Introduction
The accumulation of fluid and proteins in the alveoli can leads to a mismatch of pulmonary ventilation. The result of kidney-related severe conditions or even failure may affect the functions of the lungs, and the symptoms are difficulty breathing or extreme shortness of breath which worsens during or after activity, feeling of suffocation after lying down, palpitations, etc. Two types of pulmonary edema are cardiogenic and non-cardiogenic pulmonary edema. Pulmonary edema with cardiovascular roots is known as cardiogenic pulmonary edema, and other than cardiovascular roots is known as non-cardiogenic pulmonary edema. The detection of pulmonary edema is difficult on the stethoscope. A few tests and radiological interventions are needed to detect the edema.
What Is Nephrogenic Pulmonary Edema?
It is a condition in which acute kidney injury results in fluid accumulation in the lung at microscopic and macroscopic levels. Also, a saturation of the fluids and proteins is seen in the lungs resulting in a lack of ventilation.
What Happens in Nephrogenic Pulmonary Edema?
Due to renal failure, water imbalance and sodium retention can be observed, where fluids and certain proteins accumulate in the alveoli, resulting in respiratory problems. The condition known as a ventilation-perfusion mismatch can be seen in such situations. The seepage of poor protein fluid in the alveoli and interstitial spaces of the lungs happens. This type of edema results from changes in the starling pressure or forces that drive fluid exchange through the capillary walls.
What Is the Pathophysiology of Nephrogenic Pulmonary Edema?
Physiologically, the lungs receive more cardiac output than any other body organ, which makes them constantly exposed to peptides and regulatory immune cells. The reabsorption and excretion of these cells or molecules result in increased concentrations in the blood, which begins immune responses to the harmful effects on the other organs. After a few changes, an inflammatory cascade can be seen, affecting the lungs. The main cause behind nephrogenic pulmonary edema is renal abnormalities or acute kidney injury (AKI).
What Is an Acute Kidney Injury?
Another name for an acute kidney injury is acute kidney failure. It is a common clinical disorder primarily caused by renal ischemia, an injury with an abrupt loss of kidney functions and a decreased renal filtration fraction. Generally, kidney diseases directly or indirectly affect pulmonary functions and cause the lungs to be perceived as one of the most associated distant organs in kidney injury.
What Are the Symptoms of Nephrogenic Pulmonary Edema?
Dyspnea is difficulty breathing; the breathing pattern worsens after any activity or even after lying down, for the patient may feel drowned or suffocated. Hemoptysis with fizzy sputum can be observed in anxiety, the sensation of impending doom, cold skin, and wheezing are some common symptoms of nephrogenic pulmonary edema. Also, rapid gain in weight, sleepless nights due to persistent coughing, and fatigue can be added to the symptoms.
What Are the Phases of Lung Injury After Acute Kidney Failure?
Three phases occur after renal failure or injury as follows:
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Very early phase and has a timeline of zero to six hours.
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Early phase and has a timeline of 24 hours.
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Late phase and has a timeline of seven days.
How Does Nephrogenic Pulmonary Edema Get Diagnosed or Detected?
A quick intervention is needed to diagnose the problem when breathing complications occur. When the physician suspects pulmonary edema, he may order a chest X-ray. X-ray is an important first line of diagnosis to rule and confirm the edema. A stethoscope is not an efficient way of confirming the edema in the lungs compared to other diagnostic tools. Chest computerized tomography (CT) scan can confirm or rule out the state of pulmonary edema. It gives thorough details of the state of the lungs. A pulse oximetry test is done to estimate the oxygen level in the blood.
Another test that measures the oxygen and carbon dioxide in the blood is the arterial blood gas test. A B-type natriuretic peptide (BNP) blood test is done to see the levels of BNP in the case of cardiogenic pulmonary edema. Complete blood count, metabolic panel to check kidney functions and thyroid function test can also be done. Ultrasound of the lungs is done in many cases. Cardiac catheterization and coronary angiogram are prescribed when the cause of pulmonary edema is unknown.
How Can Nephrogenic Pulmonary Edema Be Treated?
The initial primary treatment of pulmonary edema is providing the patient with oxygen and trying to increase the oxygen levels in the blood. Depending on the severity of the case, many other treatments can be given to the patient. A mechanical ventilator can be used in severe cases. Blood pressure drugs are used in many cases to control vasodilation and vasoconstriction, which controls bronchial dilation or constriction in pulmonary edema.
Narcotics, such as Morphine, are prescribed to manage shortness of breath and anxiety. However, a few physicians may not use narcotics in patients with pulmonary edema due to their side effects. Diuretics are also used to keep the kidney functioning properly and to maintain fluid accumulation. Neutrophil elastase inhibitors are observed to decrease the symptoms of acute kidney injury (AKI). Vitamin C intake can be managed as it interacts with free radicals and can restore the property of vitamin E, which helps the oxygen level increase eventually.
How Is the Management of Nephrogenic Pulmonary Edema Done?
Few lifestyle changes are necessary to maintain good overall health. Patients should keep their blood pressure in control, manage other medical conditions, stop smoking, get a healthy diet, manage weight, and exercise daily to keep themselves healthy. If major symptoms occur, do not treat them with home remedies rather, visit the nearest doctor or hospital facility as soon as possible.
Conclusion
Pulmonary edema is a vast term associated with atypical fluid accumulation in the lungs. Nephrogenic pulmonary edema is a subtype of non-cardiogenic pulmonary edema, which can be caused due to acute kidney failure, drowning, inhalation injury, etc. Nephrogenic pulmonary edema has a significant mortality and morbidity rate. A better understanding of nephrogenic pulmonary edema may lead to various therapies to treat it and lessen the mortality rate.
