Uremia

Excerpt

Uremia is a clinical condition associated with declining renal function and is characterized by fluid overload, electrolyte imbalances, metabolic abnormalities, and physiological changes. The term "uremia" literally means "urine in the blood," which develops most commonly in chronic and end-stage renal disease. However, less commonly, this condition can also manifest in acute kidney injury if kidney function deteriorates rapidly. Urea exhibits direct and indirect toxicity to various tissues, notably affecting the neurological system.

Urea acts as a marker for uremic toxins in general, with over 100 substances identified as potential uremic toxins, which are present in varying concentrations in the blood. These substances are often metabolites that cannot be cleared due to impaired renal function. In addition to urea, other putative uremic toxins comprise parathyroid hormone, α-macroglobulin, advanced glycosylation end products, indoxyl sulfate, homocysteine, uric acid, and β-2 microglobulin. The clinical manifestations of uremia are not attributed to a single uremic toxin; instead, a combination of multiple toxins likely contributes to the physiological and clinical features of uremia.

Urea and other uremic toxins, accumulated due to impaired renal clearance, are toxic to various tissues, especially the nervous system, leading to symptoms such as nausea, vomiting, fatigue, anorexia, muscle cramps, pruritus, and altered mentation. These manifestations significantly diminish a patient's quality of life and, if left untreated, can result in morbidity and mortality. Uremic signs and symptoms typically develop gradually over time. Due to the frequent occurrence of altered mental status in patients, early recognition by healthcare professionals is crucial for promptly initiating renal replacement therapy and potential renal transplant referral. Furthermore, healthcare providers should provide guidance and make necessary arrangements for patients requiring renal replacement therapy to improve their health outcomes. They must also vigilantly monitor for any signs of uremia to prevent associated complications. Timely referral to transplantation centers is associated with improved survival rates and reduced morbidity among uremia patients.