Podcast
Questions and Answers
What is the function of the nephron in the kidneys?
What is the function of the nephron in the kidneys?
What percentage of filtered sodium and water is reabsorbed in the proximal tubule?
What percentage of filtered sodium and water is reabsorbed in the proximal tubule?
65%
Glomerular filtration rate (GFR) is the rate at which substances are cleared from ______.
Glomerular filtration rate (GFR) is the rate at which substances are cleared from ______.
plasma
Nephrotic syndrome is more prevalent in adults than in children.
Nephrotic syndrome is more prevalent in adults than in children.
Signup and view all the answers
What is recommended for both HD and PD patients in terms of fat intake due to the increased risk for CAD and stroke?
What is recommended for both HD and PD patients in terms of fat intake due to the increased risk for CAD and stroke?
Signup and view all the answers
What are the typical lipid profiles for HD and PD patients?
What are the typical lipid profiles for HD and PD patients?
Signup and view all the answers
Interdialytic weight gain for HD patients should not exceed __% of body weight.
Interdialytic weight gain for HD patients should not exceed __% of body weight.
Signup and view all the answers
PD patients' sodium and fluid intake are based on ultrafiltration.
PD patients' sodium and fluid intake are based on ultrafiltration.
Signup and view all the answers
Match the following mineral requirements with their importance in CKD nutrition intervention:
Match the following mineral requirements with their importance in CKD nutrition intervention:
Signup and view all the answers
What is the recommended daily sodium intake for HD patients?
What is the recommended daily sodium intake for HD patients?
Signup and view all the answers
What is the recommended daily fluid intake for PD patients?
What is the recommended daily fluid intake for PD patients?
Signup and view all the answers
What is the recommended daily phosphorus intake for CKD patients?
What is the recommended daily phosphorus intake for CKD patients?
Signup and view all the answers
Why is calcium intake restricted in CKD patients?
Why is calcium intake restricted in CKD patients?
Signup and view all the answers
What is the recommended daily vitamin intake for CKD patients?
What is the recommended daily vitamin intake for CKD patients?
Signup and view all the answers
Why is magnesium intake restricted in CKD patients?
Why is magnesium intake restricted in CKD patients?
Signup and view all the answers
What is the recommended protein intake for post-transplant patients?
What is the recommended protein intake for post-transplant patients?
Signup and view all the answers
Why is potassium intake restricted in post-transplant patients?
Why is potassium intake restricted in post-transplant patients?
Signup and view all the answers
What is the recommended treatment for osteoporosis in post-transplant patients?
What is the recommended treatment for osteoporosis in post-transplant patients?
Signup and view all the answers
What is the recommended dietary fiber intake for post-transplant patients?
What is the recommended dietary fiber intake for post-transplant patients?
Signup and view all the answers
What is the recommended daily protein intake for patients with Nephrotic Syndrome?
What is the recommended daily protein intake for patients with Nephrotic Syndrome?
Signup and view all the answers
What is the final stage of Chronic Kidney Disease (CKD)?
What is the final stage of Chronic Kidney Disease (CKD)?
Signup and view all the answers
Which of the following is a risk factor for Chronic Kidney Disease (CKD)?
Which of the following is a risk factor for Chronic Kidney Disease (CKD)?
Signup and view all the answers
What is a common complication of Nephrotic Syndrome?
What is a common complication of Nephrotic Syndrome?
Signup and view all the answers
What is the primary goal of nutrition therapy in Nephrotic Syndrome?
What is the primary goal of nutrition therapy in Nephrotic Syndrome?
Signup and view all the answers
What is a common manifestation of Nephrotic Syndrome?
What is a common manifestation of Nephrotic Syndrome?
Signup and view all the answers
What is the primary function of the nephron in the context of Chronic Kidney Disease (CKD)?
What is the primary function of the nephron in the context of Chronic Kidney Disease (CKD)?
Signup and view all the answers
Which of the following is a consequence of Nephrotic Syndrome?
Which of the following is a consequence of Nephrotic Syndrome?
Signup and view all the answers
What is the recommended treatment approach for Nephrotic Syndrome?
What is the recommended treatment approach for Nephrotic Syndrome?
Signup and view all the answers
What is a common risk factor for Chronic Kidney Disease (CKD)?
What is a common risk factor for Chronic Kidney Disease (CKD)?
Signup and view all the answers
What is the main focus of nutrition therapy in CKD patients with stages 1 and 2?
What is the main focus of nutrition therapy in CKD patients with stages 1 and 2?
