ACUTE RENAL FAILUREACUTE RENAL FAILURE

Carly ThompsonCarly ThompsonMD, CCFPMD, CCFP

August 27, 2008August 27, 2008

ObjectivesObjectives

DefinitionsDefinitionsEpidemiologyEpidemiologyDifferential Diagnosis Differential Diagnosis Investigations: Labs, Urinalysis, ImagingInvestigations: Labs, Urinalysis, ImagingTreatment: Treatment: – MedicationsMedications– Renal Replacement TherapyRenal Replacement Therapy

Case 1Case 1

Mrs. K. Bean 78 yo female Mrs. K. Bean 78 yo female – PMHx: liver cirrhosis, ascites, hepatic PMHx: liver cirrhosis, ascites, hepatic

encephalopathy due to hepatitis Cencephalopathy due to hepatitis C– Family is concerned that she is not drinking, Family is concerned that she is not drinking,

not eating, and having recurrent diarrhea as not eating, and having recurrent diarrhea as she is getting sleepiershe is getting sleepier

– Labs: Labs: Na 140Na 140BUN 20BUN 20Cr 247Cr 247

Case 1Case 1

Is she in renal failure?Is she in renal failure?

Definitions: Acute Renal FailureDefinitions: Acute Renal Failure

The deterioration of renal function over The deterioration of renal function over hours or days resulting in accumulation of hours or days resulting in accumulation of toxic wastes and the loss of internal toxic wastes and the loss of internal homeostasishomeostasis

Indirect Measures:Indirect Measures:– 50% increase in serum Cr50% increase in serum Cr– 50% decrease in creatinine clearance / GFR50% decrease in creatinine clearance / GFR– Highly variable across different studiesHighly variable across different studies

Definitions:Definitions:Types of Acute Renal FailureTypes of Acute Renal Failure

Non-oliguricNon-oliguric– Better prognosisBetter prognosisOliguria:Oliguria:– <1mL/kg/hr in infants<1mL/kg/hr in infants– <0.5mL/kg/hr in children<0.5mL/kg/hr in children– <400mL / day in adults <400mL / day in adults

<0.3mL/kg/hr OR 17mL / hour in 60kg x 24 hours<0.3mL/kg/hr OR 17mL / hour in 60kg x 24 hours

AnuriaAnuria– <100mL / day in adults<100mL / day in adults

Definitions: Acute Kidney InjuryDefinitions: Acute Kidney Injury

RIFLE CriteriaRIFLE Criteria MortalityMortality

RiskRisk

2.42.4

4.154.15

6.376.37

Definitions: AKIN CriteriaDefinitions: AKIN Criteria

Acute Kidney Injury NetworkAcute Kidney Injury NetworkStage Serum Cr Criteria Urine Output Criteria

1Serum Cr increase ≥  26.4 mmol/L or increase ≥ 150 to 200% from baseline

<0.5 mL/kg/hr x >6 hrs

2 Serum Cr increase ≥ 200 to 300% from baseline <0.5 mL/kg/hr x > 12 hrs

3 Serum Cr increase > 300% from baseline (or serum Cr ≥ 354 mmol/L with an acute increase of 44 micromol/L)

<0.3 mL/kg/hr x 24 hrs or anuria x 12 hrs

Quick Epidemiology SlideQuick Epidemiology SlideCommunity-acquired ARF:Community-acquired ARF:– Only diagnosed in 1% of hospital admissions at presentationOnly diagnosed in 1% of hospital admissions at presentation– Most commonly due to volume depletionMost commonly due to volume depletion– 90% may have reversible cause90% may have reversible cause

Hospital-acquired ARF:Hospital-acquired ARF:– Up to 4% of admissions, 20% of critical care admissionsUp to 4% of admissions, 20% of critical care admissions– Multifactorial: elderly, nephrotoxic medications, often in ICUMultifactorial: elderly, nephrotoxic medications, often in ICU

Mortality: Mortality: – 50% - minimal change since dialysis was invented!50% - minimal change since dialysis was invented!– 25% in children, but 45% if intrinsic renal failure25% in children, but 45% if intrinsic renal failure– 75% for hospital acquired mortality75% for hospital acquired mortality– 7% community-acquired prerenal ARF7% community-acquired prerenal ARF

