Categories of Volume Disorders

• Intravascular/acute hemorrhage• Extracellular

– Intra- and extravascular– Sodium and water loss

• Diarrhea

– Sodium and water gain• CHF with edema• Ascites

• Total body water– Water loss

• Diabetes insipidus

– Water retention• SIADH

Diagnosis of Volume Disorders

• Intravascular depletion– MAP = CO × SVR– Clinical signs

• BP HR JVP• Cool extremities• Reduced sweating• Dry mucous membranes

• ECF Depletion– Skin turgor– Weight– Hemodynamic effects

Hemodynamic Truths

• Tachycardia is never a good thing.• Hypotension is always pathologic.• There is no such thing as normal cardiac

output.• Central venous pressure is only elevated

in disease.• Peripheral edema is of cosmetic concern

Pinsky.. Chest. 2007; 132:2020-2029)

Distribution of Total Body Water

Intracellular25LK

Interstitial12 LNa

Plasma3 L

Protein

Total Body Water (40 L)

ECF (15 L)

Daily Fluid Balance

Total Body WaterInsensible losses200 ml/day/m2 BSA

Intake1-1.5 L (100-200 mEq Na+)

Sweat0.1 L (6 mEq Na+)

Urine1-1.5 L

(100-200 mEq Na+)

Intravenous Crystalloid Solutions

5% Dextrose in Water

0.45% Saline 0.9% Saline 3% Saline Lactated

Ringer’s

Other names or abbreviations

D5W Half-normal

saline

½ NS

Normal Saline

Isotonic Saline

NS

Hypertonic

saline

“Hot-salt”

LR

Hartman’s

solution

Dextrose

(gm/dL)

5 0 0 0 0

Na+

(mEq/L)

0 77 154 513 130

Cl-

(mEq/L)

0 77 154 513 109

K

(mEq/L)

0 0 0 0 4

Ca2+

(mEq/L)

0 0 0 0 3

Lactate

(mEq/L)

0 0 0 0 28

Osmolality 250 mOsm/kg 154 mOsm/kg 308 mOsm/kg 1026 mOsm/kg

274 mOsm/kg

Principles of Treatment

• How much volume?– Need to estimate volume deficit

• Which fluid?– Which compartment is predominantly

effected?– Evaluate acid-base status, electrolytes and

nutrition

Case 1

A 56 y.o. male presents with massive hematemesis.

PE: Diaphoretic BP supine 120/70 HR 100BP sitting 90/50 HR 140

Serum Na+ 140

What is the nature of the volume deficit?What IV fluid would you prescribe?

Case 2

An 28 y.o. intern returns from the intern beach weekend with intractable nausea and vomiting.

PE: BP 80/50 HR 130 supineLabs: Na+ 130 K+ 2.8

HCO3- 32What is the nature of the fluid deficit?

What would happen if D5W were administered?

Case 3

An 85 y.o. nursing home resident with dementia and a history of diabetes presents with confusion.

PE: BP supine 110/70 90/50 sitting.

Decreased skin turgor. Wt 60 kg

Labs: Na+ 150 Glucose 1200

BUN 50/Creat 1.8

How would you treat this patient?

Calculation of Water Deficit

Na × Normal body water = Na × Current body water

140 × NBW = 157 × (0.5 X 60 kg)

NBW = 33.6 L

Water deficit = 33.6 L -30 L = 3.6 L

Case 4

A 40 y.o. patient with cirrhosis and ascites is admitted with a rising creatinine.

BP 100/70 JVP 5 cm

Tense ascites No edema

BUN 12 Creat 2 Albumin 2

Urine Na 5 mEq/L

Urine volume 200 mL/24 hours

If volume depleted, how would you treat the patient?

Case 5

A 76 y.o. male with COPD is admitted for a COPD exacerbation. Oral intake over the first day of hospitalization has been poor.

