Felis ISSN 2398-2950

Kidney: acute renal failure

Synonym(s): Acute kidney injury (AKI), acute tubular nephrosis

Contributor(s): Penney Barber, Nicki Reed, Melissa Wallace

Introduction

  • Syndrome with abrupt deterioration in renal function.
  • Cause: toxins/drugs, infection, renal ischemia.
  • Signs: uremia, oliguria (in most cases), anuria or polyuria (less commonly), dehydration, lethargy.
  • Treatment: prompt treatment to limit renal damage.
  • Prognosis: guarded, depending on unerlying cause; mortality may be high and extensive renal damage may result in chronic renal failure.
    Follow the diagnostic tree for Acute Renal Failure Acute Renal Failure.

Pathogenesis

Etiology

Acute tubular necrosis

Pre-renal ARF

Post-renal ARF

Predisposing factors

General

  • Pre-existing renal damage with additional insult, eg reduced renal perfusion.
  • Any cause of reduced renal blood flow.

Specific

  • Anesthesia, especially without appropriate blood pressure monitoring and IV fluid support.
  • Chemotherapy with cisplatin.
  • Access to antifreeze (ethylene glycol).
  • Misuse of NSAIDs, aminoglycosides, diuretics or vasodilators.

Pathophysiology

Four phases

  • Initiation phase (renal insult resulting in damage to renal parenchyma; injury potentially reversible at this stage; hours to 1-2 days).
  • Extension phase (ongoing cellular injury progressing to cell death, with progressive decline in GFR and loss of urine concentrating ability).
  • Maintenance phase (elimination of inciting factors at this stage does not alter existing damage or rate of recovery; signs of uremia may be present; a prolonged maintenance phase is associated with slower recovery and increased likelihood of permanently reduced renal function).
  • Recovery phase (progressive return of renal function).
  • Reduced renal blood flow   →   reduced oxygen and energy transport to cells   →   cell swelling and membrane damage   →   vasoconstriction and inflammatory mediator release   →   further vasoconstriction.
  • Nephrons are damaged at different sites (glomerulus, tubular cell, intercellular junction, basement membrane) depending on etiology   →   acute decline in glomerular filtration rate   →   increased urea/creatinine, decrease in urine specific gravity   →   uremic signs, oliguria (sometimes anuria or polyuria), fluid and electrolyte imbalances, acidosis.

Timecourse

  • Animals may die acutely, especially if underlying cause is not detected and treated or if oliguric phase persists.
  • If treated appropriately, animals may recover, but recovery phase can take >3 weeks of intensive care.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Dorval P & Boysen S R (2009) Management of acute renal failure in cats using peritoneal dialysis: a retrospective study of six cases (2003-2007). J Feline Med Surg 11 (2), 107-115 PubMed.
  • Worwag S & Langston C E (2008) Acute intrinsic renal failure in cats: 32 cases (1997-2004). JAVMA 232 (5), 728-732 PubMed.
  • Sigrist N E (2007) Use of dopamine in acute renal failure. J Vet Emerg Crit Care 17 (2), 117-126 VetMedResource.
  • Stokes J E & Forrester S D (2004) New and unusual causes of acute renal failure in dogs and cats. Vet Clin North Am Small Anim Pract 34 (4), 909-922 PubMed.
  • Grauer G F (1998) Fluid therapy in acute and chronic renal failure. Vet Clin North Am Small Anim Pract 28 (3), 609-622 PubMed.
  • Grauer G F (1996) Prevention of acute renal failure. Vet Clin North Am Small Anim Pract 26 (6), 1447-1459 PubMed.
  • Ohashi F, Awaji T, Shimada T et al (1995) Plasma methylguanidine and creatinine concentrations in cats with experimentally induced acute renal failure. J Vet Med Sci 57 (5), 965-966 PubMed.
  • Mealey K L, Boothe D M (1994) Nephrotoxicosis associated with topical administration of gentamicin in a cat. JAVMA 204 (12) 1919-1921 PubMed.

Other sources of information

  • Langston C (2010) Acute Uraemia. In:T extbook of Veterinary Internal Medicine7th edn. Ettinger S J & Feldman E C (eds). W B Saunders, pp 1969-1985.
  • Chew D J & Gieg J A (2006) Fluid therapy during intrinsic renal failure. In: Fluid, Electrolyte and Acid-base Disorders in Small Animals. Di Bartola S P (ed). W B Saunders, pp 518-540.
  • Frenier S L & Dhein C R (1991) Diagnosis and management of acute renal failure. In: Consultations in feline internal medicine 1. (ed) J R August. W B Saunders. pp 281-288.


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