Acute pulmonary embolism

Acute Pulmonary Embolism• Part of a spectrum of venous thrombotic disease • Severity from asymptomatic to sudden death • Often occurs without prior warning • Signs and symptoms are nonsp

Acute Pulmonary Embolism

David Maldonado MD

Mayo Clinic Rochester, MN, USA

Acute Pulmonary Embolism

• Part of a spectrum of venous thrombotic disease

• Severity from asymptomatic to sudden death

• Often occurs without prior warning

• Signs and symptoms are nonspecific and therefore diagnosis often delayed or missed

• Treatments are effective in reducing risk of death

• Hospital-based prevention can reduce frequency

Tapson VF N Engl J Med

2008 Mar 52

• Only 20% had LE symptoms

• Only 3% had undergone evaluation for DVT/PE prior

• Pregnancy, Oral contraceptives, Estrogen

• Prior venous thrombosis

• Obesity

• HEREDITARY:

• Protein C or S deficiency, Protein C resistance

• Antithrombin III deficiency

• (Factor V Leiden or Prothrombin mutation)

Silverstein MD et al, Arch Intern Med 1998 Mar

23;158(6):585-93

Thrombotic Risk in Asia

Is it Different?

• Obesity less common

• According to United Nations, only 10% older

than 65, vs 20-30% in Europe and U.S.

• Asian diet may reduce risk

• Factor V Leiden and Prothrombin mutation

absent

• Joint replacement surgery less common

Ho CH, et al Am J Hematol 2000; 63: 74-8

SMART Study Group

• Analysis of published studies

• Malaysia, Thailand, Hong Kong, Korea, Singapore,

Taiwan, and Japan

SMART Study

• Large (2420 patients), prospective, multinational study

• Bangladesh, India, Indonesia, Malaysia, Pakistan,

Philippines, Singapore, South Korea, Taiwan, and

Thailand

• Orthopedic surgery patients treated without DVT/PE prophylaxis

• Rate of symptomatic DVT/PE 1.2-2.3%

• Risk factors: History of venous thrombosis, CHF,

varicose veins

Leizorovicz A et al J Thromb Haemost 2005 Jan;3(1):28-34.

AIDA Study

(Venography)

Piovella F, et al., J Thromb Haemost

2005; 3: 2664-70

Symptoms from History

Signs on Physical Examination

Wells, Ann Int Med, 2001;

135:98

• Lower Extremity Doppler Ultrasound

• Standard Pulmonary Angiography

Chest X-Ray

• Cannot diagnose or exclude PE

• Suggestive but infrequent signs

Westermark’s Sign Hampton’s Hump

Ventilation-Perfusion (V/Q) Scan

• Interpretable best in the absence of other underlying cardiopulmonary disease

• Normal V/Q rules out PE

• High probability scan effectively rules in PE and

warrants treatment

• All other combinations require further clinical

judgement regarding decision to treat

Contrast-Enhanced CT

Arteriography

• Faster than V/Q

• Visualization of other thoracic structures

• Emboli in main, lobar, and segmental

pulmonary arteries readily seen

• In patients suspected of PE who have

negative CT arteriography, the risk of DVT/PE

in 3 months 0.5%

• False positive studies very unusual

Swensen SJ et al., Mayo Clin Proc

2002; 77: 130-8

• MRI – can detect PE but speed, availability, and cost currently prohibitive

• Echocardiography – findings of right heart

dysfunction suggestive of acute PE

• Lower Extremity Doppler Ultrasound –

consider in patients unable to tolerate other diagnostic imaging

• Pulmonary Angiography – Major complication rate 1-5%, Mortality 0.5-1.0%

Laboratory Studies

• Arterial Blood Gas –

• Neither sensitive nor specific

• Does not assist in diagnosis

• D-dimer (ELISA) - 96-98% sensitivity

• When negative in a patient with low-medium suspicion, imaging not required

• In a patient of high PE suspicion, D-dimer should not be used

• Troponin –

• Elevated levels often found in those who go

on to develop complications

• Brain Natriuretic Peptide –

• Compliments D-dimer and Troponin

EKG

Anticoagulation after

hospitalization

• While in hospital on parenteral

anticoagulation, warfarin should be initiated with a target INR 2.0 to 3.0

• Duration depends on scenario

Buller HR et al.,

Chest2004;126:401S-428S.)

streptokinase, urokinase

failure may warrant thrombolysis

surgery, bleeding, pregnancy,

intracranial/spinal/ocular disease

03:30

• Catheter-based Mechanical Embolectomy

• Surgical Embolectomy

• Not supported by evidence for most PE’s

• Mortality 20-70% for surgical embolectomy

• Only in “selected highly compromised patients who are unable to receive thrombolytic

therapy or whose critical status does not allow sufficient time to infuse thrombolytic therapy”Buller HR et al.,

Chest2004;126:401S-428S.)

• All hospitalized patient should be considered and need assessed

• Medical prophylaxis superior to mechanical

• LMWH superior to UFH in knee or hip

replacement, trauma, and spinal cord injury

• LMWH equivalent to UFH in medical

inpatients

Potential Diagnostic Algorithm

• Low/moderate suspicion D-dimer

• CT Angio non-diagnostic Doppler U/S

• (No treatment still need DVT/PE prophylaxis as

inpatients)

High Suspicion Algorithm

• Consider treatment prior to testing with CT Angio

• CT Angio normal or nondiagnostic Doppler U/S

• Doppler U/S reveals DVT Treat as PE

• V/Q scan low probability No treatment

• V/Q scan positive or indeterminate Treat

Treatment Algorithm

• Anticoagulation contraindicated IVC Filter

(Echo troponin, BNP)

• Echo, troponin, BNP abnormal Consider lytics

• Thrombolytics contraindicated Embolectomy