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
hormones and kidney problems interconnection
• Renin (secreted by kidneys):
If low fluid rate –> kidney secrete renin to increase blood pressure → Hypertension … (vicious cycle)
HTN will lead to lower kidney function-> lower fluid rate-> renin-> repeaaaat
• Erythropoietin
Decrease EPO production→ lowered production of red blood cells→ Anemia
types of AKI
Acute Kidney Injury – Acute renal failure (AKI - ARF):
- Prerenal
- Postrenal
- Intrarenal
types of CKD
Chronic kidney disease - Chronic Renal Failure (CKD - CRF)
- Chronic renal insufficiency (CRI)
- End stage renal disease (ESRD)
name 4 renal disorders
- Acute kidney injury
- chronic kidney disease- chronic renal failure
- nephrotic syndrome
- urolithiasis
what are the steps of diagnosis of chronic disease?
- Based on CHANGES in GFR over TIME
• Chronic kidney disease: Less than 90ml/min/1.73m^2 for at least 3 months
• Irreversible kidney damage: Less than 60ml/min/1.73m^2 - Biopsy: Glomerulosclerosis- sclerosis is a sign that kidney function is altered
Laboratory Evaluation of Kidney Function
- Microalbuminuria
- GFR-glomerular filtration rate
- Clearance calculations (age,ethnicity,gender)
- Tubular function tests
- Microscopic evaluation of the urine
- Radiologic evaluation(IVP,MRI,ultrasound)
- Biopsy
Kidney disorder treatment
- Manage the underlying cause
- Dialysis
- Transplant
Nutrients of Concern in kidney disorders
- Energy
- Protein: intake has to be decreased in cases of loss of kidney function. intake has to be increased in case of hemodialysis
- Phosphorus • Sodium
- Potassium
- Calcium
- Fluid: sometimes has to be decreased due to extremely low kidney function-> minimal filtration-> fluid restriction
Potassium restrictions?
• Restriction varies according on the degree of kidney function, serum potassium levels, type of dialysis, drug therapy
In HD or PD blood is filtered every 2 days
Between those 2 days there might be a build up of potassium in blood-> potassium in the diet has to be restricted
• HD: 2-3 g/d
• PD: no restriction, +/- supplement
• Serum potassium : 3.5-6.0 mEq/L
• High potassium and low potassium foods
what are possible non-nutritional causes of hyperkalemia?
GI bleeding, acidosis, hypoaldosteronism
Drugs that may raise potassium
- ACE inhibitors
- ARBs
- Selective Aldosterone Receptor Antagonists (e.g. eplerenone) • Trimethoprim–sulfamethoxazole
- NSAIDs
- Beta Blockers,
- Potassium-sparing diuretics (e.g. amiloride or spironolactone)
- Antifungals(e.g.fluconazole)
Name high and low potassium foods?
High potassium foods
• Fruits (dried apricots, juice, banana, avocado)
• Vegetables such as cooked broccoli and spinach, and potatoes
• Other foods: bran products; chocolat; milk; molasses; nuts and seeds, Salt-free broth, salt substitutes. Yogurt, bran cereals, and cooked halibut
and salmon
Low potassium foods
• Some fruits: apple, berries, grapes, pineapples
• Some vegetables
• Other foods: Rice, noodles, pasta, coffee, tea
Canned fruits usually contain less potassium than fresh fruits. Drain all the fluid before serving
Fluid and sodium reqs
• Needs vary according to urine output
- > If output less than 1L/d: restrict to 1-1.5L and 2g sodium
- > If output greater than 1L/d: 2L and 2-4 g sodium
• Needs vary according to type of dialysis
- Blood pressure control
- Interdialytic weight gains (HD) (should not exceed 5% of BW)
- PD: 1-3 L and 2-3g sodium
- Presence of edema
- Congestive heart failure
• Pre-dialysis no need for fluid restriction/ sodium restriction according to BP
Phosphorus reccs
- If HD and PD: restriction 800-1000 mg/day or < 17 mg/kg of IBW
- Use of phosphate binders to limit GI absorption
Name high phosphorus foods
- Dairy products (cheese, milk, …)
- Protein (livers, oyster, sardines, carp…)
- Vegetables (beans, lentils, chick peas…)
- Other (bran cereals, seeds, whole-grain products, nuts…)
Calcium reccs
- Goal is to maintain serum calcium between 8.4 and 10.2 mg/dl
- Adjusted serum calcium calculation: ((4-albumin mg/dl) X 0.8) + Ca mg/dl
- Should not exceed 2,000 mg/d
- Careful to phosphate-binders
- Use of active Vit D Sterols increases calcium absorption in the intestine
Vitamin supplementation reccs
• Water-soluble vitamins supplement
- > Increased losses during PD and HD; anorexia; poor intake)
- > Diet restrictions
- > Impaired synthesis
