1 / 22

Acute Tubular Necrosis

Acute Tubular Necrosis. Douglas Stahura D.O. Grandview Hospital 7/24/2002. Causes of Acute Renal Failure. Pre-renal Renal parenchymal (intrinsic) Post-renal. Acute Tubular Necrosis (ATN). Pre-renal azotemia and ATN are a spectrum of manifestation of renal hypoperfusion

trilby
Download Presentation

Acute Tubular Necrosis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Acute Tubular Necrosis Douglas Stahura D.O. Grandview Hospital 7/24/2002

  2. Causes of Acute Renal Failure • Pre-renal • Renal parenchymal (intrinsic) • Post-renal

  3. Acute Tubular Necrosis (ATN) • Pre-renal azotemia and ATN are a spectrum of manifestation of renal hypoperfusion • Pre-renal – mild to moderate ischemia • ATN – severe/prolonged ischemia with injury to parenchyma which does not resolve immediately with restoration of renal perfusion • Describes the renal parenchymal injury following renal ischemia OR exposure to nephrotoxins, which particularly injure the tubular epithelium

  4. Acute Tubular Necrosis (ATN) • What segments of the nephron? Why? • How to recognize – clinical/histological • Pathophysiology • Ischemia/toxins • Clinical course

  5. Acute Tubular Necrosis (ATN) • Site of tubular injury • Proximal tubule (S3, pars recta) • Medullary thick ascending limb • Medulla receives 20% of total renal blood flow • Intense metabolic activity • O2 supply/demand balance is delicate • Multiple causes of cell injury

  6. Acute Tubular Necrosis (ATN) • Causes of cell injury • Endothelin/Nitric Oxide balance • Endothelin(ET-1 isoform) potent vasoconstrictor produced in renal endothelium, epithelium, mesangium • Nitric Oxide potent vasodilator produced in endothelium • ATP Depletion • Cell Swelling

  7. Acute Tubular Necrosis (ATN) • Causes of cell injury • Intracellular Calcium increases • Intracellular acidosis • Oxidant injury • Inflammatory response from ischemia/reperfusion

  8. Acute Tubular Necrosis (ATN) • Tubular Injury • Cell swelling, vacuolation, apical blebbing, loss of brush border, loss of cell polarity, necrosis, sloughing

  9. Acute Tubular Necrosis (ATN)Histopathology

  10. Acute Tubular Necrosis (ATN) • Nephrotoxins • Endogenous – myoglobin, hemoglobin, light chains, Crystals, Hypercalcemia • Exogenous – ethylene glycol, IV contrast, Medications: Aminoglycosides, Acyclovir, Methotrexate, Amphotericin B, Cisplatin, Ifosfamide, Foscarnet

  11. Acute Tubular Necrosis (ATN) • Clinical Course • Initiation phase • Maintenance phase • GFR = 5-10 ml/min • Lasts weeks to months • Recovery phase • Heralded by increase of urine output

  12. Acute Tubular Necrosis (ATN) • Diagnostics • FENA >1% • Una > 40 Meq/dL • Uosm < 350 mosm/dL • Renal Ultrasound – normal size • Urine microscopic – “muddy brown cast”

  13. Acute Tubular Necrosis (ATN) • Outcomes • Mortality about 50%

  14. Acute Tubular Necrosis (ATN) • Treatment • Supportive – maintain pt non-oliguric for ease in fluid balance/management • Maintain perfusion of kidneys MAP=65 • Treat underlying illness/interrupt insult

  15. Acute Tubular Necrosis (ATN) • Review • Caused by severe hypoperfusion/toxin • Parenchymal injury that is not immediately reversible • Effects the proximal and mTAL epithilium • Hallmark “muddy brown casts” • No specific treatment/remedy • Mortality 50%

  16. References • The Kidney 6th Edition, Brenner and Rector • Comprehensive Clinical Nephrology, Johnson • Clinical Physiology of Acid-Base and Electrolyte Disorders, Rose

More Related