Causes of Death:Causes of Death:– Sepsis, cardiac and pulmonary failureSepsis, cardiac and pulmonary failure

Case 1 Follow-UpCase 1 Follow-UpBaseline Cr 165 -> Now 247 Baseline Cr 165 -> Now 247 – 82 mmol/L increase, 150% increase82 mmol/L increase, 150% increaseGFR 28 -> Now 21GFR 28 -> Now 21– 25% decrease25% decreaseUrine Output: Foley insertedUrine Output: Foley inserted

Diagnosis: AKIN Criteria - Stage 1 Acute Kidney Diagnosis: AKIN Criteria - Stage 1 Acute Kidney InjuryInjuryPlan: Admitted for rehydration, monitoring, and Plan: Admitted for rehydration, monitoring, and placement issues.placement issues.

Case 2Case 2

Mr. Pastie 68 yo manMr. Pastie 68 yo manHx – unwell x 5 days, vomiting, diarrhea, Hx – unwell x 5 days, vomiting, diarrhea, lightheaded, presents confusedlightheaded, presents confusedPMHx – Htn, CHFPMHx – Htn, CHFMeds – B-blocker, lasixMeds – B-blocker, lasix

Case 2Case 2

What do you think is going on?What do you think is going on?What would you look for on physical exam?What would you look for on physical exam?

Prerenal FailurePrerenal Failure

HistoryHistory– Clues to dehydrationClues to dehydration

Physical ExamPhysical Exam– Volume status examVolume status exam

Differential Diagnosis of Prerenal Differential Diagnosis of Prerenal FailureFailure

Volume Loss- Hemorrhagic Shock, Vomiting, Diarrhea- Drugs: Diuretics- Other: Primary hypoaldosteronism, Salt-losing nephropathy, Postobstructive

diuresis

Decreased Cardiac Output- Myocardial infarction / ischemia- Obstructive: Valvular heart disease, tamponade- Cardiomyopathy- Drugs: B-blockers- High-output: thyrotoxicosis, thiamine deficiency, Paget disease, AV fistula

Renal Artery and Small Vessel Disease- Drugs: Cyclosporine, tacrolimus- Embolic disease (septic, cholesterol), Sickle Cell Disease- Artery: Malignant hypertension, preeclampsia, vasculitis- Other: Transplant rejection, Hypercalcemia, Hemolytic-uremic syndrome

Case 2Case 2

What investigations would you like to order?What investigations would you like to order?

Renal Failure Work-UpRenal Failure Work-Up

Labs:Labs:– CBC, lytes, BUN, Cr CBC, lytes, BUN, Cr

Urinalysis: R+MUrinalysis: R+MChest x-ray: Volume statusChest x-ray: Volume statusECG: Screen for hyper / hypokalemiaECG: Screen for hyper / hypokalemiaInsert foley: input / outputInsert foley: input / output

Renal Failure Work-UpRenal Failure Work-Up

How helpful is the BUN and Cr?How helpful is the BUN and Cr?

Importance of BUN and CrImportance of BUN and CrCreatinineCreatinine

A patient with a low baseline Cr can lose more than ½ of A patient with a low baseline Cr can lose more than ½ of functioning nephrons before developing and elevated Crfunctioning nephrons before developing and elevated CrBreakdown product of skeletal muscle protein creatineBreakdown product of skeletal muscle protein creatineLinked to muscle mass, thus women and elderly have lower GFR Linked to muscle mass, thus women and elderly have lower GFR for any Cr levelfor any Cr levelGlomerulonephritis causes increased tubular secretion of Cr Glomerulonephritis causes increased tubular secretion of Cr independent of GFRindependent of GFRTrimethoprim, cimetidine, salicylates cause decreased secretionTrimethoprim, cimetidine, salicylates cause decreased secretion

BUNBUNDecreased in patients with malnutrition and hepatic synthetic Decreased in patients with malnutrition and hepatic synthetic dysfunctiondysfunctionIncreased in setting of a protein load, GI hemorrhage, traumaIncreased in setting of a protein load, GI hemorrhage, trauma

Does the ratio of BUN/Cr help determine if Does the ratio of BUN/Cr help determine if the patient is dry?the patient is dry?

