Nutrition and Chronic Kidney Disease Flashcards
What are the two leading causes of kidney failure
l Diabetes-38%
l Renal Vascular Disease (including high
blood pressure)-12%
Stages of kidney failure and associated GFR values
Normal or high ≥90ml/min/1.73
Mildly decreased 60-89ml/min/1.73
Mildly or moderately decreased 45-59ml/min/1.73
Moderately to severely decreased 30-44ml/min/1.73
Severely decreased 15-29ml/min/1.73
Kidney failure <15 ml/min/1.73
A person can lose __ of their kidney function before symptoms appear
A person can lose more than 50% of their kidney function before symptoms appear
Are there symptoms at early stages of kidney failure?
no
Groups of clinical manifestations of chronic kidney disease
- gastrointestinal
- integumentary (dry skin, skin color changes)
- respiratory (increased respiratory rate)
- renal
- gastrointestinal
- Cardiovascular (High BP, increased heart rate)
- Neurological (restless legs, altered motor function)
- hematological (anemia, weakness, fatigue, pallor)
- musculoskeletal (decreased calcium, Vit D)
- immune (increased risk of infection)
Does dialysis reverse kidney damage?
No
What are the main functions of dialysis?
l Clearing wastes (urea) from the blood
l Restoring electrolyte balance in the blood
l Eliminating extra fluid from the body
what are the 3 main categories of dialysis?
- hemodialysis (HD)
- Peritoneal dialysis (PD)
- Continuous Renal Replacement Therapy (CRRT)
What are the types of HD? descriptions
l Intermittent: patients come to the hospital 3 times/week for 34 hours to be dialyzed in the hospital
l Nocturnal
l Short daily
In nocturnal and short daily the machine is at home; receive training at the hospital to get dialysis at home
types and descriptions of PD
l CAPD (Continuous Ambulatory Peritoneal Dialysis): during the day at home l CCPD (Continuous Cycle-Assisted Peritoneal Dialysis): dialysis at night with cycler (machine) that does dialysis during the night
Types of CRRT
Both are 24h/day; usually in the ICU setting l CVVH (Continuous venovenous hemofiltration) l CVVHD (Continuous venovenous hemodialysis)
HD principle
blood leaves the body and goes into the dialysis machine where it is filtered via diffusion, osmosis and ultra-filtration
filtration occurs against dialysis solution which allows waste products, toxins and fluids to be removed from the blood before it is returned back to the patient
what is the purpose of ultrafiltration?
Removal of excess fluid
What is the dialyzer
it is the artificial kidney
l Provides a semipermeable membrane between the patient’s blood and the dialysate solution
l Semipermeable membrane through which diffusion, osmosis and ultrafiltration can take place
What is dialysate and its types?
Fluid containing physiological concentration of various solutes
types: K 0, 1, 2, 3, 4
- potassium concentrations vary between 0-4. Usually use 2 and 3
- > concentration of 2 returns less potassium into the bloodstream. Only used when sK> 5mmol/L
- > concentration 3 returns more K into the blood e.g. used in hypokalemia patients.
what is the normal range for potassium?
3.5-5
What is dry weight?
- Its the target weight that needs to b achieved after each dialysis session
- No signs or symptoms of over
hydration or dehydration - This weight has no extra fluid (euvolemic)
What is used to determine how much fluid will be removed in dialysis
dry weight
define fluid weigh and goal value
Weight accumulated between dialysis sessions
-> Goal 1kg/day =1L of fluid/day
what is the main cause of HTN in renal problems
fluid accumulation
If a patient loses body weight and their dry weight is not adjusted, we can expect their BP to be?
High
they lost weight but dry weight was not adjusted-> we will providing too much fluid-> BP will be high
What are the 2 types of vascular access?
Central Venous Catheters
Arterio-Venous (AV) Fistula
Describe Central Venous Catheters
usually internal-jugular but can be subclavian or femoral
more prone to infection and infection as they are an open action to patient’s body
Describe Arterio-Venous (AV) Fistula
fistula is a preferred and safer access
can be created by a surgical procedure where artery and vein are anastomosed
high pressure from the artery will dilate the vein where the pt will be needled for dialysis
most are in the forearm or can be created in upper arm
What is a downside of AV fistula
dilation of the vein creates bumps-> quite visible and patients don’t like it
Can a person with a Central Venous Catheter
l Take a shower?
l Swim in a lake or public pool?
