Acute Kidney Injury

Sheldon Chaffer, MD Assistant Professor

Program Director, Nephrology Fellowship Division of Nephrology and Hypertension

Scott and White Clinic Texas A&M University Health Science Center

Objec&ves•  Discussdifferen&aldiagnosisofAcuteKidneyInjury(AKI).•  DiscusssignsandsymptomsofAKI,includingpre‐renal,

intrinsicandpost‐renallesions.•  Outlinediagnos&capproachintheevalua&onofAKI.•  Iden&fycommonelectrolyteabnormali&esseeninAKI,

includingtreatmentconsidera&ons•  OutlinecommonpharmacologicissuesintheseCngofAKI.•  Discusspreven&onofAKIinthehospitalizedpopula&on,

includingContrastInducedNephropathy.•  Discussindica&onsfordialysisintheseCngofAKI.

10%Interstitial

Nephritis(AIN)

5%Acute

Glomerulonephritis

Pre‐renal Intrinsic Post‐renal

AKI

85%AcuteTubularNecrosis(ATN)

50%Ischemia

35%Nephrotoxic

“When you hear hoo,eats….don’t expect to see a zebra.”               TheodoreWoodward,MD

Nobellaureate1948 

Adapted from: Thadhani, R. et al. N Engl J Med 1996;334:1448-1460

Chronic Kidney Disease vs Acute Kidney Injury

Objective data suggestive of Chronic Kidney Disease

Persistent elevation in serum Cr Often without clear etiology

Normocytic/Normochromic Anemia

Impaired Iron metabolism

Evidence of protein calorie malnutrition

Acidosis most commonly with normal anion gap

Small and/or echogenic renal parenchyma on ultrasound

Impaired bone mineral metabolism

SignsandSymptomsofUremia

•  Sleep reversal •  Dysgeusia •  Pruritis •  Nausea, vomiting, protein aversion •  Loss of appetite •  Protein calorie malnutrition •  Uremic pericarditis/uremic frost

Cross‐talk

•  Pulmonaryrenal•  Cardiorenal•  Hepatorenal•  Mineralandbonedisease•  AnemiaofCKD•  Renalacidosis•  Uremia

•  Goodpasture’s syndrome •  Wegener’s granulomatosis •  Microscopic polyangiitis •  Churg–Strauss syndrome •  Henoch–Schönlein purpura •  Mixed cryoglobulinaemia •  Behçet’s disease •  IgA nephropathy •  Idiopathic pulmonary–renal syndrome •  Propylthiouracil •  D-Penicillamine •  Hydralazine •  Allopurinol •  Sulfasalazine

•  Goodpasture’s syndrome •  Wegener’s granulomatosis •  Scleroderma •  Polymyositis •  Rheumatoid arthritis •  Mixed collagen vascular disease •  Antiphospholipid syndrome •  Thrombotic thrombocytopenic

purpura •  Infections •  Neoplasms

Pulmonary Renal Syndrome: Diagnostic Considerations

Papiris et al. Critical Care 2007, 11:213

Pulmonary Renal Syndromes

Cardiorenal Syndrome Type I

–  Acute HFAKI HTN with preserved LVpulmonary edema Acute decompesation of chronic HF Cardiogenic shock RV failure

Type II –  Chronic HFprogressive CKD

Type III –  AKIacute HF

e.g. bilateral renal artery stenosis

Type IV –  CKDchronic cardiac systolic and/or diastolic dysfunction

Roncho C, et al. J Am Coll Cardiol 2008;52:1527–39

Type I

Roncho C, et al. J Am Coll Cardiol 2008;52:1527–39

Type II

AKI in Setting of Cirrhosis

Garcia-Tsao G, et al. Hepatology 2008; 48(6):2066.

BaselineRenalFunc&onandMarkersofAKI

Interstitial Disease

Urinary Outflow

Glomerular Filtration

Rate

Renal Blood Flow

Glomerulus

Adapted from: Hosten AO. Clinical Methods: the History, Physical, and Laboratory Examinations. 3rd ed.

