The Silent Threat: Deep Vein Thrombosis

Sparked by the tragic death of NBC reporter David Bloom last year, deep vein thrombosis (DVT) has finally begun to receive the attention it deserves from the consumer health media. The journalist was seated for hours in a military tank as he reported on the war in Iraq - a situation that led to his untimely death. Although most Americans will not find themselves in such a situation, there are lessons to be learned from it about the risks associated with restricted mobility.

People do not realize that lying in a hospital bed, as well as dozens of other factors, put everyone (from healthy young people to the elderly) at risk for DVT. A national survey issued last year showed that 74% of Americans are largely unaware of DVT or its serious and sometimes fatal complications - such as pulmonary embolism (PE), which occurs when blood clots break off and travel to the lungs.¹

DVT and PE are 2 serious conditions categorized together as venous thromboembolism (VTE). VTE is becoming a national health crisis: the American Heart Association estimates that 2 million people suffer from DVT, and up to 600,000 patients are hospitalized for the condition annually. PE claims between 60,000 and 200,000 lives each year. Whereas no single medical specialty is solely responsible for the treatment of DVT, it is especially important for pharmacists to be vigilant in preventing this condition and educating their patients about it.

The Hospital Pharmacist?s Role

VTE is prevalent in the hospital setting. Many hospital patients carry at least 1 of the broad range of DVT risk factors, which include age, obesity, surgery, medical illness, cancer, pregnancy, smoking, or prolonged immobility from being bedridden. In fact, DVT leading to PE is possibly the most preventable cause of death in hospitalized patients. It is important for medical professionals to work aggressively to prevent this problem before it occurs. All medical professionals in the hospital - particularly pharmacists - should be mindful of the risk factors and the need for prophylactic treatment of DVT.

In addition to counseling patients about the risk factors and symptoms of DVT, pharmacists have the opportunity while making rounds to recommend appropriate prophylaxis regimens to physicians. If these opportunities do not exist, the pharmacist who is screening orders and inputting a physician?s request into the database can get an idea of the patient?s risk level and communicate to the physician his or her recommendations for appropriate prophylaxis. At my institution, the Moses H. Cone Memorial Hospital in Greensboro, NC, we continuously interact with physicians to improve upon safety and efficacy outcomes while seeking to ensure that all patients at risk are ?prophylaxed? against the occurrence of VTE. Dr. Groce is associate professor of pharmacy practice at Campbell University School of Pharmacy, Blues Creek, NC; clinical assistant professor of medicine at the University of North Carolina School of Medicine in Chapel Hill, NC; and clinical pharmacist specialistanticoagulation at the Moses H. Cone Memorial Hospital in Greensboro, NC.

Recently, a 51-year-old woman was admitted to our hospital with rectal bleeding, necessitating surgical consultation and endoscopic examination. Diagnosed with ulcerative colitis, she had several predisposing risk factors for VTE:

• She was >40 years old
• She had had previous thromboembolic episodes, including deep vein thrombosis and embolic stroke due to antiphospholipid antibody syndrome (APLABS)
• Her medical history included lupus and rheumatoid arthritis
• Her hospitalization was complicated by pneumonia
• She was ordered to rest in bed for >3 days

With this patient?s ongoing risk of VTE, physicians initially placed her on unfractionated heparin (UFH). Upon joining the rounding team the morning after her admission, however, the pharmacists and pharmacy students discussed with the physician team other drug therapy options available, especially considering her history of embolic events, concomitant risk factors, and disease states. APLABS was a key concern, because the use of the activated partial thromboplastin time (aPTT) test to follow UFH-treated patients is fraught with error. The aPTT test responsiveness is extremely variable, not accurately reflecting true anticoagulant status relative to UFH.

The pharmacy team recommended a change from continuous-infusion UFH to the low-molecular-weight heparin enoxaparin sodium, which requires no aPTT monitoring. The recommendation also was based on the MEDENOX study, published in the New England Journal of Medicine.² The findings showed that a similar medical patient population - including those with acute respiratory failure, inflammatory bowel disease, and rheumatologic disorders - experienced a statistically significant decrease in the incidence of VTE when given enoxaparin, compared with placebo.

This actual case is illustrative of the role that pharmacists can play in the appropriate risk stratification of patients when they are in the hospital. The pharmacists at our institution interact with physicians to improve on the outcomes of efficacy and safety, while seeking to ensure that all patients are adequately and properly prophylaxed against the occurrence of VTE.

The Community Pharmacist?s Role

As more patients begin to receive complex drug regimens in the home setting, the need for pharmacists in the community retail setting to take responsibility for VTE prevention will increase. The same opportunities exist for counseling patients about risks and preventive measures for DVT upon their transfer to long-term care facilities - or even to their homes - as in the acute care setting of the hospital. Pharmacists in each of these outpatient settings (long-term care and community pharmacy) should risk-stratify patients for their potential for VTE and should seek to intervene and make appropriate recommendations when necessary to avoid VTE altogether. It also is important to educate patients and their families about the symptoms of and risk factors for DVT, so that they are aware that this disease is preventable and can be treated.

DVT is an often-silent illness that can go unrecognized unless pharmacists remain aware of its possibility. Pharmacists are in a unique position to help solve this problem and must rise to the challenge. We need to remain vigilant, keep the possibility of DVT on our ?radar screens,? and put in place strategies to prevent DVT before it becomes a costly and life-threatening complication. For a list of references, send a stamped, self-addressed envelope to: References Department, Attn. D. Ryan, Pharmacy Times, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to: dryan@mwc.com.