As we all know about edema, interstitial spaces and seepage of excess fluids, it can happen anywhere in the body, may it be on the extremities, the brain or the lungs. We must bear in mind though, that edema is not really the disease itself but a manifestation of an underlying health illness or let us say, a resulting complication of a more serious disease or condition. Wherever it is in the body of the person, it can be threatening to the health. Pulmonary edema for instance, is a complication of several diseases and conditions.
This is a result of movement of extra fluids into the air sacs (alveoli) because of a deviation in one or more of the Starling’s force. For further explanation, Starling hypothesis postulated that movement of fluid due to the filtration across the wall of the small blood vessels (the capillaries) is solely reliant on the equilibrium between pressures. The underlying reason for this complication can either be heart related (cardiogenic), or not related to any heart conditions (non-cardiogenic).
So, what causes the specific types of pulmonary edema?
On one hand, cardiogenic pulmonary edema can result from factors that causes increased pressure in the left atrium of the heart maybe like narrowing of the mitral valves of the heart which is commonly seen among individuals with rheumatic heart disease, calcifications, infective endocarditis, and yes, this mitral valve is considered as the most common heart conditions among pregnant women.
On the other hand, noncardiogenic pulmonary edema is a result of alterations in the capillary’s ability to allow fluids or gasses to pass through it (capillary permeability) and these include conditions such as drowning, increased fluid in the body, aspiration, inhalation injury, acute kidney illnesses, allergic reaction, forms of medications and respiratory distress syndrome of the adult. In contrast to cardiogenic pulmonary edema wherein there is enlargement of the heart upon x-ray, the heart in a non-cardiogenic pulmonary edema may be normal in size.
Non-cardiogenic pulmonary edema continues to become a vital cause of morbidity and mortality. Even with the great advancement in supportive therapy, death due to the condition still exceeds 50%. Thus, early diagnosis is significant for the management and treatment of this condition.
What are the most common clinical manifestations?
There are not much differences in the clinical manifestations between cardiogenic and non-cardiogenic pulmonary edema. Because of all these fluids in the lungs (where fluid is not supposed to be found, such as in the alveoli, remember these are air sacs), patients commonly verbalized shortness of breath and difficult breathing even upon minimal exertion. The manifestation of coughing is a common complaint and may signal an early clue to worsening pulmonary edema more specifically to patients with left ventricular (part of the heart) dysfunction. Sputum may be characterized as pink, frothy and hoarseness of voice may be present.
In cases of chest pains, clinicians should be alerted as this may indicate an impending myocardial infarction or ischemia or what we commonly known as heart attack. Fast breathing (tachypnea) and fast heart rate (tachycardia) may be present and sitting upright may present air hunger. The patient may become distressed and disoriented, anxious and will have excessive perspiration.
Also, the patient may be hypertensive, and cool hands and legs may be a result of poor blood circulation on the farther body parts like the extremities, because of poor heart output of blood. Upon auscultation of the chest, the clinician or nurse may find fine clicking, rattling or crackling noise (rales) which may indicate presence of fluids as air passes through. It would usually start at the base of the lungs and when it progresses and worsens it can go up to the upper part (apices) of the lungs.
How is Pulmonary Edema diagnosed?
Diagnosis can include thorough history and physical examination, electrocardiogram (ECG), and echocardiogram and of course radiologic examination (x-ray). Upon x-ray, in cardiogenic pulmonary edema, it will show fluffy air space opacities in the center lungs as well as the outer areas of the lungs and of course the distinctive enlargement of the heart (cardiomegaly), while in noncardiogenic pulmonary edema, there is the typical batwing haziness, and absence of signs of cardiomegaly.
Treatment & Management of Pulmonary Edema
Individuals with cardiogenic pulmonary edema are usually managed with diuretics such as Lasix to eliminate extra fluids through urination. Morphine can also be given to decrease the patient’s anxiety and work of breathing. In addition to that, medications that can dilate the blood vessels such as nitroglycerine may be very helpful especially in hypertensive emergencies. Ideal position of the patient is in the upright position. However, clinicians must be ready to start ventilation if the individual will start to show further signs of respiratory fatigue and distress such as lethargy, diaphoresis, and anxiety.
Patients with non-cardiogenic pulmonary edema needs all available invasive and non-invasive approach of treatment and may have similar management with the other type of pulmonary edema. These include ventilatory support to have enough oxygenation in the blood and managing possibilities of hemodynamic instability. If it is drug-induced then additional management should be done to eliminate levels of the drugs in the blood circulation of the individual, and or be supportive in the management of symptoms brought about by the drugs.
If infection is present, which in this case may be septic, antibiotic therapy should be considered. Non-cardiogenic pulmonary edema (or even cardiogenic edema) should be considered as a threatening case with an increased mortality rate thus a decisive, quick, and comprehensive response should be done.
Nevertheless, whatever type of pulmonary edema is manifested by the patient, a thorough examination and prompt management should be done to increase positive prognosis of the patient.
Author: Sarah Catina RN