Pulmonary edema

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Pulmonary edema is swelling and/or fluid accumulation in the lungs. It leads to impaired gas exchange and may cause respiratory failure.

Contents

1 Signs and symptoms
2 Diagnosis
3 Causes
4 Therapy
5 See also
6 Reference

Signs and symptoms

Symptoms of pulmonary edema include difficulty breathing, coughing up blood, excessive sweating, anxiety and pale skin. If left untreated, it can lead to death, generally due to its main complication of hypoxia.

Diagnosis

Pulmonary edema is generally suspected due to findings in the medical history and physical examination: end-inspiratory crackles during auscultation (listening to the breathing through a stethoscope) can be due to pulmonary edema. The diagnosis is confirmed on X-ray of the lungs, which shows increased vascular filling and fluid in the alveolar walls.

Low oxygen saturation and disturbed arterial blood gas readings may strengthen the diagnosis and provide grounds for various forms of treatment.

Causes

Pulmonary edema is either due to direct damage to the tissue or as a result of inadequate functioning of the heart or circulatory system.

Cardiogenic causes:

Heart failure
Tachy- or bradyarrhythmias
Severe heart attack
Hypertensive crisis
Excess body fluids, e.g. from kidney failure
Pericardial effusion with tamponade

Non-cardiogenic causes, or ARDS (acute respiratory distress syndrome):

Inhalation of toxic gases
Multiple blood transfusions
Severe infection
Pulmonary contusion, i.e. high-energy trauma
Multitrauma, i.e. severe car accident
Neurogenic, i.e. cerebrovascular accident (CVA)
Aspiration, i.e. gastric fluid or in case of drowning
Certain types of medication
Upper airway obstruction
Reexpansion, i.e. postpneumonectomy or large volume thoracentesis
Reperfusion injury, i.e. postpulmonary thromboendartectomy or lung transplantation
Lack of proper altitude acclimatization.

Therapy

When circulatory causes have led to pulmonary edema, treatment with nitrates (glyceryl trinitrate), positive pressure oxygen, and loop diuretics, such as furosemide or bumetanide, is the mainstay of therapy. Secondly, one can start with noninvasive ventilation. Other useful treatments include CPAP and oxygen.

There are no causal therapies for direct tissue damage; removal of the causes (e.g. treating an infection) is the most important measure.

Reference

[Medical Encyclopedia entry]