ACUTE RENAL FAILURE

1. ACUTE RENAL FAILURE JAKUB ZÁVADA KLINIKA NEFROLOGIE 1.LF UK

2. ACUTE RENAL FAILURE (ARF) • ARF IS A CLINICAL SYNDROME CHARACTERIZED BY A RAPID DECLINE IN GLOMERULAR FILTRATION RATE (OVER HOURS TO WEEKS) • ARF IS ACCOMPANIED BY • DISTRUBANCES OF • EXTRACELLULAR FLUID VOLUME • ELECTROLYTE HOMEOSTASIS • ACID-BASE BALANCE • ACCUMULATION OF NITROGENOUS WASTE PRODUCTS • ARF IS OFTEN REVERSIBLE • ARF INCREASES MORBIDITY AND MORTALITY

3. ACUTE RENAL FAILURE • PRERENAL – PHYSIOLOGICAL RESPONSE TO RENAL HYPOPERFUSION IN WHICH INTEGRITY OF RENAL PARENCHYMA IS PRESERVED • INTRINSIC RENAL – CAUSED BY DISEASES OF RENAL PARENCHYMA • POSTRENAL – ACUTE OBSTRUCTION OF URINARY TRACT

5. CAUSES OF PRERENAL ARF • INTRAVASCULAR VOLUME DEPLETION • HEMORRHAGE, GASTROINTESTINAL, RENAL, SKIN AND MUCOUS MEMBRANE, THIRD SPACE LOSSES • DECREASED CARDIAC OUTPUT • DISEASES OF MYOCARDIUM, PERICARDIUM, VALVES ETC. • SYSTEMIC VASODILATION • DRUGS, SEPSIS, LIVER FAILURE, ANAPHYLAXIS • IMPAIRED RENAL AUTOREGULATION • ACEI, ATRA, NSAID

6. CAUSES OF INTRINSIC RENAL ARF • SEVERE RENAL HYPOPERFUSION (+SIRS) • TOXINS • EXOGENOUS (RADIOCONTRAST, NEFROTOXIC ANTIBIOTICS, ANTICANCER AGENTS ) • ENDOGENOUS (RHABDOMYOLYSIS, HEMOLYSIS, TUMORLYSIS, HYPERCALCEMIA, LIGHT Ig CHAINS) • DISEASES OF LARGE RENAL VESSELS: • ATHEROEMBOLISM, THROMBOSIS OF RENAL ARTERY AND VEIN • DISEASES OF SMALL VESSELS AND GLOMERULI • GLOMERULONEPHRITIS AND VASCULITIS, TTP-HUS, MALIGNANT HYPERTENSION • ACUTE DISEASES OF THE TUBULOINTERSTITIUM • ALLERGIC INTERSTICIAL NEPHRITIS, ACUTE BILATERAL PYELONEPHRITIS

7. CAUSES OF POSTRENAL ARF • BILATERAL OBSTRUCTION OF URETHERS • OBSTRUCTION OF BLADDER NECK • DISEASES OF PROSTATE GLAND • OBSTRUCTION OF URETHRA

9. DIFFERENTIAL DIAGNOSIS OF ARF • IS THE RENAL FAILURE ACUTE, ACUTE ON CHRONIC OR CHRONIC? • IS THERE RENAL TRACT OBSTRUCTION? • IS THERE EVIDENCE OF TRUE HYPOVOLEMIA OR REDUCED EFFECTIVE ARTERIAL BLOOD VOLUME? • HAS THERE BEEN A MAJOR VASCULAR OCCLUSION? • IS THERE EVIDENCE OF PARENCHYMAL RENAL DISEASE OTHER THAN ATN?

