1. Pulmonary Embolism Doug Bretzing, pgy 3

2. Definition
Obstruction of the pulmonary artery or one of its branches by material
Thrombus
Tumor
Air
Fat

3. Nomenclature
Massive – Sustained hypotension, systolic blood pressure < 90 mmHg for at least 15 minutes OR requiring inotropic support, or PE resulting in pulselessness
Submassive – Acute PE without hemodynamic instability but resulting in right ventricular dysfunction or myocardial necrosis
Clinically “Low Risk” - PE that doesn’t meet the above definitions

4. Epidemiology Incidence 112 cases in 100,000 in one database
Higher in males
Rises with increasing age
Accounts for approximately 100,000 annual deaths in the US (probably even higher due to sudden cardiac death)
Mortality
30 day – 4%
1 year – 13%

5. Risk factors for vte Virchow’s Triad Alterations in blood flow
Vascular endothelial injury
Alterations in the constituents of blood

6. source
Most arise from lower extremity proximal veins (iliac, femoral, and popliteal)
More than 50% of patients with proximal DVT have concurrent PE
Calf vein DVT rarely embolizes to the lung and two–thirds of calf vein thrombi resolve spontaneously after detection

7. pathophysiology Infarction – Occurs in about 10% of patients
Small thrombi lodge distally in to the segmental and subsegmental vessels
More likely to have pleuritic chest pain and hemoptysis
Name that sign!

8. Pathophysiology Abnormal gas exchange
due to mechanical and functional obstruction of the vascular bed altering the ventilation to perfusion ratio (V/Q Mismatch)
Cardiovascular compromise
Hypotension due to diminished stroke volume and cardiac output
Increased pulmonary vascular resistance due to physical obstruction and hypoxic vasoconstriction
RV dilation Decreased LV preload Decreased CO

16. Workup ABG Hypoxemia (74%) Respiratory alkalosis and hypocapnia (41%)
BNP
Limited diagnostic utility
Useful prognostically for risk stratification (and nomenclature)
Troponin
Similar utility as BNP

17. workup EKG Most common findings? (70%)
S1Q3T3, RV strain, new incomplete RBBB uncommon (< 10%)

18. workup Echocardiogram
Useful for prognostic purposes in patients with CONFIRMED PE
New RV strain and RV thrombus are poor prognostic indicators

19. treatment

22. Long-term anticoagulation

23. Pleural effusion

24. Indications for thoracentesis
Newly detected pleural effusion (unless there is an obvious cause, such as CHF)
Symptom relief
Imaging characteristics of complicated pleural effusion (e.g. loculations)
At least 1 cm pleural fluid on CXR or US

27. Light’s criteria
Pleural fluid protein/serum protein ratio greater than 0.5, or
Pleural fluid LDH/serum LDH ratio greater than 0.6, or
Pleural fluid LDH greater than two-thirds the upper limits of the laboratory's normal serum LDH

29. references
adults?search=pulmonary%20embolism&source=search_result&selectedTitle=1~150&usage_t ype=default&display_rank=1
initial- testing?search=pleural%20effusion&source=search_result&selectedTitle=1~150&usage_type= default&display_rank=1#H2
remember/2016/03/02/15/45/antithrombotic-therapy-for-vte-disease