Kidney Flashcards
role of kidney
1) Maintenance & regulation of fluid balance
2) Acid / Base & electrolyte balance:
-Sodium
-Potassium
-Bicarbonate
-Calcium
-Phosphate
-magnesium
3) excretion of wastes*: essential -> dialysis if not
-Urea
-Creatinine
-Nitrogenous waste
-Hydrogen ions
4) conservation:
-glucose- we dont want to filter this -> if people have too high glucose -> leaks through basement membrane and we pee glucose
-amino acids
-proteins
5)Production
- erythropoietin (EPO)
- 1,25 dihydroxyvitamin D (calcitriol)- know this
renal panel
-BUN
-creatinine
BMP
-Sodium- fluid volume, nerve conduction, neuromuscular function
-Potassium- acid-base balance, neuromuscular function, cardiac muscle contraction + conduction
-CO2 (HCO3-) - buffer
-Chloride- O2/CO2 exchange in RBC
-Creatinine- breakdown of product in muscle
-BUN- N2 in blood in form of urea
-Glucose- energy
creatinine description+ where is it produced
Description:
- waste product of MUSCLES in normal metabolism
-Produced in skeletal muscle, kidney, pancreas
-breakdown process of creatinine phosphate occurs at relatively constant rate and transported through bloodstream to kidneys
-kidneys filter out most of creatinine and dispose of it in urine
-Clearance from the kidneys = GFR
Creatinine: when is it high vs low
HIGH creatinine levels: kidneys are not getting proper flow or filtration issue
- kidney disease
- dehydration
- muscle breakdown
LOW creatinine:
- malnutrition
- low muscle mass
BUN description; when it is high vs low
BUN: urea found in blood
- urea = waste product of PROTEIN breakdown
- produced/converted in the liver: Amino acids -> Ammonia -> Urea
High:
- kidney disease
- heart failure
- dehydration
- gi bleeds
Low:
- liver failure
- malnutrition
Factors affecting BUN
-hydration
- protein intake
- BLOOD IN GI tract* -> absorbing the blood -> causes rise in BUN
- liver failure
- malnutrition
calcium abnormal results can mean
-kidney/liver problems
-bone disease
-thyroid disease
-cancer
-malnutrition
glucose abnormal results
High:
- diabetes/prediabetes
Low:
- hypoglycemia
- chronic damage to basement membrane -> damaging nephron
renal failure sx
-Malaise
-Headache
-Visual disturbances
-Nausea/ Vomiting
-dysuria
-wasting
renal failure signs
-Flank tenderness
-rash- nitrogen waste may deposit into skin -> irritation
-Volume of urine reduction <500 cc
-Anuria <100 cc (no urine)
-Hematuria (blood)
- Casts (crystals)
- Proteinuria (signs of basement membrane leaking), - Pyuria (pus)
-Hypertension- if BP is not affected by meds or lifestyle -> consider renal artery stenosis -
- renal artery stenosis - activates angiotensin-aldosterone system to increase BP when they don’t have enough blood flow
-Change in urine color or odor
-Lab changes
-AV knicking- redness shows longstanding HTN and diabetes
-abdominal bruit: renal artery stenosis, AAA
-peripheral neuropathy: secondary complication
causes of chronic renal failure
- uncontrolled diabetes
- HTN **
Prerenal azotemia causes and definition
-Prerenal (MC cause): reduced blood flow to the kidneys
causes:
- low BP/hemorrhage
- CHF: reduced cardiac output
- renal artery stenosis
- dehydration
Renal azotemia causes and definition
Renal: Kidney is dysfunctional
Causes:
-Disease of vessels, glomerulus, tubules, mesangium
-Autoimmune (lupus)
- infectious (glomerular nephritis)
- medication damage
Post-renal azotemia causes and definition
Post renal: obstruction of urine flow
causes:
- Anatomic obstruction: narrow ureters or AAA
-Ureter, bladder, or urethra stone
- tumor/neoplasm
- inflammatory lesion
-Congenital anomaly
azotemia: definition + three types
Definition: “nitrogen in the blood”
- high levels of nitrogen-containing compounds in the blood (urea, creatinine, waste products)
Three types:
- Prerenal: MC* -> reduced flow to the kidneys
- Renal -> kidney tissue itself is damaged
- Post renal -> obstruction of urine flow
BMP, SMA 7, chem 7
-Sodium
-Potassium
-Chloride
-Bicarbonate
-Bun
-Creatinine
-glucose
erythropoietin
-effect on CBC
-kidney stops telling you to make EPO -> less RBC formation in marrow
-less O2 delivery
other lab tests for kidney function
-Acid base with ABG
-Plasma calcium, albumin, phosphate, parathyroid hormone, Vitamin D panel
-Urinalysis
“A CUPPA tea - makes you wanna pee”
A -ABG; for acid/base
C - calcium
U - urine analysis
P - parathyroid hormone
P - phosphate
A - albumin
GFR and Creatinine Clearance (CrCl)
Creatinine Clearance:
-measures how well the kidneys filter waste products from blood
- CrCl: mL of blood that kidneys can clear of creatinine in 1 minute
-LOW CrCl = waste retention
eGFR:
-Estimates how much blood passes through the glomeruli in 1 minute
-Estimated from Creatinine clearance, age, sex and ethnicity
- high serum creatinine = low GFR (inverse relationship)
Method of measurement of Creatinine Clearance
24 hr urine collection for accuracy: measures creatinine cleared from body over 24 h
- urine creatinine
- serum creatinine
- urine volume
- collection time in minutes
Cockcroft-Gault Creatinine clearance formula:
- useful for DRUG CALCULATION use
- ex: 1 kidney = lower creatinine clearance -> increases risk of rhadomyolysis
Crockcroft-Gault formula for estimating creatinine clearance
Example Patient details:
Gender: Male
Age: 60 years
Weight: 70 kg
Serum creatinine: 1.2 mg/dL
CrCl = ((140 - AGE) x weight)/(72 x SERUM CREATININE)
Example Patient details:
Gender: Male
Age: 60 years
Weight: 70 kg
Serum creatinine: 1.2 mg/dL
CrCl = ((140− 60) × 70)/ (72 × 1.2)
CrCl= 64.81 mL/min
if female: multiply the CrCl value by 0.85!!!!!!
example:
64.81 x 0.85 = 55.09 mL/min
stage of chronic kidney disease based on GFR
-stage 1- kidney damage with normal kidney function - GFR >= 90
-stage 2- kidney damage with mild loss of kidney function- GFR 89-60
-stage 3a- mild to moderate loss of kidney function- GFR 59-45
-stage 3b- moderate to severe loss of kidney function- GFR 44-30
-stage 4- severe loss of kidney function- GFR 29-15
-stage 5- kidney failure- GFR <15
-aggressively treat underlying issue once you see any signs
-potassium rise and no urine -> consider dialysis
dehydration definition + categories of loss
Dehydration: volume depletion results from loss of Na+ and WATER
-dehydration causes pre-renal azotemia
categories:
- GI loss
- renal loss
- skin loss
- third space sequesteration
