Introduction:
Kidney failure and diseases to the kidneys are two major contributors to the global illness burden and a significant cause of death in developing countries. Due to its significant incidence, ability to advance to end-stage renal disease (ESRD), and tendency to cause early death, chronic kidney disease (CKD) is a significant health challenge worldwide. Suppose renal replacement therapy is not used properly to treat the decreased glomerular filtration that causes the accumulation of toxins, liquids, and electrolytes. In that case, the patient may develop uremic syndrome or die. The uremic syndrome is when uremic salts accumulate in the body, causing dysfunction of many organs.
What Is End-Stage Renal Disease?
End-stage renal disease is the final stage of chronic kidney disease. The kidneys are not able to perform their functions properly at this stage. The functioning of the organ is reduced to less than ten percent. A patient at this stage requires dialysis or a kidney transplant for the functions of the organ to be accomplished.
The kidneys filter waste and water from the blood. This is then excreted through the urine. Increased amounts of fluid, electrolytes, and other wastes accumulate in the body when the kidney does not function properly. Hence, dialysis or a kidney transplant would be required to continue the body's regular functions.
What Are the Pulmonary Complications Seen in End-Stage Renal Diseases?
The accumulation of uremic toxins in the body is one of the main reasons for pulmonary complications in end-stage renal disease. Other causes that might not be directly related to the condition include anemia, immune suppression, malnutrition, extra calcification, an imbalance in the acid-base levels, electrolyte disorders, and volume overload (an increase in the extracellular fluid volume). Some of the pulmonary complications seen in patients with end-stage renal diseases include:
-
Pulmonary Edema: This condition is caused by fluid accumulation in the lungs. In renal diseases, it is due to the accumulation of toxins in the body. Cough, chest pain, and breathing difficulties can be found. Oxygen supplements and medications can be used to treat the condition.
-
Pleural Effusion: The accumulation of fluid between the tissues that line the lungs and the chest is called pleural effusion. The fluid is removed using a process called thoracentesis. Antibiotics and diuretics are other methods of treatment.
-
Acute Respiratory Distress Syndrome: When there is fluid accumulation in the air sacs of the lungs, it is called acute respiratory distress syndrome. This prevents the organs from receiving the required amount of oxygen. It is often life-threatening and depends on the seriousness of the injury or age. Shortness of breath is a common sign. They often require a mechanical ventilator to breathe.
-
Increased Pulmonary Capillary Permeability: The permeability of the blood vessels is increased in these conditions. As a result, fluid leaks out of the vessels to the interstitium.
-
Pulmonary Fibrosis: In this condition, the walls of the air sacs in the lungs, which are usually thin, become thick and fibrotic. It affects the proper functioning of the lungs. shortness of breath, dry cough, shallow breathing, etc., are common signs of the condition.
-
Obstructive Apnea: A condition where the soft tissues in the throat, like the tongue, soft palate, etc., relax temporarily, causing difficulty in receiving oxygen. This obstructs the normal breathing process. Loud snoring, gasping for breath between sleep, etc., are some signs.
-
Muscle Myopathy: In this condition, a group of muscles lose their ability to function properly. As a result, the daily activities are interfered with. The accumulation of uremic toxins in the body could cause the condition in patients with end-stage renal disease. As a result, there are changes in the structure and functioning of the muscles.
-
Low Respiratory Muscle Strength: These occur as a part of neuromuscular disorders. As a result, the respiratory muscles might become weak and not function properly. In patients with end-stage renal disease, it is attributed to the accumulation of uremic toxins in the body. The strength and endurance of the inspiratory muscles are lost gradually.
How Does Pulmonary Functions Change in End-Stage Renal Diseases?
Several changes in pulmonary functions are seen in patients with end-stage renal diseases. This can include restriction, obstruction, and impaired diffusion capacity. Diffusing capacity is the ability of the lung to diffuse gases from the air it contains to the red blood cells in its arteries. The improvement of spirometry parameters after hemodialysis is significant despite some contradictory findings. Spirometry is the most common test done to check the pulmonary functions. Studies show a significant improvement in pulmonary function after one hour of hemodialysis. The improvement in spirometry values is mostly attributed to the correction of volume overload during hemodialysis. However, there is still confusion if the fluid accumulation in the body between the dialysis sessions influenced pulmonary functions. Even though there was an improvement in the spirometry values, they were still unable to reach normal levels.
-
Forced Vital Capacity (FVC): The maximum amount of air that can be forcefully expelled from the lungs after taking a deep breath is called forced vital capacity. The FVC values are well below the normal values in end-stage renal diseases.
-
FEV1 is the maximum air expelled from the lungs forcefully in one second. Since FVC is already less, FEV1 will automatically be less than the normal values.
-
PEFR (Peak Expiratory Flow Rate): It measures a person’s speed of expiration. It is the amount of air expelled in a quick expiration. It was also low in these patients.
Conclusion:
Abnormalities in the pulmonary function are a clinical finding seen in end-stage renal diseases. They can be improved by dialysis. However, they do not return to their normal values unless a kidney transplantation is done. Hemodialysis improves pulmonary function testing, which is likely due to a decrease in volume overload. Improved pulmonary functions may be the outcome of intervention to remove excess volume in hemodialysis patients with volume overload.
