Transcript Acute Renal Failure

Acute Renal Failure
Fall Medical/ Surgical Conference
Lubbock-Crosby-Garza
County Medical Society
Sandra Sabatini PhD, MD
Neil A Kurtzman MD
• Acute Kidney Injury now the preferred term
• It's imprecise
• Some forms of ARF are not associated with
tissue injury
• We'll stick with ARF
An elevated serum creatinine during hospitalisation is an
independent risk factor for mortality, progression to CKD,
end-stage renal disease, and reduced long-term survival.
Patients with chronically elevated serum creatinine (i.e.,
impaired baseline renal function) have a higher risk for
acute kidney injury during hospital stays and are more
often dialysis-dependent at hospital discharge than those
without.
http://bestpractice.bmj.com/best-practice/monograph/935.html
ARF is an acute decline in the glomerular
filtration rate (GFR) from baseline, with or
without oliguria/anuria. It may be due to
various insults such as impaired renal
perfusion, exposure to nephrotoxins,
outflow obstruction, or intrinsic renal
disease.
Three General Mechanisms
• Pre-renal
• Renal
• Post-Renal
ARF vs CRF
adaptation
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BP
Edema - fluid overload
Acid-Base
RBC
Ca
PO4
K
Pre-Renal
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Decreased renal perfusion
Contracted EABV
CHF
Blood loss
Vomiting
Diarrhea
Sweating
Decreased fluid intake
Cirrhosis
Pre-glomerular vascular disease
Evaluation
• History
• PE
- Pulse and BP
- Edema
- Signs of other diseases
• Urine NaCl
• BUN/Cr
• Uric Acid
Treatment and Implications
• Depends on cause
• Fluid loss different from CHF different from
Cirrhosis
• Vol contraction predisposes to ATN - more soon
Post Renal
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Prostatism
Advanced Cervical Cancer
Retroperitoneal Fibrosis
Retroperitoneal Lymphoma
Bilateral Renal Calculi
Features
• Anuria if complete
• Collecting duct dysfunction
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Polyuria - NDI
Metabolic acidosis
Hyperkalemia
NaCl loss
Treatment
• Relieve obstruction if possible
• Dialysis and supportive care if obstruction is
irreversible
Renal
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Acute glomerulonephritis
Acute vasculitides
Acute interstitial nephritis
Toxins
Acute tubular necrosis (ATN)
Acute papilary necrosis
Toxins -Ethylene Glycol
Ethylene Glycol - Anti-Freeze
Dog kidney - polarized light
Manifestations
• CNS
• Metabolic Acidosis
• Renal failure
Diagnosis
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History
CNS - "drunk", seizures
Anion gap metabolic acidosis
Oxaluria
Acute renal failure
Treatment
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Ethanol
Fomepizole (inhibits alcohol dehydrogenase)
Hemodialysis
Prognosis - good early treatment
Prognosis - bad late treatment
Acute Interstitial Nephritis
• Can be infectious
• Usually non-infectious inflammatory
• Commonly drug induced
• Allergic reaction to a drug (acute interstitial
allergic nephritis)
• Autoimmune disorders such as anti-tubular
basement membrane disease, Kawasaki’s
disease, Sjogren syndrome, systemic lupus
erythematosus, or Wegener’s granulomatosis
• Acetaminophen, aspirin, NSAIDS
• Penicillin, ampicillin, methicillin,
sulfonamide
• Furosemide, thiazide diuretics,
omeprazole, triamterene, and allopurinol
• Hypokalemia
• Hypercalcemia, hyperuricemia
Kidney International (2001) 60, 804–817
Kidney International (2001) 60, 804–817
Kidney International (2001) 60, 804–817
Treatment
• Stop offending drug
• Treat underlying disease
• Steroids may hasten recovery
Acute Papillary Necrosis
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Chronic more common
Diabetes
Infection
Often a catastrophic illness
ATN
• Requires an underperfused kidney
• Nephrotoxins (Hg, Pt)
• Major surgery (due to multiple factors)
• Third-degree burns covering > 15% of BSA
• The heme pigments myoglobin and hemoglobin
• Tumor lysis or multiple myeloma
• Herbal and folk remedies, such as ingestion of fish
gallbladder in Southeast Asia (uncommon)
Am J Med Sci. 2007, 334(2):115-24.
Cisplatin nephrotoxicity: a review.
Yao X1, Panichpisal K, Kurtzman N, Nugent K.
• Common nephrotoxins include the following:
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Aminoglycosides
Amphotericin B
Cisplatin and other chemotherapy drugs
Radiocontrast agents
NSAIDs
Colistimethate
Calcineurin inhibitors (cyclosporine, tacrolimus)
ATN
• ATN is more likely to develop in patients with the
following:
• Preexisting hypovolemia or poor renal perfusion
• Preexisting chronic kidney disease
• Diabetes mellitus
• Older age
Crush Syndrome
J Am Soc Nephrol 11: 1553–1561, 2000
J Am Soc Nephrol 11: 1553–1561, 2000
Contrast Induced ARF
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Systolic blood pressure <80 mm Hg
Intraarterial balloon pump
Congestive heart failure
Age >75 y
Hematocrit level <39% for men and <35% for
women
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Diabetes especially with ↑Cr
Contrast media volume
Renal insufficiency
Serum creatinine level >1.5 g/dL
Estimated Glomerular filtration rate < 60
ml/min
• Gadolinium enhance MRI risks NSF and CRI
Prevention
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Avoid use in high risk patients
Isotonic saline
Saline and furosemide if CHF present
HCO3 of uncertain utility
N-acetylcysteine probably ineffective
Prophylactic hemodialysis not proven effective
Prostaglandins and the Kidney
NSAIDS and Renal Disease
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AIN
Pre renal azotemia
ATN
Nephrotic Syndrome
Hyperkalemia
Hyponatremia
NSAIDS and ARF
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Relatively uncommon
Incidence increases with age
ACE inhibitors and ARBs increase incidence
Volume contraction
Diuretics
Pre-existing renal disease
Prognosis
• 65% recover to baseline in 7-10 days
• Dialysis needed <1% of patients
• 18% who need HD remain on it
• Maioli M, Toso A, Leoncini M, Gallopin M, Musilli N, Bellandi F.
Persistent renal damage after contrast-induced acute kidney injury:
incidence, evolution, risk factors, and prognosis. Circulation. Jun 26
2012;125(25):3099-107
The Centre for Adverse Reactions Monitoring, NZ 2000
Antibiotic induced ARF
Aminoglycosides
Martínez-Salgado et al. / Toxicology and Applied Pharmacology 223 (2007), 86–98
Renal Under perfusion always present
Amphotericin Nephrotoxicity
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Renal Underperfusion
Hypokalemia
Renal tubular acidosis
Liposomal formulation likely lower incidence
Acute renal failure
Pre-renal
ATN
UTO
Urine Na ↓
Urine Na ↑
Urine Na ↑
Urine K ↑
Urine K ↑
Urine K ↓
Urine Osm ↑
Urine Osm ↓
Urine Osm ↓
Fractional Excretion
FEx= Cx/Ccr X 100
Cx= UxV/Px
FEx 
FENa (<0.5%)
FEurea (<35%)
Rx Oliguric ARF
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A fluid challenge is a substitute for thought
HD a soon as diagnosis is made
Daily until clinical status improves
Better avoided than treated
http://medicine-opera.com/2014/11/acute-renal-failure/