Signup and view all the answers
What is the moderate decrease in GFR characteristic of stage 3 CKD?
What is the moderate decrease in GFR characteristic of stage 3 CKD?
Signup and view all the answers
Which of the following is a common complication of CKD?
Which of the following is a common complication of CKD?
Signup and view all the answers
What is the primary risk factor for CKD?
What is the primary risk factor for CKD?
Signup and view all the answers
What is the goal of treating underlying diseases in CKD patients?
What is the goal of treating underlying diseases in CKD patients?
Signup and view all the answers
What is the recommended assessment for nutrition therapy in CKD patients with stages 1 and 2?
What is the recommended assessment for nutrition therapy in CKD patients with stages 1 and 2?
Signup and view all the answers
Which of the following is not a common risk factor for CKD?
Which of the following is not a common risk factor for CKD?
Signup and view all the answers
What is the characteristic of stage 5 CKD?
What is the characteristic of stage 5 CKD?
Signup and view all the answers
What is a common complication of CKD related to bone and mineral disorders?
What is a common complication of CKD related to bone and mineral disorders?
Signup and view all the answers
What is the primary goal of nutrition therapy in CKD patients?
What is the primary goal of nutrition therapy in CKD patients?
Signup and view all the answers
Study Notes
Kidney Anatomy
- The nephron is the functional unit of the kidney, with approximately 1.2 million in each kidney
- The nephron consists of:
- Glomerulus within Bowman's capsule
- Afferent arteriole that carries blood to the glomerulus
- Efferent arteriole that carries blood from the glomerulus
Nephron Functions
- Maintains extracellular environment for cell function
- Excretes waste products of metabolism
- Maintains fluid, electrolyte, and acid-base balance
- Secretes hormones that modulate hemodynamics (e.g., erythropoietin and vitamin D)
Diagnostic Procedures
- Measure glomerular filtration rate (GFR)
- Clearance calculations
- Tubular function tests
- Microscopic evaluation of the urine
- Radiologic evaluation (IVP, MRI, ultrasound)
- Biopsy
Nephrotic Syndrome
- Deficiency of albumin in blood and excretion in urine due to altered glomerular function
- Characterized by:
- Proteinuria (>3.5 g/day)
- Hyperlipidemia
- Hypoalbuminemia
- More prevalent in children
- Clinical manifestations:
- Frothy urine
- Anorexia, malaise, puffy eyelids, abdominal pain, muscle wasting
- Ascites and plural effusion
- Altered blood pressure
- Oliguria due to hypovolemia
- Edema
- Loss of zinc, copper, vitamin D, and iron bound to proteins
Treatment of Nephrotic Syndrome
- Treat underlying cause
- Reduce cholesterol
- Control blood pressure
- Reduce protein in urine
- ACE inhibitors
- Check potassium levels
- Nutrition therapy: control protein intake (0.8-1.0 g/kg/day), soy- or flaxseed-based proteins, and protein supplementation with no benefit
Chronic Kidney Disease (CKD)
- Syndrome characterized by progressive loss of kidney function
- Not reversible
- Progression to end-stage renal disease (ESRD or CKD stage 5)
- Requires medication and specialized diet
- Risk factors:
- Proteinuria
- Ethnicity (African Americans with diabetes are at highest risk)
- Gender (males)
- Smoking
- Heavy non-narcotic analgesic use
- Obesity
- Most frequent causes:
- Diabetes
- Hypertension
- Glomerulonephritis
- Hereditary and cystic congenital renal disease
- Interstitial nephritis
- Neoplasm/tumor
- Common complications:
- Malnutrition
- Cardiovascular disease (aggressive management recommended)
- Bone and mineral disorders
- Anemia
- Stages:
- Stage 1 & 2: kidney damage with normal or increased GFR
- Stage 3: moderate decrease in GFR (30-59 mL/min)
- Stage 4: severe decrease in GFR (15-29 mL/min)
- Stage 5: inadequate to sustain life (ESRD)
Renal Replacement Therapy
- Dialysis: removal of excessive and toxic by-products of metabolism from the blood
- Types:
- Hemodialysis (HD)
- Peritoneal dialysis (PD)
- Indications:
- Serum creatinine ≥ 6 mg/dL for non-diabetics
- Creatine clearance < 15 mL/min for diabetics
- Nutrition therapy:
