nutrition- chapter 21 Flashcards
nephrons
kidneys
filter about 1.2 L/minute
glomerulus
Bowman’s capsule
glomerular filtration rate (GFR)
- should be >60
proximal tubule
loop of Henle
distal tubule
collecting tubule
excretory and regulatory functions
- filtration
- reabsorption
- secretion
- excretion
endocrine functions
- renin secretions
- erythropoietin secretion
- vitamin D activation
general causes of kidney disease
- infection and obstruction
- damage from other diseases
- genetic and congenital defects
risk factors for kidney disease
- diabetes
- hypertension
- cardiovascular disease (CVD)
- age > 60
- obesity
- family history
MNT in kidney disease
influenced by:
- length of disease
- degree of impaired kidney function and clinical symptoms
acute glomerulonephritis or nephritic syndrome
- disease process: inflammatory process that affects glomeruli
- clinical symptoms: hematuria, proteinuria, possible edema, mild hypertension
- oliguria and anuria may develop
- MNT: diet modifications usually not crucial for acute disease
nephrotic syndrome (nephrosis)
- disease process: nephron tissue damage allows protein to pass into tubule
- clinical symptom: hypoalbuminemia, edema, ascites, distended abdomen, reduced plasma protein level, eventual malnutrition
- additional symptoms may include: hyperlipidemia, lipiduria, blood clotting abnormalities, imbalances in several minerals
MNT for nephrotic syndrome (nephrosis)
- protein: moderate
- energy: adequate to support nutrition status
- fats: total fat intake less than 30% total kcals/day, total cholesterol less than 200 mg/day
- sodium, potassium: sodium limited to 1-2 g/day; both closely monitored
- calcium: limited to 1 to 1.5 g/day
- phosphorus: limited to 12 mg/kg/day
- fluid: restricted in response to urine output and insensible losses
acute kidney injury
disease process:
- prerenal: inadequate blood flow to kidneys and subsequent reduced GFR
- intrinsic: damage to a part of the kidney
- postrenal obstruction: obstruction of urine flow
hematuria
blood in the urine
anuria
failure of the kidneys to produce urine; output less than 100mL
oliguria
abnormally small production of urine
acute kidney injury
symptoms:
- RIFLE classification system
- acute kidney injury network (AKIN) criteria
diagnostic criteria:
- increase in serum creatinine and oliguria
- continuous renal replacement therapy (CRRT) (type of dialysis) supports kidney function for some critically ill patients
MNT:
- basic objective: improve or maintain nutrition status
- principle: appropriate intake of protein, energy, sodium, potassium, phosphorus, calcium, vitamins, minerals and fluids
chronic kidney disease (CKD)
disease process:
- progressive breakdown of kidney tissue
most often results from:
- metabolic diseases with kidney involvement
- primary glomerular disease
- inherited diseases or congenital abnormality
- other causes: immune diseases, obstruction, infection, long-term use of nephrotoxic medications
CKD
clinical symptoms:
- water imbalance: large amounts of dilute urine (polyuria) in early stages, followed by oliguria and finally anuria as disease progresses
- elevated blood urea nitrogen, serum creatinine, and serum uric acid levels
- electrolyte and mineral imbalance
- anemia
- hypertension
CKD
general signs & symptoms:
- weakness, fatigue, and shortness of breath
- anemia
- swelling in the extremities
- itchy skin rashes
- possible anorexia, nausea, and vomiting
- protein-energy wasting (PEW) syndrome
- lower resistance to infection due to malnutrition
- Kussmaul’s breathing
- mouth ulcers, a foul taste, and bad breath
- muscular twitching and peripheral neuropathy
MNT for CKD
- basic objectives: individualized treatment, adjusted to illness progression
- principles: appropriate intake of protein, energy, sodium, potassium, phosphorus, calcium, vitamins, minerals and fluids
end-stage renal disease (ESRD)
disease process:
- GFR decreases to less than 15mL/min per 1.73m^2 body surface area, indicating irreversible damage to a majority of the kidneys’ nephrons
treatment options and MNT:
- hemodialysis
- peritoneal dialysis
- transplantation
ESRD/ dialysis complications
long term:
- bone disorders, malnutrition, anemia, hormonal and blood pressure imbalances, depression, and diminished quality of life
additional complications:
- enteral or parenteral nutrition support
- osteodystrophy
- neuropathy
calcium stones
- excess calcium in the blood (hypercalcemia) or urine (hypercalciuria)
- excess oxalate (hyperoxaluria) or uric acid in the urine (hyperuricosuria)
- low levels of citrate in the urine (hypocitraturia)
struvite stones
- primarily caused by urinary tract infections
acute on chronic kidney disease
- preexisting CKD
- suddenly incur AKI on top of CKD
kidney stones
uric acid stones:
- impairment of purine metabolism with some diseases
other stones:
- hereditary disorders
- complications of medications
clinical symptoms:
- severe pain
- other urinary symptoms
MNT for kidney stones
calcium stones:
- avoid foods that are high in oxalate; add specific types of dietary fiber
uric acid stones:
- alkaline diet; potassium citrate treatments
cystine stones
- reduce urinary cystine concentrations, reduce sodium intake, increase intake of vegetables high in organic anions, and dilute the urine with copious amounts of water
urinary output (UOP)
should be at least 30mL/hr
