PULMONARY EMBOLISM BY Dr. Hayam Hebah Associate professor of internal medicine AL-Maarefa College

OBJECTIVES DEFINITION Pathogenesis CLINICAL PICTURE DIAGNOSIS MANAGEMENT.

BACKGROUND 80% of cases arise from propagation of lower limbs DVT. rare causes include: 1.septic emboli( from endocarditis of tricuspid or pulmonary valves: 2.tumour(choriocarcinoma) 3.fat,air,amniotic fluid and placenta it is a common mode of death in patients with cancer, stroke and pregnancy.

RISK FACTORS FOR VENOUS THROMBOEMBOLISM: (Virchow‘s triad)

DETERMINANTS OF THE C/P; numbersize Distribution of emboli Presence of risk factor C/P of PE

C/P:

Chronic PE: PATHOPHYSIOLOGY: Chronic occlusion of pulmonary microvasculature, right heart failure. SYMPTOMS: - Exertional dyspnea -Late S&S pulmonary hypertension - right heart failure. SIGNS: -Minimal early -late, RV heave, loud P2,then RVF. CXR: Enlarged pulmonary artery trunk, cardiomegaly, prominent right ventricle. ECG: RV hypertrophy and strain. ABG: Exertional ↓ PaO2 or desaturation on exercise. DD: other causes of pulmonary hypertension

INVESTIGATIONS: CXR exclude pneumonia and pneumothorax. ECG exclude other DD as acute MI and pericarditis. In PE,ECG shows sinus tachycardia and anterior T- wave inversion but are non specific. ABG----  ↓PaO2 and normal or ↓PaCO2 - metabolic acidosis in acute massive PE with cardiovascular collapse.

D-dimer : Elevated D-dimer is non specific and is of limited value but in high risk group, it warrants further investigations even if normal. CT pulmonary angiography: is the first line diagnostic test. Ventilation perfusion scan Doppler U/S of leg veins if suspect DVT ECHOCARDIOGRAPHY : For DD in acute circulatory collapse.

LOW RISK PE age is less than 50 heart rate less than 100 beats per minute oxygen level more than 94% on room air no leg swelling, coughing up of blood, surgery or trauma in the last four weeks NO previous blood clots, and estrogen use

PROBABILITY TESTING The Wells score: clinically suspected DVT — 3.0 pointsDVT alternative diagnosis is less likely than PE — 3.0 points tachycardia (heart rate > 100) — 1.5 points tachycardia immobilization (≥ 3d)/surgery in previous four weeks — 1.5 points history of DVT or PE — 1.5 pointsDVT hemoptysis — 1.0 points hemoptysis malignancy (with treatment within six months) or palliative — 1.0 points Traditional interpretation Score >6.0 — High Score 2.0 to 6.0 — Moderate Score <2.0 — Low

aLTernative interpretation Score > 4 — PE likely. Consider diagnostic imaging. Score 4 or less — PE unlikely. Consider D-dimer to rule out PE.D-dimer

Management A-general measures: 1.Sufficient oxygen to keep PaO2> 90% 2.IV Fluids or plasma expander in circulatory shock 3.Opiates to relieve the pain( take care with hypotension) 4.External cardiac massage 5.Avoid: -diuretics -vasodilators. ( both will reduce CO) - INOTROPES( OF limited value)

B-specific lines of management for PE: \ 1-ANTICOAGULATION 2-THROMBOLYTIC AND SURGICAL THERAPY 3-CAVAL FILTERS.

1-ANTICOAGULATION Start heparin immediately in high or intermediate probability of PE. TTT should continue for at least 5 days during which oral antoicoagulant is commenced. Best use LMWH ( or its alternative fondaparinux) Warfarin is the commonest used oral anticoagulant. Start by high loading dose followed by maintenance when INR is ≥2 for 24 hours at least. Warfarin can be replaced by the newer thrombin or activated factor X inhibitors( no coagulation monitoring required) Duration of ttt at least 3 months Those with risk factors, anticoagulation is for life in cancer associated VTE, LMWH for 6 mo before warfarin use.

2-THROMBOLYTIC AND SURGICAL THERAPY  INDICATIONS: 1. in acute massive PE accompanied by cardiogenic shock. 2.in those with PE presenting with right ventricular dilatation and hypokinesis or severe hypoxemia  SCREEN FIRST: For hemorrhagic risk( to avoid intracranial haemorrhage)  SURGICAL EMBOLECTOMY Carries high mortality so it should be restricted to selected patients

thrombolytics:

3-CAVAL FILTERS Considered in : Contraindication to Anticoagulation as in those who suffered hemorrhage or recurrent VTE despite anticoagulation-

prognosis: Immediate mortality with echofinding of right ventricular dysfunction or cardiogenic shock Risk of mortality decrease once anticoagulation is started. Recurrence is highest in first 6-12 months of the initial event.

Thank you