DVT PE Flashcards
VTE can lead to: (can cause deaths, and affect survivors)
PE - cause of death
Chronic thromboembolic pulmonary hypertension
Postphlebitic syndrome - among survivors
Three major CV causes of death?
- VTE 2. MI 3. Stroke
Most preventable cause of death?
Pulmo embo
High risk for VTE include:
Major surgery
Heart failure
Cancer
Stroke
Chronic thromboembolic pulmo HPN causes:
Breathlessness
Late effect of DVT is post phlebitic syndrome, AKA:
Post thrombotic syndrome
Chronic venous insufficiency
PPS causes ___ to the valves of the leg
Causes venous valves of the leg to become incompetent and exude interstitial fluid
PPS CVI causes what after prolonged standing?
Chronic ankle or calf swelling
Leg aching
Severe PPS causes skin ulceration in the:
Medial malleolus
What state (platelet) contributes to VTE?
Prothrombotic state
Thrombophilia
Two most common autosomal dominant genetic mutations that lead to prothrombotic states
Factor V Leiden
Prothrombin gene mutation
Factor V Leiden causes resistance to:
Activated protein C – which inactivates clotting factors V and VIII
(Resistance to the inactivators – promotes activation – prothrombotic)
Prothrombin gene mutation ___ plasma prothrombin concentration
Increases
3 Coagulation inhibitors
Antithrombin
Protein C
Protein S
Hyperhomocysteinemia can increase the risk of VTE. What can lower homocysteine levels?
Folate
Vitamin B6
Vitamin B12
(but does not lower incidence of VTE)
Most common acquired cause of thrombophilia?
Antiphospholipid antibody syndrome
Predisposing factors to VTE:
- Cancer 2. Systemic arterial HPN 3. COPD 4. Long haul air travel 5. Air pollution 6. Obesity 7. Cigarette smoking 8. Eating red meat 9. OCPs 10. Pregnancy 11. Postmenopausal HRT 12. Surgery, trauma
Paradoxical PE passes through:
Patent foramen ovale or Atrial septal defect
Most common source of paradoxical embolism
Isolated calf vein thrombi
Increases risk for upper extremity venous thrombosis:
- Chronic indwelling central venous catheter (chemo, feeding)
- Frequent insertion of permanent pacemakers and internal cardiac defibrillators
Two most common gas exchange abnormalities
Hypoxemia (decreased atrial pO2)
Increased alveolar-arterial O2 tension gradient – inefficient O2 transfer across the lungs
Breathed gas does not enter gas exchange causing increase in:
Anatomic dead space
Ventilation to gas exchange units > venous blood flow through pulmo capillaries increases:
Physiologic dead space
In PE, there is INCREASED vascular resistance, caused by:
- Vascular obstruction
2. Release of serotonin by platelet
Why is there potential discordance between small PE and large AaO2 gradient?
Due to release of vasoactive mediators – produce VQ mismatch distal to the embolus
There is impairment of gas exchange due to:
- Increased alveolar dead space from vasc obstruction
- Alveolar hypoventilation – hypoxemia
- Right to left shunting
- Impaired carbon MONOxide transfer
Constriction of airways distal to the bronchi causes
Increased airway resistance
Reflex stimulation of irritant receptors cause
Alveolar hypoventilation
Decrease in pulmo compliance is due to:
Lung edema, lung hemorrhage, loss of surfactant
Usual cause of death from PE:
Progressive right heart failure
Pathophysio of RV failure in PE
Inc PVR – Inc RV wall tension – RV dilation, dysfunction – prolonged RV contraction even at end-systole – IV septum bulges to LV – impaired LV diastole
Inc RV wall tension – compress RCA – dec perfusion – dec myocardial O2 supply – ischemia, infarction
Harrison’s labels VTE as the great:
Masquerader
Failure to improve despite standard medical treatment can be a clue. Common concomitant illnesses:
Heart failure
Pneumonia
Common history in DVT
Cramp in the lower calf that persists for days and becomes more uncomfortable over time
Most common history in PE
Unexplained breathlessness
Initial test for low to moderate likelihood of DVT
D dimer
If D dimer is abnormally elevated, next step is
Imaging
Differential diagnosis of DVT
PCR
Post phlebitic syndrome, CVI
Cellulitis
Ruptured Baker’s Cyst
DDx of PE
PPAARC Pneumonia, asthma, COPD Pleurisy: costochon, muscle discomfort ACS Anxiety; Arte Rib fracture -- pneumothorax CHF
DDx: sudden severe calf discomfort
Ruptured Baker’s cyst
Calf discomfort + Fever and chills
Cellulitis
PE finding in DVT
Mild palpation discomfort on the lower calf – mild DVT
Marked swelling of thigh and tenderness on palpation of common femoral vein – severe DVT
If leg is diffusely edematous, DVT unlikely. Most probably:
Acute exacerbation of CVI, PPS
Presentation of UE VTE:
Asymmetry of supraclavicular fossa
Circumference of upper arms
Massive PE presents as
Systemic arterial hypotension
Moderate PE presents as __ in 2d echo
RV hypokinesis, but have normal systemic arterial pressure
Small PE presents as:
Normal right heart function and normal systemic arterial pressure
Small PE can cause __ when it is lodged peripherally
Pulmonary infarction
Usually painful, near the innervation of pleural nerves
Pleuritic chest pain more common in
Small peripheral emboli
Examples of nonthrombotic emboli
- Fat emboli - after pelvic or long bone fracture
- Tumor emboli
- Bone marrow emboli
- Air emboli
- Cement and bony fragment emboli - after total knee and hip replacement
- Hair talc cotton emboli - in IV drug users
- Amniotic fluid emboli - leaky fetal membranes, tear in placental margins
Most common symptom of PE
Dyspnea
Most common sign of PE
Tachypnea - SITA - sign tachypnea