BUN:Cr RatioBUN:Cr RatioQuick Physiology Lesson:Quick Physiology Lesson:

Both Cr and BUN are passively filtered at the Both Cr and BUN are passively filtered at the glomerulusglomerulusCr remains in the tubuleCr remains in the tubuleBUN is permeable and passively reabsorbed BUN is permeable and passively reabsorbed with sodiumwith sodiumTherefore . . . In the setting of Na retention, urea Therefore . . . In the setting of Na retention, urea clearance can be as low as 30% of GFR in a clearance can be as low as 30% of GFR in a patient with normal concentrating abilitypatient with normal concentrating ability

BUN:Cr >20 can suggest hypovolemia BUN:Cr >20 can suggest hypovolemia

Any other tests that can show prerenal Any other tests that can show prerenal failure?failure?

Fractional Excretion of NaFractional Excretion of NaFractional excretion of sodium Fractional excretion of sodium FeFeNaNa = = Urine Na Urine Na ÷ ÷ Urine CrUrine Cr

Plasma Na Plasma CrPlasma Na Plasma CrIn normal kidneys under prerenal stress <1%In normal kidneys under prerenal stress <1%1-2% either ATN or prerenal failure1-2% either ATN or prerenal failure>2% ATN due to loss of concentrating ability>2% ATN due to loss of concentrating ability– Benefits: Most accurate testBenefits: Most accurate test– Limitations: Intrinsic renal failure when tubular Limitations: Intrinsic renal failure when tubular

concentrating capacity is retained (i.e. concentrating capacity is retained (i.e. glomerulonephritis), the Fe Na may be depressedglomerulonephritis), the Fe Na may be depressed

Urine SodiumUrine Sodium

Less accurate measurement of prerenal Less accurate measurement of prerenal failurefailureUrine Na concentration affected by the Urine Na concentration affected by the rate of water reabsorption -> a patient may rate of water reabsorption -> a patient may have a relatively high urine sodium have a relatively high urine sodium concentration (20 - 40 meq/L or more) but concentration (20 - 40 meq/L or more) but may be in prerenal failuremay be in prerenal failureUrine Na < 20 meq/LUrine Na < 20 meq/L

Urine OsmolalityUrine Osmolality

CauseCause OsmolalityOsmolalityPre-renalPre-renal > 500> 500RenalRenal– Tubular injuryTubular injury <350<350– Acute Interstitial NephritisAcute Interstitial Nephritis <350<350– Acute GlomerulonephritisAcute Glomerulonephritis >500>500

Post-renalPost-renal <350<350

Case 2 SummaryCase 2 SummaryPre-Renal FailurePre-Renal Failure

BUN:Cr >20BUN:Cr >20FeFeNaNa <1% <1%Urine osmolality >500Urine osmolality >500Urinalysis: May have hyaline castsUrinalysis: May have hyaline casts– Secreted from tubular epithelial cellsSecreted from tubular epithelial cells

TreatmentTreatmentRehydration!Rehydration!

Case 3Case 3

Mrs. BuckleyMrs. Buckley36 yo female36 yo femaleNausea, vomiting, SOB x 1 weekNausea, vomiting, SOB x 1 weekSore throat 3 weeks agoSore throat 3 weeks agoCr 300Cr 300

What do you think is going on?What do you think is going on?What would you like to order?What would you like to order?

Case 3Case 3Cr 300Cr 300BUN 20BUN 20BUN:Cr <20BUN:Cr <20Osmolality >500Osmolality >500Urine R+M – proteinuria and castsUrine R+M – proteinuria and castsUrine lytes – Na 20, Fe Na <1%Urine lytes – Na 20, Fe Na <1%Renal U/S - normalRenal U/S - normal

What kind of cast is this? What kind of cast is this?