PE Euvolemia

Na 140 K 3.8 BUN 13 Creat 1

What would you choose for maintenance fluids?

Chronic Hyponatremia: Epidemiology

• Most common electrolyte disorder, occurring in 15-30% of hospitalized patients

• SIADH accounts for 60% of cases of chronic hyponatremia

Incidence of HyponatremiaDepartment Na <136 mEq/L (%) Na < 125 mEq/L (%)

Internal medicine 36 4

Surgery 32 2

Cardiology 27 2

Pulmonary 33 3

Intensive care 38 2

Neurology 24 3

Gynecology 35 2

Urology 21 1

Ear, Nose, Throat 20 1

Psychiatry 5 0

All 30 3

Nephrol Dial Transplant 21: 70-76, 2006.

Symptomatic Hyponatremia

010203040506070

Volum

e Dep

letio

nCHF

SIADH

Thiaz

ide

diure

tics

Mal

ignan

cy

Alcohol

abuse

Psych

iatri

c his

tory

Multi

fact

orial

Hx Hyp

onat

rem

ia

Per centof Patients

with SymptomaticHyponatremia

27,496 Outpatients• 14% with SNa <134 mEq/L• 4% SNa < 130 mEq/L

J Am Soc Nephrol 16: 531A, 2005.

Diagnostic Evaluation of Hyponatremia

Effective Plasma Osmolality (2×Na + glucose/18)

< 275 mOsm/kgTrue Hyponatremia

Volume DepletedEdematous

Effective VolumeEuvolemic

Uosm >100 mosm/kg

Uosm >100 mosm/kg

Uosm >100 mosm/kg

Uosm <100 mosm/kg

UNa < 15meq/L(Exceptions)

True Volume Depletion

UNa < 15meq/L

CHF CirrhosisNephrosis

UNa > 25 meq/L

SIADHExclude

hypothyroidism and adrenal insufficiency

UNa < 15meq/L

Primary PolydipsiaLow Solute Intake

>290Hypertonic

Hyponatremia(Hyperglycemia) Measured Osm 275-290,

Na+ < 135 & BUN Normal

Pseudohyponatremia

Pseudohyponatremia

N Engl J Med 349: 1465-1469, 2003.

SIADH

2 4 6 8 10 12 14 16 180

140

120

1000

50

0

200

15

17

SNa+

mEq/L

Uosm

mOsm/kg

UNa+ mEq/L

ECF VolL

ADH

Water Restrict

Days

SIADH versus Volume Depletion

Favors SIADH

Serum Uric Acid < 4 mg/dL

FexUA > 10%

BUN < 5 mg/dL

FexUN > 70%

Favors Volume Depletion

Serum Uric Acid > 6 mg/dL

FexUA < 10%

BUN > 15 mg/dL

FexUN < 35%

• Response to 1-2 liters of 0.9% NaCl in patients who are not symptomatic

Causes of SIADH

SIADH

Pulmonary DisordersAcute respiratory failureInfectionsPositive-pressure ventilation

TumorsExtrathoracicMediastinalPulmonary

CNS DisordersAcute psychosisHemorrhageInflammatory and demyelinating diseasesMass lesionsStrokeTrauma

DrugsCarbemazepine OxytocinClofibrate PhenothiazinesCyclophosphamide NSAID’s, Cox-2 I’sDesmopressin SSRI’sNicotine TricyclicsOpiates VincristineMethylenedioxymethamphetamine (Ecstacy)

MiscellaneousHIV infectionPainPostoperative stateNausea

Vigorous exercise

Treatment of Hyponatremia• Treat symptomatic patients with 3% saline (and

furosemide)• Stop therapy with 3% saline when symptoms resolve• Do not exceed 10 mEq/L in 24 hours or 18 mEq/L in

48 hours in a symptomatic patient with chronic hyponatremia

• Use 0.9% NaCl for asymptomatic hyponatremia due to volume depletion

• Do not use fluid restriction alone in patients with symptoms of brain edema

• Do not use 0.9% NaCl for symptomatic patients with SIADH, especially when the urine osm is > 300 mOsm/kg

