Uremia: Difference between revisions
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==Background== | ==Background== | ||
*Uremia = clinical syndrome a/w end-stage renal disease (contamination of blood w/ urine) | |||
**Correlation exists between uremia symptoms and low GFR (15-20% of nl) | |||
**BUN/Cr 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== | ==Clinical Features and Management== | ||
===Neurologic=== | ===Neurologic=== | ||
*Uremic encephalopathy | |||
**Diagnosis of exclusion | |||
**Cognitive defects, memory loss, decreased attentiveness, slurred speech | |||
**Asterixis, seizure, coma | |||
**Improves w/ dialysis | |||
*Dialysis dementia | |||
**Similar to uremic encephalopathy except progressive, no improvement w/ dialysis | |||
**EEG findings can differentiate uremic encephalopathy from dialysis dementia | |||
*CVA | |||
**Cerebrovascular disease, trauma, bleeding dyscrasias, anticoagulant, HTN | |||
*Subdural hematoma | |||
**10x more likely than in general population | |||
**Headache, focal neurologic deficits, seizure, coma | |||
*Peripheral neuropathy | |||
**Occurs in 60-100% of dialysis pts | |||
**Paresthesias, impaired proprioception, weakness | |||
**Autonomic neuropathy (postural dizziness, gastroparesis, bowel dysfunction) | |||
===Cardiovascular=== | ===Cardiovascular=== | ||
*CK-MB and troponin are specific markers of MI even in pts undergoing regular dialysis | |||
*Mortality from CV disease is 10-30x higher in dialysis pts than general population | |||
*HTN 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 w/ AMS, hypotension, dyspnea | |||
***Rarely present w/ 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 pt | |||
****Lasix 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=== | ===Hematologic=== | ||
*Anemia | |||
**Without tx the hematocrit in ESRD pts should stabilize at 15-20% | |||
**Treatment = erythropoietin | |||
*Bleeding diathesis | |||
**Increased risk for of bleeding (GI, ICH, liver hematoma) due to impaired plt function | |||
**Treatment = desmopressin, cryoprecipitate, conjugated estrogen | |||
*Immunodeficiency | |||
===GI=== | ===GI=== | ||
*Anorexia, N/V | |||
*Increased incidence of GI bleeding, diverticular disease, ascites | |||
===Renal bone disease=== | ===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 | |||
**Tx = 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 | |||
**Tx = phosphate binding gels, vitamin D3 replacement | |||
*Vitamin D3 deficiency and aluminum intoxication (osteomalacia) | |||
**Leads to osteomalacia (defect in bone calcification) | |||
**Symptoms similar to hyperparathyroidism (muscle weakness, bone pain) | |||
**Tx = desferrioxamine | |||
*Amyloidosis | |||
**Common in pts >50yr who have received dialysis for >10yr | |||
**Complications: GI perforation, bone cysts w/ pathologic fx, arthropathies | |||
== | ==References== | ||
[[Category:Nephro]] | [[Category:Nephro]] | ||
Revision as of 11:19, 24 May 2015
Background
- Uremia = clinical syndrome a/w end-stage renal disease (contamination of blood w/ urine)
- Correlation exists between uremia symptoms and low GFR (15-20% of nl)
- BUN/Cr 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
- Excretory failure
Clinical Features and Management
Neurologic
- Uremic encephalopathy
- Diagnosis of exclusion
- Cognitive defects, memory loss, decreased attentiveness, slurred speech
- Asterixis, seizure, coma
- Improves w/ dialysis
- Dialysis dementia
- Similar to uremic encephalopathy except progressive, no improvement w/ dialysis
- EEG findings can differentiate uremic encephalopathy from dialysis dementia
- CVA
- Cerebrovascular disease, trauma, bleeding dyscrasias, anticoagulant, HTN
- Subdural hematoma
- 10x more likely than in general population
- Headache, focal neurologic deficits, seizure, coma
- Peripheral neuropathy
- Occurs in 60-100% of dialysis pts
- Paresthesias, impaired proprioception, weakness
- Autonomic neuropathy (postural dizziness, gastroparesis, bowel dysfunction)
Cardiovascular
- CK-MB and troponin are specific markers of MI even in pts undergoing regular dialysis
- Mortality from CV disease is 10-30x higher in dialysis pts than general population
- HTN 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
- Uremic pericarditis (75% of cases)
- Tamponade
- Presents w/ AMS, hypotension, dyspnea
- Rarely present w/ classic signs of Beck's triad
- Pericardiocentesis should only be attempted if hemodynamically unstable
- Presents w/ AMS, hypotension, dyspnea
- Pulmonary Edema
- Commonly ascribed to fluid overload; also consider MI
- Treat similar to non-ESRD pt
- Lasix 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
- Treat similar to non-ESRD pt
- Commonly ascribed to fluid overload; also consider MI
- CHF
- May be preexisting
- May be caused by uremic cardiomyopathy, fluid overload, AV-related high-output failure
Hematologic
- Anemia
- Without tx the hematocrit in ESRD pts should stabilize at 15-20%
- Treatment = erythropoietin
- Bleeding diathesis
- Increased risk for of bleeding (GI, ICH, liver hematoma) due to impaired plt function
- Treatment = desmopressin, cryoprecipitate, conjugated estrogen
- Immunodeficiency
GI
- Anorexia, N/V
- Increased incidence of GI bleeding, diverticular disease, ascites
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
- Tx = 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
- Tx = phosphate binding gels, vitamin D3 replacement
- Vitamin D3 deficiency and aluminum intoxication (osteomalacia)
- Leads to osteomalacia (defect in bone calcification)
- Symptoms similar to hyperparathyroidism (muscle weakness, bone pain)
- Tx = desferrioxamine
- Amyloidosis
- Common in pts >50yr who have received dialysis for >10yr
- Complications: GI perforation, bone cysts w/ pathologic fx, arthropathies