10. DIFFERENTIAL DIAGNOSIS OF ARF IS THE RENAL FAILURE ACUTE, ACUTE ON CHRONIC OR CHRONIC? • ARF: • RECENT INCREASE OF BUN AND SERUM CREATININ • CLINICAL AND HISTORY DATA CONSISTENT WITH ARF • CRF: • PREVIOUSLY RECORDED ALTERED RENAL PARAMETRES • HISTORY CONSISTENT WITH POSSIBLE CHRONIC KIDNEY DISEASE (DM, HT, AMYLOIDOSIS, NSAID) • SEVERE ANEMIA, HYPERPHOSPHATEMIA, HYPOCALCEMIA • ULTRASONOGRAPHY: SMALL, SHRUNKEN OR POLYCYSTIC KIDNEYS

11. DIFFERENTIAL DIAGNOSIS OF ARF IS THERE URINARY TRACT OBSTRUCTION? • CLINICAL POINTS: • SUPRAPUBIC PAIN, PALPABLE BLADDER DISTENTION • HISTORY OF PROSTATIC DISEASE (NOCTURIA, FREQUENY, HESITANCY) • COLICKY PAIN WITH IRADIATION TO THE GROIN • HISTORY OF MALIGNANCY IN PELVIS • HISTORY OF NEUROGENIC BLADDER • IMAGING • ULTRASOUND,CT, MRI, IVU

12. DIFFERENTIAL DIAGNOSIS OF ARF IS THERE EVIDENCE OF TRUE HYPOVOLEMIA OR REDUCED EFFECTIVE ARTERIAL BLOOD VOLUME? • HISTORY • BLEEDING, LOSS OF SOLUTES, LOW FLUID INTAKE • HEART OR LIVER FAILURE • NSAID, ACEI, ATRA • SIGNS • ORTOSTATIC HYPOTENSION, TACHYCARDIA, DRY MUCOUS MEMBRANES, LOW JUGULAR VENOUS PRESSURE, OLIGURIA, SEPSIS/SIRS • LABORATORY AND URINARY FINDINGS • HEMOCONCENTRATION, UREA/KREATININ, SPEC. GRAVITY OF URINE,  U-Na • INVASIVE MONITORING • CENTRAL VENOUS PRESSURE, SWAN-GANZ CATHETR

13. DIFFERENTIAL DIAGNOSIS OF ARF HAS THERE BEEN A MAJOR VASCULAR OCCLUSION? • ATHEROEMBOLISM • RECENT INSTRUMENTATION IN AORTA, AGE OVER 50, SEVERE ATHEROSCLEROSIS, WARFARIN • PURPURA, LIVEDO RETIKULARIS • EOSINOPHILIA, HYPOCOMPLEMENTEMIA • RENAL BIOPSY • TROMBOSIS OF RENAL ARTERY • HISTORY OF ATRIAL FIBRILLATION, RECENT MI • NAUSEA, ABDOMINAL PAIN, FLANK PAIN • ANGIOGRAPHY, AG-CT, MRI • TROMBOSIS OF RENAL VEIN • NEPHROTIC SYNDROME, PULMONARY EMBOLISM • AG, AG-CT, MRI, DOPPLER US

14. DIFFERENTIAL DIAGNOSIS OF ARF IS THERE EVIDENCE OF PARENCHYMAL RENAL DISEASE OTHER THAN ATN? • HISTORY AND PHYSICAL EXAM • ARTHRALGIAS • SKIN CHANGES • PULMONARY AND ETN DISORDER • MALIGNANT HYPERTENSION • URINANALYSIS • ACTIVE URINE SEDIMENT (PRU>1g/d, ERY-U) • LAB • SIGNS OF MICROANGIOPATIC HEMOLYSIS • IMUNOLOGY (ANCA, ANA, C3, C4, ANTI-GBM, APLA) • RENAL BIOPSY

15. ACUTE TUBULAR NECROSIS (ATN) • ETIOLOGY • ISCHEMIA • TOXINS • SIRS/SEPSIS • PATOPHYSIOLOGY • VACUOLATION, LOSS OF BRUSH BORDER, APOPTOSIS/NECROSIS OF TUBULÁR CELLS • INTRARENAL VASOCONSTRICTION, IMPAIRED RENAL AUTOREGULATION • INTRATUBULAR OBSTRUCTION • INFILTRATION BY NEUTROPHILS AND MACROPHAGES • PROGNOSIS • UNCOMPLICATED ATN REVERSES IN 2-3 WEEKS • CORTICAL NECROSIS IS IRREVERSIBLE

