibrin thromboembolus with fungal hyphae and neutrophils
d. wedge shaped peripheral infiltrate/fat thromboembolus .
|9. Pulmonary hypertension is|
a. a consequence of decreased pulmonary vascular resistance
b. linked to mutations in the bone morphogenetic protein receptor type 2 (BMPR2) signaling pathway, in many cases of primary pulmonary hypertension
c. usually primary, without associated cardiopulmonary abnormalities
d. reflected by development of atheromatous lesions in large pulmonary veins.
|10. Pulmonary veno-occlusive disease|
a. Is a type of vasculitis.
b. Is a congenital anomaly.
c. can be treated by lung transplantation.
d. usually responds to corticosteroid therapy.
|11. Which of the following statements is true?|
a. Idiopathic pulmonary hemosiderosis is associated with vasculitis.
b. Antineutrophil cytoplasmic antibodies are associated with Wegener granulomatosis.
c. Linear deposition of IgG is found in Behcet disease.
d. The kidneys are usually spared in Goodpasture Syndrome.
|12. Substances thought to be involved in the pathogenesis of ARDS include all of the following except:|
a. eosinophil major basic protein
b. oxygen-derived free radicals
|13. In the acute stage of ARDS |
a. interstitial fibrosis is present
b. ventilation-perfusion mismatch is present
c. the lung is hyperinflated
d. mechanical ventilation is not required.
|14. Histologic features of the acute stage of ARDS include all of the following except:|
a. hyaline membranes
c. sloughed epithelial cells
d. honeycomb change.
|15. Which statement is incorrect?|
a. ARDS develops slowly, and can be circumvented if therapy is instituted quickly.
b. The chest X ray in ARDS shows diffuse pulmonary infiltrates.
c. The outcome of ARDS may be resolution with variable residual lung damage, or death.
d. The mortality rate of ARDS in the U.S. is about 60%.
|16. Which pairing is correct?|
a. obstructive atelectasis --- aspirated peanut
b. obstructive atelectasis --- pleural effusion
c. compressive atelectasis --- asthma
d. contraction atelectasis --- adult respiratory distress syndrome.
REview Q's ARDS1. Which of the following is necessary in order to achieve low tidal volume ventilation in ARDS?
A. –Low PEEP
B. –High PEEP
C. –Adjusting the P/F Ratio
D. –Mild Acidosis
E. –Mild Alkalosis
ANSWER: mild acidosis
2. Which of the following is NOT seen in histology of ARDS?
A. –Hyaline membranes
B. –Fibroblastic foci
C. –Inclusion bodies
D. –Proteinaceous fluid
E. –Widening of cell junctions
ANSWER: Inclusion bodies
3. A 50 year old man is admitted to the ER with hypoxic respiratory failure. His blood pressure is 100/60, Pulse 110, RR 26 and oxygen saturation is 86% on 6L nasal cannula. He weighs 70 kg. His CXR shows patchy bilateral infiltrates. His bedside Echo reveals normal cardiac function. The patient is in respiratory distress and is emergently intubated. Which of the following tidal volumes is the correct initial setting?
A. –650 cc
B. –620 cc
D. –400 cc
E. –350 cc
ANSWER: Answer: 560 cc → 8cc/kg to start (8cc x 70kg), then wean down to 6 cc/kg = (6cc x 70kg) = 420cc
4. What are the diagnostic criteria for ARDS?
A. –Acute onset (< 1 week)
B. –Bilateral infiltrates
C. –Exclusion of heart failure
D. –PF Ratio <300