• Stop offending drugs whenever possible

Assessment of Renal Function –The MDRD Equation

• GFR should be estimated by the MDRD equation in most circumstances

• Should be applied to patients in a steady state with respect to serum creatinine concentration– not valid in the setting of a rising serum

creatinine in acute kidney injury (AKI)• Less accurate in populations with normal or

near normal GFR, extremes of age and weight, amputees, in pregnancy and cirrhosis– Measure creatinine clearance in these populations

MDRD EquationGFR in mL/min per 1.73 m2 = 175 x Cr(exp[-1.154]) ×

Age(exp[-0.203]) × (0.742 if female) x (1.21 if black)

www.kidney.org/professionals/KLS/gfr_calculator.cfm

www.nephron.com/mdrd/default.htm

Serum Creatinine (SCr) Alone Is a Poor Indicator of Kidney Function

*Calculated with the MDRD equation.

2 patients with SCr levels of 1.5 mg/dL (0.133 mmol/L)

FemaleAge = 65 years

MaleAge = 25 years

Estimated GFR*: 73 mL/min

Estimated GFR*: 37 mL/min

Problem with Serum Creatinine in Estimating GFR

0

1

2

3

4

5

6

7

8

10 20 30 40 50 60 70 80 90 100 110 120

Ser

um

cre

atin

ine

(mg

/dL

)

0

0.088

0.176

0.264

0.352

0.44

0.528

0.616

0.704

Ser

um

cre

atin

ine

(mm

ol/

L)

Creatinine 0.5 mg/dL (0.044 mmol/L) to 0.8 mg/dL (0.071 mmol/L)GFR 100 to 60 mL/min

Cystatin C

• More sensitive in identifying milder impairments in renal function than serum creatinine

• Cystatin C-based equations may more accurate in the elderly and in patients with cirrhosis

• Levels are affected by thyroid status, inflammation, and corticosteroids

• Clinical utility remains to be established

Plot of GFR vs. Time in Patients with CKD

Key Points

• The estimated GFR should be calculated using the MDRD equation whenever a serum creatinine is measured in steady state conditions

• Plots of GFR vs. time are helpful in patient management and education

• Consider 24 hour urine collections for creatinine clearance in the following populations:– Near normal GFR– Extremes of age and weight– Amputees– Pregnant women – Cirrhotics

Etiology of Hospital Acquired AKI

Nash K, et al. AJKD 2002; 39: 930-936.

Cause % (n=377) Mortality

Decreased renal perfusion 39 13.6

Medications 16 15

Radiographic contrast media 11 14

Postoperative 9 2.8

Sepsis 7 76

Post–liver transplantation 4 28.6

Post–heart transplantation 2 37.5

Obstruction 2 28.6

Hepatorenal 2 71.4

Rhabdomyolysis 1 25

Glomerulonephritis 1 33.3

Medication-Induced AKI in Hospitalized Patients

Nash K et al. AJKD 2002; 39: 930-936.

Medication %

Aminoglycosides 30

Nonsteroidal anti-

inflammatory drugs 21

Piperacillin/tazobactam 11

Amphotericin B 10

Trimethoprim/sulfa 10

Cyclosporine 5

Angiotensin-converting

enzyme inhibitors 3

Multiple nephrotoxins 3

Ciprofloxacin, cis-

platinum, acyclovir,

ceftazidime

1

Acute Kidney Injury• Prevalence

– 1% all patients admitted to hospital

– 10-30% patients admitted to ICU

• Etiology

– Hemodynamic 30%

– Parenchymal 65%

• Acute tubular necrosis 55%

• Acute glomerulonephritis 5%

• Vasculopathy 3%

• Acute interstitial nephritis 2%

– Obstruction 5%

Evaluation of Renal Failure

• Is the renal failure acute or chronic?– laboratory values do not discriminate between

acute vs. chronic– oliguria supports a diagnosis of acute renal failure– small kidneys on US more common in chronic

renal failure

• What is the etiology of the renal failure?– Prerenal 30%– Intrarenal 65%– Postrenal 5%

