Class notes
Renal Failure
- Course
- Institution
Lecture notes Renal Failure
[Show more]
Seller
Follow
polinalobacheva
Reviews received
Content preview
https://www.youtube.com/watch?v=dniCgjsgMv8Kidneys have 3 majors functions:
1. Excretion of waste
2. Maintenance of extracellular fluid (ECF) volume and
composition
3. Hormone synthesis
Why are renal function tests necessary?
- Identify renal dysfunction
- Diagnose renal disease
- Monitor disease progress
- Monitor response to treatment
- Assess changes in function that may impact on therapy
Kidneys function tests:
1. Filtering capability of kidneys - glomerular filtration
rate (GFR)
2. Presence of disease markers in urine
Glomerular filtration rate (GFR)
, - Volume of plasma from which a given substance is completely removed by glomerular filtration in a given time
- Estimation of efficiency
- 140ml/min in healthy adults
- Identifies chronic kidney disease (CKD)
- Measured using exogenous or endogenous substances
Measurement of GFR: characteristics of an ideal substance to measure GFR
- Stable concentration in plasma
- Physiologically inert
- Freely filtered at the glomerulus
- Not secreted, reabsorbed, synthesised or metabolised by kidneys
Exogenous substances to measure GFR Endogenous substances to measure GFR - Serum creatinine:
1. Radioisotopes: 1. Advantages:
a. 125I-iothalamate a. Product of muscle breakdown
b. 51Cr-ethylenediaminetetraacetic acid b. Freely filtered by glomerulus
(EDTA) 2. Disadvantages:
c. 99mTc-diethylenetriaminepentaacetic a. Timed urine collection
acid (99mTc DTPA) b. Plasma creatinine affected by age, sex, exercise, muscle mass,
2. Non-radioisotopic: certain drugs and nutrition
a. Inulin c. Increased tubular secretion of creatinine in renal insufficiency
b. Iohexol d. Extrarenal clearance in advanced kidney disease
e. Usually overestimated by 10-40% at clearances > 80ml/min
(100ml/min)
Don’t rely on serum creatinine clearance measurement alone to assess kidney function
Estimate GFR (eGFR):
- A more reliable estimate of GFR than using serum creatinine clearance alone
- Cockcroft and Gault Modification of Diet in Renal Disease (MDRD) (adults)
- Schwartz and Counahan-Barratt equation (children)
- UK department of health recommends use of MDRD in addition to serum creatinine
- Only suitable if kidney function is stable
Calculate the creatinine clearance in ml/min: A patient produced 1500ml of urine in a 24 hour
period. This patient had a urine creatinine concentration of 10mmol/L and a plasma creatinine
concentration of 100 umol/L. Calculate the creatinine clearance in ml/min.
Kidneys function tests:
1. Filtering capability of kidneys - glomerular filtration rate (GFR)
2. Presence of disease markers in urine
Presence of disease markers in urine:
- Urinalysis: colour, turbidity, foaming
- Microscopic analysis
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller polinalobacheva. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.05. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
81989 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now