• Serum vitamin A are elevated in PD and HD: no need to supplement
Magnesium reccs
- Kidney is main organ responsible for normal maintenance of serum magnesium
- Patients must avoid use of laxatives, enemas or phosphate binders containing magnesium
- Water is a potential source of excessive magnesium
- Check that source of water is low in Mg
Iron reccs
- Iron deficiency is common
* Supplement according serum markers of ferritin, iron, total iron binding capacity and transferrin saturation
Zinc reccs
- Patients undergoing maintenance hemodialysis are known to have decreased levels of zinc in serum, hair, and kidneys
- Researchers suggest that zinc supplementation in the amount of 15mg/d may improve dysgeusia (loss of taste) and may be helpful in the management of impotence in male hemodialysis patients
Selenium reccs
- Selenium has important antioxidant properties but plasma levels are low in hemodialysis patients
- Selenium supplementation has not been studied, there are no recommendations for this population
Antioxidant reccs
- Antioxidants from high nutrient density foods
- Teach patients to use whole grains, deep dark colored fruits and vegetables
- Antioxidants benefit the patient on dialysis in all the same ways that the normal population benefits from the use of foods high in nutrient density
what is nephrotic syndrome?
nephrotic syndrome—a clinical condition consisting of losses of protein in the urine exceeding 3.5 g/day, hyperlipidemia, and low albumin levels (,3.5 g/dL) with edema
is filtrate excreted or reabsorbed?
reabsorbed
kidney problems and metabolic acidosis
Metabolic acidosis increases as a result of the kidneys’ decreased ability to excrete hydrogen ions.
kidney problems and potassium levels
As GFR begins to decline, the excretion rate of potassium increases; however, as renal function continues to decline, this compensatory mechanism can no longer prevent the accumulation of potassium, which ultimately results in hyperkalemia (elevated blood potassium)
renal osteodystrophy
Parathyroid hormone (PTH) also aids in regulating serum calcium by stimulating bone resorption and kidney reabsorption, and by converting the inactive form of vitamin D to the active form (1,25[OH]2D3 ). Deficiency of the active form of vitamin D is associated with impaired intestinal calcium absorption and secondary hyperparathyroidism, both of which contribute to the development of bone and mineral disorders (renal osteodystrophy).
what are the leading causes of kidney failure?
diabetes, hypertension, and glomerulonephritis
potential causes of and risk factors for CKD
- Ethnicity—African Americans are nearly four times as likely to develop kidney failure as white Americans; Native Americans are nearly two times as likely, and Hispanic Americans have nearly twice the risk of non-Hispanic whites
- Family history—CKD runs in families, so one’s risk is greater if a family member has kidney failure
- Hereditary factors such as polycystic kidney disease (PKD)
- A direct and forceful blow to the kidneys
- Prolonged consumption of over-the-counter painkillers that combine aspirin, acetaminophen, and other medicines such as ibuprofen
HD vs PD diet
hemodialysis diet is high in protein and controls intakes of potassium, phosphorus, fluids, and sodium.
Patients receiving peritoneal dialysis have a more liberalized diet than hemodialysis patients; this diet is higher in protein, sodium, potassium (due to increased losses during the dialysis pro- cess), and fluid, but it is still limited in phosphorus.
is there a cure for end-stage kidney disease?
no
do symptoms appear early on?
no
a person can loos e 50% of their kidneys before symptoms appear
Risk factors for CKD
• Diabetes • Hypertension • Autoimmune diseases (e.g., systemic lupus erythematosus) • Systemic infections • Urinary tract infections • Urinary stones or lower urinary tract obstruction (BPH) • Certain cancers/treatments • Family history of chronic kidney disease • History of acute kidney injury • Reduction in kidney mass • Exposure to certain drugs • Low birth weight
Additional sociodemographic risk factors for CKD
• Age older than 60 years
• Exposure to certain chemical and environmental conditions
• Low income/education
• Ethnicity
• African Americans, Hispanic Americans, Asians, Pacific Islanders, and American
Indians are at higher risk for CKD.
