Acute Kidney Injury Flashcards
What is acute Kidney Injury ?
Rapid deterioration of kidney function defined as
- A rise in serum creatine over 0.3 in 48 hours.
- A rise in serum creatine of >1.5 times the baseline value eithin the previous 7 days
- A urine volume less than < 0.5 mL / kg per hour for 6 hours.
What is oliguria ?
< 400 ml urine output in 24 hours
What is Anuria ?
< 100 ml urine output in 24 hours
What are the classical AKI symptoms ?
Usually none it is discovered on labs
What are the three categories of AKI ?
- Prerenal ARF 55%
- Intrinsic Renal ARF 40%
- Postrenal ARF 5%
In a physical exam of someone who you suspect has ARF what should you look for ?
Always check volume status and perform a urine examination that can lead to the cause of the renal failure
What is the cause of pre-renal failure ?
5 causes were mentioned in lecture
- Intravascular Volume Depletion- Hemorrhage, renal artery stenosis ect.
- Decreased Cardiac Output-
- Systemic Vasodilation- Shock
- Renal Vasodilation- Hepatorenal syndrome
- Pharmacologic Agents
What are the neurohormonal responses to pre-renal ARF ?
Increaased RAAS, Vasopressin, and systemic nervous system activation
What will you see in the urine of a patient with Pre-renal failure ?
Hylane Casts
What are the diagnostic clues of pre-renal failure ?
Renal Na is abnormally low. Urin osmolality is very high
What is hepatorenal syndrome ?
It si common in patients with cirrhosis. They show decreased blood pressure in the face of increased ECFV. The kidney is structurally intact and urinalysis is usually normal. They will show worsening azotemia and progressive oliguria
What is the basic pathophysiology of HRS ?
Begins with portal hypertension –> splanchnic vasodilation –> Decreased Effective circulating volume –> RAAS –> Renal Na Avidity and Renal Vasoconstriction –> Ascites and Hepatorenal syndrome
You have a decreased effective arterial blood volume and increased activation of RAAS
