Pulmonary Edema

Outline

0Definition0Epidemiology0Pathophysiology0Classifications & causes0Pathogenesis0Staging0Clinical manifestations0Complications0Differential diagnosis

Definition Pulmonary Edema ; is a condition characterized by fluid accumulation in the lungs caused by extravasation of fluid from pulmonary vasculature in to the interstitium and alveoli of the lungs

The extent to which fluid accumulates in the interstitium of the lung depends on the balance of hydrostatic and oncotic forces within the pulmonary capillaries and in the surrounding tissue.Hydrostatic pressure -favors movement of fluid from the capillary into the interstitium Oncotic pressure -favors movement of fluid into the vesselMaintenance -lymphatic in the tissue carry away the small amounts of protein that may leak out -tight junction of endothelium are impermeable to protein

Epidemiology0Pulmonary edema occurs in about 1% to 2% of the general

population.

0Between the ages of 40 and 75 years, males are affected more than females.

0After the age of 75 years, males and females are affected equally.

0The incidence of pulmonary edema increases with age and may affect about 10% of the population over the age of 75 years.

Pathophysiology

imbalance of starling force -increase pulmonary capillary pressure -decrease plasma oncotic pressure -increase negative interstitial pressure damage to alveolar- capillary barrier lymphatic obstructionDisruption of endothelial barrier allow protein to

escape capillary bed and enhance movement of fluid in to the tissue of the lung

idiopathic or unknown

Classification

0 based on inciting mechanism1. Imbalance of Starling force A. Increased pulmonary capillary pressure -left ventricular failure -Volume overloadB. Decreased plasma oncotic pressure - Hypoalbuminemia due to different cause C. Increased negativity of interstitial pressure -Rapid removal of pneumothorax with large applied negative pressures (unilateral)

Classification Based on inciting agent…..

2. Altered alveolar-capillary membrane permeability o Infectious pneumoniao Inhaled toxins o Circulating foreign substances oAspiration o Endogenous vasoactive substances oDisseminated intravascular coagulationo Immunologic—hypersensitivity pneumonitis, drugs o Shock lung in association with non-thoracic traumaoAcute hemorrhagic pancreatitis

Classification 0 Based on inciting agent….

3. Lymphatic insufficiency   -After lung transplant  - Lymphangitic carcinomatosis   -Fibrosing lymphangitis 4. Unknown or incompletely understood  - High-altitude pulmonary edema  - Neurogenic pulmonary edema  - Narcotic overdose  - Pulmonary embolism  - Eclampsia  -After anesthesia  - After cardiopulmonary bypass

Classification Base on underlining causeoCardiogenic pulmonary edemaoNon-cardiogenic pulmonary edema

Cardiogenic pulmonary edema

Is Pulmonary edema due to increased pressure in the pulmonary capillaries because of cardiac abnormalities that lead to an increase in pulmonary venous pressure.oHydrostatic pressure is increased and fluid

exit capillary at increased rate

Cardiogenic PE

0Basic pathophysiology:

A rise in pulmonary venous and pulmonary capillary pressures pushes fluid into the pulmonary alveoli and interstitium.

Pathogenesis of CPELeft sided heart failure

Decrease pumping ability to the systemic circulation

Congestion & accumulation of blood in the pulmonary area

Fluid leaks out of the intravascular space to the interstitium

Accumulation of fluid

Pulmonary edema

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Risk Factors

0Vary by cause

-Leading risk factor is clearly underlying cardiac disease.

Causes of Cardiogenic PE

0LV failure is the most common cause.0Dysrhythmia 0LV hypertrophy and cardiomyopathy0 LV volume over load 0Myocardia infarction 0 left ventricular outflow obstruction

Non cardiogenic pulmonary edema

It is defined as the evidence of alveolar fluid accumulation with out hemodynamic evidence that suggest a cardiogenic etiology. Hydrostatic pressure is normalLeakage of protein and other molecule in to the tissue

Non cardiogenic PE

o Associated with dysfunction of surfactant lining the alveoli, increased surface force and a propensity for the alveoli to collapse at low volume.

oCharacterized by intra pulmonary shunt with hypoxemia and decrease lung compliance

Non cardiogenic pulmonary edema

Mechanism include:

0Increased alveolar–capillary membrane permeability0Decreased plasma oncotic pressure0Increased negativity of pulmonary

interstitial pressure0Lymphatic insufficiency or obstruction

Non- cardiogenic PE

0 causeI. Direct injury to the lungII. Hematogenous injury to the lungIII. possible lung injury plus elevated

hydrostatic pressure

Staging of PE

Three stages of PE can be distinguished based on the degree of fluid accumulation:

Stage-1 : all excess fluid can still be cleared by lymphatic drainage.

Stage-2 : characterized by the presence of interstitial edema.

Stage-3 : characterized by alveolar edema due to altered alveolor- capillary permeability

0Mild: Only engorgement of pulmonary vasculature is seen.0Moderate: There is extravasation of

fluid into the interstitial space due to changes in oncotic pressure.0Severe: Alveolar filling occurs.

Unusual type pulmonary edema

Neurogenic pulmonary edema 0 Patients with central nervous system disorders and

without apparent preexisting LV dysfunctionRe-expansion pulmonary edema0Develops after removal of air or fluid that has been in

pleural space for some time, post- thoracentesis0Patients may develop hypotension or oliguria

resulting from rapid fluid shifts into lung.

Unusual type pulmonary edema

High altitude pulmonary edema0occurs in young people who have quickly ascended to

altitudes above2700m and who then engage in strenuous physical exercise at that altitude, before they have become acclimatized.

