Pulmonary edema is defined as an abnormal accumulation of fluid and secretions in the lung tissue, the alveolar space and lobar cavity and is considered a severe and life-threatening condition that requires immediate medical care and intervention. Individuals suffering from this pulmonary complication usually have other preexisting medical conditions that precipitated the occurrence of fluid congestion within the pulmonary system.
Pulmonary edema most commonly occurs as a result of an increase in micro vascular pressure from a compromised and abnormal cardiac function. The back-up of blood pressure into the pulmonary vessels and underlying vasculature would often result in the insufficient and inadequate left ventricular function which causes an increase in micro vascular pressure. The resulting abnormalities in pressure result in fluid build-up within the pulmonary circulation which literally drowns the individual from his/her own fluids.
Pathophysiology of Pulmonary Edema
Pulmonary edema results when fluid begins to leak into the interstitial space and the alveoli. The causes of this pulmonary congestion vary from hypervolemia (the sudden increase in the intravascular pressure of the lungs) to fluid overload resulting from an inadequate pumping power of the heart, pneumonectomy (removal of a lobe or an entire section of the lung), cardiac output from the pulmonary circulation goes directly to the remaining portion of the lung which causes congestion. If the individual’s cardiac status is not stabilized and monitored, pulmonary edema can develop quickly.
Clinical Manifestations of Pulmonary Edema
Individuals with pulmonary edema have increased respiratory distress universally characterized by dyspnea, central cyanosis and a feeling of breathlessness. Moreover, individuals suffering from pulmonary edema are usually very anxious and often feeling agitated as if they is a sense of impending doom. As fluid leaks into the alveoli and mixes with the air, a foam or froth is formed. The individual coughs out a foamy, frothy and sometimes blood-tinged secretions. The individual may also experience an acute respiratory distress syndrome and may become extremely confused and disoriented.
Assessment findings often reveal crackles in the lung bases, since the pooling of accumulated fluid is directed by gravity which if left untreated can progress to the apices of the lungs. The crackles are usually caused by the movement of air through the fluid filled alveolus. Tachycardia is also a common finding along with worsening arterial blood gas values indicating severe hypoxemia brought about by the impaired gas exchange.
 Medical management of pulmonary edema
Management focuses primarily on correcting the underlying disorder. Should the pulmonary congestion from edema is cardiac in origin, it is imperative that ventricular function be corrected and improve. Medications such as vasodilators and cardiac contractility medications greatly improve cardiac function and prevent fluid congestion in the pulmonary circulation. If the problem is fluid overload such as overloading of intravenous fluids, diuretics are administered to eliminate fluid within the pulmonary circulation. Oxygen administration is initiated to correct hypoxemia and in some cases, intubation and mechanical ventilation are necessary to provide supplemental oxygenation for individuals whose airway may be compromised or no longer patent. Furthermore, comfort measures are provided to people with pulmonary edema to alleviate anxiety and agitation.