Nephrology Board Review
Christopher McFadden, MD
May 20, 2008
Outline
• Highlights of MKSAP• Testable Points• Multi-center Trials• Questions throughout• Questions please
Hypertension
• Prevalence– 20% adults– 60% > 65
• Natural history• SBP correlates
better than DBP
Chobanian: Hypertension, Volume 42(6).December 2003.1206-1252
HTN
• Nephropathy now a risk factor• 70% aware of diagnosis, 53% on meds,
and 27% controlled (NHANES)• Initial eval:
Duration, risk factor stratification, and signs of TOD
Goal: <140/90, <130/80 w/ DM or CKD
7
Chobanian: Hypertension, Volume 42(6).December 2003.1206-1252
Chobanian: Hypertension, Volume 42(6).December 2003.1206-1252
Initial Management per JNC 7
Chobanian: Hypertension, Volume 42(6).December 2003.1206-1252
HTN- Major Trials
• ALLHAT- thiazides = amlodopine/ ACE• AASK- ACE renoprotective w/ proteinuria
in AA patients; CCB not• SHEP- isolated SBP > 160 in elderly pts
– Limited evidence for stage I HTN• RENALL/ IDNT- ARBs beneficial in DM II• LIFE- ARB > Beta-blocker w/ LVH
• Question 1
HTN- Secondary Causes
FeaturesAge < 30 & > 55Abrupt onset/ resistantTODHypokalemia, PCKD, family hx of renal disease, abdominal bruit (particularly diastolic), ACE assoc ARF
RVD vs RAS70% criticalDoppler: 90% sensRenal Scan: 85%MRA: preferred: 90% ostial
Mgmt:Some BP improvememnt- rarely correctsRenal outcomes limitedBetter response in FMD patients
• A 45-year-old woman is referred for evaluation for a blood pressure measurement of 150/94 mm Hg. Her husband is a nurse and regularly measures her blood pressure at home. Her usual home blood pressure measurement is between 110/76 mm Hg and 120/80 mm Hg. She does not smoke cigarettes. Her mother has hypertension.
• On physical examination, her average blood pressure is 148/98 mm Hg. Results of laboratory studies, including the creatinine level, are normal.
• In addition to counseling regarding lifestyle modifications, which of the following is the most appropriate management for this patient? – A Begin hydrochlorothiazide – B Begin enalapril – C Perform ambulatory blood pressure monitoring – D Continue home blood pressure measurement
HTN Measurement
• Resting comfortably, arm at heart level• Palpate for loss of arterial impulse• Cuff bladder 80% arm circumference
– Cuff too small elevates BP• Inflate cuff 20 mm above level of BP loss• Reduce BP 2 mm/sec• Up to 30% people have white coat HTN
Kidney Function Assessment
• Creat clearance overestimates GFR• Creat lowered in malnourished diseases• MDRD estimates GFR accurately up to
60-90 ml/min
Proteinuira
• > 150 mg/ 24 hours• Normally: albumin 30%; large proportion
Tamm- Horsfall proteins• Exercise induced• Orthostatic
Hematuria
• >3 erythrocytes/ hpf on centrifuged urine• W/U: urine cytology or cysto and upper
tract imaging
Risk factors: >40, smoking, analgesic use, benzene exposure
Sometimes repetitive evaluations
Pigmenturia
• Endogenous: Bilirubin, Myoglobin, Hemogloblin, Porphyrins
• Foods: Beets, Fava Beans, Rhubarb• Drugs: Rifampin, Nitrofurantoin,
Sulfonamides, Quinine, and others
Casts
• Formed by Tamm-Horsfall mucoprotein secreted by distal tubules
• RBC casts- glomerular disease• WBC casts- inflammation or infection• Granular casts- tubular injury and death
Granular & RBC casts
Glomerulus
Nephrotic Syndrome
Proteinuria > 3.5 g
Hyperlipidemia
Edema
Hypercoagulability
Sec hyperpara
Low thyroxine (nl TSH)
• Question 3
• Questin 16
Nephrotic Diseases
• PrimaryMinimal Change
FSGS
Membranous
Membranoproliferative• Treatment
? Immuno + supportive tx
• Secondary
FSGS
Membranous
MPGN
Amyloid
• TreatmentSupportive: ACE/ HMG/ HTN control
Membranous & Amyloid
• Case 8
Acute GN
• Hematuria- often RBC casts• HTN• Possible reduced GFR
Glomerulonephritis (cont)
• IgA- synpharyngitic hematuriaSecondary dz associated w/ liver dz
Treatment controversial; 30% reach ESRD
– Henoch-Schonlein purpura: IgA deposits• Post-strep: 2-3 weeks after infection
Treatment conservative
GN (cont)
• SLE- TreatmtentStage 1(nl) and 2 (mesangial)- supportive
3 (FPGN) and 4 (DPGN)- Cytoxan/ Pred
