Prophylaxis of Venous Prophylaxis of Venous Thromboembolism Thromboembolism

Prophylaxis of Venous Prophylaxis of Venous Thromboembolism Thromboembolism

Dr Galila ZaherDr Galila ZaherConsultant Hematologist Consultant Hematologist

MRCPATH MRCPATH

VTE in medical patients• 600,000 patients / year are hospitalized

for DVT. symptomatic PE 600,000 patients and causes .

• contributes to death 200,000 annually.• Most fatal PE occur in medical patients.• A small number of randomised trials compared

with that of surgical patients. • Meta-analyses in MI ,stroke and other medical

patients have clarified the benefits of thrombo-prophylaxis .

• 85% of all medical patients admitted to an acute care hospital are eligible and/or suitable for DVT prophylaxis

ACUTE MYOCARDIAL INFARCTION

• Prior to the introduction of routine antithrombotic therapy .

• Acute MI had a risk of asymptomatic DVT of 24%, and PE of 2-9%.

• The risk increases with age and in the presence of heart failure.

MECHANICAL PROPHYLAXIS

• GENERAL MEASURES .• Compression stockings especially

when heparin prophylaxis is contraindicated. (grade A)

ASPIRIN AND THROMBOLYTIC THERAPY

• Strongly recommended that all patients with acute MI should be given aspirin (150-300 mg) . (grade A)

• Strongly recommended that all patients with acute MI should be considered for thrombolytic therapy. (grade A)

ANTICOAGULANTS

• Heparin not routinely in addition to aspirin in acute MI, but reserved for patients at increased thromboembolic risk (grade A)

High risk of thromboembolism

• Large anterior Q-wave infarction.• Severe left ventricular dysfunction. • Congestive heart failure. • History of systemic or PE or thrombophilia. • Echo evidence of mural thrombus. • Persistent AF.• Prolonged immobilization. • Marked obesity (grade A)

ANTICOAGULANTS • Full-dose heparin , followed with

warfarin for up to three months. • Bleeding risks outweigh the benefits,

thrombo-prophylaxis low-dose SC heparin (7,500 IU 12-hourly) for seven days or until ambulant.

(grade A)

Acute stroke• Asymptomatic DVT 50% of acute

hemiplegic stroke.• Clinically apparent DVT or PE

<5%.• PE may account for up to 25% of

early

General measures• Early mobilization and hydration .• Meta-analysis of haemodilution :

VTE was reduced, despite lack of overall benefit.

MECHANICAL PROPHYLAXIS

• Graduated compression stockings justified for high risk patients.

(grade C)• Compression stockings are preferred

haemorrhagic stroke. (grade D)• Intermittent pneumatic compression no

evidence effective .• Intermittent pneumatic compression is

effective in patients undergoing neurosurgery .

ASPIRIN• Significant decrease in death or

dependency.• Aspirin significantly reduced PE from 0.5%

to 0.3%. • Aspirin is started as soon as ICH is

excluded by CT or MRI. (grade A)• Aspirin can be given by NG tube or

rectally : unable to swallow.

ANTICOAGULANTS

• Systematic reviews RCTs .• Heparin reduces asymptomatic DVT after

stroke.• Prevention of DVT& PE is offset by an increase

in haemorrhagic complications.• The bleeding risk is dose-related. • If heparins are to be used , low dose should

be selected• LMWH preferred due to a lower risk of

bleeding.• UFH (5,000 IU SC BID) .• LMWH .

ACUTE MYOCARDIAL INFARCTION

• aspirin (150-300 mg).grade A• thrombolytic therapy. Grade A.• Heparin should not be used

routinely but reserved for patients at increased thromboembolic risk grade A.

• Compression stockings especially when heparin prophylaxis is contraindicated grade A

Acute stroke• graduated compression stockings may be

justified for some high risk patients. Grade C

• Compression stockings are preferred for patients with haemorrhagic grade D

• Aspirin as soon as intracranial haemorrhage is excluded by CT or MR brain scanning. Grade A

• Aspirin can be given by nasogastric tube or rectally for those who are unable to swallow.

• UFH or a LMWH at higher than average risk of VTE . Grade A

Other medical patients

• low dose UFH or LMWH should be considered. grade A

• LMWH carries a lower risk of bleeding. grade A

• heparin prophylaxis is contraindicated, GECS may be considered grade C

Cancer patients

• Minidose warfarin (1 mg/day, no INR monitoring) with central venous catheters. Grade A

• Low-dose warfarin (target INR 1.6, range 1.3-1.9) during chemotherapy in stage IV breast cancer. Grade A

ANTICOAGULANTS• In patients with ischaemic stroke

at higher than average risk of VTE :• History of previous VTE.• known thrombophilia .• Active cancer.• Lower than average risk of

haemorrhagic complications. (grade A)

Other medical patients

• Autopsy : PE cause of deaths in immobilized patients in medical wards.

• Heparin :56% decrease in asymptomatic DVT &PE

• The reduction in mortality was not statistically significant .

• The risk of major bleeding was higher• LMWH as effective as UFH in reducing DVT,

PE and mortality; lower risk of major bleeding.

Thrombo-prophylaxis in medical patients

• Heart failure.• Respiratory failure .• Infections. (chest infections).• Diabetic coma.• Inflammatory bowel disease.• Nephrotic syndrome.• Intensive care patients.

Low dose UFH or LMWH . LMWH lower risk of bleeding. (grade

A)

MECHANICAL METHODS

• Significant risk of VTE :prophylaxis is contraindicated, GECS may be considered.  (grade C)

Cancer patients

• Cancer patients have an increased risk of VTE.

• Central venous line thrombosis .• Chemotherapy-induced thrombosis. • Immobilised cancer in medical or

surgical wards should be considered for prophylaxis.

ANTICOAGULANTS• Minidose warfarin: (1 mg/day, no INR

monitoring) in cancer patients with central venous catheters.

(grade A)

• Low-dose warfarin (target INR 1.6) during chemotherapy stage IV breast cancer.

(grade A)• Patients receiving antipsychotic drugs

•The Medenox study clearly showed a dose-effect relationship with enoxaparin and the ineffectiveness of the lower prophylactic dose trend toward mortality reduction with enoxaparin. did not reach statistical significance.

• CONCLUSIONS :• Enoxaparin, given once daily at a dose of 40

mg subq once daily for 6-14 days reduces the risk of VTE by 63%,

• without increasing the frequency of hemorrhage.

• Enoxaparin is the only LMWH with an approved, FDA indication for prophylaxis of DVT in medical patients.

• should be maintained for at least 7 days,

• The majority of fatal PE have not undergone recent surgery.

• MEDENOX :confirmed the effectiveness of enoxaparin in preventing VTED in medical patients.

• In PRIME: enoxaparin versus heparin new VTE 0.2% and 1.4% .

• Ageno et al. 112 patients with clinical indications for VTE prophylaxis without contraindications to anticoagulation prophylaxis was underprescribed.

• only 46.4% received thromboprophylactic treatment.