From the Guidelines
Uremia is a nonspecific constellation of symptoms and signs superimposed on a low GFR, characterized by the buildup of waste products and toxins in the blood due to kidney failure, leading to symptoms such as seizures, amenorrhea, reduced core body temperature, protein-energy wasting, and serositis. The clinical manifestation of uremia includes a wide range of symptoms, such as uremic frost, renal osteodystrophy, asterixis, coagulation defects, congestive heart failure, and ammonia taste and breath 1. According to the kdoqi clinical practice guideline for hemodialysis adequacy, uremia is a state of intoxication that involves multiple extra-renal systems, including the bone, heart, vasculature, and lungs 1.
The decision to initiate maintenance dialysis should be based upon an assessment of signs and/or symptoms associated with uremia, which can be challenging due to the lack of definitive identifiers of uremia 1. Providers need to be aware of uremia "mimickers," especially in the elderly and those receiving poly-pharmacy, and be diligent in their search for reversible causes of symptoms prior to dialysis initiation 1.
Key symptoms of uremia include:
- Seizures/change in seizure threshold
- Amenorrhea
- Reduced core body temperature
- Protein-energy wasting
- Insulin resistance
- Heightened catabolism
- Serositis (pleuritis, pericarditis)
- Hiccups
- Platelet dysfunction
- Somnolence 1. The condition requires prompt treatment, typically involving dialysis to artificially filter the blood, along with addressing the underlying cause of kidney failure. If left untreated, uremia can lead to serious complications, including seizures, coma, and death as the toxic substances continue to accumulate and damage multiple organ systems 1.
From the Research
Definition of Uremia
- Uremia is a clinical state associated with the retention of nitrogenous metabolic products, characterized by a raised blood urea concentration 2.
- It is a syndrome that involves all systems of the body, resulting from biochemical alterations in the internal environment due to retained metabolic products and changes in water, electrolyte, and acid-base homeostasis 2.
- Uremia can be acute or chronic, with acute uremia presenting as a syndrome of gastrointestinal symptoms, pericarditis, pleuritis, and central nervous system alterations, while chronic uremia can result in damage to multiple organ systems 3.
Characteristics of Uremia
- Uremia is caused by the accumulation of organic waste products that are normally cleared by the kidneys, including urea, creatinine, guanidines, and other metabolites 2, 4.
- The gut microflora and microbiometabolome play a significant role in the generation of uremic retention solutes, with toxins such as advanced glycation end products, phenols, and indoles contributing to the pathogenesis of chronic kidney disease 4.
- Uremia can lead to a range of complications, including systemic microinflammation, cardiovascular disease, immunodeficiency, malnutrition, anemia, bone metabolism disorders, and polyneuropathy 3.
Biochemical Aspects of Uremia
- Urea, a marker of uremic retention, has been found to be toxic at concentrations representative of chronic kidney disease, inducing molecular changes related to insulin resistance, free radical production, and apoptosis 5.
- Urea can also generate cyanate, ammonia, and carbamylated compounds, which have been linked to biological changes and post-translational protein modifications involved in atherogenesis and other functional changes 5.