Classification of CKD stages according to GFR
• Normal: GFR ≥ 90 mL/min per 1.73 m2 with no kidney damage
• Stage 1: normal or increased GFR (≥90mL/ min per 1.73m^2) with kidney
damage
• Stage 2: mildly decreased GFR (60–89mL/min per 1.73 m^2) with kidney damage†
• Stage 3a: mild to moderately decreased GFR (45–59mL/min per 1.73m^2)
• Stage 3b: moderate to severely decreased GFR (30-44mL/min/1.73m2)
• Stage 4:severely decreased GFR (15–29mL/min per1.73m2)
• Stage 5: kidney failure (GFR<15mL/min per 1.73m2)
what is the definition of CKD
When GFR is <60 for three months or more, chronic kidney disease (CKD) is present.
which CKD stage is tipping point? What does it mean?
Stage 3a, beyond this point there are irreversible complications
we start to see things like hyperkalemia and edema that limit the interventions
which stages of CKD can be impacted the most? How?
stages 1-3a is where we have the most capacity to introduce change
should be done in the community
lifestyle intervention and treatment to manage complications like HTN, diabetes
we can try to limit progression to end-stage, but its not 100% guarantee
link between age of diagnosis and risk of kidney disease
if diagnosed early in life, there is a higher time frame for kidney function deterioration -> higher chance of kidney failure
risk of excess of diuretics and anti-HTN drugs
patients with too many diuretics and antihypertensive will see a decline in kidney function
which 2 markers are used to assess CKD prognosis
GFR and albuminuria
CKD Main Causes Include:
Diabetes, hypertension, CVD, obesity and other renal specific diseases (chronic glomerulonephritis, polycystic kidney disease, interstitial nephritis, obstructive uropathy etc.).
CKD symptoms
Asymptomatic in earlier phases but as failure progresses – increasing fatigue, nausea, vomiting, anorexia, insomnia, uremic syndrome
describe Mild-moderate renal insufficiency
- Diminishing renal function but without accumulation of the end-products, the patient is generally asymptomatic.
- Stages 1-3a
- Diet and lifestyle modifications are key
Describe Moderate-severe renal insufficiency
- Stages 3b and 4
- Waste products begin to accumulate.
- Complications of CKD are more common
- Diet and lifestyle modifications maybe more difficult d/t complications
Describe ESRD
Stage 5
• Remaining kidney function cannot adequately regulate the balance of fluids, salts, and waste products in the body - uremia
• < 15% of normal function (DM) ; < 10% (no DM)
• Nutrition focus becomes symptom management and delayed time until dialysis
• Dialysis and/or transplant is eventually needed to prevent complications and death
• Some patients are asymptomatic
what is the main consideration when initiating dialysis?
Symptoms are generally the main consideration when initiating dialysis (fatigue, poor appetite, fluid overload and electrolyte abnormalities)
Confirmed and suspected toxins in urine
Confirmed toxins: Water, Sodium, Potassium, Hydrogen, inorganic Phosphate, Urea, Cyanate, Oxalic acid, B2-microglubulin
Suspected toxins: Leptin, AGE’s, Uric acid, creatinine, Mg, homocysteine and many more.