5 Key Steps in Evaluating Acute Kidney Injury

1) Obtain a thorough history; review the chart in detail

2) Do everything you can to accurately assess volume status

3) Always order a renal ultrasound

4) Look at the urine5) Review urinary indices

Clinical Approach to Acute Kidney Injury

HistoryVolume status

UltrasoundUrinalysis US shows

Hydronephrosis

Post-Renal

Urinalysis Normal

UrinalysisAbnormal

Tubulointerstial Disorders

Glomerular and Vascular Disorders

Pre-renal

Clinical Approach to Acute Kidney InjuryHistory

Volume StatusUltrasoundUrinalysis

Hydronephrosis

Post-Renal

Prostate disease BPH CancerPelvic malignancyStonesStrictureRetroperitoneal fibrosis

Normal Urinalysis

Pre-Renal

Low ECF Volume GI losses Hemorrhage Diuretics Osmotic diuresis

Altered renal blood flowor hemodynamics Sepsis Heart failure Cirrhosis/Hepatorenal syndrome Hypercalcemia Medications NSAIDs/Cox-2 inhibitors ACE inhibitors Angiotensin II receptor blockers Vascular disease

Vascular Disorders

TubulointerstitialDisorders

Glomerular Disorders

Tubular obstruction Crystals Calcium oxalate (Ethylene glycol, orlistat) Indinivir Acyclovir Methotrexate Tumor lysis syndrome Myeloma cast nephropathy

Acute tubular necrosis Ischemic Nephrotoxic Contrast-induced Rhabdomyolysis

Acute interstitial nephritis Medication-induced Autoimmune Sjogren syndrome Sarcoidosis Infection-related

Arterial Renal artery stenosis Renal artery thromboembolism Fibromuscular dysplasia Takayasu arteritisMedium vessel Polyarteritis nodosa Kawasaki diseaseSmall vessel Glomerulonephritis Thrombotic microangiopathies Cholesterol emboliRenal vein Renal vein thrombosis Abdominal compartment syndrome

Renal parenchymal disorders

Urinalysis abnormal

Pre-renal Azotemia

History Effective Arterial VolumeNormal Renal Ultrasound

Normal Urinalysis

Altered renal blood flowor hemodynamics Sepsis Heart failure Cirrhosis/Hepatorenal syndrome Hypercalcemia Medications NSAIDs/Cox-2 inhibitors ACE inhibitors Angiotensin II receptor blockers Vascular disease

Low ECF Volume GI losses Hemorrhage Diuretics Osmotic diuresis

Intrarenal Acute Kidney Injury

History

Nephrotoxins

Decreased perfusion

Crush injury

Other organ involvement

Volume statusECF usually normal to increased (effective arterial blood volume may be decreased)

Ultrasound Increased echotecture

UrinalysisCasts, cells

Isosthenuria with tubular injury

Urinary IndicesUosm 300-350 UNa+>40 FeNA > 4%

Glomerular disease: often mirror those of pre-renal

Acute Kidney Injury in the ICUDecreased Effect Renal Blood FlowSepsisSystemic inflammationImpaired cardiac output

NephrotoxinsAminoglycosidesAmphotericinFoscarnetRhabdomyolysisIodinated radiocontrast