Intrinsic Renal FailureIntrinsic Renal Failure

Tubular DiseaseTubular DiseaseGlomerular DiseaseGlomerular DiseaseInterstitial DiseaseInterstitial DiseaseVascular DiseaseVascular Disease

GlomerulonephritisGlomerulonephritisPost-infectious (strep)Post-infectious (strep)IgA nephropathyIgA nephropathySLE, PAN, Hep C, HIV, Wegener’s, SLE, PAN, Hep C, HIV, Wegener’s, Goodpasture’sGoodpasture’sHSPHSPHUS/TTPHUS/TTPRapidly progressive glomerulonephritis RPGNRapidly progressive glomerulonephritis RPGNMembranoproliferative glomerulonephritisMembranoproliferative glomerulonephritisDrugsDrugsTumors (leukemia, lymphoma)Tumors (leukemia, lymphoma)

Work-UpWork-Up

ASO TiterASO TiterRenal biopsyRenal biopsyASA / ANCA / serologiesASA / ANCA / serologiesAnti-GBM antibodiesAnti-GBM antibodiesMedication HxMedication HxCT ScanCT Scan

Renal BiopsyRenal Biopsy

Should be considered in all causes of acute Should be considered in all causes of acute intrinsic renal failureintrinsic renal failure– Significantly changed dx and tx in 40% of casesSignificantly changed dx and tx in 40% of casesshould be considered in all causes of intrinsic ARF: should be considered in all causes of intrinsic ARF:

significantly changed the dx and tx in 40% of casessignificantly changed the dx and tx in 40% of cases

Complications:Complications:– Common: HematuriaCommon: Hematuria– Serious: Blood transfusions, nephrectomy, puncture Serious: Blood transfusions, nephrectomy, puncture

of other organs, perinephric hematomas – 2%of other organs, perinephric hematomas – 2%– Mortality: 0.1%Mortality: 0.1%

Post-Strep GlomerulonephritisPost-Strep Glomerulonephritis

6-14 days after pharyngitis with Group A 6-14 days after pharyngitis with Group A Strep or after skin infectionStrep or after skin infectionHypertension, edema, pulmonary Hypertension, edema, pulmonary congestion common presentationcongestion common presentationUrinalysis: RBC, RBC castsUrinalysis: RBC, RBC castsPrognosis:Prognosis:– 5% progress to RPGN5% progress to RPGN– 70% recover70% recoverAntibiotics may be considered for contactsAntibiotics may be considered for contacts

Case 3 SummaryCase 3 Summary

Intrinsic Renal Failure: GlomerulonephritisIntrinsic Renal Failure: GlomerulonephritisBUN:Cr <20BUN:Cr <20FeFeNaNa <1% <1%

Urine osmolality >500Urine osmolality >500Urinalysis: RBC, RBC casts, proteinUrinalysis: RBC, RBC casts, protein

Case 3 ContinuedCase 3 ContinuedYou insert a foley for Mrs. Buckley. Finish your You insert a foley for Mrs. Buckley. Finish your shift and go home for the night.shift and go home for the night.

Your friend is on internal medicine call that night, Your friend is on internal medicine call that night, and calls you to debate whether he should start and calls you to debate whether he should start a diuretic for Mrs. Buckley whose urine output a diuretic for Mrs. Buckley whose urine output has dropped to <0.5mL/kg/hr for the past 6 has dropped to <0.5mL/kg/hr for the past 6 hours.hours.

What should you tell your friend?What should you tell your friend?

Diuretic Use in Renal FailureDiuretic Use in Renal FailureRationale: Pts with non-oliguric ARF have improved Rationale: Pts with non-oliguric ARF have improved mortality and renal function recovery rates, therefore mortality and renal function recovery rates, therefore using a diuretic to “convert” oliguric to nonoliguric ARF using a diuretic to “convert” oliguric to nonoliguric ARF may be beneficial.may be beneficial.Evidence: RCTs have failed to show a benefit in Evidence: RCTs have failed to show a benefit in administering diuretics to patients with ARF.administering diuretics to patients with ARF.– Shilliday IR, Quinn KJ, Allison ME.Shilliday IR, Quinn KJ, Allison ME.