How about someone with a AV Fistula?
Central venous catheter is an open system-> cannot take a shower or swim
AV Fistula-> can do both of those things
Mechanics of Peritoneal Dialysis
- Done at home
- A sterile catheter is surgically implanted into patient’s peritoneum.
- Special dialysate solution is run through this catheter into the peritoneal cavity
What is exchange in PD? How long is it ?
- Exchange is the process of draining and filling
- 30-40 minutes
What is dwell time in PD? How long is it ?
- Dwell time is the time the dialysate solution is left in the peritoneal cavity
- 4-6 hours
Constipation in PD
Constipation can displace/compress peritoneal dialysis-> disruption
constipation can also result in displacement of bacteria into peritoneal cavity-> peritonitis (severe infection) which results in inability to do peritoneal dialysis
Thus all patients in PD are on stool softeners or/and laxatives to ensure regular bowel movement
What are the 2 types of PD?
- CAPD Continuous Ambulatory Peritoneal Dialysis
- CCPD Continuous Cycle-Assisted Peritoneal Dialysis
Describe CCPD Continuous Cycle-Assisted Peritoneal Dialysis
- Requires a machine (cycler)
- While the patient sleeps
- 3-5 exchanges/night
Describe CAPD Continuous Ambulatory Peritoneal Dialysis
- During the day
- 4 exchanges/day
- Usually 2-3 liters /exchange
frequency of HD vs PD
PD is done daily
HD is 3-4x/week
What are the 2 types of solutions for PD dialysate?
- Dextrose based
2. Special solutions
Describe dextrose based solutions for PD
provides the osmotic “pull”
- 0.5%, 1.5%, 2.5%, 4.25%
- Consider kcal from dextrose absorption
- Diabetics-adjust insulin
- Sclerosing of the peritoneal membrane
Describe special solutions for PD
- Nutrineal (amino acid 1.1%)-glucose polymer instead of dextrose -> can be used for patients who are not meeting their protein reccs; can be used as one of the exchanges
- Extraneal (Icodextran 7.5%)
- > glucose polymer-> not as absorbed as dextrose solution; equivalent to dextrose 4.25- great pool, but less calories (great for diabetic pt, or those pt that need to lose a lot of fluid
- Physioneal-most biocompatible solution
- > because pH of the solution is similar to pH of the blood
1.5% dextrose Peritoneal Dialysate: kcal available, CAPD absorbed, CCPD absorbed
kcal available: 15 kcal
CAPD absorbed: 31-36 kcal/L
CCPD absorbed: 20-26 kcal/L
2.5% dextrose Peritoneal Dialysate: kcal available, CAPD absorbed, CCPD absorbed
kcal available: 25 kcal
CAPD absorbed: 51-60 kcal/L
CCPD absorbed: 34-43 kcal/L
4.25% dextrose Peritoneal Dialysate: kcal available, CAPD absorbed, CCPD absorbed
kcal available: 42.5 kcal
CAPD absorbed: 87-102 kcal/L
CCPD absorbed: 58-73 kcal/L
Dextrose absorbed: CAPD vs CCPD
CAPD ~60-70% dextrose absorbed
CCPD ~40-50% dextrose absorbed
What is the starting type of PD?
CAPD is the 1st type of PD aka PD for beginners
How does the type of PD change with decreased kidney function or when peritoneal membrane degrades?
if kidney function degrades, peritoneal membrane degrades, cycler becomes insufficient, and they require more dialysis-> keep the cycler and add 1-2 manual dialysis per day, so they don’t have to come to hospital that often
what is the test to assess peritoneal membrane? when is it done?
PET (Peritoneal Equilibration Test) used to assess permeability of the peritoneal membrane (gives us % dextrose absorption)
any new patient that starts PD after they have been on it for 6 weeks, they do a PET test - e.g. solutes, or fluid pass better or both; also give % of dextrose absorption-> helps decide whether manual exchange during the day is better or night cycler, the concentration of the solution to use