Pre-renal Azotemia

Acute tubular necrosis

Nephrotoxic tubular injuryIschemic tubular injury

ATN versus Prerenal Azotemia

Indices Prerenal ATN

UNa < 20 > 40

FeNa < 1% > 4%

U/PCreat > 40 < 20

FeUN < 35% >70%

Urine SedimentPre-renalPost-renal

Normal Abnormal

RBCRBC CastsProteinuria

WBCWBC CastsEosinophils

PyelonephritisInterstitial nephritis

Allergic INAtheroemboli

Glomerulonephritis

RTE cellsPigmented casts

Tubular EpithelialInjury -ischemic -nephrotoxic aminoglycoside rhabdomyolysis

GlomerulonephritisVasculitis

Thrombotic microangiopathy

Atheroemboli

Urinalysis Findings in Acute Kidney Injury

Dysmorphic HematuriaRed cell casts

Oval fat bodiesFatty Casts

Muddy brown castsRenal tubular epithelial cells and casts

White cellsWhite cell castsEosinophiluria

MonomorphicHematuria

Crystalluria

Glomerulonephritis

Acute tubular necrosis

Acute interstitial nephritisUrinary tract infection

Obstructing tumorRenal vein thrombosisRenal infarction

Cholesterol emboli

Minimal change diseaseFocal segmental glomerulosclerosis

Thrombotic microangiopathy

Drug toxicityUrate crystals/calcium-phosphate crystals -tumor lysis syndromeCalcium oxalate crystals -ethylene glycol -orlistat

Minimal abnormalities(few cells, minimal protein)

+Blood on dipstick with noRBCs on microscopic

-Protein on dipstick with +Sulfasalicylic acid assay for protein

Pigment nephropathy(Rhabdomyolysis with ATN)

Myeloma cast nephropathy

1+ protein

3+ protein

Obstructing stone

Urinary Sediment Urine DipstickDiagnosis

Key Points on Medication-induced AKI

• Medications are the second most common cause of cause of AKI in hospitalized patients (pre-renal azotemia is #1)– THINK DRUGS

• NSAIDs can result in significant nephrotoxicity in the elderly, and in patients with diabetes and/or CKD

• Consider AIN in patients on PPI’s with unexplained kidney injury and pyuria

• Use of oral phosphasoda preparations for bowel prep should be abandoned-use PEG based preps

Renal Biopsy-When?

• Exclude pre- and post-renal failure, and clinical findings are not typical for ATN

• Extra-renal manifestations that suggest a systemic disorder

• Heavy proteinuria• RBC casts

Tumor Lysis Syndrome• Acute oliguric renal failure associated with urate

levels > 15 mg/dl and hyperphosphatemia• Associated with overproduction and excretion of

urate and cell lysis resulting in increased release of potassium and phosphorus in patients undergoing chemotherapy or with a heavy tumor burden

• Urine urate/creatinine > 1• Urinary alkalinization may worsen calcium

phosphate precipitation and NS is as effective as urinary alkalinization alone

• Early dialysis indicated for oliguric AKI to decrease urate burden

Risk Stratification for TLS

Type of cancer

Risk

High Intermediate Low

NHLBurkitt's, lymphoblastic, B-ALL

DLBCL Indolent NHL

ALL WBC ≥100,000/microL WBC 50,000-100,000/microLWBC ≤50,000/microL

AMLWBC ≥50,000/microL, monoblastic

WBC 10,000-50,000/microLWBC ≤10,000/microL

CLL  WBC 10,000-100,000/microL treated with fludarabine

WBC ≤10,000/microL

Other hematologic malignancies (including CML and multiple myeloma) and solid tumors

 Rapid proliferation with expected rapid response to therapy

Remainder of patients

*From Coiffier B, Altman A, Pui CH, Younes A, Cairo MS. Guidelines for the management of pediatric and adult tumor lysis syndrome: an evidence-based review. J Clin Oncol. 2008; 26:2767-78.

Prevention of TLS• If there is a concern about tumor lysis, as predicted by an

elevated serum LDH, serum uric acid, or heavy tumor burden, the patient should be admitted for hydration and close monitoring of kidney function, serum potassium, phosphorus and uric acid.