- Focus on co-morbid conditions (diabetes, hypertension, hyperlipidemia, progression of CVD)
- K/DOQI guidelines for GFR ≤ 20
- Dietary interviews and food intake or nPNA every 3-4 months
Stages 1 & 2 Nutrition Therapy
- Focus on co-morbid conditions
- K/DOQI guidelines for GFR ≤ 20
- Dietary protein: 0.6-0.75 g/kg
- Energy: 30-35 kcal/kg
Stages 3 & 4 Nutrition Therapy
- See ADA guidelines
- Nutrition assessment recommendations
- Nutrient recommendations (protein, energy, sodium, potassium, phosphorus, calcium, vitamins, minerals, fluid)
- Emphasize usual foods
Stage 5 Nutrition Therapy
- On dialysis:
- Hemodialysis (HD): high protein, control intake of potassium, phosphorus, fluids, and sodium
- Peritoneal dialysis (PD): more liberalized; higher in protein, sodium, potassium, and fluids, and limit phosphorus
- Goals:
- Meet nutritional requirements
- Prevent malnutrition
- Minimize uremia
- Minimize complications
- Maintain blood pressure, fluid status
- Adjusted edema-free body weight should be used to calculate body weight for calculating protein and kcal needs
Post-Transplant Nutrition Therapy
- Protein and energy: increased for up to 6-8 weeks, then RDA for protein and low in saturated fat
- Carbohydrate: glucose intolerance common; insulin or OHA may be warranted, emphasize dietary fiber
- Fat: low-fat diet
- Sodium: hypertensions common; restrict sodium
- Potassium: restrict potassium in acute period
- Immunosuppressants: avoid grapefruit and grapefruit juice
- Cardiovascular disease: TLC, lipid-lowering agents
- Hypomagnesemia: supplementation to lower LDL and apolipoprotein B
- Obesity: diet, behavior modification, exercise
- Calcium, phosphorus, and altered bone metabolism: osteoporosis and altered vitamin D, hypercalcuria from corticosteroids
CKD - Stage 5
- Obtained post-dialysis for HD patients, and after drainage for PD patients
- Nutrition Intervention:
- Fat: increased risk for CAD and stroke
- HD: typically have normal LDL, HDL, TG
- PD: higher TC, LDL, TG
- Recommend TLC diet guidelines for both
- Fluid and Sodium:
- Highly individualized based on residual urine output and dialysis modality
- Interdialytic weight gain (HD) should not exceed 5% of body weight
- 2-gram sodium diet
- Not more than 1 L fluid daily
- If urine output > 1 L/day, sodium and fluid can be liberalized to 2-4 g and 2 L
- Phosphorus:
- Hyperphosphatemia: GFR 20-30 mL/min
- Dietary phosphorus restriction: 800-1000 mg/day, < 17 mg/kg body weight
- Phosphate binders; calcium salts
- Limit calcium intake
- Calcium requirements:
- Higher in CKD
- Restrict foods high in calcium
- Take supplements on empty stomach
- Limit to 2000 mg/day from all sources
- Vitamin Supplementation:
- Water-soluble vitamins
- Daily requirements - Table 20.14
- "Renal" vitamins include B12, folic acid, vitamin C
- Avoid high doses of vitamins A & C
- May need vitamin K if on antibiotics
- Mineral supplementation:
- Avoid Mg-containing phosphate binders, antacids, and supplements
- Iron
- Zinc
Post Transplant
- Protein and Energy:
- Increased for up to 6-8 weeks
- After 8 weeks: RDA for protein and low in saturated fat
- Carbohydrate:
- Glucose intolerance common; insulin or OHA may be warranted
- Emphasize dietary fiber
- Fat:
- Low-fat diet
- Sodium:
- Hypertension common; restrict sodium
- Potassium:
- Potassium restriction in acute period
- Immunosuppressants:
- Used to prevent acute rejection
- Avoid grapefruit and grapefruit juice
- Cardiovascular Disease:
- TLC
- Lipid-lowering agents
- Hypomagnesemia:
- Supplementation of Mg to lower LDL and apolipoprotein B
- Obesity:
- Weight gain common; may complicate hyperlipidemia and glucose intolerance
- Emphasize diet, behavior modification, exercise
- Calcium, Phosphorus, Altered Bone Metabolism:
- Osteoporosis and altered vitamin D
- Hypercalcuria from corticosteroids
- Supplement with calcium, vitamin D, anti-resorptive agents
- Increase phosphorus
- Monitor serum potassium
Kidneys - Anatomy
- Regulatory and metabolic functions
- Nephron: functional unit; approximately 1.2 million in each kidney
- Glomerulus within Bowman's capsule:
- Afferent arteriole - carries blood to glomerulus
- Efferent arteriole - carries blood from glomerulus
- Nephron:
- Ultrafiltrate formed by glomerulus
- Similar to composition of blood
