Pulmonary edema overview

Pulmonary edema Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Pulmonary Edema from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Diagnostic study of choice
History and Symptoms
Physical Examination
Laboratory Findings
X Ray
Electrocardiography
CT
MRI
Echocardiography or Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Interventional Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Pulmonary edema overview On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Pulmonary edema overview
CDC on Pulmonary edema overview
Pulmonary edema overview in the news
Blogs on Pulmonary edema overview
Directions to Hospitals Treating Pulmonary edema
Risk calculators and risk factors for Pulmonary edema overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Pulmonary edema is fluid accumulation in the lungs. This fluid accumulation leads to impaired gas exchange and hypoxia.

Pathophysiology

Pulmonary edema is due to either failure of the heart to remove fluid from the lung circulation ("cardiogenic pulmonary edema"), or due to a direct injury to the lung parenchyma or increased permeability or leakiness of the capillaries ("noncardiogenic pulmonary edema").

Cardiogenic

• Severe arrhythmias (tachycardia/fast heartbeat or bradycardia/slow heartbeat)
• Arteriovenous malformation
• Anomalous pulmonary venous return
• Aortic Regurgitation
• Aortic Stenosis
• Arrhythmia
• Cardiomyopathy
• Congestive heart failure
• Coronary Heart Disease
• Hypertensive crisis
• Left Heart Failure
• Left-to-Right Shunt
• Mitral Regurgitation
• Mitral Stenosis
• Myocarditis
• Pericardial Disease. Pericardial effusion with tamponade
• ST elevation MI with left ventricular failure

Non-cardiogenic

This form is contiguous with ARDS (acute respiratory distress syndrome):

• Acute Bronchial Asthma
• Acute Renal Failure
• Bacterial toxins
• Blood Transfusions
• Burns
• Chronic mediastinitis
• Decompression sickness
• Disseminated Intravascular Coagulation
• Drowning
• Drugs
• Fibrotic/inflammatory disease
• Fluid overload, e.g. from kidney failure
• Gastric content aspiration
• Goodpasture's Syndrome
• High altitude sickness. Ascent to high altitude occasionally causes high altitude pulmonary edema (HAPE)
• Hyperhydration
• Hypoalbuminemia / Albumin deficiency
• Idiopathic Venoocclusive Disease
• Inhalation of toxic gases
• Infection
• Leukemia
• Malaria
• Miliary Tuberculosis
• Neurogenic, e.g. subarachnoid hemorrhage
• Pheochromocytoma
• Pneumonia
• Pulmonary contusion, i.e. high-energy trauma
• Pulmonary Embolism
• Reexpansion, i.e. post pneumonectomy or large volume thoracentesis
• Reperfusion injury, i.e. postpulmonary thromboendartectomy or lung transplantation
• Sepsis
• Shock
• Toxic Shock Syndrome
• Multitrauma, e.g. motor vehicle accident
• Upper airway obstruction
• Uremia

Natural History, Complications and Prognosis

If left untreated, acute pulmonary edema can lead to coma and even death, generally due to its main complication of hypoxia.

Diagnosis

Symptoms

Acute Pulmonary Edema

• Anxiety
• Cough, particularly coughing up blood or bloody froth
• Difficulty breathing
• Excessive sweating or diaphoresis
• Feeling of "air hunger" or "drowning" (if this occurs suddenly, awakening the patient from sleep and causing the patient to sit up and catch their breath, it's called "paroxysmal nocturnal dyspnea")
• Grunting or gurgling sounds with breathing
• Pale or blue skin
• Blue or cyanotic lips
• Restlessness
• Shortness of breath
• Shortness of breath when lying down (orthopnea)
• Wheezing

Chronic Pulmonary Edema

If pulmonary edema develops gradually, there may be symptoms of fluid overload:

• Ankle or pedal edema (swelling of the legs, generally of the "pitting" variety, where the skin is slow to return to normal when pressed upon)
• Nocturia (frequent urination at night)
• Orthopnea (inability to lie down flat due to breathlessness)
• Paroxysmal nocturnal dyspnea (episodes of severe sudden breathlessness at night)

Physical Examination

General Appearance of the Patient

• Anxious
• Decrease in level of alertness (consciousness)
• Inability to speak in full sentences

HEENT

• Nasal flaring

Lungs

• End-inspiratory crackles (sounds heard at the end of a deep breath)

Cardiovascular

• A third heart sound (S3) may be present

Laboratory Studies

Brain Natriuretic Peptide

B-type natriuretic peptide (BNP) is elevated in the patient with cardiogenic pulmonary edema. A low BNP (<100 pg/ml) makes a cardiac cause very unlikely and is associated with non-cardiogenic pulmonary edema.

Oxygen Saturation

Low oxygen saturation or hypoxia may be present on arterial blood gas readings.

Chest X Ray

Pulmonary edema

The diagnosis is confirmed on X-ray of the lungs, which shows increased fluid in the alveolar walls. Kerley B lines, increased vascular filling, pleural effusions, upper lobe diversion (increased blood flow to the higher parts of the lung) may be indicative of cardiogenic pulmonary edema, while patchy alveolar infiltrates with air bronchograms are more indicative of noncardiogenic edema

Echocardiography

Echocardiography is useful in confirming a cardiac or no-cardiac cause of pulmonary edema. Among cardiac causes, echocardiography can identify if systolic or diastolic dysfunction is present. Echocardiography is useful in identify if focal segment wall motion abnormalities are present which would suggest ischemia or myocardial infarction as an underlying cause. If there is a global impairment of left ventricular function, then this suggests a cardiomyopathy may be present. Echocardiography may identify the presence and severity of valvular causes of pulmonary edema including aortic stenosis, aortic insufficiency, mitral stenosis. mitral insufficiency, and hypertrophic cardiomyopathy.

Cardiac Catheterization

Insertion of a pulmonary arterial catheter (a.k.a. a Swan-Ganz catheter) may be required to distinguish between the two main forms of pulmonary edema and to help guide management. In patients with cardiogenic pulmonary edema the pulmonary artery pressure will be elevated. Among patients with non-cardiogenic pulmonary edema the wedge pressure will not be elevated.

Treatment

See also the chapter on congestive heart failure.

Acute Pulmonary Edema

In patients with acute pulmonary edema, the goal is to reduce both preload and afterload and to diurese the patient. Intravenous nitroglycerin can be used to reduce both the preload and afterload. Diuretics such as furosemide or bumetanide can be used to reduce volume overload. The dose that the patient is on chronically should be doubled and administered intravenously in the setting of flash pulmonary edema. Morphine sulfate may be helpful in reducing the drive to breathe, improving patient comfort, and reducing the preload.

Oxygen therapy is required to minimize cyanosis and to maintain adequate oxygenation. High-flow oxygen, noninvasive ventilation (either continuous positive airway pressure (CPAP) or variable positive airway pressure (VPAP) may be effective). If the simple measures are not effective then mechanical ventilation may be required.

Treatment should also be directed at managing the underlying cause of an episode of acute pulmonary edema. This would include managing as acute myocardial infarction, mitral regurgitation, aortic regurgitation, or any other condition that causes an increase in left ventricular filling pressures.

Chronic Pulmonary Edema

Reoccurrence of FPE is thought to be associated with hypertension and may signify renal artery stenosis. Prevention of reoccurrence is based on managing hypertension, coronary artery disease, renovascular hypertension, and heart failure.

See also

• High Altitude Pulmonary Edema
• Myocardial infarction

Template:WikiDoc Sources