Contrast induced nephropathy

22Contrast-induced Contrast-induced

NephropathyNephropathy Dr. Mohamed AbbassDr. Mohamed Abbass

NephrologistNephrologistPGDD,CARDIFF,UKPGDD,CARDIFF,UK

Contrast agentContrast agent

Types of contrast agentsTypes of contrast agents

Osmolality(mosm/kg)

High (>1400)

Low (600)

Low(600-1000)

Iso (290)

Ionicity Ionic Ionic Nonionic Nonionic

Dimer or Monomer

Monomer Dimer Monomer Dimer

Name Diatrizoate Ioxaglate Iohexol Iodixanol

The nephrotoxic effects of contrast The nephrotoxic effects of contrast agents are changed by agents are changed by 1-The osmolality 1-The osmolality 2- The volume 2- The volume 3- The types 3- The types 4-The route of administration of 4-The route of administration of contrast agents contrast agents

The nephrotoxic effect The nephrotoxic effect increase with :increase with :1- 1- The nonionic > the ionicThe nonionic > the ionic2- The high osm >Low osm > Iso-2- The high osm >Low osm > Iso-osmolalityosmolality3- The large volume ( >100 mL)3- The large volume ( >100 mL)4- The repeated dose (<72 hours ), 4- The repeated dose (<72 hours ), better two weeks between the better two weeks between the contrast exposure contrast exposure 5-The intra-arterial > intravenous 5-The intra-arterial > intravenous

PathophysiologyPathophysiology

Risk FactorsRisk Factors

To identify the high risk patients use the To identify the high risk patients use the risk score predictionrisk score prediction

Concomitant Concomitant medications medications

DiagnosisDiagnosis

Clinical diagnosisClinical diagnosis Contrast agents usually cause rise of creatinine within 24 to 48 hours after exposure to contrast

if >27 hours another causes is suspected

AKI due to CM is usually nonoliguric if oliguric another causes is suspected or patient has underlying renal insufficiency

The peak of elevation of serum creatinine usually 3 to 5 days after contrast and return to baseline within 7 to 10 days 1% of patients may need Renal Replacement Therapy , this patients will take long time for recovery

This patient mostly has another coexisting disease like diabetes and will presented with oliguria

Generally, the CIN is reversible If not reversible , means patient already has significant renal disease or another co excitant disease

Contrast agents may causes renal athroemboli ( livedo reticularis ) which cause renal injury with prolonged course Uremic symptoms and signs are very rare

Diagnostic testsDiagnostic testsUrine analysis :1-Fractional excretion of sodium is usually <1% (due to VC )This not diagnostic 2-In urine sediment , the granular casts are rare This test is not conclusive ,but essential to evaluate other causes

3-Contrast agents may causes elevate urine specific gravity

CBC Eosinophilia or low complement may suggest renal athroemboli

Renal imaging Not diagnose CIN only exclude other causes (ultrasound to role out obstruction )

Kidney biopsy not recommended except for further evaluation

PreventionPrevention

Volume ExpansionVolume ExpansionHydration is essential in preventing CIN by decrease renal vasoconstriction, improve medullary blood flow and decrease the serum creatinine •I.V hydration better than oral •Normal saline better than ½ normal saline1-IV hydration :1mL/kg/hr NS for 12 hrs before AND 12 hrs after contrast OR 3 ml/kg/hr NS for 1 - 3 hrs before, and for 6 hrs after contrast.(Should receive at least 300-500 mLs before the contrast)

2-Oral regimen (mostly used for outpatients): 300 - 500 mLs at the evening day before contrast and the morning of the contrast study (up to 2 hrs before), then at least extra 300 – 500 mLs for the next 24 hrs. (Isotonic fluid is better than other fluid )3-Rehydration using NaHCO3:•Isotonic NaHCO3 dose 3 mL/kg/hr for 1 hr before contrast and 1 mL/kg/hr for 6 hr post contrast administration•To prepare the isotonic NaHCO3 (150 meq in 850 mL D5W)Sodium bicarbonate has not any advantage over saline

4-N-acetylcysteine (NAC)•• It has antioxidant character•• Mostly used in conjugation with hydration•• Rare side effects • • Oral dose:600 – 1200mg capsules Oral dose:600 – 1200mg capsules PO twice /day for one day before PO twice /day for one day before contrast and one day after contrast contrast and one day after contrast • • IV dose: 600-1200 mg IV one dose IV dose: 600-1200 mg IV one dose over 15 minutes, then 600-1200 mg over 15 minutes, then 600-1200 mg PO every 12h for 4 doses after PO every 12h for 4 doses after contrast.contrast.

ThanksThanks

Dr M AbbassDr M Abbass