VENOUS THROMBOEMBOLISM (VTE)is the number-one cause of pre-ventable death in hospitalized pa-tients. (See VTE facts.) A thrombusis a clot that forms in a blood ves-sel, most often in a deep vein,which results in deep vein throm-bosis (DVT). The danger lies in thethrombus breaking loose from thevein and traveling through the rightside of the heart to the lungs, re-sulting in a pulmonary embolism(PE). This process is different froma thrombus that forms in an arteryand results in a myocardial infarc-tion or cerebral vascular accident.(See DVT and PE defined.)

Beyond the immediate dangers,both DVT and PE can produce long-lasting debilitating effects. Chronicthromboembolic pulmonary hyper-tension, which develops in about5% of individuals who survive a PE,is characterized by progressive dysp-nea, eventually leading to right-sidedheart failure. After a DVT, aroundone-third of patients will developpost-thrombotic syndrome withchronic lower-extremity edema,pain, and skin changes that canprogress to weeping ulcerations.More than 20% of patients withproximal DVT (thrombus located inthe popliteal, femoral, or iliac veins)or PE will suffer a recurrent eventafter discontinuing anticoagulation,and patients may experience loss of function, financial burdens fromtreatment, and fear of recurrence.

VTE risk factorsVirchow’s triad illustrates VTE riskfactors based on blood flow stasis,endothelial damage, and hyper -coagu lability. (See VTE risk factors.)

Normal venous return of bloodfrom the extremities depends onthe pumping action from the mus-cles and competent one-way valvesin the vein. Reduced mobility canresult in decreased blood return,and damaged valves can contributeto blood pooling in the distal ex-tremities. Damage to the endotheliallayer of the veins from trauma, I.V.catheters, or surgery initiates thecoagulation cascade. In addition, in-herited hypercoagulable disordersand other conditions—such as dehy-dration, inflammatory bowel disease,and cancer—can produce varyingdegrees of hypercoagulability.

Hospitalization is the most impor-tant risk factor for VTE. Surgery pa-tients have long been considered atgreater risk for VTEs, but recent evi-dence suggests that they developequally between patients admittedfor medical illness and those admit-ted for surgery. Overall risk factorsinclude lung disease, prior VTE,family history of VTE, and older age.

Oncology patients are at particularrisk for developing VTE becausemany cancers (pancreatic, lympho -ma, brain, liver, leukemia, colorectal,and metastatic) produce a hyperco-agulable state. Cancer is so often as-sociated with VTE that the develop-ment of a VTE in a patient with noknown risk factors may warrantscreening for occult cancers. A sys-tematic literature review by van Esand colleagues noted that cancerwas found in one in 20 patientswithin a year of developing an un-provoked (no known risk factor)VTE, with rates seven times higher inpatients age 50 years and older. Inaddition, many patients with cancerare less mobile and have vascularcatheters, compounding their risk.

Commitment to preventionThromboprophylaxis for at-risk hos-pitalized patients can reduce VTEby 30% to 65%, has a low incidenceof major bleeding complications,and is cost-effective. However, de-spite widely published guidelines,public reporting, and incrementalpayment withholding for VTE, pre-vention recommendations remainlargely underused. Because VTE riskfactors are spread across patientpopulations and medical specialties,no one group takes responsibilityfor addressing prevention; “every-one’s problem” becomes “no one’sproblem.” Passive approaches, suchas relying on staff and providereducation or order sets have notproven effective.

The Agency for Healthcare Re-search and Quality (AHRQ) recom-mends “measure-vention” to boostcompliance with adequate prophy-

Venous thromboembolism: Very troubling events

Engage patients to help prevent this possibly deadly condition.By Carolyn E. Crumley, DNP, RN, ACNS-BC, CWOCN

LEARNING OBJECTIVES

1. Explain how to assess patients forrisk of venous thromboembolism(VTE).

2. Describe strategies to prevent VTE.

3. Discuss treatment of VTE.

The authors and planners of this CNE activity havedisclosed no relevant financial relationships withany commercial companies pertaining to this ac-tivity. See the last page of the article to learn howto earn CNE credit.

