Exam #1 Review
* Renin-angiotensin aldosterone system (RAAS) regulates renal blood flow.
* ACUTE RENAL FAILURE -rapid decline in renal function with progressive azotemia.
* AZOTEMIA An excess of metabolic waste products in the blood Urea Nitrogen and Creatinine
* OLIGURIA Urine Volume less than 400CC/24 hours for a non-trauma, non-surgical adult.
* ACUTE TUBULAR NECROSIS (ATN) Clinical syndrome of ARF secondary to ischemia or toxic injury to the renal tubules
* BUN and Creatinine DO NOT START TO RISE until GREATER than 60 % loss of renal function= Failure.
* BUN and Creatinine DO NOT GET HIGH until 90% loss of renal function = Failure.
* 24 Hour Creatinine clearance = good early indicator of renal Function (GFR).
* Elevated levels BUN/Creatinine are considered to be the “hallmarks” of acute renal failure.
* Creatinine Normal value 0.5 - 1.0 mg/dl
* In general – Creatinine is 1/10 of BUN
Acute Renal Failure * Description: Sudden, reversible cessation of renal function associated with an identifiable toxic or ischemic trauma or obstruction - onset - hours to days.
* Risk Factors: * Advanced Age: GFR decline by 1ml/min/year after age 40 * Renal Blood Flow 10% per decade * Decreased muscle mass – decreased production Cr; Vit D * Diabetes Type I or II * Severe HTN or peripheral vascular disease * Preexisting CKD or proteinuria * CHF * Cirrhosis * NSAIDS, ACEi, vasodilators * Sepsis
* Depressed RBF kidneys vulnerable to further insults - iatrogenic renal injury most common
* Common iatrogenic combinations: * Preexisting renal disease, radio contrast agents, aminoglycosides, atheroembolism, or cardiovascular surgery * ACE inhibitors with diuretics * NSAIDs * Hypovolemia
* Recovery dependent upon restoration of RBF
Once RBF restored - remaining functional nephrons