Chronic Kidney

Disease

Heidi AndersonErica Bailey

Anai Villalobos Katie Pearce

Anatomy of the Kidney

2 major parts: Cortex Medulla

Functional Unit Nephrons

Renal Pyramid Renal Pelvis Ureter

Nephrons

1.) Glomerular Filtration

Fluids and solutes in the blood plasma of the glomerulus pass into the glomerular capsule (glomerular filtrate) Mechanisms to cause this fluid to be filtered is

High hydrostatic pressure of the blood in the glomerulus

Large number of pores

Substances present in the glomerular filtrate: water, electrolytes, glucose, AA, urea, hormones, and vitamins. -exclude large molecules that are in the blood.

GFR

The best way to measure levels of kidney function. GFR= urine volume x inulin conc. In urine

inulin conc. In plasma (mg/ml)

Best estimates of GFR: Inulin clearance Creatine clearance Plasma creatinine concentration Blood urea nitrogen (BUN)

2.) Tubular Reabsorption

Trans-epithelial transport Most solutes reabsorped

completely Urine volume is regulated by

the needs of the body Active vs. Diffusion Tm

3.) Tubular Secretion

Movement from the peritubular capillaries into the lumen of the tubule.

Main Substances secreted H+ K+ Some organic anions

http://ccn.aacnjournals.org/cgi/content/full/26/4/17/F1

Functions of the Kidney

Elimination of wastes, excess water and solutes, and conserves nutrients

Acid-base balance Renin-angiotensin system Erythropoietin release Activation of Vitamin D

Elimination of Waste

Kidney receives 20% of cardiac output, which allows the filtering of approximately 1600 L/day of blood.

This is translated into 1.5 L of urine a day to be excreted, on average

The fluid filtered from the blood plasma is modified and reabsorbed as it travels along the tubules. The remainder finds its way into the ureter, which carries the urine to the bladder from each kidney.

Acid-Base Balance

Kidney is responsible for 2 major activities: Reabsorption of filtered bicarbonate Excretion of the fixed acids (acid anion and

associated H+) Both of these processes involve secretion of H+

into the lumen by the renal tubule cells Only the 2nd one leads to excretion of H+ from

the body.

Acidosis vs. Alkalosis

Renin-

Angiotensin

System Regulation

Of Blood

Pressure

Erythropoietin Release

EPO is a hormone primarily produced by the kidney Occurs when a drop in blood oxygen level is perceived. Used to treat anemia. Glycosylated erythropoietin comes in 3 forms:

alpha (the most commonly used type in veterinary medicine),

beta (of similar clinical efficacy to alpha)

Darbepoetin (which is particularly heavily glycosylated and lasts the longest).

Vitamin D Activation

Parathyroid hormone is able to drive stored calcium and phosphorus from the bones as is vitamin D so these hormones are able to work in concert here but in the kidney they have different functions. In the kidney, while vitamin D saves both calcium and phosphate, parathyroid hormone causes only calcium to be saved and phophate to be dumped. There is a third hormone called “calcitonin” that keeps the blood calcium level from indefinitely rising. When blood calcium starts to get too high, calcitonin is released to begin storing calcium and phosphate back in the bones until it is needed again.

At Risk Populations

Racial Groups: African Americans Native Americans Hispanics Pacific Islanders

Risk Factors: Diabetes Hypertension Family history of kidney failure

Looking at Geographics

Hypertension

CKD

Genetics

The angiotensinogen promotor G(-6) allele lowers transcription and is inversely associated with hypertension.

the A1166C 3'-UTR variant of angiotensin II type 1 receptor (AT1R) has been associated with CKD.

The AT1R C1166 allele may increase susceptibility but only in the presence of hypertension.

What is CKD? CKD is the gradual loss of the kidney’s ability

to filter waste and fluid from the bloodstream. Nephrons filter waste out of the blood. Nephrons become damaged and lose their

filtering ability overtime. As more nephrons are damaged, the healthy

ones work harder. Kidneys become scarred or may shrink in size.

Etiology

• Diabetes is the number one cause of kidney disease, responsible for about 40% of all kidney failure.

• High blood pressure is the second cause, responsible for about 25%.

• About 12.2% of Native Americans over the age of 19 have type 2 diabetes.

Diabetes and high blood pressure are the leading causes of CKD.

Etiology-cont.

Other causes include:- Glomerulonephritis (kidney inflammation)- Genetic diseases (i.e. polycystic kidney

disease)- Autoimmune diseases (i.e. lupus)- Birth defects- Obstructions caused by problems like kidney

stones or tumors

Pathophysiology

As the renal tissue loses function, the remaining tissue increases its performance

↓ renal function interferes with the ability to maintain fluid and electrolyte homeostasis.

↓ability to concentrate urine ↓ability to excrete phosphate, acid and K ↑creatinine and urea and ↓GFR Heart failure can result from Na and water overload

Pathophysiology-cont.

↓production of calcitriol leads to hypocalcemia→osteopenia or osteomalacia.