Expiration: 8/1/21

CNE1.74 contact

hours

16 American Nurse Today Volume 13, Number 8 AmericanNurseToday.com

AmericanNurseToday.com August 2018 American Nurse Today 17

laxis and to reduce rates of hospi-tal-acquired VTE. This approach involves active measurement of ad-herence to and lapses in VTE pre-vention recommendations, com-bined with concurrent interventionsto correct lapses, including notifica-tion of the primary team. The prin-ciples of prevention efforts are:• institutional support and prioriti-

zation for the initiative• a multidisciplinary team focused

on reaching VTE prophylaxis tar-gets and reporting to key med-ical staff committees

• reliable data collection and per-formance tracking

• specific goals or aims that areambitious, time defined, andmeasurable

• proven quality improvementframeworks to coordinate stepstoward breakthrough improve-ment

• evidence-based protocols thatstandardize VTE risk assessmentand prophylaxis

• institutional infrastructure, poli-cies, practices, and educationalprograms that promote use ofthe protocol.A three-bucket model based on

risk level (low, moderate, high)may be an effective protocol. (SeeThree-bucket model: An example.)Protocols should be “opt-out” be-cause nearly all hospitalized pa-tients are at risk for developingVTE. In this model, mechanical andpharmaceutical interventions are ac-tivated for all patients, with thoseconsidered low risk or with con-traindications to preventive meas-ures “opted out.” Patients consid-ered to be low risk in this modelcan ambulate independently andhave no other risk factors.

Treatment recommendations Guidelines published and regularlyupdated by the American Collegeof Chest Physicians provide recom-mendations for the choice and du-ration of anticoagulant therapy totreat VTE, modified based on un-

Numbers—In the United States, venous thromboembolism (VTE) is estimated toaffect as many as 600,000 people annually, including at least 100,000 deaths—more than AIDS, breast cancer, prostate cancer, and motor vehicle crashes com-bined. However, those estimates may be low; VTE may be unrecognized in casesof sudden death or a terminally ill patient who rapidly “takes a turn for the worse.”

Demographics—African Americans are at greater risk of developing VTE thanWhites, while Hispanics appear to be at lower risk. Risk increases with age, andmen are at greater risk than women.

Costs—The average cost to treat deep vein thrombosis is between $7,712 and$10,804; costs to treat pulmonary embolism are between $9,566 and $16,644—ora combined total of $1.5 billion per year in the United States.

VTE facts

Deep vein thrombosis (DVT)A DVT can develop in the upper extremities, but it’s far more common in the low-er extremities. The thrombus can cause varying degrees of partial occlusion to acomplete blockage. Proximal DVTs developing above the popliteal trifurcation inthe popliteal and femoral veins of the thigh are more dangerous and exhibit moresigns and symptoms than distal DVTs forming below the popliteal trifurcation inthe veins of the calf. Note that although the name is somewhat misleading, thesuperficial femoral vein is considered a deep vein.

Signs and symptomsSuspect a DVT in the presence of unilateral lower-extremity pain, edema, erythe-ma, warmth, and/or tenderness.

DiagnosisFor many years, nurses were taught to check for a Homan’s sign (pain in the calfwith dorsiflexion of the foot) as a sign of DVT, but this assessment tool is no longerconsidered reliable. A serum D-dimer test measures substances released by thethrombus. A negative test essentially rules out a thrombus. A duplex ultrasoundcan detect occlusions in the deep veins and has replaced the more invasive con-trast venography. Some patients develop a DVT in the absence of obvious risk fac-tors (an “unprovoked” DVT). In those cases, thrombophilia testing should be con-sidered; 15% to 20% of these patients will demonstrate a hypercoagulable state.

Pulmonary embolism (PE)Roughly one-third of patients with a DVT will develop a PE, with sudden deaththe initial presentation for approximately one-fourth. As the embolism becomeslodged in the lungs, the alveoli distal to the thrombus are ventilated but not per-fused, resulting in increased alveolar dead space and increased pulmonary vascu-lar resistance.

Signs and symptomsSigns and symptoms of a PE can be vague and nonspecific; they include short-ness of breath, pleuritic chest pain, cough, hemoptysis or frothy sputum, tachy-cardia, diaphoresis, and lightheadedness. Patients may exhibit anxiety and de-scribe a feeling of impending doom.

