chronic kidney disease Flashcards
What is the GFR
Glomerular filtration rate - the rate of filtrate coming from the glomerulus to bowman’s capsule
What is the effect of higher pressure on the GFR
higher pressure causes an increased GFR
How do you measure excretory renal function
Measure substances that are only cleared by the kidney - e.g creatinine
At what GFR does plasma creatinine begin to increase
As GFR drops below 50%
What factors affect the serum creatinine
Age
ethnicity - African Americans have a higher serum creatinine due to higher muscle mass
gender
weight
other illnesses
muscle mass
Diet
How is creatinine generated
The breakdown of muscle
How do we classify excretory function using eGFR
International Chronic kidney disease classification system
Describe the eGFR and give a description for stage 1 on the International Chronic kidney disease classification system
Kidney damage /normal or high GFR - GFR is greater than 90
Describe the eGFR and give a description for stage 2 on the International Chronic kidney disease classification system
Kidney damage / mild decrease in GFR - GFR is between 60-89
Describe the eGFR and give a description for stage 3a and 3b on the International Chronic kidney disease classification system
3a - moderately impaired - GFR 45-59
3b - moderately impaired - GFR 30-44
Describe the eGFR and give a description for stage 4 on the International Chronic kidney disease classification system
Severely impaired - GFR 15-29
Describe the eGFR and give a description for stage 5 on the International Chronic kidney disease classification system
Advanced or on dialysis - GFR is less than 15
How is the filtering function of the kidney assessed
Checking if the glomerular basement membrane is letting larger substances through - e.g Red blood cells, albumin and other high molecular weight proteins
Checking glucose as it should be reabsorbed and not excreted
It is checked by urinalysis (dipstick)
or protein quantification (Protein creatinine ratio)
What can cross the glomerular basement membrane
electrolytes and creatinine
What can’t cross the glomerular basement membrane
Red blood cells and white blood cells
High molecular weight proteins like albumin and globulins
What can cross the glomerular basement membrane but should be reabsorbed in the proximal tubule
glucose
What are issues in the glomerular basement membrane usually called
Glomerular nephritis
Define chronic kidney disease
A GFR of less than 60 or the presence of kidney damage that is present for more than or equal to 3 months
The kidney damage can be found by - abnormal blood, urine or x-ray findings
What is the relationship between CKD and age
A s age increases, risk of CKD increases
What is the most potent detector of end stage kidney disease
Proteinuria
What is renal replacement therapy
Dialysis or kidney transplant
What are the most common causes of chronic kidney disease
Diabetes
Glomerulonephritis
Systemic disease
Reno-vascular disease
Genetic disorders like polycystic kidney disease
What tests are done to find the cause of a patients chronic kidney disease
Blood tests - U&E and a full blood count
Urine tests - dipstick and protein creatinine ration
Histology and radiology
What imaging is used in finding the cause of CKD
Ultrasound - it is non invasive with no radiation and can show how large the kidney is - small kidneys indicate chronic kidney disease
