Difference between revisions of "Hemolytic uremic syndrome"
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===Types=== | ===Types=== | ||
#Typical | #Typical | ||
| − | #*Occurs 2-14d after development of infectious diarrhea (bloody, no fever) | + | #*Occurs 2-14d after development of infectious [[diarrhea]] (bloody, no fever) |
#Atypical | #Atypical | ||
#*Occurs in older children and adults | #*Occurs in older children and adults | ||
#*Extrarenal involvement is common (difficult to distinguish from [[TTP]]) | #*Extrarenal involvement is common (difficult to distinguish from [[TTP]]) | ||
| − | #*May be caused by atypical pathogens (EBV, S. pneumo) or immunosuppression | + | #*May be caused by atypical pathogens ([[EBV]], [[S. pneumo]]) or immunosuppression |
==Clinical Features== | ==Clinical Features== | ||
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*Enteritis | *Enteritis | ||
*[[Nausea/vomiting]], [[diarrhea]] (usually bloody), +/- [[fever]] | *[[Nausea/vomiting]], [[diarrhea]] (usually bloody), +/- [[fever]] | ||
| − | *Hyperglycemia | + | *[[Hyperglycemia]] |
| − | *Pancreatic beta-cell death due to microthrombi within pancreas | + | **Pancreatic beta-cell death due to microthrombi within pancreas |
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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*[[Colitis]] | *[[Colitis]] | ||
*[[Intussusception]] | *[[Intussusception]] | ||
| − | *IBD | + | *[[IBD]] |
*Perforation | *Perforation | ||
*[[SLE]] | *[[SLE]] | ||
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==Evaluation== | ==Evaluation== | ||
*CBC | *CBC | ||
| − | **Anemia | + | **[[Anemia]] |
| − | **Thrombocytopenia | + | **[[Thrombocytopenia]] |
**Peripheral smear checking for schistocytes, burr cells, helmet cells, spherocytes and segmented red blood cells | **Peripheral smear checking for schistocytes, burr cells, helmet cells, spherocytes and segmented red blood cells | ||
*LDH (elevated) | *LDH (elevated) | ||
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**Shiga toxin, E. coli O157:H7 test | **Shiga toxin, E. coli O157:H7 test | ||
*[[Urinalysis]] | *[[Urinalysis]] | ||
| − | **Hematuria, casts | + | **[[Hematuria (peds)|Hematuria]], casts |
| − | * | + | *[[LFTs]] |
**Increased bilirubin | **Increased bilirubin | ||
*Chemistry | *Chemistry | ||
| − | **Creatinine, hyperkalemia (renal failure) | + | **Creatinine elevation, [[hyperkalemia]] ([[renal failure]]) |
==Management== | ==Management== | ||
| − | *Fluid resuscitation | + | *[[IVF|Fluid resuscitation]] |
| − | *Insulin therapy if hyperglycemic and ketones (pancreatic insufficiency complication) | + | *[[Insulin]] therapy if hyperglycemic and ketones (pancreatic insufficiency complication) |
| − | * | + | *[[Antihypertensives]] |
**[[Nifedipine]]ER (0.25-0.5 mg/kg/day oral) | **[[Nifedipine]]ER (0.25-0.5 mg/kg/day oral) | ||
| − | ** | + | **[[Labetalol]] 1-3 mg/kg/day, divided into twice daily dosing (12 mg/kg/day up to 1200 mg/day) |
| − | **Nitroprusside 0.3-0.5 ug/kg/min IV (max 10 ug/kg/min) | + | **[[Nitroprusside]] 0.3-0.5 ug/kg/min IV (max 10 ug/kg/min) |
*[[Plasma exchange]] (plasmapheresis) | *[[Plasma exchange]] (plasmapheresis) | ||
**Usually performed if anuria or neurologic sequela | **Usually performed if anuria or neurologic sequela | ||
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*Transfusion of RBCs(only severe bleeding) | *Transfusion of RBCs(only severe bleeding) | ||
**Generally only indicated if plasma exchange cannot be performed immediately | **Generally only indicated if plasma exchange cannot be performed immediately | ||
| − | *Platelet | + | *[[Platelet transfusion]] is AVOIDED |
**Only used for life-threatening bleeding or intracranial hemorrhage under guidance from hematologist | **Only used for life-threatening bleeding or intracranial hemorrhage under guidance from hematologist | ||
**Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death | **Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death | ||
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*AVOID Antimotility agents | *AVOID Antimotility agents | ||
**Leads to prolonged gut exposure to toxins | **Leads to prolonged gut exposure to toxins | ||
| − | **Risk of toxic megacolon | + | **Risk of [[toxic megacolon]] |
==Disposition== | ==Disposition== | ||
Latest revision as of 00:44, 15 September 2019
Contents
Background
- Abbreviation: HUS
- Similar to TTP (which is more common in adults), but associated with less central nervous system and more renal involvement.