DiagnosisComputerized tomography pulmonary angiography is the preferred imagingstudy to evaluate for a PE. When concerns exist regarding the contrast material in-jected for the test (for example, allergy to contrast, impaired renal or liver func-tion), a nuclear medicine ventilation-perfusion scan can be used to identify a mis-match between ventilation and perfusion, indicative of a PE.

DVT and PE defined

18 American Nurse Today Volume 13, Number 8 AmericanNurseToday.com

derlying risk factors. For patientswith a PE or proximal DVT, a mini-mum course of 3 months of antico-agulant therapy is recommended.For patients with underlying can-cer, low molecular weight heparin(LMWH) is preferable. For all otherpatients, direct oral anticoagulants(DOACs, also called NOACs [non-vitamin K antagonist oral anticoagu-lants]) are preferred over vitamin Kantagonist therapy. Dabigatran andedoxaban require initial parenteralanticoagulation. After completingthe initial 3 months of treatment,patients with transient risk factors,such as surgery, typically don’tneed additional therapy. For pa-tients with unprovoked VTE, theprovider should evaluate the risksand benefits of continued therapy.Most patients with active cancerwill need to continue therapy.

Anticoagulants Anticoagulants are indicated for theprevention and treatment of VTE.Understanding anticoagulant op-tions will help when educating pa-tients and monitoring for adverseeffects. Keep in mind that all anti-coagulants carry the risk of bleed-ing, so monitor for and immediatelyreport any unusual bleeding.

Parenteral anticoagulantsUnfractionated heparin (UFH) andnewer LMWHs are the parenteralagents used. UFH was the first par-enteral anticoagulant; approved in1939, it’s indicated for VTE preven-tion and treatment. It can be admin-istered as a subcutaneous injectionor I.V. infusion. Patients receiving acontinuous infusion should havetheir partial thromboplastin time(PTT) monitored and dosage adjust-

ed to maintain a PTT 1.5 to 2 timesnormal range. Most hospitals have aprotocol for monitoring and adjust-ing heparin infusions. Protamine sul-fate is the reversal agent.

The LMWH enoxaparin is indicat-ed for DVT prevention in patientswho’ve had abdominal surgery orhip or knee replacement. It’s also in-dicated for patients whose mobilityis severely restricted because ofacute illness and for treatment ofacute DVT, with or without PE. Prot-amine sulfate is the reversal agent.Other LMWHs approved in the Unit-ed States include dalteparin and tin-zaparin.

When administered subcutane -ously, both UFH and LMWH are in-jected into the abdomen. Hold askinfold between the thumb and in-dex finger throughout the injection,and don’t rub the site.

VTE risk factorsVirchow’s triad illustrates venous thromboembolism (VTE) risk factors. Examples are listed for each category.

Endothelial damage

Heart diseaseSmokingFracture

Severe muscle injuryMajor surgery

Indwelling central venouscatheter

I.V. drug use

Blood flow stasis

ObesityImmobility

Stroke/paralysisVaricose veins

HypercoagulabilityEstrogen (oral contraceptives/

hormone replacement therapy)Pregnancy and recent birth

CancerInflammatory bowel disease

Inherited thrombophiliaDehydration

AmericanNurseToday.com August 2018 American Nurse Today 19

Oral anticoagulantsWarfarin has been the mainstay oforal anticoagulants for many years,but several new agents have beenapproved, including DOACs.

The vitamin K antagonist war-farin was approved in 1954. Be-cause warfarin takes several days tobecome effective, it’s generally notused for immediate VTE prevention.Although relatively inexpensive andeffective, warfarin requires lab mon-itoring of the patient’s internationalnormalized ratio (INR) and frequentdose adjustments to maintain itsnarrow therapeutic range. Dosing isfurther complicated by metabolismvariations based on DNA variants intwo genes: CYP2C9 and VKORC1.Dosing algorithms are availablebased on genetic data. Warfarin canbe affected by many other medica-tions and foods. It can be reversedwith vitamin K.