• Patients with a preexisting reduction in GFR, oliguria and/or acidic urine, and volume depletion should also be hospitalized for hydration and observation.

• High-risk patients should be hospitalized for aggressive intravenous hydration and prophylactic rasburicase.

• Intermediate risk patients should receive allopurinol rather than rasburicase for prophylaxis in the absence of pretreatment hyperuricemia.

• Patients at low risk for TLS should receive hydration, but do not require hypouricemic therapy.

Renal Disease Associated with Multiple Myeloma

• Myeloma cast nephropathy– direct precipitation of casts in tubules– Factors favoring cast precipitation:

-affinity of light chains for Tamm-Horsfall protein

-high luminal Cl-

-volume depletion – Plasmapheresis may be beneficial

• Hypercalcemic nephropathy• Glomerular lesions (MPGN, Amyloid, Light chain

deposition disease)

Acute Glomerulopathies

• RPGN most commonly seen with:– Lupus nephritis (DPGN, class IV)– Pauci-immune GN (ANCA associated)– Anti-GBM disease– less commonly: IgA, post-infectious

• Nephrotic presentations of ARF– Collapsing FSGS (HIV nephropathy)– Minimal change disease with ATN

• Thrombotic microangiopathies (HUS, TTP, malignant hypertension, scleroderma kidney, pre-eclampsia)

Atheroembolic Renal Disease

• ARF in patient with erosive atherosclerosis• Often follows aortic manipulation (angiography,

surgery, trauma) or anticoagulation• Pattern is often an acute worsening of renal function

due to showering of emboli, followed by more insidious progression over several weeks to months due to ongoing embolization of atheromatous plaques

• Livedo reticularis, Hollenhorst plaques• Nephritic sediment, eosinophilia, eosinophiluria, low

C3• Poor prognosis

Diagnostic Criteria for Hepatorenal Syndrome

• Cirrhosis with ascites• Serum creatinine >1.5 mg/dL (>133 µmol/L)• No improvement of serum creatinine (decrease to a level of <

1.5 mg/dL) after at least 2 days with diuretic withdrawal and volume expansion with albumin. The recommended dose of albumin is 1 g/kg of body weight per day up to a maximum of 100 g/day.

• Absence of shock.• No current or recent treatment with nephrotoxic drugs.

Absence of parenchymal kidney disease as indicated by proteinuria >500 mg/day, microhematuria (>50 red blood cells per high power field) and/or abnormal renal ultrasonography.

Salerno F, Gerbes A, Ginès P, Wong F, Arroyo V: Diagnosis, prevention and treatment of hepatorenal syndrome in cirrhosis. Gut 2007: 56: 1310-8.

Hepatorenal syndromeMinor Criteria

• Urine volume < 500 mL/day

• Urine sodium < 10 mEq/L

• Urine osmolality > plasma osmolality

• Urine red blood cells < 50 per high-power field

• Serum sodium concentration < 130 mEq/L

Vasoconstriction in Hepatorenal Syndrome

Contrast-Induced Nephropathy(CIN)

• Most common definitions– absolute increase in serum creatinine level

of 0.5 to 1 mg/dL (0.044 -0.088 mmol/L) within 48-72 hours

– 25% increase in serum creatinine level within 48-72 hours

• Accounts for 12% of cases of acute kidney injury

• Marker for increased mortality

Contrast-Induced Nephropathy Risk Score in Patients Undergoing Coronary Angiography

Mehran, R. et al. J Am Coll Cardiol 2004;44:1393-1399.

