Chapter 3- Kidney Flashcards
Define glomerular filtration rate
Volume of fluid filtered from glomerular capillaries to bowmans capsule per unit time
What are the 4 clinically important functions of the kidney
Filtration
Salt and water control
Production of EPO
hydroxylation of vitD
Two types of markers used to measure filtration
Exogenous
Endogenous
Name the three types of exogenous markers used to measure filtration
Inulin
Cr51 EDTA
iohexol
Name two types of endogenous markers used to measure filtration
Creatinine
Cystatin C
What is creatinine
Waste product from muscle generated at a relatively constant rate in individuals
Is creatinine largely removed by filtration?
YES
What’s the downside of estimating GFR using actual creatinine clearance
24 collections are cumbersome
Inaccurate
What three main things is creatinine significantly affected by
Age
Race
Weight
The estimated GFR gives a result standardised for what?
BSA 1.73m^2
Which method of measuring filtration is inaccurate for GFR>60ml/min
Estimated GFR
What is CKDEPI and what does it aim to do
Chronic kidney disease epidemiology collaboration aims to improve accuracy of eGFR
When is CKDEPI better than MDRD eGFR
Better accuracy at higher GFR
When is CKDEPI less accurate that MDRD?
Obese
Black
Female
What are the stages of CKD
1 2 3A 3B 4 5
If you’ve got stage 3A CKD what is your GFR?
45-59
If you’ve got stage 1 CKD what is your GFR?
> 90
Patient has stage 2 CKD what is there GFR?
60-89
Patient stage 3B CKD what’s their GFR?
30-44
Stage 4 CKD has what range GFR
15-29
5
What is normalised GFR appropriate for estimating?
How abnormal the kidney function is but NOT for dose adjustment
Name two drugs that have significant renal clearance
Aciclovir
Gabapentin
Name two classes of drug that affect residual renal function
NSAID
ACEI/ARB
What are the three types of AKI causes?
Pre renal
Intrinsic
Post renal
Name three types of pre renal causes of AKI?
Volume depletion
Sepsis
Cardiogenic
Name three types of intrinsic causes of AKI
Prolonged pre renal insult causing tubular necrosis
Inflammation/glomerulonephritis
Drugs
Name the causes of post renal AKI
Outflow obstruction e.g bladder, prostate, ureter
Why do you get renal anaemia?
Reduction in red cell production and increased red cell turnover
How do you treat renal anaemia?
EPO replacement
Iron replacement
Why are target ESA and Hb lower in patients with renal failure
Because three major studies showed suggested harm with higher/normal targets: increased risk of VTE
What does ESA stand for
Erythropoiesis stimulating agent
What is alfacalcidol
Post renal vitD used to treat renal bone disease
Two ways of treating tertiary hyperparathyroidism
Parathyroidectomy
Calcimimetics (cincalcet)
What’s the causes of tertiary hyperparathyroidism in renal patients
After prolonged stimulation of parathyroid glands
Sustained CKD
High phosphate
What does haemofiltration require
Anti coagulation:
Heparin
Prostaglandins
Citrate
Explain process of haemofiltration
Water and solutes filtered and discarded
Blood re-diluted with solution
Constant low efficiency RRT
Does haemodialysis require anticoagulation
YES
Give two examples of a drug that is not dialysed so would required dose adjustment in dialysis?
Warfarin
Diazepam
If a drug is dialysed when would you give it? Give two examples
End/post dialysis
E.g tazocin, meropenem
Explain the process of haemodialysis
Removal of solute only (water possible to- ultrafiltration)
Semi permeable membrane allows movement of solutes from high to low
Three 4hr sessions per week
Explain peritoneal dialysis
Fluid placed in peritoneum
Peritoneum forms semipermeable membrane
High conc to low conc solutes
Once fluid reached equilibrium it is removed and replaced
Define acute kidney injury
A rapid deterioration in kidney function, rise in creatinine, reduction in urine output
Prostaglandins cause what at the afferent blood vessels
Vasodilation
NSAIDs inhibit the synthesis of prostaglandin which has what result on afferent blood vessels
Vasoconstriction
What’s the bodies normal response to a reduction in renal blood flow
Vasodilation of afferent blood vessels
Vasoconstriction of efferent blood vessels
What does CANDA mean
C- contrast media A- ACEI N- NSAID D- Diuretics A- ARB
Does CKD often exist with other conditions
YEAH
Name 9 further complications of CKD
Anaemia Hyperphosphataemia Renal bone disease Oedema Hypertension Itching Nausea Electrolyte imbalance Restless legs/cramps
In renal patients what’s the aim for Hb levels?
10-12 g/dL
How do you manage anaemia in renal patients
Erythropoiesis stimulating agents and iron
In renal patients how do you manage high phosphate levels?
Dietary control and phosphate binders
Give the 5 options of phosphate binders
Calcium acetate Calcium carbonate Sevelamer Lanthanum Aluminium capsules
What’s 2 key problems for phosphate binders
Large tablet burden
Can bind to other meds
List 4 things that make a drug less likely to removed by dialysis
>500Da >80% protein bound >1L/kg Lipid soluble Not normally cleared by kidney
