Signs and Symptoms
- Leg swelling: most commonly noticed in posterior calf
- Leg warmth and redness
- Leg pain and tenderness
- Palpable cord, dilated superficial veins
- In superficial thrombophlebitis, a red pipe cleaner-like cord may be visible and palpable
- Arm swelling, warmth, or tenderness:
- Upper extremity or subclavian vein involved, may see cyanosis of hand /fingers
- Phlegmasia cerulea dolens:
- Cold, tender, swollen, and blue leg (secondary arterial insufficiency with venous gangrene)
- In phlegmasia alba dolens:
- Cold, tender, and white leg (secondary arterial insufficiency)
Essential Workup
- Determination of a patient's clinical (pretest) risk is a key step in a workup for DVT. The Wells score (or modified Wells score) is most commonly used
- A careful history and physical exam, interpreted in the context of the risk-factor profile, is the most important driver of subsequent diagnostic evaluation as individual clinical findings are poorly predictive in isolation
- Consider further evaluation for underlying malignancy when appropriate, as VTE may be initial manifestation
Diagnostic Tests & Interpretation
Lab
d-dimer testing:
- d-dimer, a byproduct of endogenous clot formation, is useful in evaluation of patients for both DVT and PE
- Only useful when the result is negative (to exclude DVT). Positive d-dimer does not make the diagnosis; it only mand ates further testing (highly sensitive but not specific test)
- Patients with low or moderate probability can be screened using D-dimer first, whereas high-probability patients should have imaging first
- Methods of measuring d-dimer level differ (be aware of institutional test):
- Latex agglutination (first-generation tests) and microlatex agglutination (second-generation) are generally insufficient
- Whole-blood latex agglutination (SimpliRED) is valuable if negative in low probability patients (using Wells criteria)
- Enzyme-linked immunosorbent assay (ELISA) testing gives a quantitative result and has been validated in large clinical studies in ED patients; particularly when combined with assessment of pretest probability
Imaging
- Contrast venography:
- Once the imaging test of choice; now rarely performed because it is invasive, expensive, and has complications
- Involves injection of contrast medium into a leg vein, which can cause thrombophlebitis in patients undergoing the procedure; as well as contrast dye reactions and possible renal damage
- Compression US:
- Stand ard first-line diagnostic test:
- Proximal (common femoral/femoral/popliteal veins) or whole leg
- Venous study. Normal veins compress; those with clots do not
- Color Doppler can be useful for identifying the vein but does not add substantially to accuracy. Duplex scanning refers to the combination of compression B-mode US and color Doppler
- Has a sensitivity in the high 90% range
- Should be repeated in 48-72 hr in high-risk patients with negative US
- Other tests include CT, MRI, radionuclide venography and impedance plethysmography; however, these are not as commonly used in clinical practice
- CXR should be performed in upper-extremity cases
Differential Diagnosis
- Superficial thrombophlebitis
- Cellulitis
- Torn muscle and /or ligaments (including plantaris and gastrocnemius tears)
- Ruptured Baker cyst
- (Bilateral) edema secondary to heart, liver, or kidney disease
- Venous valvular insufficiency
- Drug-induced edema (calcium channel blockers)
- (Unilateral) edema from abdominal mass (gravid uterus or tumor) or lymphedema
- Postphlebitic syndrome (from prior thrombophlebitis)
Initial Stabilization/Therapy
In cases of phlegmasia cerulean, or alba dolens or large clot burden
- IV access
- Supplemental oxygen as needed
- Prompt surgical or vascular consultation should be considered
ED Treatment/Procedures
- Systemic anticoagulation:
- In patients without contraindications as PE will occur in ∼50% of untreated DVT so incidentally found DVTs should still be treated
- Can use unfractionated heparin, low-molecular-weight heparin (LMWH), fondaparinux, or an oral anticoagulant
- Many patients can be primarily treated as outpatients
- Using either gestalt or risk stratification (e.g., HAS-BLED score) and pursue systemic treatment if risk of bleeding felt to be reasonably low
- Warfarin: Vitamin K antagonist