Loop diuretics in the management of acute renal failure: a prospective, Loop diuretics in the management of acute renal failure: a prospective, double-blind, placebo-controlled, randomized study. double-blind, placebo-controlled, randomized study. Nephrol Dial Transplant 1997 Dec;12(12):2592-6Nephrol Dial Transplant 1997 Dec;12(12):2592-6

– No change in recovery, hemodialysis, or deathNo change in recovery, hemodialysis, or death

Bottom-Line: Diuretics are only useful in the Bottom-Line: Diuretics are only useful in the management of volume-overloaded patients. management of volume-overloaded patients.

What about “renal dose” What about “renal dose” dopamine?dopamine?

Low-dose “renal” dose dopamine (1-5ug/kg/min) Low-dose “renal” dose dopamine (1-5ug/kg/min) was used for many years to treat ARFwas used for many years to treat ARF

Rationale: Increases urine outputRationale: Increases urine outputEvidence: No evidence that it improves renal Evidence: No evidence that it improves renal

recovery or mortalityrecovery or mortalitySide effects: Pro-arrhythmic, and may cause Side effects: Pro-arrhythmic, and may cause

increased medullary O2 consumption without increased medullary O2 consumption without increased O2 deliveryincreased O2 delivery

Bottom Line: Say NO to “renal dose” dopamine!Bottom Line: Say NO to “renal dose” dopamine!

Case 4Case 4Mr. DyeMr. Dye 50 year old male50 year old male CC: Not peeingCC: Not peeing HPI: 4 days of minimal urine outputHPI: 4 days of minimal urine output

– Cardiac catheterization 1 week agoCardiac catheterization 1 week ago PMHx: 15 years of DM II, lisinopril, insulinPMHx: 15 years of DM II, lisinopril, insulin O/E: BP 190/110O/E: BP 190/110

– JVP 9cmJVP 9cm– Bibasilar cracklesBibasilar crackles– EdemaEdema

Labs:Labs:– BUN: 20BUN: 20– Cr: 450 (Baseline = 150)Cr: 450 (Baseline = 150)

What is going on?What is going on?

Intrinsic Renal FailureIntrinsic Renal FailureTubular DiseaseTubular Disease Ischemic acute tubular necrosisIschemic acute tubular necrosis NephrotoxinsNephrotoxins Heme pigments: rhabdomyolysis, massive hemolysisHeme pigments: rhabdomyolysis, massive hemolysis

Interstitial DiseaseInterstitial Disease Acute interstitial nephritis (drug reaction)Acute interstitial nephritis (drug reaction) Infiltrative diseaseInfiltrative disease Autoimmune disease: SLEAutoimmune disease: SLE Infectious: Legionnaire, hanta virusInfectious: Legionnaire, hanta virus

Vascular DiseaseVascular Disease Malignant hypertensionMalignant hypertension SclerodermaScleroderma TTP, HUS, PANTTP, HUS, PAN

Renal Vein ThrombosisRenal Vein Thrombosis

Glomerular DiseaseGlomerular Disease

NephrotoxinsNephrotoxinsDrugs that alter blood flowDrugs that alter blood flow NSAIDs, ACEI, cyclosporine, tacrolimus, contrast, amphotericin B, interleukin-2NSAIDs, ACEI, cyclosporine, tacrolimus, contrast, amphotericin B, interleukin-2

Drugs that are toxic to tubulesDrugs that are toxic to tubules Aminoglycosides, contrast, cisplatin, cyclosporine, tacrolimus, amphotericin B, Aminoglycosides, contrast, cisplatin, cyclosporine, tacrolimus, amphotericin B,

methotrexate, solvents, heavy metals, IVIGmethotrexate, solvents, heavy metals, IVIG

Heme-Pigment-Induced toxicityHeme-Pigment-Induced toxicity Cocaine, EtOH, lovastatinCocaine, EtOH, lovastatin

Drugs that precipitate and cause tubular obstructionDrugs that precipitate and cause tubular obstruction Acyclovir, sulfonamides, ethylene glycol, chemo drugs, methotrexateAcyclovir, sulfonamides, ethylene glycol, chemo drugs, methotrexate

