Session 15_DVT Flashcards
List several complications associated with bed rest:
- Decubitus ulcers (injury to skin and underlying tissue resulting from prolonged pressure on the skin)
- Pneumonia
- DVT
- Constipation
- Urinary infection
- Osteoporosis
- Urostasis (stoppage of urination flow)
List several complications associated with surgery:
- Hypoxemia
- hypercapnea
- anemia
- pain
- atelectasis (complete or partial collapse of a lung or a section (lobe) of a lung)
- pneumonia
- DVT
- PE
- Sepsis (a life-threatening complication of an infection)
- multi system failure
What does thrombosis refer to? When does it occur?
- Thrombosis refers to “a condition” of a blood clot
- Thrombosis occurs with slowing or disruption of blood flow
- It is most frequently occurs in the calf (“the formation or presence of a blood clot in a blood vessel. The vessel may be any vein or artery as, for example, in a deep vein thrombosis or a coronary (artery) thrombosis. The clot itself is termed a thrombus.”)
What can DVT turn into when the clot breaks off and travels to the lung circulation?
a PE
a traveling thrombosis =
emboli
VTE =
venous thromboembolism
Where do DVT occur?
deep veins of the leg (eg. iliac, femoral, popliteal, tibial)
List potential causes of a DVT:
- long flights
- immobility due to anesthesia/ post surgical
- oral contraceptives
- paralysis
- pressure to the calf
- septicemia
- cancer
- disorder of clotting
- atrial fibrillation or other heart failure
- damage to a blood vessel
- post trauma
- congestive heart failure
- genetics
- age
- smoking
- dehydration
- pregnancy
What veins are implied when talking about DVT?
- Peroneal vein in the calf
- Femoral vein of the thigh
- Axillary or subclavian vein of the arm
- pelvic veins
How do you prevent DVT?
~ Prophylaxis ~ •compression hose • SCDs (sequential compression device) • Preventative anticoagulation e.g. coumadin • mobilizing
Despite prophylaxis, 31% of patients undergoing total knee replacement develop DVT, and 27% of patients operated on for hip fracture develop DVt. What alternative method has been shown to reduce incidence to 16%?
low-molecular weigth heparin prophylaxis
How are DVTs diagnosed?
•Ultrasound of the blood vessels
•Wells DVT criteria
•Homans sign (?) - (senstivity and specificity not optimal)
–> dorsiflexion/ resistance test
Describe the procedure of Doppler ultrasonography:
- A blood pressure cuff is wrapped around the pt’s ankle
- A transducer with gel on it is placed over the pulse points of the foot and lower leg. High-frequency sound waves bounce off the soft tissue, and the echoes are converted into images on a monitor.
- This procedure is very accurate in detecting clots. Usually performed in a physicians’ office or hospital outpatient diagnostic center.
Describe Well’s criteria:
- Active caner? +1
- Bedrest >3 days or recent major surgery? +1
- Calf swelling >3cm compared to other leg? +1
- Entire leg swollen? Yes +1
- Calf tenderness along deep veins? +1
- Pitting edema, in the symptomatic leg? Yes +1
- Paralysis, paresis, or immobilization of the lower extremity? Yes +1
- Previous DVT? +1
- Alternative diagnosis to DVT likely? -2
How is Wells DVT criteria scored?
- High = >/- 3 points = DVT risk 75%
- Moderate = 1-2 points = DVT risk 17%
- Low =
Describe what D-Dimmer is and what a negative result implies:
- A blood test to help diagnosis DVT
- D-DIMER is a fibrin degradation product (FDP), a small protein fragment present in the blood after a blood clot is degraded
- Only present if the coagulation process has been activated
- A NEGATIVE result practically rules out thrombosis, a positive result can indicate thrombosis but does not rule out other potential causes
- Introduced in 1990
What are some signs and symptoms of DVT?
- Pain in the calf
- Calf swelling
- redness
- Well’s criteria
- Positive Homans sign??
What are some complications of DVT?
PULMONARY EMBOLUS:
•Most PEs result from DVT
•Piece of the thrombus breaks off, travels through the R side of the heart and into the pulmonary artery
•Can lodge in one of the smaller pulmonary capillaries
•Blockage to the pulmonary artery
Can you see a PE on a x-ray?
NO, can’t see PE on x-ray
What are the signs and symptoms for when a DVT has become a PE (VTE)?
Symptoms = shortness of breath, cough, sharp/sudden chest pain Signs = rapid pulse, hyotension, sweating, tachypnea, desaturation of the blood
Diagnosing PE; VQ (ventilation-perfusion) scan. Findings indicate what?
VQ scan finding = VQ mismatch in PE (high)
VQ mismatch in COPD, emphysema or atelectasis (low)
How do you prevent PE?
•Greenfield filter:
- -> It is introduced through the jugular vein and is lodged in the inferior vena cava
- -> Catches emboli
List some common pharmacological treatments of DVT/ pulmonary emoli:
- Anticoagulation such as: enoxaparin a.k.a. low molecular weight heparin (drug of choice since mid ’90s)
- Standard unfractionated Heparin
- Coumadin aka. warfarin
(** note: while heparin does not break down clots that have already formed, it allows the body’s natural clotlysis mechanisms to work normally to break down clots that have formed)
(After a DVT) when can a patient ambulate?
•When dose of anticoagulation is “theraputic”; usually within 6 hours
•Opinion varies by doctor
Recommendation from research: walk as soon and as much as possible with good compression therapy following anticoagulation therapy.
• Ambulation also leads to better outcomes: decreased pain, swelling and concurrence/severity of postthrombotic syndrome
see slide 25 for algorithm on ambulation
see slide 25 for algorithm on ambultation
Research shows:
When compared to bed rest, early ambulation was not associated with a higher incidence of a new PE. Furthermore, early ambulation was assocated with:
•lower new PE and new or progression of DVT
•lower incidence of new PE and overall mortality
What are the 5 APTA recommendations?
- Don’t employ passive physical agents except when necessary to facilitate participation in an active treatment program
- Don’t prescribe underdosed strength training programs for older adults. Instead, match the frequency, intensity, and duration of exercise to the individual’s abilities and goals.
- Don’t recommend bed rest following diagnosis of acute deep vein thrombosis after the initiation of anticoagulation therapy unless significant medical concerns are present.
- Don’t use continuous passive motion machines for the postoperative management of patients following uncomplicated total knee replacement
- Don’t use whirlpool for wound management
