Respiratory Firstaid

Front 1

What are causes of decreased PaO2 (hypoxemia) that have a normal A-a gradient?

Back 1

High altitude (because barometric pressure is reduced so that PAO2 will decrease according to the alveolar gas equation), hypoventilation (barbiturates, CNS injury- alveolar ventilation is inversely proportional)

Front 2

What are causes of decreased PaO2 (hypoxemia) that have an increased A-a gradient?

Back 2

V/Q mismatch (most lung diseases such as asthma, pneumonia, pulmonary edema), diffusion limitation (interstitial fibrosis), Right-to-left shunt (ASD, pulmonary AVM)

Front 3

What are caused of decreased O2 to tissue (hypoxia)?

Back 3

Decreased cardiac output, hypoxemia, anemia (decreases oxygen CONTENT of blood even though PaO2 is normal- because Hb is decreased and most oxygen is bound to Hb), cyanide poisoning (Irreversibly inactivates mitochondrial enzymes so that ox-phos is stopped and the oxygen is not utilized), CO poisoning (decreases Hb saturation)

Front 4

What are causes of ischemia (decreased blood flow)?

Back 4

Impeded arterial flow (arterial occlusion), reduced venous drainage, hypotension

Front 5

What is the V/Q ratio at the apex of the lung?

Back 5

3 (wasted ventilation because perfusion is decreased)
PA > Pa > Pv

Front 6

What is the V/Q ratio at the base of the lung?

Back 6

0.6 (wasted perfusion because ventilation is decreased). However, both ventilation and perfusion are increased at the base of the lung compared to the apex.
Pa > Pv > PA

Front 7

What is the V/Q ratio of a shunt?

Back 7

V/Q = 0 because there is an airway obstruction. 100% O2 will not improve the PO2

Front 8

What is the V/Q ratio of a blood flow obstruction?

Back 8

V/Q approaches infinity because there is no flow. This is what happens with a PE. If there is < 100% dead space, 100% O2 will improve the PO2

Front 9

How far do pseudostratified ciliated columnar cells extend?

Back 9

To the respiratory bronchioles

Front 10

How far do the goblet cells extend?

Back 10

Bronchi

Front 11

Where would an object go if aspirated while upright?

Back 11

Lower portion of right inferior lobe

Front 12

Where would an object go if aspirated while supine?

Back 12

Superior portion of right inferior lobe

Front 13

What is the relationship of the pulmonary artery to the bronchus at each lung?

Back 13

Right- Anterior
Left- Superior

RALS

Front 14

What is collapsing pressure?

Back 14

Collapsing pressure = 2(surface tension)/radius

surfactant decreases surface tension

Front 15

What is dead space

Back 15

VD = VT (PaCO2 - PeCO2)/PaCO2; the apex of the lung is the largest contributor to dead space because volume of inspired air in that does not take part in gas exchange.

Front 16

What DECREASES compliance?

Back 16

Pulmonary fibrosis, pulmonary edema, insufficient surfactant

Front 17

What shifts the hemoglobin dissociation curve to the RIGHT?

Back 17

INCREASE:
Cl-, H+, CO2, 2,3BPG, temperature, high altitude, increased metabolic needs

Front 18

What shifts the hemoglobin dissociation curve to the LEFT?

Back 18

Decreased:
Metabolic needs, CO2, temperature, H+, 2,3DPG, Fetal Hb, carboxyhemoglobin (CO)

Front 19

What is diffusion?

Back 19

Diffusion = Area/Thickness x Dk(P1-P2)

A decreases in emphysema
T increases in fibrosis

Front 20

What does BMPR2 do?

Back 20

Inhibits vascular smooth muscle proliferation- mutated in primary pulmonary hypertension

Front 21

What PFTs are seen in obstructive lung disease?

Back 21

markedly decreased FEV1, decreased FVC, decreased FEV1/FVC (hallmark), V/Q mismatch, increased RV

Front 22

What is the Reid index?

Back 22

gland depth/total thickness of bronchial wall

Front 23

Asthma findings

Back 23

Pulsus paradoxus, decreased I/E ratio

Front 24

What PFTs are found in restrictive lung disease?

Back 24

Decreased everything, FEV/FVC > 80%. There is increased expiratory flow rate because of increased elastic recoil pressure and increased radial traction on the conducting airways by the fibrotic pulmonary interstitium.

Front 25

What physical findings are found in bronchial obstruction?

Back 25

Decreased/absent breath sounds over lesion, decreased resonance, decreased fremitus, trachea deviates TOWARD lesion

Front 26

What physical findings are seen in pleural effusion?

Back 26

Decreased breath sounds over the effusion, dullness, decreased fremitus

Front 27

What physical findings are seen in lobar pneumonia?

Back 27

Bronchial sounds over the lesion, dullness, INCREASED fremitus

Front 28

What physical findings are seen in tension pneumothorax?

Back 28

Decreased breath sounds, HYPERRESONANT, absent fremitus, trachea deviates AWAY from lesion

Front 29

What are the airway, alveolar, and intrapleural pressures at FRC?

Back 29

Airway and alveolar = 0
Intrapleural - negative to prevent pneumothorax

Front 30

What are causes of secondary pulmonary hypertension?

Back 30

Mitral stenosis (increased resistance and pressure), recurrent thrombemboli (decreased cross-sectional area of pulmonary vascular bed), autoimmune disease (systemic sclerosis; inflammation leading to intimal fibrosis and medial hypertrophy), L-R shunt (shear stress), sleep apnea, high altitude (hypoxic vasoconstriction)

Front 31

When does arterial PO2 decrease?

Back 31

In chronic lung disease because the physiologic shunt decreases the oxygen extraction ratio?

Front 32

What determines oxygen delivery to tissues?

Back 32

CO x (oxygen content of blood)

Front 33

What is a complication of bronchiectasis?

Back 33

Aspergilliosis- allergic bronchopulmonary aspergillus infection

Front 34

What does asbestosis look like?

Back 34

Ivory white calcified pleural plaques; affects LOWER lobes

Front 35

What are causes of decreased lung compliance?

Back 35

Pulmonary fibrosis, pulmonary edema, insufficient surfactant