- Filters large proteins and blood cells
- Modified by tubules
- Reabsorption of amino acids, glucose, select minerals, water
- Secretion of solutes, water
- 65% of filtered sodium and water reabsorbed (active transport in proximal tubule)
- Nephron functions:
- Maintain extracellular environment for cell function
- Excretion of waste products of metabolism
- Maintain fluid, electrolyte, and acid-base balance
- Vasopressin - in response to blood volume, maintains fluid balance
- Secretion of hormones that modulate hemodynamics
- Erythropoietin - red blood cell production
- Vitamin D - bone metabolism
Diagnostic Procedures
- GFR: glomerular filtration rate; rate at which substances are cleared from plasma
- Clearance calculations - see p. 613
- Tubular function tests
- Microscopic evaluation of the urine
- Radiologic evaluation (IVP, MRI, ultrasound)
- Biopsy
Nephrotic Syndrome
- Deficiency of albumin in blood and its excretion in the urine due to altered glomerular function
- Proteinuria > 3.5
- Hyperlipidemia
- Hypoalbuminemia
- Result of underlying disease
- More prevalent in children
- Clinical manifestations:
- Frothy urine
- Anorexia, malaise, puffy eyelids, abdominal pain, muscle wasting
- Anasarca with ascites, plural effusion
- Altered blood pressure
- Oliguria due to hypovolemia
- Edema
- Loss of zinc, copper, vitamin D; iron bound to proteins lost
- Treatment:
- Treat underlying cause
- Reduce cholesterol
- Control blood pressure
- Reduce protein in urine
- ACE inhibitors
- Check potassium levels
- Nutrition therapy:
- Control intake of protein
- 0.8-1.0 g/kg/day
- Soy- or flaxseed-based proteins
- Protein supplementation no benefit
Chronic Kidney Disease (CKD)
- Syndrome in which progressive loss of kidney function occurs
- Not reversible
- Progression to end-stage renal disease (ESRD or CKD stage 5)
- Requires medication and specialized diet
- Risk factors:
- Proteinuria
- Ethnicity - African American with diabetes highest
- Gender - males
- Smoking
- Heavy consumption of non-narcotic analgesics
- Obesity
- Most frequent causes:
- Diabetes
- Hypertension
- Glomerulonephritis
- Hereditary and cystic congenital renal disease
- Interstitial nephritis
- Neoplasm/tumor
- Common complications:
- Malnutrition
- CVD - aggressive management recommended
- Bone and mineral disorders
- Anemia
- Stages:
- Stages 1 & 2 - kidney damage with:
- Normal or increased GFR, mild decrease in GFR
- Stage 3 - moderate decrease: GFR 30-59 mL/min
- Stage 4 - severe decrease: GFR 15-29 mL/min
- Stage 5 - inadequate to sustain life
- Stages 1 & 2 - kidney damage with:
- Pathophysiology:
- Microcytic anemia and iron deficiency
- Inadequate erythropoietin
- Renal osteodystrophy
- d/t impaired intestinal calcium absorption and secondary hyperparathyroidism
- Microcytic anemia and iron deficiency
- Treatment:
- Treat underlying disease, delay progression
- Stages 1 & 2 - EPO replacement, vitamin D supplementation
- Stage 5 - renal replacement therapy, nutrition therapy crucial, transplant
- Post-transplant - immunosuppresants
- Renal Replacement Therapy:
- Dialysis - removal of excessive and toxic by-products of metabolism from the blood, replacing the filtering function of the kidney
- Fluid and electrolyte balance must be maintained
- Passing blood across selective membrane exposed to rinsing fluid (dialysate)
- Serum creatinine 6 mg/dL for non-diabetics or
- Creatine clearance < 15 mL per minute for diabetics
- Hemodialysis (HD) or Peritoneal Dialysis (PD):
- Type based on underlying kidney disease and co-morbid factors
- Both require selective, permeable membrane
- Allows passage of water and small molecules
- Excludes larger molecules such as protein
- Hemodialysis (HD):
- Membrane is man-made dialyzer - "artificial kidney"
- Preferred access site - AVF, AVG
- Typical regimen - 3 days/week for 4 hrs/treatment
- Peritoneal Dialysis (PD):
- Lining of patient's peritoneal wall is the selective membrane
- Types - CAPD, CCPD
- Access via catheter into peritoneal cavity
- Range of dextrose concentrations
- Dwell time and number of exchanges
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of the nephron, the functional unit of the kidney, and its functions in maintaining homeostasis.
