PULMONARY EMBOLI

Kenney Weinmeister M.D.

PULMONARY EMBOLI

Over 500,000 cases per year. Results in 200,000 deaths. Mortality without treatment is 30%. With therapy mortality drops to 2-8%.

RISK FACTORS FOR THROMBOEMBOLIC DISEASE Obesity has an increased risk factor of 2.9. Tobacco use:

• 25-35 cigarettes/day risk factor is 1.9.• >35 cigarettes/day risk factor is 3.3.

Hypertension caries a risk factor of 1.9. Factor V Leiden mutant is seen in 40% of

idiopathic thromboembolic disease.

Signs And Symptoms

Tachypnea 70% Rales 51% Tachycardia 30% S4 24% Accentuated P2 23%

Dyspnea 73% Pleuritic Chest Pain

66% Cough 37% Hemoptysis 13%

Task Force on Pulmonary Embolism, European Society of Cardiology. Eur Heart J 2000

MASSIVE PE DEFENITION

Systolic BP less than 90 mmHg Drop in systolic BP of > 40 mmHg from

baseline for > 15 minutes, not explained by hypovolemia, sepsis, or a new arrhythmia

Two or more lobar arterial occlusions

MASSIVE PE PATHOPHYSIOLOGY

Increased afterload on right ventricle• Occlusion of vascular bed• Vasoconstriction

Elevated pulmonary artery pressure• 50% obstruction before mean PAP rises

Right ventricle fails• 75% obstruction of vascular bed

Death

DIAGNOSIS

ECG ABG CHEST X-RAY D-dimer:

• ELISA method D-dimer < 500ng/ml has a negative predictive value of 95 to 99%.

• Turbidimetric D-dimer

D-dimer

Unidirectional. A negative quantitative rapid ELISA result

is as diagnostically useful as a normal V/Q scan or negative venous dopplers.

Unlikely to be helpful in patients with recent surgery (within three months) or with malignancy.

ECHOCARDIOGRAPHY

RV dysfunction Mobile cardiac emboli were seen in 18% of

130 patients with massive PE Prospective study of 317 pts, 27% had RV

dysfunction on Echo. Mortality with RV dysfunction 13%, without 0.9%• Heart 1997

DIAGNOSIS: Ventilation Perfusion Scan High probability:

• > 2 Large segmental defects• > 2 Moderate segmental defects with 1 Large• > 4 Moderate segmental defects

Intermediate probability: not falling into low or high probability.

DIAGNOSIS: Ventilation Perfusion Scan Low probability:

• Nonsegmental perfusion defects.• Single moderate mismatched segmental

perfusion defect with normal cxr.• Large or moderate segmental defects with

matching defects.• > 3 small segmental perfusion defects.

Normal: no perfusion defects.

Venous Doppler

B-Mode compression ultrasound:• 6 level one studies;

• Sensitivity 89 - 100%• Specificity 86 - 100%• Positive Predictive Value 92 - 100%• Negative Predictive Value 75 - 100%

Duplex US and Color flow doppler US have similar results.

PULMONARY ANGIOGRAPHY

Gold standard. Mortality 0.2 - 0.5% Morbidity 1 - 4%

SPIRAL COMPUTED TOMOGRAPHY Greatest sensitivity for emboli in the main,

lobar or segmental pulmonary arteries. Only level 2 studies which show:

• Sensitivity 60 -100%• Specificity 78 - 97%

Lancet 2002 Dec 14;360(9349):1914-1920

Spiral Computed Tomography

1041 patients, anticoagulation withheld for negative CTA and dopplers. 360 (34%) dx with PE. 55 had + dopplers and negative CTA. 76 pts high probability PE but negative CTA & dopplers 4 had + V/Q or PAG. 507 not treated, 9 (1.8%) had TED at f/u.

Radiology 2000 May;215(2):535-42

Spiral Computed Tomography

548 pts negative or low probability V/Q or negative CTA. PE found in 2 (1%) of 198 pts with neg CTA, 0 pts of 188 with neg V/Q, and five (3%) of 162 pts with low prob V/Q.

TREATMENT

Anticoagulation Thrombolitics IVC filter Thrombectomy

• Catheter• Surgery

ANTICOAGULANTS

Heparin Low molecular weight heparin Direct thrombin inhibitors Factor Xa inhibitors Coumadin

HEPARINS

Heparin• dose on weight base

LMWH• Some trials illustrate safety and efficacy of

outpatient therapy or initiation of in hospital use and discharge on coumadin and LMWH.

Direct Thrombin Inhibitors

Hirudin Lepirudin Argatroban Ximelagatran Bivalirudin

Factor Xa Inhibitors

Fondaparinux Razaxaban

DURATION OF THERAPY BY RISK FOR RECURRENCE First event, age < 60 First event, age > 60

or idiopathic disease Recurrent event or

first event with a nonreversible risk factor

3-6 months 6-12 months

12 months to lifetime

INFERIOR VENA CAVA FILTER

No large studies have been performed to evaluate the impact on recurrence of PE.

No large prospective studies have been performed with regards to safety and efficacy.

Mortality 0.1 to 0.2% Morbidity up to 18% risk of thrombosed IVC.

CONCLUSION

The diagnosis of PE is difficult and cannot be made on clinical criteria.

Large clinical trials are needed to evaluate the new imaging techniques as well as new diagnostic tests.

Failure to diagnose continues to be one of the largest causes of malpractice claims.