Respiratory Flashcards Preview

Step 1 High Yield > Respiratory > Flashcards

Flashcards in Respiratory Deck (58)
Loading flashcards...
1
Q

What is the equation for physiologic dead space?

A
Vd = Vt x (PaCO2 - PeCO2)/PaCO2
Vd = physiologic dead space
Vt = tidal volume
PaCO2 = arterial O2 pressure
PeCO2 = expired air PCO2
2
Q

Alveolar ventilation equation?

A
Va = (Vt-Vd) x RR
RR = respiratory rate
3
Q

Which form of hemoglobin has low affinity for O2?

A

T (taut) form

4
Q

What causes hemoglobin to favor the taut form (5)?

A

Cl-, H+, CO2, 2,3-BPG, temperature

5
Q

On the oxygen-hemoglobin dissociation curve, what is the significance of a shift to the right?

A

Decreased affinity of Hb for O2

6
Q

How is diffusion assesed (calculation)?

A

Volume of gas = A/T x Dk (P1-P2)
A = area
T = thickness
Dk (P1-P2) = difference in partial pressure

7
Q

How do emphysema and pulmonary fibrosis affect lung diffusion?

A

Both decrease it
Area of diffusion decreases in emphysema
Thickness increases in pulmonary fibrosis

8
Q

What is pulmonary wedge pressure

A

Pressure in the left atrium

9
Q

What is the alveolar gas equation?

A
PAO2 = PIO2 - (PaCO2/R)
PAO2 = alveolar PO2
PIO2 = PO2 in inspired air
R = Respiratory quotient (CO2 produced/O2 consumed) = usually 0.8
10
Q

What can increase the A-a gradient?

A

V/Q mismatch (ideally should = 1)
Diffusion limitaiton
Right-to-left shunt

11
Q

What is the function of the BMPR2 gene and what happens when it is mutated?

A

BMPR2 gene functions to inhibit vascular smooth muscle proliferation - mutation results in primary pulmonary hypertension

12
Q

What are the activating metastases for adenocarcinoma of the lung?
Where is adenocarcinoma located?
How does it appear on histology?

A

What are the activating metastases for adenocarcinoma of the lung?: k-ras, EGFR, ALK
Where is adenocarcinoma located?: peripheral lung
How does it appear on histology?: grows along alveolar septa (thickening of alveolar walls)

13
Q

What is Lambert Eaton myasthenic syndrome

A

Autoimmune disorder that is characterized by muscle weakness of the limbs. It is the result of an autoimmune reaction in which antibodies are formed against presynaptic voltage-gated calcium channels - These antibodies can be produced by small cell carcinoma of the lung

14
Q

What can small cell carcinoma of the lung produce?

A

ACTH, ADH, Antibodies against calcium channels

15
Q

What are the organisms associated with Lobar pneumonia?

A

S. pneumoniae (most frequent); Legionella, Klebsiella

16
Q

What organisms are associated with Bronchopneumonia

A

S. Pneumoniae; S. Aureus; H. Influenzae; Klebsiella

17
Q

What organisms are associated with interstitial pneumonia?

A

Viruses (influenza, RSV, adenoviruses), Mycoplasma, Legionella, Chlamydia

18
Q

What are causes of transudate pleural effusion (decreased protein content)?

A

CHF, nephrotic syndrome, hepatic cirrhosis

19
Q

What are causes of exudate pleural effusion (increased protein content, cloudy)?

A

Malignancy, pneumonia, collagen vascular disease, trauma - must be drained

20
Q

Where is the least airway resistance in the conducting zone of the lung?

A

terminal bronchioles (large numbers in parallel)

21
Q

What is the cell distribution throughout the lung passages?

A

Conducting zone: Cartilage and goblet cells extend to end of bronchi; Pseudostratified ciliated columnar cells extend to beginning of terminal bronchioles
Respiratory zone: At terminal bronchioles, PCCC cells transition to ciliated cuboidal cells up through respiratory bronchioles; simple squamous up to alveoli

22
Q

What is the function of club (clara) cells?

A

Secrete component of surfactant
Degrade toxins
Act as reserve cells

23
Q

What is the function of Type II pneumocytes?

A

Secrete pulmonary surfactant
Serve as precursors to type I cells and other type II cells
Proliferate during lung damage

24
Q

Structures perforating diaphragm and T-level?

A

“I ate ten eggs at twelve”
IVC: T8
Esophagus: T10
Aorta: T12

25
Q

At FRC, what is happening to the following measures?
airway and alveolar pressure:
intrapleural pressure:
Pulmonary vascular resistance:

A

airway and alveolar pressure: zero
intrapleural pressure: negative
Pulmonary vascular resistance: at a minimum

26
Q

Which type of hemoglobin has higher affinity for cyanide?

How is this used to treat cyanide poisoning?

A

Methemoglobin (Fe3+)
To treat cyanide poisoning, use nitrites to oxidize Hb to methemoglobin which binds cyanide. Use thiosulfate to bind this cyanide, forming thiocyanate, which is renally excreted

27
Q

How do you calculate peripheral vascular resistance?

A
PVR = (Pressure in pulm artery - pressure in left atrium)/CO
R = (viscosity of blood x length)/(radius^4)
28
Q

What is the V/Q at…
Zone 1 (apex):
Zone 2:
Zone 3 (base):

A
Zone 1 (apex): V/Q > 1 (Q decreases more than V decreases)
Zone 2: V/Q = 1
Zone 3 (base): V/Q
29
Q

What is the haldane effect?

What is the Bohr effect?

