Case Study of the Week: DVT

This weekend, my husband and took a road trip to Indianapolis giving me plenty of time behind the wheel to contemplate various road-trip related medical conditions for this week's case study.  I ultimately decided on the DVT (deep vascular thrombosis).  DVT is a diagnosis I make, or at least rule-out frequently in my practice.  As a nurse practitioner, whether you work in primary care or a more specialized practice, you will see patients with DVT's and must know how to accurately diagnose and treat this condition.  Undiagnosed DVT can lead to pulmonary embolism and death.

Estimates suggest that 60,000 to 100,000 Americans die each year as a result of a DVT.  10 to 30 percent of individuals diagnosed with DVT die within one month of diagnosis.  Among those diagnosed with DVT, one-half will suffer long-term complications and one-third will have a recurrence within ten years. Five to eight percent of the U.S. population has a genetic predisposition increasing risk of thrombosis.  Given these numbers, nurse practitioners must be familiar with the diagnosis of DVT as it is prevalent and a life-threatening medical condition.

Case Presentation

A 62 year-old female presents to your clinic with pain, swelling and redness to her right lower leg.  She states that she is exeriencing right calf pain worse with walking.  She does note that she returned home from a vacation to Europe last week which included a 15 hour flight.  The patient's vital signs are stable.  She is afebrile.  The patient has a past medical history including hypertension and type two diabetes both of which are controlled with oral medications. 

On exam, you notice this patients right leg to be slightly erythematous and her calf is tender to touch.  She has trace pedal edema in the affected leg and limps slightly when walking.  Her right calf is greater in size compared to her left.  Given this patient's medical history as well as her recent sedentary activity on her long flight, you are concerned she may have a DVT and order a venous ultrasound of her left leg.  Ultrasound results reveal a deep venous thrombus in her popliteal vein.

Management and Outcome

Based on this patient's ultrasound results, you prescribe her five days of subcutaneous injectable heparin as well as coumadin.  You instruct her to return to the clinic in five days to recheck her INR.  You also issue strict instructions to return should she develop chest pain or shortness of breath educating her about the complication of pulmonary embolus.

The danger of a deep venous thrombus is that part or all of the clot dislodges and travels to the lung resulting in pulmonary embolism and death.  DVT must be treated with anticoagulants and can often be treated on an outpatient basis depending on the patient's ability to care for themselves and their comfort level with giving themselves injections.  Anti-coagulation is the treatment for DVT.  Subcutaneous heparin must be administered for at least five days.  Oral Warfarin must also be given simultaneously and continued for three to six months.  Ultrasound should be repeated in one week post-diagnosis to monitor for extension of the clot.  In individuals with bleeding disorders or those who cannot take anticoagulants, a vena cava filter can be inserted to prevent pulmonary embolus.  Compression stockings should be worn to relieve the pain and swelling associated with DVT and prevent chronic complications.

Discussion

Risk factors for DVT include sedentary lifestyle or recent sedentary behavior such as a long road trip, genetic clotting disorder, prolonged bed rest such as hospitalization, recent injury or surgery, pregnancy, cancer, heart failure, use of birth control pills or hormone supplements, smoking, obesity and family or personal history of DVT.  The Well's DVT Criteria can help you calculate risk of DVT for your symptomatic patients.  Patients presenting with symptoms of DVT must be promptly diagnosed and treated as the most serious complication of DVT, pulmonary embolism is often fatal.  DVT sufferers may also continue to suffer from edema, paresthesia and ulcerations in the affected limb therefore compression stockings should be recommended.

When in doubt, ultrasound!  It is always better to order an ultrasound in a patient presenting with symptoms of DVT rather than miss this diagnosis.  I have seen patients develop DVT from simply wearing a knee brace for a week after a knee strain injury.  DVT can be deadly.  Educating your pateints with risk factors for DVT is a must.  The CDC provides free, educational handouts you can print and offer to your patients with risk factors. 

References

CDC. Deep Venous Thrombosis/ Pulmonary Embolism. http://www.cdc.gov/ncbddd/dvt/index.html

A.D.A.M Medical Encyclopedia Deep Venous Thrombosis February 19, 2012 http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001209/

Wedro, Benjamin; MedicineNet, Deep Venous Thrombosis http://www.medicinenet.com/deep_vein_thrombosis/page6.htm#what_are_the_complications_of_deep_vein_thrombosis

Comments

Very usefull case.

Gaol

Wouldn't you ultrasound her right leg? Not her left?

Brittany