DOACs address some of the is-sues surrounding warfarin; for in-stance, they don’t require routinemonitoring and have fewer drug in-teractions. A downside is that they’remore expensive than warfarin.

Recent studies suggest similar ef-ficacy rates between warfarin andDOACs. Risks of bleeding appearsimilar, possibly favoring some of theDOACs over warfarin, even thoughno reversal agents are available, ex-cept for dabigatran. Extensive clinicaltrials have provided information onthe safety and efficacy of DOACsin study populations; specifically,younger and healthier subjects. Post-marketing observational studies in-volving real-world, older individualswith more comorbidities have beenperformed primarily in patients withatrial fibrillation taking DOACs be-cause they were approved for thatindication before approval for VTEprevention and treatment.

Several DOACs have been ap-proved for VTE prevention, includ-ing one that is a direct thrombin in-hibitor (dabigatran) and four thatare factor Xa inhibitors (apixaban,rivaroxaban, edoxaban, and betrixa-

ban). Dosages must be adjusted forfactors such as decreased creatinineclearance and whether the intentionis treatment or prevention.

Dabigatran is indicated for VTEprevention in patients after hip re-placement, treatment of VTE after 5to 10 days of parenteral anticoagu-lation, and recurrent VTE reduction.Side effects include GI upset. Idaru-cizumab is the reversal agent.

Rivaroxaban and apixaban areindicated for DVT prevention in pa-tients who’ve had hip or knee re-placement, VTE treatment, and re-currence reduction. Patients shouldavoid concomitant use of rivaroxa-ban with drugs that are combined

P-gp and strong CYP3A4 inducers(for example, carbamazepine, phen -y toin, rifampin, and St. John’s wort).Menorrhagia and longer periodshave been reported with rivaroxa-ban use. Andexanet alfa has beenapproved as a reversal agent for ri-varoxaban and apixaban, althoughits supply is expected to be limiteduntil early 2019.

Edoxaban is indicated for VTEtreatment and has no reversal agent.

Betrixaban is indicated for VTEprophylaxis in adult patients hospi-talized for an acute medical illnesswho are at risk for thromboemboliccomplications because of moderate-ly or severely restricted mobility

This three-bucket model for venous thromboembolism (VTE) prevention is in use atthe University of California San Diego. University of California Davis Medical Centerhas developed an algorithm (bit.ly/2yayxWK) based on this model.

Risk level Recommended intervention

Low risk • Observation status, expected length • No prophylaxis of stay (LOS) < 48 hours • Reassess periodically• Minor ambulatory surgery unless • Ambulate multiple strong risk factors • Medical patients ambulatory in hall and not moderate or high risk • Ambulatory cancer patients admitted for short chemotherapy infusion

Moderate risk • Most general, thoracic, open gynecologic, • Unfractionated heparin or low or urologic surgery patients molecular weight heparin (LMWH) • Active cancer or past VTE/known prophylaxis* thrombophilia in medical patient with LOS > 48 hours• Medical patients with decrease in usual ambulation and VTE risk factors (myocardial infarction, stroke, heart failure, pneumonia, active inflammation/infection, dehydration, age > 65 years)

High risk • Hip or knee arthroplasty • Intermittent pneumatic compression • Hip fracture surgery device (IPCD) and LMWH or other • Multiple major trauma anticoagulant* • Spinal cord injury or major neurosurgery• Abdominal-pelvic surgery for cancer

*For those at moderate or high VTE risk and contraindications to anticoagulation, use IPCD alone until bleed-ing risk subsides.

Three-bucket model: An example

20 American Nurse Today Volume 13, Number 8 AmericanNurseToday.com

and other VTE risk factors. It hasno reversal agent.

Anticoagulants and dischargeAt discharge, provide patients withverbal instructions and supplemen-tal written information about allmedications—generic and tradenames, dosage, frequency, possiblefood or drug interactions, and pre-cautions—follow-up appointments,including lab monitoring, and signsand symptoms they should report.Explain the importance of continu-ing treatment beyond discharge andthat patients shouldn’t stop antico-agulant therapy without discussingit with their provider. In addition,you can direct patients to resources

to help cover the cost of anticoagu-lant therapy.

