NURS 7425 ADVANCED
PATHOPHYSIOLOGY LATEST
UPDATED STUDY GUIDE FOR
MODULE 2 AUGUSTA UNIVERSITY
, RENAL SYSTEM
Functions Of Renal System
- Ureters, Bladder, Urethra
- Storage and transport of urine
- Micturition reflex begins when the bladder has ~ 200 mL of urine
Major Kidney Functions
- Endocrine Functions
- Synthesizes renin to control volume / pressure
- Synthesizes erythropoietin
- Synthesizes precursor to vitamin D (calcitriol)
Kidney Malfunction?
- Waste accumulation
- Fluid balance
- Electrolyte balance (Na / K / Phos / Mg / Ca)
- Acid base disorders
- Hypertension
- Anemia
- Vitamin D synthesis
The Nephron
- Filtration occurs at the glomerulus.
- Reabsorption occurs all through the kidneys, but mainly at the proximal tubules.
- Secretion occurs at the distal tubules and collecting duct.
Glomerular Function
- Main Function: high filtration pressure into Bowman’s Capsule
- GFR = 125 mL/min
Tubular Function
- Most reabsorption occurs in proximal tubule
- Loop of Henle determines concentration
- Secretion and fine tuning occurs at the distal tubule and collecting ducts
Nephrons Must Be Perfused
- Must have adequate perfusion to have good kidney function
GFR Measurement
- Cannot be directly measured
- Formula used to determine “estimated” amount of blood passing through the kidneys each minute
- The eGFR is inversely related to serum creatinine
- Normal is 120 - 130 mL/min/1.73m2
- eGFR < 60 which means only half (if not less) of nephrons are working
Tests of Kidney Function
- Urinalysis
- Basic metabolic panel
- Na, K, CO2, Cl, BUN, creatine, glucose, eGFR
- Renal panel
- Includes BMP, phosphorus and albumin (urinary protein loss due to filtration)
, - Complete Blood Count
Oliguria is when the body produces less than 400 mL/day of urine.
The Urias
- Polyuria: increased volume of urine voided
- Oliguria: urine output is less than 400 mL/day
- Anuria: urine output is less than 50 mL/day
- Nocturia: excessive urination at night
- Hematuria: blood cells in the urine
- Proteinuria: abnormal amounts of protein in the urine
- Dysuria: painful or difficult voiding
Indicators of renal Function
- BUN (blood urea nitrogen)
- Urea – byproduct of protein metabolism
- Creatinine
- End product of skeletal muscle metabolism
Acute Kidney Injury
- Incidence increases with age (7% of all hospitalized patients – 66% ICU)
Prerenal
- Hypovolemia = most common cause
Intrarenal
- Due to prolonged ischemia or nephrotoxins
- Ischemia: prolonged hypertension
- Nephrotoxins: drugs (antibiotics, NSAIDS), contrast media, heavy metals, myoglobin
Application Question
- So if your patient has had a hypotensive episode and has a urine output less than 30 mL/hr,
which action is most appropriate in the prevention of acute renal failure? Administer IV fluids to
increase urinary output
Chronic Kidney Disease
- Most Common Causes
- Diabetes (#1)
- Hypertension (#2)
- Irreversible, may be asymptomatic for years
- Goal is to prevent or delay onset
- Control blood sugar and blood pressure
Causes of CKD
- Diabetic Neuropathy
- Hypertension
Chronic Kidney Disease Labs
- Increased BUN, creatinine
PATHOPHYSIOLOGY LATEST
UPDATED STUDY GUIDE FOR
MODULE 2 AUGUSTA UNIVERSITY
, RENAL SYSTEM
Functions Of Renal System
- Ureters, Bladder, Urethra
- Storage and transport of urine
- Micturition reflex begins when the bladder has ~ 200 mL of urine
Major Kidney Functions
- Endocrine Functions
- Synthesizes renin to control volume / pressure
- Synthesizes erythropoietin
- Synthesizes precursor to vitamin D (calcitriol)
Kidney Malfunction?
- Waste accumulation
- Fluid balance
- Electrolyte balance (Na / K / Phos / Mg / Ca)
- Acid base disorders
- Hypertension
- Anemia
- Vitamin D synthesis
The Nephron
- Filtration occurs at the glomerulus.
- Reabsorption occurs all through the kidneys, but mainly at the proximal tubules.
- Secretion occurs at the distal tubules and collecting duct.
Glomerular Function
- Main Function: high filtration pressure into Bowman’s Capsule
- GFR = 125 mL/min
Tubular Function
- Most reabsorption occurs in proximal tubule
- Loop of Henle determines concentration
- Secretion and fine tuning occurs at the distal tubule and collecting ducts
Nephrons Must Be Perfused
- Must have adequate perfusion to have good kidney function
GFR Measurement
- Cannot be directly measured
- Formula used to determine “estimated” amount of blood passing through the kidneys each minute
- The eGFR is inversely related to serum creatinine
- Normal is 120 - 130 mL/min/1.73m2
- eGFR < 60 which means only half (if not less) of nephrons are working
Tests of Kidney Function
- Urinalysis
- Basic metabolic panel
- Na, K, CO2, Cl, BUN, creatine, glucose, eGFR
- Renal panel
- Includes BMP, phosphorus and albumin (urinary protein loss due to filtration)
, - Complete Blood Count
Oliguria is when the body produces less than 400 mL/day of urine.
The Urias
- Polyuria: increased volume of urine voided
- Oliguria: urine output is less than 400 mL/day
- Anuria: urine output is less than 50 mL/day
- Nocturia: excessive urination at night
- Hematuria: blood cells in the urine
- Proteinuria: abnormal amounts of protein in the urine
- Dysuria: painful or difficult voiding
Indicators of renal Function
- BUN (blood urea nitrogen)
- Urea – byproduct of protein metabolism
- Creatinine
- End product of skeletal muscle metabolism
Acute Kidney Injury
- Incidence increases with age (7% of all hospitalized patients – 66% ICU)
Prerenal
- Hypovolemia = most common cause
Intrarenal
- Due to prolonged ischemia or nephrotoxins
- Ischemia: prolonged hypertension
- Nephrotoxins: drugs (antibiotics, NSAIDS), contrast media, heavy metals, myoglobin
Application Question
- So if your patient has had a hypotensive episode and has a urine output less than 30 mL/hr,
which action is most appropriate in the prevention of acute renal failure? Administer IV fluids to
increase urinary output
Chronic Kidney Disease
- Most Common Causes
- Diabetes (#1)
- Hypertension (#2)
- Irreversible, may be asymptomatic for years
- Goal is to prevent or delay onset
- Control blood sugar and blood pressure
Causes of CKD
- Diabetic Neuropathy
- Hypertension
Chronic Kidney Disease Labs
- Increased BUN, creatinine
