PE + Pulmonary HTN + Cor Pulmonale Flashcards
pulmonary embolism def + description
Definition: A result of a thrombus formation within deep venous circulation traveling into pulmonary circulation
Description:
-3rd leading cause of death among hospitalized patients
- most pts will have PE and DVT on evaluation
- PE typically present in multiples!!!!
- Often affects LOWER LOBES- Lobes of greater perfusion
substances that can embolize to pulmonary circulation
-Thrombus* (MC) -> most pts have DVT and PE
-Air
-Amniotic fluid
-Fat
-Foreign bodies
-Parasite eggs
-Septic emboli
-Tumor cells
PE and DVT: risk factors
Risk factors = Virchow’s triad
-Venous stasis
-Injury to the vessel wall
-Hypercoagulability
what increases venous stasis
-immobility** * (pts in bed)
-hyperviscosity
-increased central venous pressures
bloodflow through veins slows down when you dont move at all, blood is too thick, when you have a condition that causes too much blood in veins (HF, obese)
what damages vessels
- prior thrombosis
- orthopedic surgery
- trauma
what causes hypercoagulability
-medications
-disease
-genetic defects
pathophysiologic response to PE
PE are typically multiple, with lower lobes being involved in majority of the cases
–Abnormal gas exchange
- Cardiovascular compromise: right ventricular strain
- infarction (rare)
Infarction - RARE
- 2 circulations to lungs so rare
- need large PE
PE typically present as ______.
PE affects which lobes?
- PE typically present in multiples!!!!
- Often affects LOWER LOBES- Lobes of greater perfusion
PE signs and symptoms
-Difficult to diagnose
-Depend on size of the embolus and the patient’s preexisting cardiopulmonary status
MC:
- dyspnea (on rest or exertion)
- SOB
- CALF/THIGH PAIN or SWELLING
- Orthopnea: >2 pillows at night
PE presentation: acute vs subactue vs chronic
Acute
- S/S present IMMEDIATELY after obstruction of pulmonary vessels
Subacute
- S/S present within DAYS or WEEKS following initial event
Chronic
S/S slowly develop over many YEARS
most signs of PE
Signs:
-Tachypnea (MC)
-Tachycardia (24 percent)
-Rales (18 percent)
-Decreased breath sounds (17 percent)
-Accentuated pulmonic component of the second heart sound (ddx with PHTN)*
-JVD (14 percent)
hemodynamically unstable PE
PE results in HYPOTENSION
-this is not good…
Hypotension:
- systolic blood pressure <90 mmHg OR
-Drop in systolic BP ≥40 mmHg from baseline for >15 minutes OR
-Hypotension requiring vasopressors or inotropic support
-not due to other causes
PE-Wells criteria
How to determine Probability of Pulmonary Embolism:
“DA PITCH”
- DVT signs + synmptoms: 3
-Alternative Dx not likely: 3 - Previous DVT/PE: 1.5
- Immobilization > 3 days: 1.5
- Tachycardia: 1.5
- Cancer with active tx: 1
- Hemoptysis: 1
If < 4 Pts = PE Unlikely
If > 4 Pts = PE Likely
PE: abg
ABG: NOT diagnostic
- hypoxemia
- hypocapnia (low CO2)
- respiratory ALKALOSIS -> tachypnea
PE EKG
Abnormal in 70%!!!
-Sinus tachycardia and nonspecific ST and T wave changes
-S1Q3T3 pattern
Plasma D-dimer: PE
Very sensitive but non specific: ONLY HELPFUL IF ITS NEGATIVE!!!!
-May be elevated in the presence of thrombus (non-specific)
- D-dimer is used to r/o diagnosis of PE if <500 ng/mL
–
PE: lab values
-Leukocytosis: increase WBC
- elevated ESR: inflammation
- LDH: nonspecific tissue damage
PE CXR
-Excludes other common lung diseases
-Need for interpretation of V/ ˙Q scan
-Westermark’s sign
-Hampton’s hump: uncommon
Westermark’s sign
Prominent central pulmonary artery [black arrow] with local oligemia (Decrease in lung markings) [white arrow]
Hampton’s Hump
PE sign:
Increased opacity that represents intraparenchymal infarct
Hard to differentiate from consolidation in Pn
Ventillation-perfusion (V/Q) scan
Perfusion scan:
- Inject radiolabeled albumin into the venous system
- normal scan: exclude dx of clinically significant PE
- > 2 segmental perfusion defects with normal ventilation is highly suggestive of PE
Ventilation scan:
- Breathe a radioactive gas/ aerosol while the distribution of radioactivity in the lungs is recorded.
–Both scans are interpreted together to give a high, low, or intermediate (indeterminate) probability that PE is the cause of the abnormalities.
spiral CT pulmonary angiography
MC evaluation: GOLDEN STANDARD
- Very sensitive in proximal pulm arteries
- Less sensitive in distal arteries
- normal chest CT not adequate to exclude PE
“spiral-> more important for center and the ends not as sensitive”
pulmonary angiography
Definitive Dx:
-An intraluminal filling defect in more than one projection
Secondary findings highly suggestive of PE
-Abrupt arterial cutoff
-Asymmetry of blood flow: especially segmental oligemia
pulmonary angiography indications
-Other testing is negative, but high clinical suspicion
-Anticoagulation is contraindicated
- Placement of IVC filter is contemplated
- Catheter based extraction or thrombolysis