insulin, insulin resistance and CKD
patient with CKD can develop hyperinsulinima while also developing insulin resistance
CKD complications
Uremic syndrome (high urea and rate creatinine) Anemia (decreased erythropoietin) Fluid imbalances (Na imbalance, edema) Electrolyte imbalances (high K, acidity, PO4)
CKD tests
Creatinine and creatinine clearance BUN Electrolytes Iron status measurements 24 h urine collection for protein and sodium PTH Renal biopsy or u/s
Side effects of CKD
Neurological
Hematological: anemia, weakness, fatigue, pallor
musculoskeletal: Renal osteodystrophy, decreased calcium, vitamin D impairment, hyperparathyroidism
immune
cardiovascular
respiratory
gastrointestinal
cut-offs for CKD diagnosis in diabetes
ACR ≥2.0 mg/mmol
and / or
eGFR <60 mL/min/1.73 m2
define diabetic nephropathy
Progressive increase in proteinuria in people with longstanding diabetes, followed by declining function which can eventually lead to End-Stage Renal Disease (ESRD
screening for CKD in people with diabetes
- Screen annually were not transient causes of albuminuria or low eGFR are present, and when acute kidney injury or non-diabetic kidney disease is not suspected
T1DM: annually in postpubertal individuals with duration of diabetes >5 years
T2DM: at diagnoses and annually thereafter
2.order random urine ACR and serum creatinine for eGFR
potential causes of transient albuminuria
recent major exercise Urinary tract infection febrile illness decompensated congestive heart failure menstruation acute severe elevation in blood glucose acute severe elevation in blood pressure
describe urinalysis test
– Identifies the presence of proteinuria (ranges may vary)
LGH ranges
– Quickest screening method, includes other screening parameters
– less precise if proteinuria > 300mg/L(0.3g/L) Ranges on urine dipstick tests may differ,`
describe Urine chemistry tests: microalbuminuria, Creatinine and ACR
– (Microalbuminuria (meaused in mg/L), urine creatinine and albumin to crea. ratio)
– more precise for proteinuria, and can be done as a spot check (no need to collect urine and return to the hospital)
– lacks other screening parameters such as glucose and hematuria
Describe 24h urine collection test
– most accurate because urine protein excretion varies during the course of the day.
– More difficult to collect the samples (1-3L of urine) and transport to the hospital.
effort heavy
if dipstick test shows a value of 1- which actual values can we expect?
In theory, we would expect a microalbuminura value between 0.5 and 3.0 g/L (the numbers nearby the value of 1 since this test is so inaccurate), however this is obviously not always the case
what is Nephrotic-range proteinuria
Nephrotic-range proteinuria is the loss of 3 grams or more per day of protein into the urine or, on a single spot urine collection, the presence of 2 g of protein per gram of urine creatinine.
Causes of CKD: diabetes vs no diabetes
Non-Diabetes: HTN renovascular and other kidney diseases
Diabetes: diabetic nephropathy, HTN renovascular and other kidney diseases
factors that favour diabetic nephropathy
Persistent albuminuria bland urine sediment slow progression of disease reduced eGFR associated with overt proteinuria other complications of diabetes present duration of diabetes >5 years
factors that favour alternate diagnosis (other than diabetic nephropathy)
Extreme proteinuria
Persistant haematuria (micro or macroscopic) or active urinary sediment
rapidly falling eGFR
reduced eGFR are with little or no proteinuria
Other complications of diabetes not present or relatively not as severe
Known duration of diabetes <5 years
family history of non-diabetic renal disease (e.g. polycystic kidney disease)
signs or symptoms of systemic disease (lupus, cancer)
Describe classic form of diabetic nephropathy
The classical description of diabetic nephropathy is a slow and progressive increase in albuminuria, followed later in the disease by a decrease in estimated glomerular filtration rate
w/o proteinuria there’s usually no diabetic proteinuria
Prevention of CKD in Diabetes
- Optimal glycemic control in type 1 and type 2 diabetes has been shown to reduce the development and progression of nephropathy.
- Optimal BP control
- Lifestyle modifications
- ACE-inhibitor or ARB
Protein, potassium and phosphorus restriction may conflict with diabetes recommendations.
ACE-inhibitor or ARB in diabetic nephropathy
these help to reduce proteinuria, which helps to reduce kidney damage, however this often comes at the cost of potassium
diabetes patients are prone to hyperkalemia even in absence of these meds due to tubular acidosis
What is pre-dyalisis eGFR?