•  Muscle:crea&neandphosphocrea&ne

•  Freelyfiltered•  Secretedinproximal

tubule:15‐50%ofUCr•  Diurnalvaria&on

Crea&nine

RIFLE Criteria for Diagnosis of Acute Kidney Injury

Serum Creatinine Trend

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

8/7/2002

11/7/2002

2/7/2003

5/7/2003

8/7/2003

11/7/2003

2/7/2004

5/7/2004

8/7/2004

11/7/2004

2/7/2005

5/7/2005

8/7/2005

11/7/2005

2/7/2006

5/7/2006

8/7/2006

11/7/2006

2/7/2007

5/7/2007

8/7/2007

11/7/2007

2/7/2008

5/7/2008

8/7/2008

Serum Creatinine Trend

0.00

5.00

10.00

15.00

20.00

25.00

8/2/09

8/16/09

8/30/09

9/13/09

9/27/09

10/11/09

10/25/09

11/8/09

11/22/09

12/6/09

12/20/09

1/3/10

1/17/10

1/31/10

2/14/10

2/28/10

3/14/10

3/28/10

4/11/10

4/25/10

5/9/10

5/23/10

Serum Creatinine Trend

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

9/23/2002

12/23/2002

3/23/2003

6/23/2003

9/23/2003

12/23/2003

3/23/2004

6/23/2004

9/23/2004

12/23/2004

3/23/2005

6/23/2005

9/23/2005

12/23/2005

3/23/2006

6/23/2006

9/23/2006

12/23/2006

3/23/2007

6/23/2007

9/23/2007

12/23/2007

3/23/2008

6/23/2008

9/23/2008

12/23/2008

3/23/2009

6/23/2009

9/23/2009

12/23/2009

Serum Creatinine Trend

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

8/21/2003

10/21/2003

12/21/2003

2/21/2004

4/21/2004

6/21/2004

8/21/2004

10/21/2004

12/21/2004

2/21/2005

4/21/2005

6/21/2005

8/21/2005

10/21/2005

12/21/2005

2/21/2006

4/21/2006

6/21/2006

8/21/2006

10/21/2006

12/21/2006

2/21/2007

4/21/2007

6/21/2007

8/21/2007

10/21/2007

12/21/2007

2/21/2008

4/21/2008

Urine specific gravity: 1.010 Recurrent sterile pyuria

“Why is American beer served cold? So you can tell it from urine.” David Moulton

HemoglobinuriaMyoglobinuriaPorphyrinuriaAlkaptonuriaNitrofurantoinChloroquinSennaRhubarb

HematuriaHemoglobinuriaMyoglobinuriaCrystallinuriaPhenytoinBeetroot

Prerenal azotemia ATN Bilirubinuria

HypercalciuriaCrystallinuriaChyluria

UrineColor

GFRDecline:microalbuminuriavs.progressiontoovertproteinuria

Lemli KV, et al. AJP Renal 2005; 289:863-870

MethodstoEvaluateProteinuria•  Randomurine

•  Protein/Cr•  Microalbumin/CrIndex

•  24hoururinecollec&on•  Protein•  UPEP/Immunofixa&on

Red Blood Cell Cast

Tubular Epithelial Cell Cast White Blood Cell Cast

Waxy (Broad) Cast

“Muddy Brown” Granular Cast

Palmer, B. F. N Engl J Med 2002;347:1256-1261

Varia<onsinMeanArterialPressureandConceptofAutoregula<on

Thadhani, R. et al. N Engl J Med 1996;334:1448-1460

Tubular-Cell Injury and Repair in Ischemic Acute Renal Failure

NaturalHistoryAcuteTubularNecrosis(ATN)

Electrolyte Abnormalities in AKI

HyonatremiaandHypernatremiaDuringMaintenancePhaseofATN

Hyperkalemia

Hyperkalemia

Hyperkalemia

44yearoldWMwithhistoryofchronicalcoholabuseandprevioussuicideaaemptswasfoundnon‐responsiveinhisgaragebyhiswifewithuncleardown&me.Prehospitalservicesfoundpa&entwithspontaneousrespira&ons,thoughunabletoadequatelyprotecthisairway.Thereforepa&entwasendotracheallyintubated.Ini&allaboratoriesweredrawnintheemergencydepartmentandthepa&entwastransferredtothemedicalintensivecareunitforfurtherevalua&on.

134 103 20

4.7 9 1.1

ABG: pH 7.14, PaCO2 22

• Acidemia or Alkalemia? • What is the anion gap? • What is the primary disorder? • Compensation appropriate? • In setting of AGMA

• What is the ∆/∆ gap (ratio)?

Anion Gap Metabolic Acidosis due to ethylene glycol intoxication

CommonPharmacologicIssuesintheseCngofAKI

•  Diure&cdosingisGFRdependent–  Oneexcep&onismineralocor&coidreceptorblockers(spironolactoneand

eplerenone)•  Avoidmedica&onsthatmayimpairGFR

–  ConsiderholdingACE‐I/ARB–  NSAID’s

•  Hyperkalemia–  Loopdiure&cs–  Insulin–  Βblockers–  Sodiumpolystyrenesulfonate(Kayexalate®)–  Dialysis

•  AvoiduseofIVcontrast

Decreased eGFR Furosemide dose= age+BUN

-House of God. Samuel Shem

Hypoalbuminemia Serum albumin <2.0 g/dL May need to double dose

Proteinuria Nephrotic range:

May require serial doubling of dose to achieve diuresis

Hypotension Prerenal azotemia:

May result in “apparent” diuretic resistance

Furosemide

Preven&onofContrastNephropathy

•  IVF•  Bicarbonate•  Acetylcysteine(Mucomyst®)•  Sta&ntherapy•  “Renaldose”dopamine•  Fenoldopam

Indications for Dialysis

•  Acidosis, refractory •  Electrolyte abnormalities

–  Hyperkalemia

•  Ingestions –  Toxic alcohol, drugs

•  Overload, fluid •  Uremia