Renal 1 Paulson Flashcards
This disease is categorized by a rapid worsening of renal function and a quickly rising BUN/Cr. Happens because all the stuff the kidney is supposed to be filtering concentrates in the blood
Acute Renal Failure (ARF) AKA Acute Kidney Injury (AKI)
Basically kidney failure
What is the AKI Criteria? (3)
- *Only need to meet one criteria
1. Abrupt (within 48 hours) absolute increase in the serum creatinine of ≥0.3 mg/dl above baseline –or-
2. Serum creatinine increases ≥50% (known or presumed to have occurred in the past 7 days) -or-
3. Oliguria of <0.5 ml/kg/hour for >6 hours
**need to know patient’s baseline Cr
What are some sxs of AKI?
- Weakness, lethargy
- Anorexia
- N/V
- Persistent hiccups
- General malaise
What are some signs of AKI?
-usually point towards underlying cause
• Ie: Prerenal, could be tachycardic and hypotensive
• Postrenal: distended bladder, CVA tenderness, enlarged prostate
-anuria/oliguria (pee a lot or little)
-AMS, weight change
What is the #1 test to dx AKI?
- BMP
- Also urinalysis & urine microscopy
When should you dialyze a patient?
- Serum creatinine >5-10 mg/dl
- Unresponsive acidosis
- Severe electrolyte disorders
- Fluid overload
- Uremic complications
What is the most common cause of AKI?
Prerenal failure
**Caused by reduced effecitve blood circulating to the kidney
What are some examples of true intravascular volume depletion?
- Traume
- Hemorrhage
- Burns
- Diuretics
What are some examples of decreased effective circulating volume? (basically same amt of fluid but in the wrong places)
- CHF
- Cardiac tamponade
- Aortic stenosis
What are some examples of impaired renal blood flow?
- ACEI
- NSAIDs
- Renal artery stenosis
- Renal vein thrombosis
What are the labs that distinguish prerenal failure?
- BUN:Cr
- Urine Sodium
- FENa
- Urine specific gravity
• Serum BUN:Cr ratio: ≥20:1
• Urine sodium: <20 meq/L
• Fractional Excretion of Sodium (FENa): <1%
—Measures the percent of sodium fitered by the kidney that is excreted into urine
• Urine specific gravity: >1.020
• Occur because the kidney is responding to prerenal failure by increasing reabsorption
What is the treatment for pre-renal failure?
-Correct the underlying cause:
• CHF: Diurese the patient
• Dehydration: IVF
• Hemorrhage: Blood+fluids
What are the two mc causes of postrenal failure?
Nephrolithiasis & BPH
**something blocking ureters or bladder and this is backing up into the kidneys
Symptoms of postrenal failure?
- Abd or groin pain, bladder discomfort
- mass at flank, suprapubic area or abdomen
What diagnostic testing should we order for postrenal failure?
- Post void residual >100 = bladder obstruction
- U/S or IVP (intravenous pyelogram) to use contrast and visualize
Treatment for postrenal failure?
Relieve the obstruction
This is when one or both kidneys have been damaged and don’t work properly
Intrinsic renal failure
Two main causes of intrinsic renal failure?
- ATN (acute tubular necrosis) **MC
- Nephrotoxins (NSAIDs, contrast agents, AGs)
Labs that define intrinsic renal failure?
- BUN:Cr
- Urine Sodium
- FENa
- Urine specific gravity
**the kidney itself is the problem so it lets all of the sodium flow out into the urine
- Serum BUN:Cr ratio: 10-15:1
- Urine Sodium: ≥40 meq/l
- FENa: >2%
- Urine specific gravity: 1.010-1.020
This is the mc cause of AKI and is where there is death of the tubular epithelial cells (renal tubules)
Acute Tubular Necrosis (ATN)
What are the three major causes of ATN?
- Renal ischemia
- Nephrotoxins (AGs, contrast)
- Sepsis
On UA, you will see “Muddy brown granular epithelial cell casts and free renal tubular epithelial cells” in this diagnosis?
Acute tubular necrosis
What labs dx ATN?
• FENa, BUN:Cr ratio, urine specific gravity, urine osmolality consistent with
intrinsic AKI
• May also have hyperkalemia and have metabolic acidosis
What is the tx/prognosis for ATN?
Hold nephrotoxins (NSAIDs, metformin, AGs, etc)
- Treat underlying cause
- better prognosis if they are nonoliguric
