Renal Flashcards
Protein Restriction, CKD Patients Not on Dialysis and Without Diabetes
- a low-protein diet providing 0.55–0.60 g dietary protein/kg body weight/day, or
- a very low-protein diet providing 0.28–0.43 g dietary protein/kg body weight/day with additional keto acid/amino acid analogs to meet protein requirements (0.55–0.60 g/kg body weight/day)
Protein Restriction, CKD Patients Not on Dialysis and With Diabetes
In the adult with CKD 3-5 and who has diabetes, it is reasonable to prescribe, under close clinical supervision, a dietary protein intake of 0.6-0.8 g/kg body weight per day to maintain a stable nutritional status and optimize glycemic control.
Dietary Protein Intake, MHD and PD Patients Without Diabetes
In adults with CKD 5D on MHD (1C) or PD (OPINION) who are metabolically stable, we recommend prescribing a dietary protein intake of 1.0-1.2 g/kg body weight per day to maintain a stable nutritional status.
Dietary Protein Intake, Maintenance Hemodialysis and Peritoneal Dialysis Patients With Diabetes
In adults with CKD 5D and who have diabetes, it is reasonable to prescribe a dietary protein intake of 1.0-1.2 g/kg body weight per day to maintain a stable nutritional status. For patients at risk of hyper- and/or hypoglycemia, higher levels of dietary protein intake may need to be considered to maintain glycemic control
functions of kidney
Maintain of homeostasis (→regulate blood content) • Control of fluid (water) • pH • Electrolyte balance • Blood pressure
Excretion of metabolic end products (→remove waste) ** most important function
• Filtering waste products from metabolic processes
• Urea and excess water from blood excreted as urine
Production of enzymes and hormones
• Renin (blood pressure): decreased blood flow-> renin production will be triggered to increase water reabsorption to increase pressure
• Erythropoeitin (Red Blood Cell synthesis)
• Vitaimin D (Ca absorption, bone health, muscle contractions)
Which particles can pass through walls of glomerulus?
Walls of glomerulus permit the free flow of water soluble materials (e.g., blood cells and large protein molecules remaining in the blood)
What is glomerular filtrate?
the fluid that enters the Bowman’s capsule (contains waste products like urea, and needed materials like glucose)
how does glomerulus differentiate what should it pass out and what it shouldn’t?
Glomerular filter discriminates on the basis of Size and Charge
What can GFR be used as an estimation of?
Glomerular filtration rate (GFR)
What is GFR?
Expression of the quantity of glomerular filtrate formed each minute in the nephrons of both kidneys, calculated by measuring the clearance of specific substances (inulin or creatinine)
What is usually used for GFR estimation: inulin or creatinine?
inulin is usually harder to assess, thus we usually assess the creatinine
How does GFR compare across ages and genders?
older people and women have lower GFR
WHat is the normal eGFR
eGFR = normal; 90‐120 ml/min/173m^2
Which substances are filtered? which are excluded?
Substances ‘Filtered’: Water, electrolytes (Na, K, etc,) glucose, nitrogenous waste (urea, creatinine) …
Substances ‘Excluded’: Substances of size > 70 kDa Plasma protein bound substances
Which factors can affect serum creatinine levels
- Amount of protein in the diet
- Age
- Muscle breakdown
- Antibiotics inhibit secretion
- Levels are prone to calibration bias
Estimating creatinine clearance: MDRD
Modification of Diet in Renal Disease Equation =
eGFR (mL/min/1.73 m2) =
175 × (Scr)-1.154 × (age)-0.203 × 0.742 (if female) × 1.212 (if black)
Using conventional unit
175 × (Scr/88.4)-1.154 × (Age)-0.203 × (0.742 if female) × (1.212 if African American) (SI units)
- uses 4 values
- adjust for age, gender and ethnicity
- The equation does not require weight because the results are reported normalized to 1.73 m2 body surface area, which is an accepted average adult surface area.
Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) vs MDRD accuracy
- More accurate than MDRD if eGFR >60 mL/min/1.73 m2
* As accurate as MDRD if eGFR < 60 mL/min/1.73 m2
What does CKD-EPI adjust for?
- gender and ethnicity
when does CKD-EPI over and under estimate?
- Surestimation : low IMC
* Underestimation: patients with muscular hypertrophie
WHat are the 3 types and chareactersitics of kidney disease?
Chronic Kidney disease (CKD)
- Slow decrease in function
• Decrease ability to filter blood
• diabetes is the main cause; HTN is the next cause
End-stage renal disease: stage 5- requires hemodialysis
Acute kidney injury (AKI)
• may be reversible
• Sudden damage to the kidneys that causes loss of function- occurs over hours or days
- damage may occur before or after the kidney
how is the amount of urea produced affected when there are kidney problems?
less will be produced
what is the consequence of decreased GFR?
• If decrease GFR→urea cannot be excreted and build up in the blood
-> azotemia
• General symptoms: Nausea, Loss of appetite
• Encephalopathy: Asterixis (tremor of the hand), Coma and death
- Pericarditis
- Bleeding (less clot formation • Uremic frost
Potassium and decreased GFR interconnection
If decrease GFR → Hyperkalemia → Cardiac arrythmias
Calcium and kidney problems interconnection
Less activation of Vitamin D by Kidney→ lowered Ca2+ absorption from diet →Hypocalcemia
→If Ca decrease→ Parathyroid hormone is release→ Bones lose Ca2+ →The loss of Ca2+ by bones can lead to renal osteodystrophy