Nursing implicationsIn addition to administering pro-phylaxis as ordered by the provider,you can help reduce your patient’srisk of developing a VTE. (See VTEprevention.) Patients are more likelyto engage in prevention measures ifthey’re educated about their individ-ual VTE risk factors, appreciate theconsequences of a VTE, and under-stand the effectiveness of preventivemeasures.

Maintain and improve you pa-tient’s mobility level by helping himor her walk to the bathroom, sit in achair for meals, and walk in the hall

with assistance. You also can teachyour patient how to perform lower-extremity range-of-motion exercisesand the rationale for compressionstockings or lower-extremity me-chanical devices. Remind patients toreapply devices after walking, andconsistently reinforce your efforts. Inaddition, ensure patients are wellhydrated; dehydration can contributeto hypercoagulability.

Even with preventive measuresin place, VTE can develop. Earlyidentification and treatment withanticoagulants can minimize seri-ous long-term consequences.

Immediately report any signs andsymptoms of a VTE. DVT symptomscan be subtle, so continually monitorfor edema, pain, erythema, warmth,or tenderness in an extremity. Al-though DVTs typically are unilateral,also evaluate for bilateral symptoms.PE symptoms may be more dramat-ic, but still nonspecific. Suspect a PEin any patient with a sudden onsetof shortness of breath, pleuritic chestpain, cough, hemoptysis or frothysputum, tachycardia, or lightheaded-ness. These symptoms can be verydistressing for the patient, so reas-sure him or her that the condition isbeing addressed and provide emo-tional support.

Administer treatment for VTE,such as anticoagulants, as instruct-ed, and monitor for adverse effects.

Laying a foundationUnderstanding VTE risk factors, pre-vention measures, and treatmentoptions gives you a foundation foreffectively engaging with patientsand their families. Provide them withthe information they’ll need to pre-vent VTE and to recognize signsand symptoms if they occur.

Visit americannursetoday.com/?p=49059 for alist of selected references.

Carolyn E. Crumley is an adjunct assistant professorand clinical nurse specialist program coordinator atthe University of Missouri-Columbia. She’s also awound, ostomy, and continence nurse at Saint Luke’sEast Hospital in Lee’s Summit, Missouri.

Venous thromboembolism (VTE) prevention requires nurses to stay current withVTE prevention guidelines and to participate in related quality-improvement proj-ects. Assess your patients for VTE risk factors and take these monitoring and pa-tient education steps:

Increase mobility• Assist patient with ambulation at least three or four times per day• Teach patient how to perform lower-extremity range-of-motion exercises and

verify completion

Avoid constrictive clothing or devices• Ensure that any socks or stockings aren’t tight around the patient’s leg; remea-

sure for compression stockings if edema develops• If wrapping the extremity, extend the wrap over a larger area to avoid multiple

layers within a small area• If a leg strap is used to secure urinary catheter tubing or a leg bag, make sure

it’s not too tight

Promote adequate hydration • Ask patient for preferred beverage and keep it within reach at the bedside• Encourage fluid intake throughout the day (unless contraindicated)

Provide mechanical prophylaxis as ordered• Intermittent pneumatic compression and foot impulse devices

• Ensure proper fit• Encourage consistent use

• Graduated compression stockings (14 mmHg to 15 mmHg)• Explain contraindications: arterial disease, significant skin issues, heart fail-

ure, unusual leg size or deformity• Ensure proper fit and remeasure as indicated• Instruct patient to remove daily for skin care and inspection

Monitor closely for any signs of VTE and report immediately • Deep vein thrombosis—edema, pain, erythema, warmth, or tenderness in an

extremity• Pulmonary embolism—sudden onset of shortness of breath, pleuritic chest

pain, cough, hemoptysis or frothy sputum, tachycardia, or lightheadedness

VTE prevention

AmericanNurseToday.com August 2018 American Nurse Today 21

Please mark the correct answer online.

1. Risk factors for venous thromboembolism(VTE) are related to the triad of

a. endothelial damage, blood flow stasis, andhypocoagulability.

b. endothelial damage, increased blood flow,and hypercoagulability.

c. epithelial damage, blood flow stasis, and hy-percoagulability.

d. endothelial damage, blood flow stasis, andhypercoagulability.