↓excretion of phosphate leads to hyperphosphatemia

Secondary hyperparathyrodism is common→renal osteodystrophy.

Normochromic-normocytic anemia (Hct of 20-30%) caused by ↓erythropoietin production due to ↓functional renal mass.

Phosphorus Pathophysiology

Decreased renal function

Increased blood phosphorus

Decreased active vitamin D

Increase blood calcium levels

Decreased bone massIncreased blood

PTH

Cacliphylaxis

Cacliphylaxis

Deposition of calcium phosphate in soft tissues This occurs when the phosphorus-calcium

product is too high (greater than 4.5 (mmol/l)2

Cacliphylaxis is associated with CVD Calcium phosphate is deposited on heart

valves and blood vessels

Diagnosis

Based on laboratory testing of renal function:- Creatinine- GFR- BUN

Urinalysis (check for protein, blood and WBC in urine-which should not be there).

Sometimes renal biopsy.

MRI or ultrasound to check the size.

LABS

Glomerular filtration rate (GFR) is the best measure of kidney function.

A doctor will order a blood test to measure the serum creatinine level. As kidney function ↓, blood levels of creatinine ↑.

Creatinine

It is a waste product that is passed through the kidneys.

A by-product formed by muscle contractions. It also comes from protein foods we eat.

↑creatinine may signal that the kidneys aren’t eliminating this waste, leaving it in the body.

Normal range: 0.8-1.4mg/dL

Glomerular Filtration Rate (GFR)

Measures the kidney function and the stage of CKD.

As the kidneys become more damaged, the GFR will decrease.

Normal range: >90, with little or no protein or albumin in the urine.

Blood Urea Nitrogen (BUN)

The BUN test measures the amount of urea in your bloodstream.

Urea is a waste product left over from the protein we eat, which is normally eliminated through the kidneys.

↑urea mean the kidneys are not getting rid of waste and it remains in the body.

Normal range: 7-20 mg/dL

S/SCKD is a silent, but devastating

disease. Azotemia Uremia ↑↓urination (nocturia) Fatigue/weakness Nausea and vomiting Bruising/bleeding Uremic frost (crystals in and on skin)

S/S – cont.

Loss of appetiteEdema in feet, ankles, hands, or faceBack pain ItchingShortness of breath (fluid can build up I

lungs)Ammonia breath or taste in the mouth

5 Stages of CKD

Help doctors give the best treatment to patients

Each stage requires different tests and treatments

Stage GFR Level DescriptionStage 1 90 mL/min or

moreHealthy kidneys or kidney damage with normal or high GFR

Stage 2 60 to 89 mL/min Kidney damage and mild decrease in GFR

Stage 3 30 to 59 mL/min Moderate decrease in GFR

Stage 4 15 to 29 mL/min Severe decrease in GFR

Stage 5 Less than 15 mL/min or on dialysis

Kidney failure

Stage 1

GFR > 90 ml/min Kidney damage Normal or increased function No symptoms of damaged kidney People aren’t usually diagnosed unless they

are being tested for something else

Stage 2

GFR 60-89 ml/min Mild decrease in kidney function This GFR is normal for some people People with GFR >60 are still considered to

have Chronic Kidney Disease if they have some kind of damage to their kidney

Stage 3

GFR 30-59 ml/min Moderate decrease in kidney function Uremia Symptoms may start to develop

Stage 4

GFR 15-29 ml/min Severe decrease in kidney function Patients will start thinking about dialysis or

transplant Think about getting a fistula so it has time

to mature

Stage 5

Less than 15 ml/min Kidney failure with treatment End stage renal disease Kidneys are unable to remove waste and

fluid from the body

Complications of CKD

Cardiovascular disease Anemia High blood pressure Bone disease

Can CKD be Halted or Reversed?

Cannot be reversed No known cure (other than kidney

transplant) Can be halted!

Use preventative techniques to halt the progression.

Prevention

Prevent and control high blood pressure Prevent and control diabetes Early diagnosis

Routine physical examinations

Stop smoking Decrease alcohol consumption

Hypertension Prevention/Control

Most important thing to prevent of CKD Maintain Healthy weight Exercise to raise your heart rate Reduce Sodium in diet Take Medication

Can slow rate of kidney damage by 50%!

Diabetes prevention

Eat a healthy Diet Fiber, whole grains Fruits and vegetables

Maintain normal blood glucose levels Exercise Obtain and maintain healthy weight

Prevention Programs

National Kidney Foundation’s KEEP Free screening Educational materials Designed to raise awareness

Need a better global effort Require a lot of man power and funds

Diabetes and Birth

Can lead to complications for the fetus as soon as the first 6-8 weeks of life CNS deformities Musculoskeletal deformities Congenital heart disease Spontaneous abortion

Large birth weights Shoulder dystocia

Diabetes and Birth

Large birth weight If diabetes is not controlled Baby gets high blood sugar Baby makes more insulin Stores the extra calories as fat “overfed”

Compliance with Diabetes treatments and development of CKD

Study done showing that intensely treated diabetics were 21% less likely to have nephropathy.