- Started shortly after a heparin has been administered; not before because of theoretic risk of induction of transient hypercoagulable state
- No longer first line for most DVT/VTE
- Direct oral anticoagulants:
- Dabigatran, rivaroxaban, apixaban, or edoxaban
- Generally first line unless DVT associated with cancer diagnosis, in which case LWMH may be more beneficial
- Vena cava filters:
- Main indication is for patient with contraindications to systemic anticoagulation:
- If new thromboembolic event occurs while on adequate anticoagulation, change to LMWH or increased dose of LMWH usually preferred
- Vena cava filters can be placed transcutaneously, usually by a vascular or trauma surgeon or radiologist
- Empiric filter placement may be useful in certain settings:
- Ongoing risk such as cancer, polytrauma
- Risk of a recurrent PE could be fatal because of poor cardiopulmonary reserve or a recent PE
- Rand omized data suggest that filter placement is no more effective than anticoagulation and may increase risk of DVT secondary to vascular injury
- Filters can also be deployed in the superior vena cava in the setting of upper-extremity DVT, although rare
- Thrombolysis:
- Rarely indicated, generally only for phlegmasia cerulean dolens; still give systemic anticoagulation
- Roughly a 3-fold increase in bleeding complications
- Catheter-administered lytic therapy is used more commonly in upper-extremity DVT
- Thrombectomy (surgical or percutaneous):
- Occasionally recommended for patients with extensive disease
- Consult a vascular surgeon; still give systemic anticoagulation
- Septic thrombophlebitis:
- Surgical excision of the vein or IV antibiotics
Medication
- Warfarin: 5 mg/d starting dose with a prothrombin time being checked on the third day; have to maintain IV or SQ treatment until INR therapeutic for 2 consecutive days
- Fondaparinux: Weight based; either 5 mg, 7.5 mg, or 10 mg SC per day; overlapped with warfarin
- Heparin (unfractionated): 80 units/kg IV bolus followed by an 18 units/kg/hr IV drip, with the activated partial thromboplastin time (aPTT) titrated 1.5-2.5 times normal
- LWMH (enoxaparin): 1 mg/kg SC b.i.d for outpatients (alternative: 1.5 mg/kg SC per day)
- Dabigatran: 150 mg PO b.i.d; for use in patients initially treated with parenteral anticoagulant
- Rivaroxaban: 15 mg PO b.i.d for 21 d, then 20 mg PO per day
- Apixaban: 10 mg PO b.i.d for 7 d, then 5 mg PO b.i.d
- Edoxaban: if <60 kg, 30 mg PO per day; otherwise 60 mg PO per day; for use in patients initially treated with parental anticoagulant
- Dalteparin: 200 units/kg/d SC divided b.i.d, not to exceed 18,000 units/dose; overlapped with warfarin
- Dosing regimens are based on total body weight; however, in obese patients alternative dosing should be considered
- Treatment usually maintained for at least 3 mo, but total length is individualized
- Note that most treatment medications need to be adjusted for renal function
Disposition
Admission Criteria
- Patients with DVT unable to receive LMWH or obtain oral medications as an outpatient or those with poor follow-up
- Patients with concomitant PE or other serious diseases (i.e., renal failure)
- Patients who are high bleeding risk
- Patients with iliofemoral disease, phlegmasia
Discharge Criteria
- Outpatient treatment:
- No serious concomitant disease that requires hospitalization, hemodynamically stable, no significant renal insufficiency
- Patient has means of communication and transportation to return to the hospital if needed, as well as appropriate follow-up
- Patient (or family member) is willing and able to inject the medication for LMWH
- Patients with superficial or distal thrombophlebitis can also be discharged with close follow-up
Issues for Referral
- Consult vascular surgery if there is any question about arterial insufficiency
- Consider need for inferior vena cava filter in patients who have contraindications to full anticoagulation
- Consider referral for hypercoagulable work-up if unprovoked VTE
ALERT |
| When the clinical suspicion is high but the US is negative, remember to advise the patient to follow-up with his or her primary care physician, and to have a follow-up US within the week |
Follow-up Recommendations
- For LMWH: Patient needs hematocrit, platelet count, and INR checked in 2-3 d
- Ambulation is recommended and is not thought to propagate clot
- Graduated compression stockings are not routinely recommended