2. Demographics related to VTE include whichof the following?

a. Most VTEs occur in patients younger than age50.

b. Women are at greater risk than men for VTE. c. African Americans are at greater risk of

developing VTE than Whites.d. Hispanics are at greater risk of developing VTE

than Whites.

3. Which statement about the risk of VTE inpatients with cancer is correct?

a. Oncology patients have a low risk of VTE.b. An unprovoked VTE is not a sign of cancer. c. Oncology patients are at particular risk of

VTE.d. Few cancers are associated with

hypercoagulability.

4. A successful organizational strategy toprevent VTE includes all of the following except:

a. a nurse-pharmacy team focused on VTEprophylaxis targets.

b. quality improvement frameworks tocoordinate steps.

c. institutional support and prioritization forthe initiative.

d. reliable data collection and performancetracking.

5. What is the likely VTE risk level for your 70-year-old patient who’s undergoing thoracicsurgery?

a. Minimalb. Lowc. Moderate d. High

6. Your 64-year-old patient is undergoing kneearthroplasty. What would you expect her VTEprevention to include?

a. intermittent pneumatic compression device(IPCD) or low molecular weight heparin(LMWH) or other anticoagulant

b. IPCD and LMWHc. None because the risk is lowd. Unfractionated heparin (UFH) or LMWH

7. For patients with a proximal deep veinthrombosis (DVT) or a pulmonary embolism(PE), anticoagulation therapy should be contin-ued for a minimum of

a. 1 month.b. 3 months.c. 6 months. d. 1 year.

8. Which statement about parenteralanticoagulants is correct?

a. Enoxaparin is indicated for DVT preventionin patients who’ve had abdominal surgery.

b. In patients receiving LMWH, the partialthromboplastin time (PTT) should be kept at1.5 to 2 times the normal range.

c. Idarucizumab is the reversal agent for UFH.d. UFH is administered orally or

subcutaneously.

9. When administering parenteral anticoagu-lants subcutaneously, you should

a. inject the medication into the deltoidmuscle.

b. inject the medication into the abdomen.c. stretch the skin tautly.d. rub the injection site afterwards.

10. Which statement about warfarin is correct? a. It is effective immediately.b. It requires no lab monitoring.c. It has no reversal agent.d. It is a vitamin K antagonist.

11. A direct oral anticoagulant (DOAC) thatdirectly inhibits thrombin is

a. apixaban.b. dabigatran. c. edoxaban.d. rivaroxaban.

12 Menorrhagia and longer periods have beenreported with

a. apixaban.b. dabigatran. c. edoxaban.d. rivaroxaban.

13. An anticoagulant that has no reversal agentis

a. apixaban.b. dabigatran. c. warfarin.d. enoxaparin.

14. Which of the following actions that nursescan take to prevent VTE is correct?

a. Use graduated compression stockings forpatients with arterial disease.

b. Have patients remove compressionstockings every 3 days for skin care.

c. Extend an elastic bandage wrap over alarger area.

d. Be sure elastic bandages are wrappedtightly.

POST-TEST • Venous thromboembolism: Very troubling events Earn contact hour credit online at americannursetoday.com/article-type/continuing-education/

Provider accreditationThe American Nurses Association’s Center for Continuing Edu-cation and Professional Development is accredited as aprovider of continuing nursing education by the AmericanNurses Credentialing Center’s Commission on Accreditation.ANCC Provider Number 0023.

Contact hours: 1.74

ANA’s Center for Continuing Education and Professional Devel-opment is approved by the California Board of Registered Nurs-ing, Provider Number CEP6178 for 2.09 contact hours.

Post-test passing score is 80%. Expiration: 8/1/21

ANA Center for Continuing Education and Professional Devel-opment’s accredited provider status refers only to CNE activitiesand does not imply that there is real or implied endorsement ofany product, service, or company referred to in this activity norof any company subsidizing costs related to the activity. Theauthor and planners of this CNE activity have disclosed no rele-vant financial relationships with any commercial companiespertaining to this CNE. See the banner at the top of this pageto learn how to earn CNE credit.

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