eGFR between 10 and 30 mL/min/1.73m2
Why would u not start dialysis even if your eGFR is <10
Acceptable laboratory values (not necessarily WNL)
Lack of physical symptoms (fatigue, loss of appetite and fluid overload)
Conservative care (eventual palliation)*
Refusal without planning
Common Medications For electrolyte imbalances (K,CO2, PO4)
1.. K supplements:Hypokalemia d/t poor intake, vomiting, diarrhea or due to medical conditions and/or medications
- cardiac patients often end up on potassium supplements as they are often on meds that deplete potassium
2. K binders: Hyperkalemia d/t excessive intake, medical conditions and/or medications
2 options: Sodium polystyrene sulfate and patiromer (new)
3. Sodium Bicarbonate: Treatment for acidosis (↓CO2 )
*1/3 of the dose provides Na (ex. 1500mg= 500 mg Na) and typical doses range from 1000-3000mg/d
4. PO4 binders: Treatment of hyperphosphatemia in addition to dietary restriction
• Ca carbonate or citrate (Should not exceed 1000-1200mg/d)
• Sevelamer, Lanthanum, Velphoro (new)
• Mg/Al(veryrarelyused)
Common Medications: antihypertensives and Diuretics
• ACE inhibitors (K sparing) • ARB (K sparing) • Alpha-Blockers • B-blockers • Vasodilators • K+ Sparing diuretics (ex.Spironolactone) • K+Depleting diuretics - Thiazides (Deplete Na/retain H20)-> risk for hyponatremia - Loop diuretics (deplete Na and fluid)
diet considerations with Antihypertensives and Diuretics
- many classes react with grapefruit/black licorice
- most Antihypertensives and Diuretics require low/reduced sodium diet
- Thiazides (Deplete Na/retain H20)-> risk for hyponatremia
name all type of common meds in CKD
- for electrolyte imbalances
- anti-hypertensive and diuretics
- erythropoietin and iron (oral or iv)
- diabetes meds
- Vit D
metformin and CKD
metformin has to be stopped due to the risk of acidosis
vitamin D supplements
• Inactive Vitamin D (D2 or D3) to treat 25(OH) deficiency • Active Vitamin D (calcitriol, alfacalcidol) to treat hypocalcemia and secondary hyperparathyroidism (↓ PTH, ↑ Ca and PO4 abs.- downside for people with high Ca and PO4) • Cinacalcet or parathyroid resection are also treatments for ↑PTH and/or severe hypercalcemia (mostly seen dialysis)
CKD: Nutritional Goals
- Delay the progression of CKD while providing adequate calories to maintain or achieve ideal BW
- Prevent or alleviate symptoms of uremia and restore biochemical balance while providing adequate calories to maintain or achieve ideal BW
- Maintain or improve 3 Health via lifestyle
modification - Maintain or improve Quality of life
MNT Consideration for CKD
Low protein (or protein reduction)
Restricted Phosphorous Restricted Potassium
Restricted Sodium
Adequate Calories and Lifestyle modifications
Healthy foods and eating habits where possible
Adapting recommendations to various cultures
energy reccs for CKD
25 -35 (adjust for BW gain or loss)
protein amount reccs
CKD stages 1-2: 0.8 – 1.4
CKD stages 3-4: 0.6 – 0.8
Phosphorus intake reccs
Stages 1-2: Maintain serum P and PHT WNL
stages 3-4: 800 – 1000 Adjust to meet protein needs: 10-12 mg/d
potassium intake reccs
Unrestricted unless serum level is high
calcium intake reccs
DRI (1000 -1200): maintain serum levels WNL
sodium intake reccs
<2400
is malnutrition common in CKD
yes, especially with HD
CKD and malnutrition assessment
Nutrition assessment in CKD is relatively similar, however:
• Many patients already have at least 2 risk factors for
malnutrition: edema and decreased appetite
is it recommended to use bioelectrical impedance in CKD
no sufficient evidence
how often should body weight and BMI be reassessed
monthly in MHD and PD patients
every 3 month with CKD 4-5 or post-transplantation
every 6 months with CKD 1-3
Albumin as a marker in CKD
Albumin may be used as a predictor of hospitalization and mortality, but should be used in conjunction with other markers
Lower levels indicate higher risk
Acidosis effect on potassium
Acidosis can increase potassium
factors that can lead to hyperkalemia
Hyperkalemia is often multifactorial
- Medications
- Diet
- Medical conditions such as deteriorating renal function, metabolic acidosis/respiratory alkalosis, hyperglycemia
- Fever, Infection, Trauma, Sepsis
- Lab errors such as Hemolysis
- Hyperkalemia is more common in diabetic patients d/t renal tubular acidosis type 4. In addition, they may require an ACEi or ARB
