12.2: Disorders of Pulmonary Circulation Flashcards
What happens to most of fluid that moves from vessels to interstitium?
Whisked away in lymphatics
What is another name for high pressure edema? What is the main problem with it?
- Cardiogenic pulmonary edema
- Elevated LVEDP causes elevated hydrostatic pressures resulting in increased edema formation in alveoli
Physical exam findings in high pressure pulmonary edema?
- JVD
- S3
3 Hepatomegaly - Edema
- Good extremities
- Thready pulse
CXR signs of high pressure edema?
- Vascular engorgement
- Perihilar infiltrate
- Cephalization
- Kerly B lines
- Pleural effusion
Causes of high pressure edema?
- LV dysfunction
- Mitral valve disease
- Hypervolemia with normal cardiac function
What is cephalization?
- Vessels moving towards top of lungs that are plump
Treatment for high pressure pulmonary edema?
- O2 mask ventilation
- Decrease preload: Nitrates, diuretics, venodilators
- Decreased afterload: ACEI, hydralazine
- Increase contractility: Dobutamine, milrinone
Another name for low pressure edema?
- ARDS
- “Acute lung injury” ALI
- No evidence of high pressure
- *Systemic process (usually inflammatory)Leaky capillaries leading to edema with protein [] reaching serum
What can cause low pressure edema?
- Trauma
- Sepsis
- Pancreatitis
- Inhalation injury
In which edema are capillaries leaky?
- Low pressure
- Leads to edematous fluid that has higher [protein]
Problems in low pressure edema?
Early: Refractory hypoxemia as alveoli flood
Late: Hypercapnia
PE in low pressure edema?
Lack of finding indicating high pressure as seen in high pressure edema
How does swan ganz catheter work?
Flow takes catheter through RA, RV, PA and into pulmonary capillaries
Pulse pressure in high and low pressure edema?
Low: Wide
High: Narrow
Wedge pressure in high and low pressure edema?
HIgh: >20
Low:
Treatment of low pressure pulmonary edema?
- Fix underlying problem: stop inflammation
- Lower hydrostatic pressure
- Oxygen
- Mechanical ventilation: high peep, low tidal volume
- Salvage therapy: ECMO
What is PEEP?
“Positive end expiratory pressure”
- Distended alveoli preventing collapse
- Makes interstitial space a bit negative in pressure pulling water into it
What is ECMO?
“Extracorporeal Membrane Oxygenation”
- Large catheter place in IJV to suck out blood
- Removes CO2 and adds O2
- Then dumps into RA
- *Done in lung failure
What leads to pulmonary embolism
- Hypercoagulable state from venous stasis or intimal injury leading to thrombus formation
- Clot can move proximally or DVT may dislodge and embolize
What does pulmonary artery obstruction lead to?
- Increased PVR straining right heart
- Redistribution of flow: V/Q mismatch
- Hyperventilation
- RV pressure overload and ischemia
Risk factors for pulmonary embolism?
- > 40yo
- Stasis
- History of thromboembolism
- Surgery
- Trauma: long bone fracture with fat embolism
- Cancer
- Obesity
PE clinical presentation?
- Chest pain
- Dyspnea
- Apprehension
- Cough / hemoptysis
Why is PE hard to diagnose?
- Symptoms and presentation are extremely non specific
Physiology of PE?
- Well formed clot from leg shoots up and lodges in pulmonary vessel