Hypotension

IABP

CHF

Age > 75 years

Anemia

Diabetes

Contrast media volume

Serum creatinine > 1.5 mg/dL

OReGFR<60mL/min/1.73 m2

eGFR (mL/min/1.73 m2) =188 × (SCr)-1.154 × (Age)-0.203

× (0.742 if female) × (1.210 If African American)

Markers Integer Score

5

5

5

4

3

3

1 for each 100 mL

4

2 for 40-604 for 20-406 for < 20

Calculate

Risk

Score

Risk of CIN

Risk of

Dialysis

< 5 7.5% 0.04%

6 to 10 14.0% 0.12%

11 to 16 26.1% 1.09%

> 16 57.3% 12.6%

Risk of CIN vs. Estimated GFR

0

10

20

30

40

50

60

70

10 20 30 40 50 60 70 80 90 100 120

CIN Rate (%)

Estimated GFR (ml/min)

Modified from McCullough PA et al. Am J Cardiol 2006;98[suppl]:27K–36K.

ModerateRisk

HighRisk

DiabetesWithoutDiabetes

Intervention Quality of Evidence

Benefit Recommendation

Volume expansion with normal saline

Moderate quality

Clear Indicated and acceptable

Volume expansion with NaHCO3

Moderate quality

Clear Indicated and acceptable

Oral N-acetylcysteine

Moderate quality

Low risk; possible benefit

May be considered; possible impact

Iso-osmolar and low-osmolar (vs. high osmolar)

Moderate quality

Clear Indicated and acceptable in high risk patients

Iso-osmolar vs. low-osmolar contrast

Moderate quality

Unclear Use of either agent in high risk patients is acceptable based on available evidence

Oral hydration (vs. iv hydration)

Low quality Unclear Insufficient evidence to recommend

Management of Patients Receiving Iodinated Contrast MediaAssess CIN RiskCalculate eGFR

Discontinue metforminDiscontinue NSAIDsDiscontinue diuretics

•Same strategies as eGFR 31-60 mL/min•Consider hospitalization•Nephrology consultation•Dialysis planning

•Isotonic NaCl or NaHCO3 at 1-1.5 mL/kg/hr•Optimize cardiac output•Use non-ionic low osmolar or iso-osmolar contrast•Limit contrast volume to <100 mL•Consider NAC 600-1200 mg 2X/d one day prior to and 2X/d on day of study •Avoid repeat contrast exposures over course of next 4 weeks when possible

Good clinical practice

eGFR < 30 mL/min eGFR = 31-60 mL/min eGFR > 60 mL/min

Serum Creatinine before discharge and then in 3 days

•Serial serum creatinine and electrolytes•Initially obtain above labs daily

Modified from McCullough PA, et al.Am J Cardiol. 2006; 98:2K-4K.

Withdrawal of Medications Around the Time of Contrasted Studies

• NSAIDs and Cox-2 inhibitors– Hold 1 day prior to the study until there is confirmation that

CIN has not occurred• Metformin

– Hold 1 day prior to the study until there is confirmation that CIN has not occurred

• Diuretics– May be detrimental– Hold for 1 day prior to the procedure and restart 1 day

following the procedure• ACE inhibitors and ARBs

– No data available – reasonable to continue during the procedure in the absence of hypotension or recent acute change in renal function

Interventions to Limit Risk of CIN-Key Points

• Optimize the effective circulating volume– Delay studies in patients with volume depletion,

circulatory collapse or decompensated congestive heart failure when possible

– Optimize congestive heart failure when possible

• Hydration with isotonic saline or sodium bicarbonate 1-1.5 ml/kg/hr starting 3-12 hours prior to the study and continuing for at least 12 hours after the study in moderate risk patients

Interventions to Limit Risk of CIN-Key Points

• N-acetylcysteine 600-1200 mg twice daily starting one day prior to and twice daily on the day of the study is reasonable

• Use minimal volumes of low osmolar or iso-osmolar non-ionic contrast

Nephrotoxicity of Gadolinium

• Ergün et al. Nephrol Dial Transplant 2006; 21: 697–700.– Retrospective review 473 patients with stage 3-4

CKD receiving intravenous gadolinium at a dose of 0.2 mmol/kg body weight (gadopentetate dimeglumine, gadodiamide and gadoterate meglumine)

– AKI defined as a 0.5 mg/dL rise in serum creatinine

• Frequency of AKI was 12.1% • Older age, low baseline creatinine clearance,

diabetic nephropathy and lower hemoglobin and albumin levels were risk factors for AKI.