18. ACUTE TUBULAR NECROSIS (ATN) DIFF.DG. OF PRERENAL AZOTEMIA AND ATN: • PRERENAL AZOTEMIA: • ADEQUATE KIDNEY RESPONSE TO VOLUME DEPLETION: • ↑ URINE OSMOLALITY (U-OSM>500 mOsm/kg) • ↑ SPECIFIC GRAVITY (>1,018) • LOW URINARY SODIUM (U-Na<10 mmol/l, FeNa <1%) • RAPID RESTORATION AFTER VOLUMEXPANSION • ATN: • DISTURBED CONCENTRATING AND VOLUMEREGULATORY KIDNEY FUNCTION: • ↓ URINE OSMOLALITY (U-OSM<250 mOsm/kg) • ↓ SPECIFIC GRAVITY (< 1,012) • HIGH URINARY SODIUM (U-Na > 20 mmol/l, FeNa > 2%)

19. NEFROTOXIC AGENTS • HEME PIGMENTS • MYOGLOBIN – RHABDOMYOLYSIS • MUSCLE TRAUMA, ETHANOL, SEIZURES, LIMB ISCHEMIA, STATINS, FIBRÁTES • ↑ CK, MYOGLOBIN IN PLASMA • HEMOGLOBIN – HEMOLYSIS • INKOMPATIBILE TRANSFUSION, AIHA, SNAKE VENOM, MALÁRIA, G6PDH DEFICIENCY, PNH • RADIOCONTRAST • NEPHROTOXIC DRUGS • NSAID, ACEI, ATRA • AMINOGLYKOSIDS, AMFOTERICIN B, PENTAMIDIN, ACYCLOVIR • CYCLOSPORINE, TAKROLIMUS • CISPLATINE, IFOSFAMIDE • ETHYLENGLYKOL, HEAVY METALS, HERBAL REMEDIES

21. ACUTE RENAL FAILURE –COMPLICATIONS • HYPERVOLEMIA • HYPERKALEMIA • METABOLIC ACIDOSIS • UREMIA • HYPERURICEMIA • HYPOCALCEMIA, HYPERPHOSFATEMIA • RECOVERY PHASE OF ARF • POLYURUIA • HYPERNATREMIA, HYPOKALEMIA, HYPOMAGNESEMIA, HYPOPHOSFATEMIA

22. ACUTE RENAL FAILURE–MANAGEMENT • PRERENAL ARF → RESTORATION OF RENAL PERFUSION • REPLACEMENT OF FLUID LOSSES (CRYSTALOIDS, COLLOIDS) • MANAGEMENT OF CIRCULATORY FAILURE (INVASIVE HEMODYNAMIC MONITORING, TREATMENT OF HEART FAILURE, IONOTROPES, VASOACTIVE DRUGS) • POSTRENAL ARF → RELIEVE OBSTRUCTION • MULTIDISCIPLINARY APPROACH (RADIOLOGIST, UROLOGIST, NEPROLOGIST) • URINARY BLADDER CATHETER • NEPHROSTOMY

23. ACUTE RENAL FAILURE–MANAGEMENT INTRARENAL ARF • PREVENTION • OPTIMAL HYDRATION OF PATIENTS AT RISK • MONITORING OF LEVELS OF AMINOGLYCOSIDES AND CYKLOSPORINE • N-ACETYLCYSTEINE? • CAVE ACEI, NSAID, DIURETICS • SUPPORTIVE TREATMENT • ADRESSING COMPLICATIONS (ACIDOSIS, ELECTROLYTE ABNORMALITIES, HYPERVOLEMIA) • DIALYSIS (OR HEMOFILTRATION) • TREATMENT OF SPECIFIC CAUSES OF ARF • TTP-HUS, RPGN, ATIN

26. ACUTE RENAL FAILURE –INDICATIONS OF DIALYSIS • UREMIA • HYPERKALEMIA • HYPERVOLEMIA • SEVERE ACIDOSIS