Allergic interstitial nephritisAllergic interstitial nephritis Penicillins, cephalosporins, sulfonamides, rifampin, cipro, NSAIDs, TZDs, Penicillins, cephalosporins, sulfonamides, rifampin, cipro, NSAIDs, TZDs,

furosemide, cimetidine, phenytoin, allopurinolfurosemide, cimetidine, phenytoin, allopurinol

Hemolytic-Uremic SyndromeHemolytic-Uremic SyndromeCyclosporine, tacrolimus, cocaine, quinine, conjugated estrogensCyclosporine, tacrolimus, cocaine, quinine, conjugated estrogens

What puts Mr. Dye at risk for renal failure?What puts Mr. Dye at risk for renal failure?(i.e. What are the risk factors for contrast-(i.e. What are the risk factors for contrast-

induced renal failure?)induced renal failure?)

Contrast-Induced Renal FailureContrast-Induced Renal FailureCourse:Course:

– Increasing Cr for 3-5 days, then resolutionIncreasing Cr for 3-5 days, then resolutionRisk Factors:Risk Factors:

– Chronic renal insufficiencyChronic renal insufficiency– DM (Approximately 40% risk!)DM (Approximately 40% risk!)– AgeAge– HypovolemiaHypovolemia– HypoalbuminemiaHypoalbuminemia– MyelomaMyeloma– Type and Dose of ContrastType and Dose of Contrast

How can you prevent contrast-induced renal How can you prevent contrast-induced renal failure?failure?

PreventionPrevention Alternative studies – MRI, ultrasoundAlternative studies – MRI, ultrasound Low-dose contrast, avoid repetitive studies (<72 hours), Low-dose contrast, avoid repetitive studies (<72 hours),

low or iso-osmolal nonionic contrastlow or iso-osmolal nonionic contrast Avoid hypovolemiaAvoid hypovolemia

– IV NS or NaHCO3IV NS or NaHCO3 Avoid NSAIDsAvoid NSAIDs N-AcetylcysteineN-Acetylcysteine

– Minimizes vasoconstriction and free radicals?Minimizes vasoconstriction and free radicals?– Much heterogeneity in trials, largest meta-analysis showed RR Much heterogeneity in trials, largest meta-analysis showed RR

0.62 (.44 - .88)0.62 (.44 - .88)– NAC 600 - 1200mg po bid day before and of procedureNAC 600 - 1200mg po bid day before and of procedure– IV NAC for emergent scans? Risk of anaphylaxis, unclear data.IV NAC for emergent scans? Risk of anaphylaxis, unclear data.

What if Mr. Dye had just been started on his What if Mr. Dye had just been started on his ACE inhibitor? What condition would you ACE inhibitor? What condition would you

be concerned about?be concerned about?

ACE InhibitorsACE Inhibitors

Dilate postglomerular capillaries -> Dilate postglomerular capillaries -> increase renal blood flow and decrease increase renal blood flow and decrease GFR -> natural increase in serum Cr 10-GFR -> natural increase in serum Cr 10-20%20%

ARF after ACEI initiation -> bilateral renal ARF after ACEI initiation -> bilateral renal artery stenosisartery stenosis

ARBs may also cause ARFARBs may also cause ARFCheck Cr, lytes 2 weeks after starting ACECheck Cr, lytes 2 weeks after starting ACE

NSAIDs / COX InhibitorsNSAIDs / COX Inhibitors

Risk Factors for Renal Failure:Risk Factors for Renal Failure:– AgeAge– Chronic Renal FailureChronic Renal Failure– CHFCHF– DMDM– HypovolemiaHypovolemia– DiureticsDiuretics– ACEIACEI

AminoglycosidesAminoglycosides

Trough concentration is relevantTrough concentration is relevantOnce daily dosing can reduce toxicityOnce daily dosing can reduce toxicity