- Most cases occur in children <10yr (⅔ of cases in < 5yr)
- 80-90% cases due to E. coli O157:H7 infection
- Shiga toxin may induce autoantibody to CD36 (found on endothelial cells and platelets)
- May also be caused by shigella, yersinia, campylobacter, salmonella
Types
- Typical
- Occurs 2-14d after development of infectious diarrhea (bloody, no fever)
- Atypical
Clinical Features
Triad
Other Associated Conditions
- Enteritis
- Nausea/vomiting, diarrhea (usually bloody), +/- fever
- Hyperglycemia
- Pancreatic beta-cell death due to microthrombi within pancreas
Differential Diagnosis
- Gastroenteritis
- Appendicitis
- Colitis
- Intussusception
- IBD
- Perforation
- SLE
Causes of Glomerulonephritis
- Poststreptococcal glomerulonephritis
- Hemolytic-uremic syndrome
- Henoch-Schonlein purpura
- IgA nephropathy
- Lupus nephritis
- Alport syndrome
- Goodpasture syndrome
- Paraneoplastic
Microangiopathic Hemolytic Anemia (MAHA)
- Disseminated Intravascular Coagulation (DIC)
- Thrombotic Thrombocytopenic Purpura (TTP)
- Hemolytic Uremic Syndrome (HUS)
- HELLP syndrome
- Heparin-Induced Thrombocytopenia (HIT)
- Hereditary spherocytosis
- Paroxysmal nocturnal hemoglobinuria (PNH)
- Malignant hypertension
- Scleroderma
- Antiphospholipid Syndrome (APS)
- Other medical causes: malignancy, renal allograft rejection, vasculitides like polyarteritis nodosa and Wegener's granulomatosis
- Drugs: chemotherapy; Clopidogrel (Plavix) associated with TTP
- Nonvascular causes: prosthetic valve (more common with mechanical, more common at aortic valve), LVAD, TIPS, coil embolization, patched AV shunt, AVM
Thrombocytopenia
Decreased production
- Marrow infiltration (tumor or infection)
- Viral infections (rubella, HIV)
- Marrow suppression (commonly chemotherapy or radiation)
- Congenital thrombocytopenia
- Fanconi anemia
- Alport syndrome
- Bernand Soulier
- Vitamin B12 and/or folate deficiency
Increased platelet destruction or use
- Idiopathic thrombocytopenic purpura
- Thrombotic Thrombocytopenic Purpura (TTP)
- Hemolytic Uremic Syndrome (HUS)
- Disseminated Intravascular Coagulation (DIC)
- Viral infections (HIV, mumps, varicella, EBV)
- Drugs (heparin, protamine)
- Postransfusion or Posttransplantation
- Autoimmune destruction (SLE or Sarcoidosis)
- Mechanical destruction
- Artificial valves
- ECMO
- HELLP syndrome
- Excessive hemorrhage
- Hemodialysis, extracorporeal circulation
- Splenic Sequestration
- Occurs in Sickle cell disease and Cirrhosis
Drug Induced
- sulfa antibiotics, ETOH, ASA, thiazide diuretics/furosemide
Comparison by Etiology
| ITP | TTP | HUS | HIT | DIC | |
|---|---|---|---|---|---|
| ↓ PLT | Yes | Yes | Yes | Yes | Yes |
| ↑PT/INR | No | No | No | +/- | Yes |
| MAHA | No | Yes | Yes | No | Yes |
| ↓ Fibrinogen | No | No | No | No | Yes |
| Ok to give PLT | Yes | No | No | No | Yes |
Evaluation
- CBC
- Anemia
- Thrombocytopenia
- Peripheral smear checking for schistocytes, burr cells, helmet cells, spherocytes and segmented red blood cells
- LDH (elevated)
- Haptoglobin (decreased)
- Reticulocyte count (appropriate)
- PT/PTT/INR (normal; differentiates from DIC)
- Stool tests
- Shiga toxin, E. coli O157:H7 test
- Urinalysis
- Hematuria, casts
- LFTs
- Increased bilirubin
- Chemistry
- Creatinine elevation, hyperkalemia (renal failure)
Management
- Fluid resuscitation
- Insulin therapy if hyperglycemic and ketones (pancreatic insufficiency complication)
- Antihypertensives
- NifedipineER (0.25-0.5 mg/kg/day oral)
- Labetalol 1-3 mg/kg/day, divided into twice daily dosing (12 mg/kg/day up to 1200 mg/day)
- Nitroprusside 0.3-0.5 ug/kg/min IV (max 10 ug/kg/min)
- Plasma exchange (plasmapheresis)
- Usually performed if anuria or neurologic sequela
- Eculizumab
- Monoclonal anti-C5 antibody that interrupts complement cascade
- Transfusion of RBCs(only severe bleeding)
- Generally only indicated if plasma exchange cannot be performed immediately
- Platelet transfusion is AVOIDED
- Only used for life-threatening bleeding or intracranial hemorrhage under guidance from hematologist
- Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death
- Hemodialysis/Hemoperfusion
- Often needed for renal failure and hyperkalemia treatment
- AVOID Antibiotics
- May lead to worsening lysis of bacteria and further shiga toxin release
- AVOID Antimotility agents
- Leads to prolonged gut exposure to toxins
- Risk of toxic megacolon
Disposition
- Admit
See Also
References
- Corrigan J. Boineau FG. Hemolytic-uremic syndrome. Pediatr Rev. Nov 2001;22(11):365-9
- George J. Clinical practice. Thrombotic thrombocytopenic purpura. N Engl J Med 2006; 354:1927