Flashcards in 11.2: Clinical I Deck (40):
Definition of AKI?
Any of the following renal changes within 48 hours:
1. Serum Cr. increase > .3 mg/dl
2. % increase serum Cr. > 50%
3. Oliguria 6 hours
What is RRT?
- Renal replacement therapy: Dialysis
What is AKI often associated with?
1. Critically ill patients
2. Septic patients: 50% with bacteremic septic shock
3. MSOD: mult. syst. organ dysfunction
3 categories of AKI?
2. Intrinsic renal
Types of prerenal failure / azotemia?
1. Absolute decrease in BV: hemorrhage / depletion
2. Low ECV: relative decrease in BV: CHF / cirrhosis
3. Renal stenosis / occlusion
4. Impaired autoregulation: NSAID/ACEI/ARB
Types of intrinsic renal failure?
2. Acute glomerular disease
3. AIN: acute interstitial nephritis
4. ATN: acute tubular necrosis
Types of postrenal failure
1. Bladder outlet obstruction
2. Bilateral ureteral obstruction
3. Unilateral ureteral obstruction
Most common causes of AKI?
1. Prerenal azotemia
2. Ischemic ATN
***75% of all cases
- Thought that prerenal azotemia becomes ischemic ATN
What is prerenal azotemia?
- Appropriate physiologic response to renal hyperperfusion: success not failure
What does prerenal azotemia progress to?
What is normal renal autoregulation in response to drop in BP? What mediates this?
1. Dilation of afferents: NO and prostaglandins
2. Constriction of efferents
What antagonizes auto dilation of renal afferents? efferents
Affernets: COX I/II inhibitors: NSAIDS
Efferents: ACEI / ARBs
What is the NSAID effect?
- NSAIDs cause tonic constriction of renal afferent
- If volume / ECV drops, kidney is compromised as cannot respond
- Drop in GFR
Who is at greatest risk for postrenal failure?
1. Older men with prostate disease
2. Solitary kidney
3. Intra abdominal pelvic cancer
What is post renal intervention sequelae?
1. Post obstructive diuresis > 4L / day
- Lose ability to concentrate urine
2. Hyper K / Cl RTA that can become chronic
How do diagnose postrenal failure?
1. Physical exam: dullness to percusion in superpubic area, fullness / discomfort here
- Easier in skinny ptn.
- Urge to urinate when push in area
2. Increased post void residual volume: ultrasound
- Hard to tell with ascites
Two types of ATN?
**Sepsis surgery and toxic exposures can cause
Two types of AIN?
1. Drug associated
2. Non drug associated
Vascular causes of intrinsic renal failure?
1. Malignant Htn.
2. HUS / TTP
Definition of malignant HTN?
- BP > 180 / 120
- Evidence of end organ damage must be occurring
What is hypertensive urgency?
High BP but not yet any sign of end organ injury
Two general types of glomerular diseases?
1. Nephritic: Inflammatory, sedimentation, blood, casts
2. Nephrotic: Proteinuria
Main causes of drug related acute interstitial nephritis?
Classic triad of Acute interstitial nephritis?
3. Peripheral eosinophilia: urine too
What is urine eosinophils indicative of?
Acute interstitial nephritis
What is abdominal jugular reflex?
- Ptn at 30 degrees
- Push on abdomen sustained, if it goes up by 4cm means they are over loaded on fluids
What are S3 gallop and abdominal jugular reflux highly predictive of?
What are two highly predictive exam findings for CHF?`
2. Abdominal jugular reflux
Urinalysis in PRA vs. ATN?
ATN: abnormal, tubular epithelial casts
PRA: usually normal, maybe non specific hyaline casts
Urine osmolality in PRA vs. ATN?
PRA: Very high
ATN: middle of road
Urine Na and FENa and FE urea in PRA and ATN?
Should Cr. be measured in AKI?
- No, is only reliable in steady states
- AKI is not a steady state
What does BUN ration > 10:1 indicate?
What BUN:Cr. ration means prerenal azotemia?
What does BUN ration 10:1 indicate?
- Also can be normal or chronic kidney disease
What BUN:Cr. ration means ATN?
What nutritional support is given in AKI?
1. Ensure carb intake to prevent protein breakdown
General indications for hemodialysis?
2. Electrolyte imbalance: usually HYPER K
3. Intoxication syndrome
4. Overload: pulmonary edema
1. Most recover
2. 10% Irreversible