Heme-Pigment Induced Heme-Pigment Induced Acute Renal FailureAcute Renal FailureHistory:History: Crush injuriesCrush injuriesExam:Exam: Pigmented granular casts, heme pigment in urinePigmented granular casts, heme pigment in urinePathophysiology: Pathophysiology: Deposited in and concentrated in tubulesDeposited in and concentrated in tubules Obstruction and direct toxicity depending on acidic urineObstruction and direct toxicity depending on acidic urine TreatmentTreatment Volume ReplacementVolume Replacement

– Normal saline 1-2L / hourNormal saline 1-2L / hour– Urine output 200 – 300 mL/hourUrine output 200 – 300 mL/hour

Forced Alkaline-Mannitol DiuresisForced Alkaline-Mannitol Diuresis– Urine pH >6.5Urine pH >6.5– Once diuresis established 75mmol/L of NaHCO3Once diuresis established 75mmol/L of NaHCO3– Caution re: hypercalcemiaCaution re: hypercalcemia– Consider mannitol / diuretic if not effective diuresisConsider mannitol / diuretic if not effective diuresis

Case 4 SummaryCase 4 SummaryCondition Dipstick Sediment Urine

OsmFe of Na

(%)Prerenal Trace or no

proteinuriaHyaline casts possible >500 <1

Renal- Tubular injury

(ischemic or toxic)

- Acute Interstitial Nephritis

- Acute Glomerulonephritis

- Mild to mod proteinuria

- Mild to mod proteinuria; Hb, WBC

- Mod to severe proteinuria; Hb

- Pigmented granular casts

- WBC, white cell casts, eosinophils and eosinophil casts; red cells

- RBC and red cell casts

<350

<350

>500

>1

>1

<1

Case 5Case 5

Mr. PeebodyMr. Peebody69 yo male69 yo maleCC: Unable to urinate for 24 hoursCC: Unable to urinate for 24 hoursPMHx: BPHPMHx: BPHMeds: Amitriptyline – started recently for Meds: Amitriptyline – started recently for

insomniainsomniaO/E: Distended bladder, tender O/E: Distended bladder, tender

suprapubic areasuprapubic area

What is going on?What is going on?

Post-Renal Failure in AdultsPost-Renal Failure in AdultsUrethra and Bladder OutletUrethra and Bladder Outlet Infiltration: Cancer – prostate, bladder, cervix, colonInfiltration: Cancer – prostate, bladder, cervix, colon Blockage: Calculi, clotBlockage: Calculi, clot Pressure: BPHPressure: BPH Narrowing: Stricture, phimosisNarrowing: Stricture, phimosis Innervation: Neurogenic bladderInnervation: Neurogenic bladder TraumaTrauma

UreterUreter Infiltration: Cancer, Retroperitoneal fibrosis, IBDInfiltration: Cancer, Retroperitoneal fibrosis, IBD Blockage: Calculi, crystals, clot, ligationBlockage: Calculi, crystals, clot, ligation Pressure: AAA, PregnancyPressure: AAA, Pregnancy Narrowing: StrictureNarrowing: Stricture RefluxReflux TraumaTrauma

IntrarenalIntrarenal Crystals: Uric acid, sulfonamide, acyclovir, indinavirCrystals: Uric acid, sulfonamide, acyclovir, indinavir Protein casts: multiple myeloma, amyloidosisProtein casts: multiple myeloma, amyloidosis

What conditions might cause this in What conditions might cause this in children?children?

Post-Renal Failure in ChildrenPost-Renal Failure in ChildrenUrethra and Bladder OutletUrethra and Bladder Outlet Blockage: Urethral atresia, phimosis, meatal stenosis, Blockage: Urethral atresia, phimosis, meatal stenosis,

anterior and posterior urethral valves (males), calculus, anterior and posterior urethral valves (males), calculus, clotclot

Innervation: Neurogenic bladderInnervation: Neurogenic bladder

UreterUreter RefluxReflux Blockage: ureterovesical junction obstruction, Blockage: ureterovesical junction obstruction,

ureterocele, clotureterocele, clot Anatomic: megaureter, retrocaval ureterAnatomic: megaureter, retrocaval ureter Pressure: retroperitoneal tumourPressure: retroperitoneal tumour

What orders would you like?What orders would you like?