Practical Tips: Potassium (K+) and Creatinine (Cr)
Check serum K+ and Cr
• Baseline
• Within 1-2 weeks of initiation or titration of medication
• During acute illness
If K+ becomes elevated or Cr >30% increase-> Review therapy; Recheck serum K+ and Cr
Practical tips for Mild to moderate stable hyperkalemia
- Counsel on a low potassium diet
- If persistent, consider adding non-potassium sparing diuretics and/or oral sodium bicarbonate (in those with metabolic acidosis)
- Consider temporarily holding or discontinuing culprit medication
- Potassium lowering medications(less common)- try to restrict potassium first, explain why u do it
Practical tips for severe hyperkalemia
- Hold or discontinue culprit medication
* Emergency management strategies
Which method can be used to asses protein-energy status
handgrip strength
what is the preferred method of dietary intake assessment
3-day food record
Main food sources of potassium
• Preservatives in processed foods: Potassium lactate/ chloride, potassium bitartrate (cream of tartar)- target and eliminate these first • Fruits and vegetables • Milk products (usually restricted) • Nuts, seeds, legumes and lentils • Whole grain/high fiber grains 75 g of chicken: 21 g protein 178 mg potassium 124 mg phosphorus • Meat and alternatives: A patient who consumes too much protein also consumes additional potassium and phosphorus. Thus when we suggest to decrease animal protein intake we also benefit from decreased potassium consumption
Main food sources of phosphorus
• Food additives- eliminate these first
• Milk/soy products
• Milk alternatives should be verified for source of calcium (Ca carbonate vs Calcium phosphate)
• Nuts and seeds
• Legumes and lentils
• Whole grains
- also present in medications, especially liquid medications.
Bioavailability of phosphorus across food sources
- (90-100%) Food additives: sodium phosphate, calcium phosphate, etc.
- (40-70%) Animal protein sources
- (40-50%) Vegetable proteins
tips of phosphate binders
work directly on dietary phosphate and hence need to be taken with food- have to be taken in the beginning of meals
how can we decrease net acid production?
- Increased fruit and vegetable intake (if
possible) - Reduced protein intake
what is renal acidosis?
What is renal tubular acidosis (RTA)? Renal tubular acidosis (RTA) is a disease that occurs when the kidneys fail to excrete acids into the urine, which causes a person’s blood to remain too acidic.
what can be used as a marker for acid-base status?
spot urinary citrate to creatinine ratio
is there a correlation between serum albumin and degree of proteinuria?
no
when can additional protein be reasonable to cover for urine losses?
Additional protein for patients with heavy proteinuria and low albumin may be reasonable
Factors that complicate the treatment of malnutrition in CKD
- Hyperkalemia
- Fluid overload
- Hyperphosphatemia
- Hyperglycemia
- Dyslipidemia
- Past dietary restrictions
Treatment for malnutrition
- High (or adequate) calorie diet: Increase fat intake, Increase carbohydrates
- Adequate but not excessive protein
- Type and quantity will depend on your evaluation and may evolve along with patients condition
- ONS: Suplena, Novasource renal, Nepro, standard ONS
PUFA recommendations
suggestion to prescribe 2g/d of PUFA to lower serum TG levels
focus of treatment in Nephrolithiasis
• Primary focus: Lower sodium and increased fluid intake
• Secondary focus is balanced eating habits:
1. Increased fruit and vegetable intake
2. Reduction in protein portions/increased plant protein*
3. Attaining a healthier weight
4. Low fat calcium sources at meals
5. Oxalate restriction for Calcium-oxalate stones, only if oxalate is high and stones occur despite successful implementation of prior points.
6. Purine restriction in addition to protein restriction for uric acid stones
Which of the following are not optimal to treat hypoglycemia in a patient with moderate to severe renal impairment : Apple Juice Glucerna Cola Gingerale Lifesavers Honey Jolly ranchers Dex tabs Orange juice Sugar
- Cola: acceptable in an emergency but contains phosphoric acid (not acutely dangerous)
- Orange juice: not ideal especially if high in potassium (possibly dangerous)
- Glucerna: Not ideal to treat hypoglycemia in general, high in protein, potassium and phosphorus.