5 (Membranous)- controversial
6 Scarred
SLE Nephritis
RPGN
• ANCA associated (pauci-immune)Wegener’s
Microscopic Polyangitis/ Churg Strauss• Anti GBM
Goodpastures, Idiopathic• Immune Complex
SLE, Post infection, Cryo, HSP
• Question 6
GN Case (# 7)
• 28 yo w/ arthralgias, cough, hemoptysis, and dark urine for 2 weeks
• PMH negative• BP elevated; exam w/ basilar rales• UA 30 RBC, 2 + protein• Creat 2.3 mg/ dL, Hgb 9.8 g/ dL• Serologic wu: anti GBM positive• Renal biopsy: crescents and linear GBM
staining
RPGN
• Question 7
Tubulointersitial Disease
• Inactive Sediment• Cause- injury by
infection, crystals, medications, ischemia, immunologic including sarcoid/ sjogrens
• Triad of eosinophilia, fever, rash limited to PCN AIN
• Medications– Analgesics– Aristocholic Acid– Lithium– Amphotericin B– Cisplatinum
• Question 15
Acute Interstitial Nephritis
Myeloma Kidney Analgesic Nephropathy
• Light chains in urine toxic insult (LCDD), cast nephropathy, amyloidLamda chains: amyloidKappa chains: LCDDDipstick NOT adequate
• Long duration/ combo• Lobulated• Transitional cell CA of GU tract
Case 8
• 65 yo w/ cc fatigue & back pain• New onset nocturia, polyuria• Vitals normal, thoracic back pain• Ca 12.8 mg/ dL, Creat 2.6 mg/dL• UA: trace protein, no cells
PCKD AD >> AR AD 1:1000 Cerebral aneurysmsHepatic cysts; Valvular dz
Alports X linked Collagen defect Men- Renal failureHet women- hematuria
Benign Familial Hematuria
AR Hematuria; not renal failure
Barter’s/ Gitelman’s
AR Tubular d/o (CL transport; nl bp, low K
B- worse, hypercalciuriaG- subtler, lower serum magnesium
Fabry’s Disease X-linked Alpha-galactosidase
Progressive systemic dz
Hyperoxaluria AR Glyoxalate aminotransferase
Liver disease
Genetic Renal Disorders
PCKD
• Abx penetrating the cystsTMP/SXT
Chloramphenicol
Ciprofloxacin
• Question 14
Fluid/ Electrolytes- Formulas
Body= 60% water, 2/3 intracellular, 1/3 extracellular
Expected dec Na= 1.6 x (plasma gluc- 100)/100
AG= Na – (Cl + HCO3)
Delta/ Delta= [AG change/ hco3 change] w/ nl 1-2
Winter’s Formula= 1.5 (HCO3) + 8 +/- 2 = pCO2
Plasma osmol= 2x Na + BUN/ 2.8 + gluc/ 18
Unmeasured anion if calcul vs meaured > 10
Fluid/ Electrolytes- Pearls
• Hyponatremia- treat vol statusIf euvolemic, check TSH, cortisol levels
Drugs causing SIADH: cyclophosphamide, chlorpropamide, vincristine, carbamazepine, haldol, fluoxetine, hctz, and other cns agents
Max correction rate- 12 meq/ L in 24 hours
• Hypernatremia- acquired NDI from lithiun, foscarnet, hypokalemia, hypercalcemia
Fluid/ Electrolytes- Pearls
• Hypokalemia- urine K (20 meq/24 hrs) to differentiate high loss (met alkalosis or RTA) vs GI loss/ shift/ poor intake
• Hypophosphatemia- redistribution common w/ refeeding, insulin to control hyperglycemia, acute resp alk
• Hypomagnesemia- renal tubular loss due to cisplatinum, ampho B, aminoglycosides,
Fluid/ Electrolytes- Pearls
• Met acidosis- urine contacting GI tract Cl absorption and K/ HCO3 excretion
• Ethylene glycol associated w/ Ca oxalate crystals
• Formic acid (methanol) assoc w/ blindnesss
• RTAProximal (2)- variable urine pHDistal (1)- low K, high urine pHDistal (4)- high K, high urine pH
• Met acidosis and resp alkalosisEval for sepsis or saliclylate intoxication
Acute Renal Failure
• ACE-I- efferent vasodilation• NSAIDs- afferent vasoconstriction• FENA- (U Na/ P Na)/ (U Cr/ P Cr) * 100
Less than 1% in oliguric pre-renal patients
Renal Replacement Therapy
• CVVHD not proven to be more effective than intermittent HD
• Increased ultrafiltration w/ CVVH better outcomes
• Daily dialysis better outcomes in single center study
• “Renal dose” dopamine not effective
Contrast Nephropathy
• Creat peaks 4-5 days after exposure• Acetyl-cysteine has varying results• Limiting risk- decreased contrast volume,
use of isotonic contrast, and vol expansion pre-procedure
ARF- Other causes
• Aminoglycosides: 1-2 weeks; lower troughs!• Amph B: 2 grams cumulative dose; risk w/ vol
depletion, elderly, & CSA use• Cisplatinum: may have NDI; often recovers• MTX: ATN and tubular obstruction• Mitomycin C: consider HUS
