DVT/PE therapeutics tutorial Flashcards
what are the cardiac causes of chest pain?
- -STEMI/NSTEMI
- -Aortic dissection
- -cardiac tamponade
- -pericarditis
what are the GI causes of chest pain?
- -GERD and erosive esophagitis
- -esophageal perforation
- -PUD
- –Acute pancreatitis
- -Mallory-Weiss syndrome
what are the pulmonary causes of chest pain?
- -PE
- -tension pneumothorax
- -pneumonia
- -asthma exacerbation
- -pleura leffusion
what are the other causes of chest pain except for cardiac, pulmonary and GI?
- -costochondritis
- -pannic attack
- -herpes zoster
what is the differential diagnosis of a 2-hour history of pleuritic chest pain, dyspnoea, hemoptysis, and pleural rub?
Pulmonary Embolus
Pneumonia with Pleuritic Involvement
–Chronic/long-standing conditions unlikely causes of 2-hour history
1)Bronchiectasis / Chronic Bronchitis
2)Chronic infections such as TB or lung abscess
3)Lung Cancer
4)An inflammatory condition such as Sarcoidosis, Good Pasteur’s Syndrome
what are the symptoms of PE?
- -Acute onset of symptoms, often triggered by a specific event (e.g., on rising in the morning, sudden physical strain/exercise)
- -Dyspnea and tachypnea (> 50% of cases)
- -Sudden chest pain (∼ 50% of cases), worse with inspiration
- -Cough and hemoptysis
- -Possibly decreased breath sounds, dullness on percussion, split-second heart sound audible in some cases
- -Tachycardia (∼ 25% of cases), hypotension
- -Jugular venous distension
- -Low-grade fever
- -Syncope and shock with circulatory collapse in massive PE (e.g., due to a saddle thrombus)
- -Symptoms of DVT: unilaterally painful leg swelling
what are the risk factors for DVT and PE?
- -History of DVT or PE (30x increased risk)
- -Immobilization: e.g., post-surgery, long-distance flights, trauma (20x increased risk)
- -Age > 60 years
- -Malignancy
- -Hereditary thrombophilia (especially factor V Leiden)
- -Pregnancy, estrogen use (oral contraceptives)
- -Obesity
- -Smoking
- -IV drug use
- -Nephrotic syndrome
- -Insufficient thrombosis prophylaxis, noncompliance with prophylaxis
- -To remember the risk factors of deep vein thrombosis, think “THROMBOSIS”: Travel, Hypercoagulable/HRT, Recreational drugs, Old (> 60), Malignancy, Blood disorders, Obesity/Obstetrics, Surgery/Smoking, Immobilization, Sickness (CHF/MI, IBD, nephrotic syndrome, vasculitis)!
name direct Factor Xa Inhibitor
apixaban/rivaroxaban
name direct thrombin inhibitor
dabigatran
Indirect Inhibitor of Factor Xa??
LMWH
Indirect Inhibitor of both Factor Xa and Thrombin??
heparin
an anticoagulant that Interferes with the synthesis of clotting factors by preventing the reduction of vitamin K?
warfarin
UFH vs LMWH?
1) Unfractionated Heparin (UFH) – complexes with and activates anti-thrombin, and is therefore an indirect inhibitor of factor Xa and thrombin – monitored by APTT.
2) Low molecular weight heparin (LMWH) eg enoxaparin – complexes with and activates anti-thrombin, and is therefore an indirect inhibitor of factor Xa – Laboratory monitoring usually not indicated.
does LMWH require monitoring of PTT?
no
how warfarin is monitored?
by INR
do dabigatran and rivaroxaban require lab monitoring?
No
- -Dabigatran – direct thrombin inhibitor (binds thrombin and prevents the cleavage of fibrinogen to fibrin). Laboratory monitoring not indicated.
- -Rivaroxaban and Apixaban – reversible direct inhibitors of factor Xa. Laboratory monitoring not indicated.
what anticoagulants can be used in hemodynamically stable patients with PE?
1)Subcutaneous Low Molecular Weight Heparin
–eg Enoxaparin 1 mg/kg subcut twice daily.
(Unfractionated heparin (UFH) in patients with renal failure and those who may still require thrombolysis)
2)New Factor Xa Inhibitors have been shown to be equally effective, to result in less major bleeding events, and no need to monitor the anticoagulant effect
–Apixaban
–Rivaroxaban
in a patient with PE and the hypoxia and hypotension, what are the management options?
1) The patient should be admitted to the Intensive Care Unit (ICU)
2) Active resuscitation with oxygen should be commenced immediately.
3) Intravenous fluid and possibly inotropic agents (vasopressors such as norepinephrine, dopamine or dobutamine) should be commenced immediately.
4) Given the presence of hypotension (SBP <90mmHg) systemically administrated thrombolytic therapy is indicated (Intravenous tPA) followed by intravenous unfractionated heparin (IV UFH).
5) Initial intravenous heparin bolus: 80 units/kg.
6) Continuous intravenous heparin infusion: 18 units/kg/hour
7) If no improvement gained surgical or catheter embolectomy could be considered.
what are the indications for thrombolytic therapy?
n cases of massive PE causing right heart failure
In hemodynamically unstable patients requiring resuscitation
What investigation(s) should be performed so as to confirm the diagnosis of pulmonary emboli?
- -Spiral (Helical) CT scanning with intravenous contrast [CT pulmonary angiography (CTPA)]
- -Ventilation Perfusion Scan
- -Pulmonary angiography (with intra-arterial contrast)
- -Are all possible confirmatory investigations
what are the indications of ventilation/perfusion scans?
–Indication: alternative to CT angiography in patients with severe renal insufficiency or contrast allergy
–Method: detects areas of ventilation/perfusion (V/Q) mismatch via perfusion and ventilation scintigraphy
Assessment
–Perfusion failure in normally ventilated affected pulmonary area (mismatch) suggests PE
–Evidence of normal lung perfusion rules out PE → ventilation scintigraphy superfluous
what is the indication of pulmonary angiography?
- -Indications: only conducted if CT angiography unavailable
- -Procedure: right heart catheterization → insertion of a catheter into a pulmonary artery → radiograph after administration of contrast agent
what is the best test for PE?
- -Helical spiral CT/CT pulmonary angiography (CTPA): best definitive diagnostic test
- -Contrast-enhanced imaging of the pulmonary arteries
- -High sensitivity, specificity and immediate evidence of pulmonary arterial obstruction
- -Visible intraluminal filling defects of pulmonary arteries
- -Wedge-shaped infarction with pleural effusion is almost pathognomonic for PE
what meds are used for long-term anticoagulation and prophylaxis of PE?
- -Oral anticoagulant therapy should be commenced once the diagnosis of pulmonary embolus is confirmed.
- -Warfarin was most commonly prescribed.
- -Recent trial data suggest that Dabigatran, Apixaban, and Rivaroxaban;
1) Provide very similar protection against recurrent thrombosis,
2) Causes less bleeding,
3) Need less/no monitoring,
4) Monoclonal antibody binders acting as reversal agents now available - -Patients with a hypercoagulable state with DVT or PE: heparin followed by 3–6 months of warfarin for the first event, 6–12 months for the second, and lifelong anticoagulation for further events
