Deep vein thrombosis resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Abdurahman Khalil, M.D. [2]
Definition
Deep vein thrombosis (also known as deep venous thrombosis or DVT and colloquially referred to as economy class syndrome) is the formation of a blood clot ("thrombus") in a deep vein. The risk is significantly increased if the thrombus embolizes to the lungs, causing pulmonary embolism.
Causes
Life Threatening Causes
Common Causes
- Long term immobility
- Clotting disorders
- Cardiac failure
- Hip replacement
- Estrogen in OCP and HRT
- Nephrotic syndrome
- Obesity
- Pregnancy
Diagnostic approach
| Pretest Probability of DVT Major points 1-Active cancer 2-Paralysis,paresis or plastic immobilization of leg or foot 3-Recent bed rest >3 days or major surgery in the last 4 weeks or both 4-Calf or thigh swelling 5->3 cm calf swelling below the tibial tuberosity 5-Strong F/H of DVT Minor points 1-H/O recent trauma to the suspected leg 2-Pitting edema in the suspected leg 3-Dilated superficial veins in the suspected leg 4-Hospitalization in the last 6 months 5-Erythema | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Low probability* | Moderate probability* | High probability* | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| D-Dimer | D-Dimer | U/S | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| No DVT | U/S | No DVT | U/S | Repeat in 7 days | D-Dimer | Treat | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| No DVT | Treat | Repeat in 7 days | Treat | No DVT | Repeat in 7 days | U/S[1] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
- High probability:
>3 major points+ no alternative diagnosis
or 2 major points + 2 minor points + no alternative diagnosis.
Low probability:
1 major point +≥2 minor + alternative diagnosis
or 1 major + ≥1 minor + no alternative diagnosis
or no major points+ irrespective of minor points +irrespective of diagnosis.
Moderate probability:
neither high or low probability.[2]
Management
| DVT confirmed | |||||||||||||||||||||||||||||||
| Hemodynamically unstable(massive PE) SBP<90 mm Hg or 40 mm Hg drop Syncope Severe hypoxemia or respiratory distress | Hemodynamically stable | Contraindication for Anticoagulation therapy Absolute Active severe hemorrhage Intracranial hemorrhage Relative Recent surgery, trauma, anemia,GI bleeding, PUD | |||||||||||||||||||||||||||||
| Thrombolytic therapy | LMWH or UFH(target INR:2.5, monitor Plt count)+ Warfarin or Fondaparinux | IVC filter | |||||||||||||||||||||||||||||
Do's
- Start vitamin K antagonist no more than 1 or days after start UFH or LMWH.The initial dose for the first 2 days should be 10 mg daily then in accordance to the required INR measurements.
- INR therapeutic ranges are 2.0-3.0 and Target INR is 2.5 and that is applied for patients with hypercoagulable state (antiphospholipid syndrome).
- For IV UFH administration use weight adjusted dose for the initial bolus(80 unit/kg) and the following continuous infusion(18 unit/kg/hr), and for subcutaneous UFH (first dose 333 units/kg, then 250 units/kg).[3]
Don'ts
References
- ↑ Bates SM, Jaeschke R, Stevens SM, Goodacre S, Wells PS, Stevenson MD; et al. (2012). "Diagnosis of DVT: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e351S–418S. doi:10.1378/chest.11-2299. PMC 3278048. PMID 22315267.
- ↑ Wells PS, Anderson DR, Bormanis J, Guy F, Mitchell M, Gray L; et al. (1997). "Value of assessment of pretest probability of deep-vein thrombosis in clinical management". Lancet. 350 (9094): 1795–8. doi:10.1016/S0140-6736(97)08140-3. PMID 9428249.
- ↑ Holbrook A, Schulman S, Witt DM, Vandvik PO, Fish J, Kovacs MJ; et al. (2012). "Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e152S–84S. doi:10.1378/chest.11-2295. PMC 3278055. PMID 22315259.