What is Pulmonary Embolism?
When a blood clot breaks loose from somewhere else & floats into the pulmonary circulation
When does Pulmonary Infarction develop? What does an Infartion lead to?
- When embolus interrupts pulmonary blood flow.
- Atelectasis, consolidation, and tissue necrosis
Changes in lungs from Pulmonary Embolism & Infarction
- Bronchoconstriction: release of mediators-serotonin, histamine & prostaglandins. Also hypocapnia & hypoxemia
- 1 big clot (fatal) or bunch of smaller ones
Summary of Pulmonary Embolism & Infarction changes in the lungs
- Blockage of pulmonary vessel
- Pulmonary infarction
- Maybe bronchoconstriction
How many cases of PE are missed? Common symptoms?
- 90% in pts younger than 70 years
- Dyspnea, hemoptysis & pleuritic chest pain are seen in over 20% of pts
When to suspect Pulmonary Embolism?
Dyspnea, tachypnea & chest pain
What's the most common cause of Pulmonary Embolism?
Where do clots come from?
- Deep veins in legs, pelvis or inferior vena cava.
- When a piece breaks off, clot moves through veins RA and RV of heart and impacts in the PA or artioles
Risk factors of Pulmonary Embolism?
- Venous statis: lengthy bed rest
- Trauma: bone fx.
- Post-op/postpartum: hip surgeries or "milk leg"
- Misc: obesity, cancer & burns
Clinical signs/symptoms of Pulmonary Embolism
- High resp rate
- High heart rate
- Systemic hypotension
- Swollen, tender liver
- Chest pain/decrease chest expansion
- AbNL heart sounds
- Crackles/wheezes/pleural friction rub
ABGs of Pulmonary Embolism
- Mild to moderate PE: acute alveolar hypervent'n with hypoxemiaSevere PE/Infarction: acute vent'y failure with hypoxemia
Oxygenation of PE?
- Increase: shunting/total flow & O2 extraction ratio
- Decrease: O2 delievery & mixed venous O2 consumption
- NL: venous O2 & arterial to mixed venous oxygen content difference
Hemodynamics of Pulmonary Embolism?
- Increase: Central Venous Pressure, Right Arterial Pressure, Pulmonary Artery Pressure & Pulmonary Vascular Resistance
- Decrease: PCWP, Stroke Volume, Stroke Volume Index, CO & Cardiac Index
- NL: System Vascular Resistance
What to use to diagnosis Pulmonary Embolism?
- Pulmonary angiography
- CT scan
- Fibrinogen test
- Extremity venography
- Duplex ultrasonography
Diagnosis of Pulmonary Embolism: ECG:
- Sinus/atrial tach
- Right Bundle Branch Block
Diagnosis of Pulmonary Embolism: CXR:
- Increase density (whiter)
- Hyperradiolucency distal to embolus in non-infarcted areas
- big PA
- Pulmonary Edema
- Cor pulmonale
- Small pleural effusion
Diagnosis of Pulmonary Embolism: V/Q
- Shows noramal ventilation
- Normal perfusion
Diagnosis of Pulmonary Embolism: Pulmonary angiography:
- abNL filling or cutoff
- areas with no perfusion will be darkIf V/Q scan is NL, this angiogram will be negative
Diagnosis of Pulmonary Embolism: CT Scan:
- Good to dx PE
- Less invasive
- Don't need pulmonary cath
Diagnosis of Pulmonary Embolism: Fibrinogen test:
- Checks for high levels of fibrinogen (blood clotting protein)
- Normal result rules out PE
Diagnosis of Pulmonary Embolism: Extremity Venography:
- Put cath in arm or leg vein, inject dye
- not used much today
Diagnosis of Pulmonary Embolism: Duplex ultrasonography:
- Uses high-frequency sound waves to I.D. clots in thigh veins
- Good to dx DVT above knee, bad for DVT below knee
Diagnosis of Pulmonary Embolism: MRI:
- Good to use if kidneys may be harmed by dyes
- useful in pregnancy
Management of Pulmonary Embolism?
- Pulse ox
- ECG monitoring
- Anticoagulants: blood thinner. Fast: Heparin Slow: Warfarin DON'T use with IBUPROFEN
- Thrombolytics: urokinase, streptokinase, alteplaseVein filter
- O2 therapy: decrease WOB & myocardial work, treat hypoxemiaElastic stockings
- Meds: for bronchoconstrictionMechanical ventilation
- Pulmonary embolectomy: last resort-high mortality