Flashcards in Introduction to Renal Disease Deck (24)
What is the equation for GFR?
GFR = (UCr x UVol)/PCr
What are the problems with the GFR equation?
- Can only be used reliably in patients with stable renal function
- May be less accurate in certain populations
• High/normal/near normal renal function
• Certain ethnic groups
• Pregnant women
• Unusual muscle mass, body habitus, or weight
What is the use of fractional Na excretion in the assessment of renal disease?
It is measured in terms of plasma and urine sodium, rather than by the interpretation of urinary sodium concentration alone, as urinary sodium concentrations can vary with water reabsorption. Therefore the urinary and plasma concentrations of sodium must be compared to get an accurate picture of renal clearance.
Why is fractional urea excretion better to use than fractional Na excretion?
FE of urea is useful no matter what the range of values is while FE of Na is not helpful between 1-2%
What is normal urine output?
1500 mL/24 hours
Elevation in nitrogen containing compounds in the plasma and usually indicates renal problems
Clinical syndrome that can accompany kidney failure, usually when advanced and/or severe due to an elevated level of urea.
Little urine output 500mL/day
High urine output 3000mL/day
No urine output
Acute Kidney Injury
Chronic Kidney Disease
End Stage Renal Disease
How is AKI defined?
An abrupt (within 48 hours) reduction in kidney function, defined as:
• ↑ in serum creatinine of > 0.3mg/dL OR
• Percentage ↑ in serum creatinine of 50% OR
• Oliguria of 6 hours
How is CKD defined?
• Progressive decline in GFR over time
• Duration at least three months
• With or without albuminuria
Protein in urine
• “Nephrosis”: > 3 – 3.5gm/24 hours
Blood in the urine
Can be gross or microscopic (≥ 2 RBC/hpf)
Kidney stones - most common are Ca2+ stones
What are the characteristics of nephrotic syndrome?
• > 3 – 3.5gm protein/24 hours
• Peripheral edema
• Bland urinary sediment
• Noninflammatory renal biopsy
What are the characteristics of nephritic syndrome?
• Inflammatory renal biopsy
• Active urinary sediment
• Dysmorphic RBC’s
• RBC casts
• Variable proteinuria
• Azotemia, oliguria
• Mild/moderate HTN
• Other systemic features
What is the ratio of ICW to ECW of the body fluid?
ICW is 2/3
ECW is 1/3
What are crystalloid solutions?
They disperse across the ECW - examples are saline and lactated Ringer's solution
What are colloid solutions?
They remain within the plasma volume - examples are packed RBCs and albumin