What would you get if you order urine lytes What would you get if you order urine lytes for Fe Na and osmolality?for Fe Na and osmolality?

Post-Renal FailurePost-Renal Failure

Insert foley (consider coude tip)Insert foley (consider coude tip)Bladder scanBladder scanMonitor urine outputMonitor urine outputUrine R+MUrine R+M

– May see Hb, protein, WBCMay see Hb, protein, WBC– Osmolality <350Osmolality <350

Urine lytesUrine lytes– Fe Na >1Fe Na >1

What complication are you concerned What complication are you concerned about?about?

Postobstructive DiuresisPostobstructive Diuresis

Monitor urine output x 2 hoursMonitor urine output x 2 hours>250mL / hour for >2 hours after >250mL / hour for >2 hours after

uncomplicated urethral obstruction -> uncomplicated urethral obstruction -> consider admissionconsider admission

May result in severe dehydration and May result in severe dehydration and hyponatremiahyponatremia

End-Stage Renal DiseaseEnd-Stage Renal Disease

Azotemia: Accumulation of nitrogenous Azotemia: Accumulation of nitrogenous wasteswastes

Uremia: Contamination of blood with Uremia: Contamination of blood with urine, the clinical syndrome resulting from urine, the clinical syndrome resulting from ESRDESRD

Results of UremiaResults of Uremia

Renal Bone DiseaseRenal Bone Disease– Loss of vitamin D3 -> decreased calcium Loss of vitamin D3 -> decreased calcium

absorption -> secondary hyperparathyroidismabsorption -> secondary hyperparathyroidism– Metastatic calcificationMetastatic calcification

HematologicHematologic– Anemia -> Loss of erythropoietinAnemia -> Loss of erythropoietin– ImmunodeficiencyImmunodeficiency

Can you name some of the outcomes of Can you name some of the outcomes of uremia?uremia?

Results of UremiaResults of Uremia NeurologicNeurologic

– Uremic encephalopathyUremic encephalopathy– Dialysis dementiaDialysis dementia– Subdural hematomaSubdural hematoma– Peripheral neuropathyPeripheral neuropathy

CardiovascularCardiovascular– Coronary Artery DiseaseCoronary Artery Disease– HypertensionHypertension– CHFCHF– PericarditisPericarditis

GastrointestinalGastrointestinal– Anorexia, nausea, vomiting, metallic tasteAnorexia, nausea, vomiting, metallic taste– GI bleedGI bleed– Diverticulosis, DiverticulitisDiverticulosis, Diverticulitis– AscitesAscites

When would you consider hemodialysis?When would you consider hemodialysis?

Indications for HemodialysisIndications for HemodialysisVolume overloadVolume overloadHyperkalemia >6.5 or risingHyperkalemia >6.5 or risingAcid-base imbalanceAcid-base imbalanceSymptomatic uremia (pericarditis, Symptomatic uremia (pericarditis,

encephalopathy, bleeding dyscrasia, nausea, encephalopathy, bleeding dyscrasia, nausea, vomiting, pruritis)vomiting, pruritis)

Uremia (BUN >100)Uremia (BUN >100)Dialyzable intoxications – methanol, ethylene Dialyzable intoxications – methanol, ethylene

glycol, theophylline, ASA, lithiumglycol, theophylline, ASA, lithiumConsider severe dysnatremia <115 or >165)Consider severe dysnatremia <115 or >165)Consider dysthermiaConsider dysthermia

SummarySummaryThink pre-renal, renal, post-renalThink pre-renal, renal, post-renalLabs:Labs:

– Recognize the limitations of CrRecognize the limitations of Cr– Use BUN:Cr, urinalysis, urine lytes (Fe Na), Use BUN:Cr, urinalysis, urine lytes (Fe Na),

osmolality to your advantage!osmolality to your advantage!Admit and monitor invasively (foley, etc)Admit and monitor invasively (foley, etc)Treat underlying condition, maintain hydration.Treat underlying condition, maintain hydration.Consider hemodialysis and it’s complications.Consider hemodialysis and it’s complications.

Thank You!Thank You!