0Reversible (in less than 48 hours)

Pathophysiologyon ascending to high altitude, falling level of Po2 trigger hypoxic

pulmonary vasoconstriction

This directs blood flow away from hypoxic areas of lung towards area that are well oxygenated

This results in a rise in mean pulmonary artery pressure & a

heterogeneous blood flow to different parts of the lung

Cont…

0 In areas that receive high blood flow the capillary trans-mural pressure rises & walls of the capillary &alveolus are exposed to stress failure

0 Extensive damage to alveolar capillary membrane

0 Edema which is rich in high molecular weight proteins & RBCs to pass freely in to the alveoli & impair oxygenation.

0 patient present with Headache, Insomnia, Fluid retention, Cough,Shortness of breath

Clinical manifestation

Symptom 0 Acute (sudden)0Chronic (long-term)

Symptom

ACUTE0Shortness of breath0A Feeling of suffocating0Anxiety ,restlessness0 Cough-frothy sputum that may be tinged with blood0 excessive sweating 0 pale skin 0 chest pain if PE is cause by cardiac abnormality0 palpitation

symptom

Long term(chronic)0Paraxosomal nocturnal dyspnea0 orthopnea0 Rapid weight gain0Loss of appetite0 fatigue 0 ankle and leg swelling

Sign

0 Tachycardia0 Tachypnea0 Confusion 0 Agitation0 Anxious0 Diaphoric 0 Hypertension 0 Cool extremities0 Rales0 Wheezing0 CVS findings ; S3 ,accentuation of pulmonic component of S2,

jugular venous distention…..

Special considerations

Unilateral pulmonary edema after rapid evacuation of large pneumothorax 0 Findings may be apparent only by radiography.0 Occasionally, dyspnea with physical findings localized to

edematous lung

Special consideration

Lymphatic blockade secondary to fibrotic and inflammatory diseases or lymphangitic carcinomatosis 0 Both clinical and radiographic manifestations are

dominated by the underlying disease process.Neurogenic pulmonary edema

0 Symptoms usually occur within minutes to hours of the injury

Complications

leg swelling(edema), abdominal swelling(ascites), Pleural effusion, Congestion & swelling of liver, acute heart attack (myocardial infarction [MI]), cardiogenic shock, arrhythmias, electrolyte disturbances, mesenteric insufficiency, protein enteropathy, respiratory arrest, and death.

Differential diagnosis

0Pneumothorax0Bronchitis0Cardiac tamponed0COPD0Pericarditis0Pneumonia (bacterial ,viral , PCP)0Pulmonary embolism0Shocks (cardiogenic ,septic ,anaphylactic)0Venous air embolism

Distinguishing Cardiogenic from Non-cardiogenic Pulmonary Edema

Finding suggesting cardiogenic edema -S3 gallop -elevated JVP -Peripheral edemaFindings suggesting non-cardiogenic edema -Pulmonary findings may be relatively normal in the early stages -.

Distinguishing …..

Chest radiographyA cardiogenic cause is favored with0 Cardiomegaly0 Kerley B lines and loss of distinct vascular margins0 Cephalization: engorgement of vasculature to the apices0 Perihilar alveolar infiltrate 0 Pleural effusionNon cardiogenic cause-Heart size is normal-Uniform alveolar infiltrate-pleural effusion is uncommon -lack of cephalization

Distinguishing…..

Hypoxemia0 Cardiogenic - due to ventilation perfusion miss match-respond to administration of oxygen

0 Non cardiogenic-due to intrapulmonary shunting-persist despite oxygen supplimentation

Exertional DyspneaOrthopneaAspiration of food or foreign bodyDirect Chest injuriesWalking High altitudeChest Pain(right or left)Leg pain or swelling(Pulmonary Embolism)A cough that produces frothy sputum that may be tinged

with blood(cardiogenic)

History Taking

Approach a Patient with Pulm.Edema

Cont…

PalpitationsExcessive sweatingSkin color change-Pale skinChest pain(if it is Cardiogenic)Rapid weight gain(cardiogenic)FatigueLoss of appetiteSmoking History

Past Medical History

COPD, heart failure, HIV risk factors(pulmonary Kaposi’s sarcoma). Prior chest X-rays, CT scans,tuberculin testing (PPD).

Medications0Anticoagulants0Aspirin0NSAIDs0Narcotic 0Heroin0Morphine0Methadone and0Dextropropoxyphene

Physical Examination

General AppearanceVital signsHEENTLymphoglandular systemRespiratory systemCardiovascular systemAbdomen Musculoskeletal……

Laboratory Investigations

Routine; CBCLiver function testsRenal Function TestsArterial blood gas analysisSerum cardiac biomarkers

INVESTIGATION

Imaging chest radiography

EchocardiographyUltrasound

INVESTIGATION…..

Pulmonary artery catheterizationindicated when;

-Cause remains uncertain -Pulmonary edema which is refractory to therapy -PE accompanied by hypotensionPulmonary capillary wedge pressure < 18 mmHg is consistent with a non-cardiogenic cause.Pulmonary capillary wedge pressure >20 mmHg favors a cardiogenic cause.

Treatment approach

Emergence management -Support of oxygenation and ventilation -oxygen therapy -positive pressure ventilation0Reduction of pre load -loop diuretics -nitrate - morphine

Treatment approach

reduction of after load and inotropic supportcondition that complicate PE must be corrected -infection -academia -renal failure -anemia