Gadolinium and Nephrogenic Systemic Fibrosis

• Gadolinium was initially thought to be safe in renal disease and was widely used

• An unusual skin condition first identified in 1997 appeared in dialysis patients initially called nephrogenic fibrosing dermopathy, and more recently nephrogenic systemic fibrosis (NSF) or gadolinium-associated systemic fibrosis

• Nearly all patients with NSF have been exposed to gadolinium-based contrast agents and an association was first noted in 2006

• Usually seen in patients with advanced kidney disease

• Gadolinium has been found in tissue of patients with NSF

O

NO-

H3C-N H O

N

O

O-

N

N-CH3

H O

OO

N

O

N

O

O-

N

O

O

HO

O-

O-

Gd3+ Gd3+

O

O-

O-

N

N

N

N

O

O-

O

OH

Gd3+

O

O-

O-

N

N

N

N

O

O-

OH

Gd3+

OO

Gadolinium Chelates

Gadodiamide (Omniscan) Gadopentetate dimeglumine (Magnevist)

Gadoterate meglumine (Dotarem) Gadoteridol (ProHance)

Bomgartz G. Mag Reson Mater Phy 2007;20:57-62.

Perazella, M. A. Clin J Am Soc Nephrol 2008;3:649-651

Transmetallationof Gadodiamide

Nephrogenic Systemic Fibrosis

• Plaques, papules and nodules with a brawny wooden texture

• Starts symmetrically in legs, and may then involve the arms and trunk. The face is spared.

• Skin and periarticular fibrosis• Heart, lungs, skeletal muscle and diaphragm

can be involved• Associated with increased mortality (50% at

2 years, most deaths occurring within 6 months of diagnosis )

Nephrogenic Systemic Fibrosis

CD34 positive staining

From Clev Clin J Med 2008;75:95-111.

Influence of Inflammation on Development of NSF

*Proinflammatory event defined as all processes in which the body has sustained major tissue injury, such as vascular surgery, transplantation surgery, or other major surgery; sepsis, pneumonia, osteomyelitis, or other major infection; and arterial or venous thrombosis that has caused ischemia or organ or limb damage.

Sadowski EA et al. Radiology 2007;243:148-157.

Variable Odds Ratio

No. of proinflammatory events* per patient

5.068

No. of MR examinations per patients

2.618

NSF: Risk Factors

• Usually seen in stage IV-V CKD and severe AKI, but has been described in earlier stages (5-15% incidence and RR 10.7 in stage V disease)

• More patients with CKD have been exposed to gadodiamide (Omniscan) at higher doses (MRA)

• Active inflammation (recent surgery, infection)

Dialysis and Gadolinium

• Gadolinium-chelates rapidly equilibrate in the extracellular space and are excreted unchanged in the glomerular filtrate

• 65-80% is removed in a single hemodialysis session

• Peritoneal dialysis does not efficiently remove gadolinium-chelates

Recommendations Regarding Gadolinium-Key Points

• Evaluate patients for renal dysfunction prior to giving GBCA

• Avoid in patients with acute or chronic kidney disease when the eGFR is < 30 ml/min

• Strictly avoid in the setting of hepatorenal syndrome or in the perioperative period of liver transplant

• When use is deemed essential in high risk patients, an agent other than gadodiamide should be used at the lowest possible dose

• Obtain informed consent• For ESRD patients, dialysis should be performed

within 24 hours on 2 consecutive days

Gadolinium and Iodinated Contrast:When are they Unsafe?

Risk

High

Moderate

CKD: Stage 1 Stage 2 Stage 3 Stage 4 Stage 5 DialysisGFR: > 90 60-90 30-60 15-30 < 15

CIN

NSF