Ver el código de «Uremia»

==Background==
*Uremia = clinical syndrome associated with end-stage renal disease 
**Correlation exists between symptoms of uremia and low GFR (15-20% of nl)
**BUN/creatinine are inaccurate markers of clinical syndrome of uremia
*Contributing Factors:
**Excretory failure
***Leads to toxin accumulation
**Biosynthetic failure
***Loss of Vitamin D and erythropoietin
**Regulatory failure
***Uremic state produces excess free radicals → atherosclerosis, amyloidosis

==Clinical Features and Management==
===Neurologic===
*Uremic [[encephalopathy]]
**Diagnosis of exclusion
**Cognitive defects, memory loss, decreased attentiveness, [[dysarthria|slurred speech]]
**Asterixis, [[seizure]], [[coma]]
**Improves with [[dialysis]]
*Dialysis [[dementia]]
**Similar to uremic encephalopathy except progressive, no improvement with dialysis 
**EEG findings can differentiate uremic encephalopathy from dialysis dementia
*[[CVA]]
**[[Stroke|Cerebrovascular disease]], trauma, [[coagulopathy|bleeding dyscrasias]], anticoagulant, hypertension
*[[Subdural hematoma]]
**10 times more likely than in general population
**Platelet dysfunction
**[[Headache]], [[focal neurologic deficits]], [[seizure]], [[coma]]
*Peripheral neuropathy
**Occurs in 60-100% of dialysis patients
**[[Paresthesias]], impaired proprioception, [[weakness]]
**Autonomic neuropathy (postural [[dizziness]], [[gastroparesis]], bowel dysfunction)

===Cardiovascular===
*CK-MB and [[troponin]] are specific markers of MI even in patients undergoing regular dialysis
*Mortality from cardiovascular disease is 10-30 times higher in dialysis patients than general population
*hypertension is common
*Uremic [[cardiomyopathy]]
**Diagnosis of exclusion
**Circulating digitalis-like substances have been implicated
**Dialysis rarely improves LV function
*[[Pericarditis]]
**Uremic pericarditis (75% of cases)
***Most common when the other symptoms of uremia are most severe
***BUN is nearly always >60
***Loud friction rub that is often palpable
***Typical pericarditis ECG changes are absent (inflammation does not involve myocardium)
****If ECG does have typical changes consider infection
**Dialysis-related (25% of cases)
***Most common during increased catabolism (trauma, sepsis) or missed dialysis sessions 
***Constitutional symptoms, such as fever, are more common  than in uremic pericarditis
**Treatment
***[[Dialysis]]
*[[Tamponade]]
**Presents with [[altered mental status]], [[hypotension]], [[dyspnea]]
***Rarely present with classic signs of Beck's triad
**[[Pericardiocentesis]] should only be attempted if hemodynamically unstable
*[[Pulmonary Edema]]
**Commonly ascribed to fluid overload; also consider MI
***Treat similar to non-ESRD patient
****[[Furosemide]] 80mg IV may be effective even if minimal urine output (pulmonary vasodilation)
***Preload reduction can be accomplished via:
****Induced [[diarrhea]] (sorbitol)
****Phlebotomy - withdrawal of as little as 150 mL is safe and effective
*[[CHF]]
**May be preexisting
**May be caused by uremic cardiomyopathy, fluid overload, AV-related high-output failure 

===Hematologic===
*[[Anemia]]
**Without treatment, the hematocrit in ESRD patients should stabilize at 15-20%
**Treatment = erythropoietin
*Immunodeficiency
*Bleeding diathesis ([[Uremic bleeding syndrome]])
**Increased risk for of bleeding (GI, ICH, liver hematoma) due to impaired platelet function
**Treatment = [[desmopressin]], [[cryoprecipitate]], conjugated estrogen, EPO, dialysis<ref>Hedges SJ et al. Evidence-based treatment recommendations for uremic bleeding. Nature Clinical Practice Nephrology (2007) 3, 138-153.</ref>

===GI===
*Anorexia, [[nausea/vomiting]]
*Increased incidence of [[GI bleeding]], diverticular disease, [[ascites]]

===Dermatologic===
*Uremic frost
*Generated from crystallized nitrogenous waste from sweat
*Typically in BUN > 200mg/dL
*Treatment is lowering BUN

===Renal bone disease===
*Metastatic calcification ([[calciphylaxis]])
**When calcium-phosphate product (Ca x PO4) > 70-80, metastatic calcification can ensue
**Symptoms of [[pseudogout]], skin/finger necrosis (small vessel involvement)
**Life-threatening calcifications can occur in the cardiac and pulmonary systems
**Treatment = use of low-calcium dialysate and phosphate-binding gels
*[[Hyperparathyroidism]] (osteitis fibrosa cystica)
**Calciphylaxis + vitamin D3 deficiency results in depressed Ca, stimulation of PTH
**Leads to high bone turnover → weakened bones → increased [[fracture]] susceptibility
**Treatment = phosphate binding gels, vitamin D3 replacement
*[[Vitamin D deficiency|Vitamin D3 deficiency]] and [[aluminum toxicity|aluminum intoxication]] (osteomalacia)
**Leads to osteomalacia (defect in bone calcification)
**Symptoms similar to hyperparathyroidism (muscle weakness, bone pain)
**Treatment = desferrioxamine
*[[Amyloidosis]]
**Common in patients >50yo who have received dialysis for >10yr
**Complications: GI perforation, bone cysts with pathologic fracture, arthropathies

===[[Anion gap acidosis|Anion Gap Metabolic Acidosis]]<ref>Angus S. Uremic Acidosis. University of Connecticut, 2006. http://fitsweb.uchc.edu/student/selectives/TimurGraham/Uremia.html</ref><ref>Nickson C. Renal Tubular Acidosis and Uraemic Acidosis. LITFL. http://lifeinthefastlane.com/ccc/renal-tubular-acidosis/.</ref>===
*Early chronic kidney disease associated with hyperchloremic [[non anion gap acidosis|normal anion gap metabolic acidosis]]
*Late stage disease causes anion gap
**Failure to excrete acid anions, phosphate and sulfate
**Bone demineralization - bone buffers H+, releasing calcium from bone, leads to osteopenia
*Treatment: PO [[sodium bicarbonate]] 1 mEq/kg/day

==See Also==
*[[AKI]]

==References==
<references/>
[[Category:Renal]]