Chronic Kidney Disease

Chronic Kidney Disease

Chronic kidney disease arises from various disease pathways that alter the functions and structure of the kidney irreversibly for a period of time. The overall Kidney function is best indicated by the Glomerular Filtration Rate (GFR), which is equal to the total fluid filtered per unit a time through all the functioning nephrons. Therefore, chronic kidney disease is defined as decreased kidney function shown by markers of kidney damage or a GFR of less than 60 mL/min per 1·73 m² or both for at least three months (Webster et al., 2017). This disease is chronic as it affects patients over a long period and in stages. It is characterized by persistent renal damage and loss of renal function. Diabetes and hypertension are the leading cause of chronic kidney disease in developed and developing countries. However, other causes such as glomerulonephritis, environmental exposures (such as air pollution and herbal remedies), and infection are common in sub-Saharan Africa, Asia, and many developing countries (Chen et al., 2019). Genetic risks such as sickle cell trait could also be a contributing factor. According to Chen et al. (2019), chronic kidney disease affects about 8% to 16% of the population worldwide. Therefore, clinical physicians need to detect this disease early because as it progresses, it can cause end-stage kidney disease, cardiovascular disease, and even death. In 2012 kidney disease caused 1.5% of deaths worldwide and was ranked fourteenth on the top list of deaths Webster et al. (2017).

Chronic kidney disease can be detected through urine studies, routine screening with serum chemistry profile, or an incidental finding (Chen et al., 2019). Patients may sometimes present symptoms such as gross hematuria, flank pain, or decreased urine output. However, in more advanced kidney disease, patients report fatigue, metallic taste, nausea, vomiting, peripheral edema, and changes in mental status. Therefore, when evaluating a patient with known or suspected kidney disease, physicians should do a thorough follow-up and check for hemoptysis, rash, neuropathy, or urinary obstruction symptoms. Moreover, patients should be assessed on any prior exposure to potential nephrotoxins (such as antibiotic therapies such as gentamicin and chemotherapies), history of recurrent urinary tract infections, hypertension, diabetes, or history of family kidney disease. For one to be diagnosed with kidney disease, the GFR should show less than 60 mL/min per 1·73 m² for at least three months.

Nevertheless, in some instances, the duration of the kidney disease is unclear. In such circumstances, a series of assessments should be performed to distinguish CDK from acute kidney injury, which is the change of kidney function for 2- 7 days, and acute kidney disease, which is decreased kidney function occurring for less than three months (Chen et al., 2019). Chronic kidney disease will progress to the end-stage without treatment, but the discovery of early new surrogate markers such as neutrophil gelatinase-associate protein, apolipoprotein A-IV, kidney injury molecule-1, and soluble urokinase receptor may allow potential intervention and treatment (Zhong et al., 2017). The progression rate of CKD varies according to individual.

Organs in the human body have different roles, but they work together to keep the human body at equilibrium. This organ may fail due to a disorder or an illness causing multiple organ failures. However, in this study, the focus is on the effects of chronic kidney disease on the circulatory and pulmonary systems. The circulatory system consists of the heart, blood vessels, and blood. When the blood pressure is too low, healthy kidneys release renin which stimulates hormones that increase blood pressure. Damaged kidneys release too much renin, which causes very high blood pressure, which could lead to a heart attack or a stroke. Another significant effect on the circulatory system is fluid build-up in the heart and increased potassium levels. Kidneys are responsible for regulating fluid balance in the body and maintaining conducive potassium levels. If the kidneys fail to maintain fluid balance, the excess fluid will build up in the heart, increasing the heart's workload.

Moreover, failed kidneys will not regulate potassium levels, which are harmful to the heart. Besides heart failure, kidney failure could cause dangerous heart inflammations (“renal failure and its effect on the cardiovascular system," 2011). Kidneys are the body's waste collectors, and when they fail, waste builds up in the blood. Dietary protein breakdown causes the formation of urea which is referred to as uremia when in large quantities. Uremia means that there is urine in the blood, which causes heart inflammations on the outer layer. Additionally, when the kidneys are not working correctly, more stress is put on the heart as it has to pump harder to get enough blood to the kidneys. The circulatory system and the renal system have to work together to ensure proper blood flow.

