09: Lungs & Heart

Question 1

Right atrial pressure?

Answer 1

2-8mmHg

Question 2

Right ventricle pressure?

Answer 2

15-30/2-8mmHg

Question 3

Pulmonary artery pressure?

Answer 3

15-30/4-12mmHg

Question 4

Pulmonary capillary wedge pressure?

Answer 4

2-10mmHg

Question 5

Left atrial pressure?

Answer 5

2-10mmHg

Question 6

Left ventricle pressure?

Answer 6

100-140/3-12mmHg

Question 7

Aortic pressure?

Answer 7

100-140/60-90mmHg

Question 8

Describe the blood flow distribution of the lungs

Answer 8

Uneven; in upright position, Zone 1 has lowest flow and Zone 3 has greatest.

In the supine position, blood flow is uniform.

Question 9

Describe pulmonary circulation.

Answer 9

• Low resistance, high compliance vascular bed
• Reacts differently to stimuli (e.g., hypoxia) than does systemic circulation
• Normally in a state of mild vasodilation

Question 10

Describe pulmonary circulation during exercise.

Answer 10

• ↑CO (4-5x baseline levels)
• Accommodated by recruitment and vasodilation
• Net effect: ↓PVR

Question 11

What causes high-altitude pulmonary edema?

Answer 11

• At high altitude, ↓O2 –> hypoxia
  
  • Hypoxia –> vasoconstriction of pulmonary bed
• Causes abnormal ↑PA pressure and ↑PVR
• Reversal rapid by going to lower altitude or O2 administration

Question 12

Describe pulmonary venous hypertension.

Answer 12

• Post-capillary
• PA pressure >/= 25mmHg (rest) or >/=30mmHg (exercise), AND
• PCW/LVED pressure >15mmHg

Question 13

Describe pulmonary arterial hypertension.

Answer 13

• Pre-capillary
• PA pressure >/=25mmHg (rest) or >/=30mmHg (exercise)
• PCW/LVED pressure =15mmHg
• Pulmonary vascular resistance index (PVRI) >/=3
• No left-sided ehart disease

Question 14

What are etiologies of PVH?

Answer 14

• Valvular heart disease
• Cardiomyopathies
• Ischemic heart disease
• Pericardial disease
• Tumors (myxoma)
• Congenital (cor triatriatum, coarctation)

Question 15

What factors influence microvascular fluid exchange in the lungs?

Answer 15

Net difference between **hydrostatic **and protein oncotic pressure and the **permeability **of the capillary membrane.

Question 16

What is adult respiratory distress syndrome?

Answer 16

Non-cardiogenic pulmonary edema in which crtically ill patients have injury to microvascular membranes resulting in marked increase in the amount of fluid and protein leaving the vascular space.

Question 17

Describe a normal chest X-Ray.

Answer 17

PCWP: 8-12mmHg; lower lobe vessels 2-3x larger in diameter than upper lobe vessels.

Question 18

Describe a chest X-Ray of pulmonary vascular redistribution (cephalization).

Answer 18

PCWP: 12-18mmHg; blood flow redirected to upper lobes; patient may be asymptomatic.

Question 19

Describe a chest X-Ray of pulmonary interstitial edema.

Answer 19

PCWP >18mmHg; haziness of vessels, Kerley B lines (linear markings at periphery of lower lung fields), Sx: SOB, PND, orthopnea, cough.

Question 20

Describe a chest X-Ray of pulmonary edema.

Answer 20

PCWP >25mmHg; alveolar edema with opacification of the air spaces, butterfly pattern around the hila, pleural effusions; Sx: cyanotic, rales and wheezing, frothy pink sputum, marked distress.

Question 21

What adaptations occur in chronic changes of pulmonary venous pressure?

Answer 21

Higher PCWPs can be accomodated with fewer clinical and radiological signs due to enhanced lymphatic drainage and chronic changes to vasculature.

Question 22

What symptoms are associated with pulmonary congestion?

Answer 22

• Dyspnea: abnormally uncomfortable awareness of breathing
• Orthopnea: dyspnea in recumbent postion
• Paroxysmal nocturnal dyspnea (PND): due to reduced adrenergic support of LV function during sleep
• Hemoptysis: spitting up blood
• Cough
• Fatigue

Question 23

What is brain natriuretic peptide (BNP), and why is it measured in the ER?

Answer 23

• Vasoactive peptide released by myocardial stress
• Oppose the physiologic abnormalities of heart failure
• If patient presents to ER with dyspnea:
  
  • BNP (-) suggests lung disease
  • BNP (+) suggests heart disease
    
    • Levels correlated with severity

Question 24

Describe the mechanisms of dyspnea in heart failure.

Answer 24

1. Decreased pulmonary function (↓complaince, ↑airway resistance)
2. Increased ventilatory drive
3. Respiratory muscle dysfunction

Question 25

What symptoms are associated with systemic congestion?

Answer 25

• Edema (anasarca = total body edema)
• RUQ discomfort (liver congestion)
• Ascites
• Central/peripheral cyanosis
• Clubbing

Question 26

What are the etiologies of right-sided heart failure?

Answer 26

• Cardiac:
  
  • Left heart failure
  • Right ventricular infarction
• Lung:
  
  • Parenchymal pulmonary disease –> cor pulmonale
• Pulmonary vascular:
  
  • Pulmonary emboli,
  • Primary pulmonary hypertension (PAH)