Patients who more tightly control their blood sugar are less likely to have renal complications

The longer a patient is noncompliant with diabetes treatments, the greater risk he/she has of developing CKD.

Quality of Life

Physical Function Social Activity Energy Cognition Emotion (anxiety, fear, denial, anger, depression, etc) Sleep patterns-sleep apnea Health Perception General Life Satisfaction

Life Expectancy

Mortality increases as kidney function decreases.

Leads to increased risk of CVD Life expectancy of a 40- to 44-year-old

white male in the general population in the US is more than 35 years.

Long Term Dialysis can add about 8 more years

Organizations/Support Groups

Organizations National Kidney Foundation American Kidney Fund

Support Groups Renal Support Network American Association of Kidney Patients

Medical Treatment

There is no cure to CKD, but there are ways to slow the progression of the disease: Control blood glucose

Insulin therapy Metformin Other diabetes medications

Medical Treatment—cont.

Control blood pressure ACE inhibitors ARBs Diuretics

MNT Decrease protein intake Decrease phosphorus intake

Phosphorus binders Decrease sodium intake

Effect of diet on progression

For diabetic patients, management of their diabetes can prevent or decrease the progression of CKD.

Managing blood pressure can also help to control the progression of CKD.

Cochrane Database study found that lower protein diets reduced “renal death” by 32% in non diabetic adults

MNTEnergy 30-35 kcal/kg IBWProtein 0.6-1.0 g/kg IBWFluid Ad libitumSodium Variable, 2-3 g/dayPotassium Variable, usually ad libitum or

increased to cover losses with diuretics

Phosphorus 0.8-1.2 g/day or 8-12 mg/kg IBW

MNT--ProteinUrine Output Percent HBV Protein

Recommendations> 55 ml/min 60% 0.8 g/kg/day25-55 ml/min 60% 0.8 g/kg/day<25 ml/min 50% 0.6 g/kg/day *

*This can increase to 0.75 g/day if the patient cannot get 35 cal/kg IBW.

MNT—ProteinExcess protein in the diet

Excess ammonia in the blood

Increased stress on the kidney

More rapid kidney failure

MDRD Study

Kidney Failure Death Kidney Failure or Death

Low protein diet (.58 g/kg/day) 90.7% 23.3% 96.1%Very low protein diet (.28 g/kg/day with .28 g/kg/day EAA)

87.3% 38.9% 95.2%

MNT—Sodium

Restriction of sodium to 2-3 grams/day. This may help decrease blood pressure . It may also decrease proteinuria.

MNT--potassium

In stages I-IV CKD, potassium intake may need to be increased or decreased depending on the lab values for the specific patient.

Fruits and vegetables are generally high in potassium. The potassium content can be decreased by

soaking vegetables in water.

MNT--Phosphorus

Phosphorus is normally excreted in the kidneys. In CKD, phosphorus can build up in the blood.

Depending on lab values, it may be necessary to decrease dietary intake of phosphorus.

High-Phosphorus Foods Dairy products Meat Nuts

MNT—Vitamin D

When serum active vitamin D is low, PTH is secreted. This causes increases in calcium and phosphorus which can lead to calciphylaxis.

Vitamin D supplementation is still controversial.

MNT--Carbohydrates

It is important for diabetic patients to manage their diabetes: Spread carbohydrates throughout the day. Eat at consistent times throughout the day.

Case Study--ET

24 YOF Pima Indian Dx with type 2 DM at 13 years old, poorly

compliant GFR decreasing over the past year 1 + pitting generalized edema

Lab ValuesParameter Normal Value Patient’s Value RationaleAlbumin 3.6-5.0 3.2 Albumin is being

lost in the urineOsmolality 275-295 400 Glucose is highBUN 8-26 80 Indicates kidney

dysfunctionCreatinine 0.6-1.3 1.5 Indicates kidney

dysfunctionCholesterol 140-199 443 High sat fat dietHDL 40-85 37 High sat fat dietLDL <130 132 High sat fat dietTriglyceride 35-160 300 High sat fat dietHbA1C 4.8-7.8 8.2 Glucose has been

consistently too high

PES Statement

Excessive fat intake relating to eating too many high fat foods as evidenced by 24 hour recall and high blood lipid levels (chol: 443 mg/dl, LDL: 132 mg/dl, TG: 300 mg/dl).

Sample Diet

Pt weighs 63.6 kg Recommended amounts: .8 g protein/kg = 51 g 30-35 kcal/kg = 1908-2226 kcals 8-12 mg/kg phosphorus = 509-763 mg 3 g sodium restriction

Sample Diet

Breakfast Lunch

Apple juice - Taco: Toast w/ butter ground beef,

tortilla, Margarine onion, tomato, lettuce Peach - Grapes Rice krispies Milk

Sample Diet

Dinner Penne pasta Marinara Green beans Caesar salad

Romaine lettuce, croutons, tomato, dressing Rolls with butter

Sample Diet

Actual from Diet: Protein: 46 g Calories: 1954 kcals Phosphorus: 785 mg Sodium: 3111 mg