The renal and pulmonary systems work together to regulate acid-base equilibrium, control blood pressure and fluid homeostasis, and modify partial pressure of carbon dioxide and bicarbonate concentration (Visconti et al., 2016). Chronic kidney disease causes pulmonary edema. Pulmonary edema is a condition caused by fluid accumulation around the lungs. As earlier discussed, the kidneys are responsible for fluid regulation in the body, and damaged kidneys cannot regulate body fluids which causes accumulation around the lungs and other body organs. Alteration of the renal system can cause severe damage to the circulatory and pulmonary systems. Kidneys are body cleaners, and damaged kidneys can lead to toxicity in the body. Accumulation of harmful toxins in the body causes damage to the organs. In this study, kidney failure causes heart inflammation, hypertension, and pulmonary edema. The circulatory and pulmonary systems depend on the renal system to function correctly.

Body organs work together to maintain a better internal environment. The endocrine and nervous system regulates them. The nervous system virtually controls all the body's activities while the endocrine secrets hormones which regulate these activities. The process of maintaining a balanced internal environment is known as homeostasis. The kidneys are responsible for maintaining this balance by regulating body fluids, ions, and other body substances by excreting the excess in the form of urine. The kidneys work together with other systems to maintain homeostasis; for instance, they work together with the circulatory system to filter blood and the urinary system to remove excess waste. Kidneys also release hormones that help maintain homeostasis, such as erythropoietin, which stimulates the bone marrow to produce more red blood cells whenever needed (“CK-12 Foundation,” 2018). They also release calcitriol which helps maintain calcium levels for the bones since it is an active form of vitamin D and renin to regulate the blood pressure. The renal system plays a vital role in the body. However, renal failure is a condition that affects the renal system, and the body has to maintain its equilibrium despite the mal-functioning of the renal system. The attempt of the body to maintain equilibrium is referred to as compensation. Whenever one system fails, the body finds other ways to maintain balance; for instance, according to an article on homeostasis (2018), the respiratory system can help maintain balance by removing excess carbon dioxide through faster breathing. The endocrine system also releases insulin from the pancreas when the blood sugar is high. The insulin absorbs excess sugars from the blood. When the kidneys are not completely damaged, the working part works extra hard to maintain the required balance. For the patients whose kidneys are severely damaged, dialysis is performed (cleaning the blood using machines). However, if there are no improvements after the treatments processes, a transplant is recommended.

Systems in the human body work together under the nervous system's control. Despite having different roles in the body, all organs must work together to ensure equilibrium in the internal environment. As earlier seen, the kidneys clean up the blood for the heart to pump and boost the heart's pressure by secreting renin. The heart also pumps blood to the kidney to function correctly. The kidneys also regulate fluid balance, ensuring that the lungs are fluid-free for better functioning, ensuring that the body has enough oxygen and excess carbon dioxide is exhaled. Proper aeration of the blood and body ensures that blood taken to the kidneys is clean, enhancing the kidneys. Failure of one system can lead to life-long illness and suffering for the individual. As discussed, renal failure has severe effects on other systems, such as the circulatory and pulmonary systems, which are essential in the body. Therefore, individuals should take care of their bodies by maintaining a healthy environment. 

References

Chen, T. K., Knicely, D. H., & Grams, M. E. (2019). Chronic kidney disease diagnosis and management: a review. Jama, 322(13), 1294-1304.

CK12-Foundation. (2018). CK-12 Foundation. https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/13.43/primary/lesson/kidneys-bio/

Homeostasis. (2018, August 8). CK-12 Foundation. Retrieved April 11, 2022, from https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/13.2/primary/lesson/homeostasis-bio/

Renal failure and its effect on the cardiovascular system. (2011, February 17). Health24. https://www.news24.com/health24/medical/kidney-and-bladder/the-effect-of-kidney-failure/renal-failure-and-its-effect-on-the-cardiovascular-system-20120721

Visconti, L., Santoro, D., Cernaro, V., Buemi, M., & Lacquaniti, A. (2016). Kidney-lung connections in acute and chronic diseases: Current perspectives. Journal of Nephrology, 29(3), 341-348. https://doi.org/10.1007/s40620-016-0276-7

Webster, A. C., Nagler, E. V., Morton, R. L., & Masson, P. (2017). Chronic kidney disease. The lancet, 389(10075), 1238-1252.

Zhong, J., Yang, H. C., & Fogo, A. B. (2017). A perspective on chronic kidney disease progression. American Journal of Physiology-Renal Physiology, 312(3), F375-F384.