• HIV: Indinavir crystals obstruction• HRS: low FENa• Rhabdo: rapid Cr increase (trauma, cocaine, HMG-
CoAs);Dipstick incosistent
• Cancer: r/o obstruction!Uric acid crystallization (allopurinol/ bicarb)Radiation (> 23 Grays)
ARF Case (# 15)
• 61 yo w/ ascites and edema• Longstanding etoh abuse• BP 96/70, P 112 w/ distened abdomen,
edema• Na 122, K 3.1, Cl 102, CO2 20, Cr 1.2• Urine Na 6, osmol 670 mosm/ kg H20• Previous creat 0.6
Indinavir Crystals
CV Risk Reduction
Complications
Prepare for RRT
RRT
Cause of ESRD: 40% DM, 27% HTN, 10% GN
• Question 9
• Question 12
CKD- Internist Managment
• Refer Cr > 1.5 (women) or >2.0 (men)• HTN
AASK- control w/ ACE better
• DM control• Protein Restriction• Anemia management: goal Hgb 11-12• ROD: Phosphorus restriction/ Binders/ Vitamin D
analogues (monitor Ca and Phos)
• A 54-year-old woman is evaluated for a creatinine level of 1.3 mg/dL (114.95 μmol/L); 18 months ago, this value was 0.9 mg/dL (79.58 μmol/L). She has a 5-year history of type 2 diabetes mellitus; hyperlipidemia; and hypertension well controlled with lisinopril, hydrochlorothiazide, and atenolol. She also uses glipizide and simvastatin. Laboratory studies reveal a normal hemoglobin level.
• Which of the following diagnostic studies is most appropriate for this patient?– A 24-Hour urine collection for proteinuria– B Kidney ultrasonography – C Measurement of urine microalbumin – D Serum protein electrophoresis – E Measurement of hemoglobin A1c
• Question 11
• Question 19
ESRD
• Poor survival• 20-40 % at 5 years (DM vs non)• PD vs HD• Main cause of death: CVD & Infection• Historically, ESRD worse response w/
PTA; stent effect unclear
• Question 5
Transplant
• Better Survival
LRRT 5ys: 90%
CRT 5ys: 81%
DM 5ys: 50%
• CSA: HTN, nephrotoxicity hirsutism, gum hypertrophy
• Tacrolimus: HTN, nephrotoxicity, DM
• MMF: diarrhea and leukopenia
• Aza: reduce dose of allopurinol!
Question 2
• A 60-year-old woman with a history of type 1 diabetes mellitus and stage 4 chronic kidney disease comes for a routine follow-up examination. She asks about modalities of renal replacement therapy.
• Which of the following is the best option for this patient?• A 0-Antigen-mismatched deceased donor kidney transplantation • B Peritoneal dialysis • C Hemodialysis • D Living donor kidney transplantation after a course of dialysis • E Preemptive living donor kidney transplantation
t
• Question 18
Nephrolothiasis
• Most patients: hypercalciuria– Tx: low salt, low protein, thiazides– NO calcium restriction (increases oxalate)
• Struvite stones: chronically infected; staghorn• Uric acid- radiolucent
– Tx- alkalinize urine and allopurinol• Cystine: metabolic (AR) defect
– Tx- volume, alkalinize, d-penicillamine or alpha mercaptoppropionyl glycine (more soluble cysteine disulfide compound)
Nephrolothiasis Images
Nephrolothiasis Images
Nephrolothiasis
• Work-up• Initial: chemistry, UA, stone analysis (if
available), and imagingHydration!!! 50% recurrence at 10 years
• Recurrent stones: metabolic/ 24 hr urinesDiarrhea think IBD with ca oxalate stones
Renal Disease in Pregnancy
• Tx asymptomatic bacteriuria• Chronic HTN- present before pregnancy or dx
before 20 weeks• Gestational HTN- dx after 20 weeks; “transient
HTN of pregnancy”• Preeclampsia
If before 20 weeks- consider hydatiform mole
Tx HTN when DBP 100-110 or symptomatic
Meds: 1st line- Methyldopa, Hydralazine
Renal Disease in Pregnancy
• Higher risk w/ proteinuria and Creat > 1.4• Mild hydro common- difficult to determine
signficance
Emphysematous Pyelonephritis
• Similar to pyelo• Majority pts have DM• Gas in renal/ perirenal
tissues• Drainage mild-
moderate cases; nephrectomy if severe
• CT if pyelo pts not getting better!
HTN Case (# 3)
• 76 yo for fu; several elevated BP recently• PMH negative; No medications• No etoh, tobacco use• BP 178/68, no orthostasis• No volume overload• Creat 1.0
HTN Case cont.
• Evaluation
BP change recently?
Ideal 1st line agent:
JNC 6: CCB or diuretics
JNC 7: Stage 2: combination
Auto regulation