A

Haldane effect: Oxygenation of Hb promotes dissociation of H+ from Hb which shifts the equilibrium toward CO2 formation (carbonic anhydrase); therefore CO2 is released from RBCs
Bohr effect: In peripheral tissue, increased H+ from metabolism shifts curve to right, unloading O2

30
Q

The majority of CO2 is carried as _______

A

HCO3- in the plasma

31
Q

What does Cl- decrease in peripheral tissue?

A

CO2 in the RBC is converted to HCO3- by carbonic anhydrase and this is released into the plasma in exchange for Cl- uptake by the RBC

32
Q

What is the body’s response to high altitude? (acute and chronic)

A

High altitude:

1) Decreased atmospheric oxygen → decreased arterial O2 pressure → hyperventilation → decreased arterial CO2 pressure
2) Chronic increased ventilation → increased erythropoietin; increased hematocrit/Hb; increased 2,3 BPG (more O2 release); Increased mitochondria → Increased HCO3- exretion to compensate for respiratory alkalosis

33
Q

What is the body’s response to exercise?

*bonus: what happens to arterial blood gas levels

A

Increased CO2 production → Increased O2 consumption → Increased ventilation to meet O2 demand → V/Q at apex approaches 1 → Increased pulmonary blood flow (increased CO) → Decreased pH (lactic acidosis)

  • no change in PaO2 and PaCO2 but increasd in venous CO2 and decrease in venous O2 content
34
Q

What superimposed bacterial infections occur after rhinosinusitis?

A

S. pneumoniae; H. influenzae; M. catarrhalis

35
Q

Pulmonary embolism leads to respiratory _______

A

alkalosis (secondary to hypoxemia)

36
Q

Obstructive lung disease general findings:

A

Air trapping in the lungs
Increased RV
Decreased FEV1/FVC

37
Q

Requirements for chronic bronchitis are a productive cough for > _ months per year for > _ years

A

3;2

38
Q

Which obstructive lung disease presents with increased compliance?
Which obstructive lung disease presents with crackles?
Which presents with pulsus paradoxus?
Which presents with permanently dilated airways?

A

Increased compliance: Ephysema
Crackles: Chronic bronchitis
Pulsus paradoxus: Asthma
Dilated airways: Bronchiectasis

39
Q

What are charcot-leyden crystals associated with? What are they made from?

A

Asthma; formed from breakdown of eosinophils in sputum

40
Q

What lung disease is associated with allergic bronchopulmonary aspergillosis?

A

Bronchiectasis

41
Q

What restrictive lung disease are due to…
Poor muscular effort:
Poor structural apparatus:

A

Poor muscular effort: polio, myasthenia gravis

Poor structural apparatus: Scoliosis, morbid obesity

42
Q

What drugs can cause restrictive lung disease?

A

Bleomycin, busulfan, amiodarone, methotrexate

43
Q

Hypersensitivity pneumonitis is due to what type of hypersensitivity reaction?

A

Type III/IV reaction to environmental antigen

44
Q

What is caplan syndrome?

A

Rheumatoid arthritis, ad pneumoconiosis with intrapulmonary nodules

45
Q

Which type of pneumoconiosis is associated with increased incidence of both bronchogenic carcinoma and mesothelioma?

What histology finding is associated with mesothelioma?

A

Asbestosis (lower lobes)

Mesothelioma - psammoma bodies

46
Q

Which pneumoconioses increases the risk of TB and how?

A

Sillicosis - Sillica may disrupt phagolysosomes and impair macrophages (which produce the fibrosis in this disease), increasing susceptibility to TB

47
Q

Why does maternal diabetes lead to neonatal respiratory distress syndrome?

A

Increase in fetal insulin due to maternal hyperglycemia can cause decreased surfactant production

48
Q

What is released in ARDS that causes damage (besides the formation of the intra-alveolar hyaline membrane)?

A

Damage due to release of neutrophilic substances toxic to alveolar wall, activation of coagulation cascade, and oxygen derived, free radicals

49
Q

Pulmonary hypertension > __ at rest results in arteriosclerosis, medial hypertrophy, and intimal fibrosis of pulmonary arteries

A

25 mmHg

50
Q

Most common lung cancer in non-smokers?

A

Adenocarcinoma

51
Q

Which lung carcinoma can secrete PTHrP? How is it identified on biopsy?

A

Squamous cell carcinoma; Keratin pearls and intercellular bridges

52
Q

What two lung carcinomas are of neuroendocrine origin? What positive stain is associated with neuroendocrine tumors?

A

Small cell cacrinoma and Bronchial carcinoid tumor; Chromogranin A positive

53
Q

Which lung carcinoma is not treated with surgery?

Which has the best prognosis?

A

No surgery: Small cell carcinoma

Best prognosis: Bronchiol carcinoid tumor

54
Q

What is Superior vena cava syndrome? (what causes it?)

A

An obstruction of SVC that impairs blood drainage from the head, neck and upper extremities (commonly caused by malignancy and thrombosis from indwelling catheters)

55
Q

What are the common causes of lung abscess due to aspiration?

A

S. aureus (or anaerobes), bacterioides, fusobacterium, peptostreptococcus

56
Q

Where is air accumulation in spontaneous pneumothorax:
What is the most frequent demographic:
What is the most frequent cause:

A

Air accumulation in the pleural space
Tall thin young males
Rupture of apical blebs

57
Q

What is a hamartoma? What is a lung hamartoma?

A

A hamartoma is an excessive growth of a tissue type native to the organ of involvement
The lung is the most common location - lung hamartomas often contain islands of mature hyaline cartilage, fat, smooth muscle and clefts lined by respiratory epithelium

58
Q

Which cancer of the lung arises from clara cells and grows along preexisting bronchioles and alveoli?

A

Bronchioloalveolar carcinoma