Chronic Kidney Disease Flashcards
Describe the distribution of body fluid
2/3s: Intracellular fluid Volume = 28L 1/3: Extracellular fluid 11L Interstitial fluid (80% of ECF) 3L Plasma volume (20%)
Determinants of fluid movement
Hydrostatic pressure (into IF) Osmotic pressure (salt and electrolytes) Oncotic pressure (protein)
Hormones involved in fluid balance
Angiotensin II
Aldosterone (from adrenal cortex by angiotensin II)
ADH
Functions of ADH in fluid balance
Vasoconstriction of blood vessels
Increased reabsorption of water in kidney
Functions of Aldosterone in fluid balance
Increases water reabsorption and decreases urine volume
Increased BP
Function of Angiotensin II on blood vessels
Vasoconstriction (increased BP)
What is daily fluid intake for adults on a relatively sedentary lifestyle
1.5-2.5L
Examples of fluid losses from body
Urination
Sweating
D+V
Surgery
5 functions of kidney
Blood Volume/Fluid status
Waste/Toxin/Drug excretion
Vitamin D metabolism (Vitamin D to 1-hydroxyvitamin D)
Generates erythropoietin (red cell production)
Acid-Base Regulation (excretes H+ ions and reabsorbed HCO3- ions)
Measurement of kidney function
Creatinine:
Waste product of muscle metabolism (but not good measurement in people with abnormal muscle mass)
Purely excreted by kidneys
Longstanding measure of kidney function
DEscribe relationship between sCreatinine (y) and GFR (x)
Reciprocal or as GFR increases, sCr decreases (rapidly at start then decreases less rapidly)
What is taken into account when calculating persons eGFR
Age
Gender
Race
(estimate how well the kidney is working)
How to detect protein in the urine
Dipstick
Give example of something that is excreted by the kidney on a constant rate
Creatinine
How can you measure proteinuria/albuminuria
Albumin Creatinine Ratio
Albumin in urine can be diluted or concentrated depending on urine volume
Creatinine is excreted in the urine at a constant rate (irrespective of urine volume)
Therefore the ratio of albumin to creatinine should be constant irrespective of urine volume
Describe staging of CKD
Good - GFR At least 60 and albuminuria <3mg/mmol;
Less good - GFR 45-59 and albuminuria <3mg/mmol; GFR at least 60 and moderatlly increased albuminuria 3-30mg/mmol
Quite bad - GFR 30-44 and albuminuria <3mg/mmol; GFR 45-59 and albuminuria 3-30mg/mmol; GFR at least 60 and albuminuria >30mg/mmol
Bad - all others (v low GFR and v high albuminuria)
Aetiology of CKD
Any renal disease Diabetes Mellitus Glomerulonephritis Cystic disease AKI Hypertension Malignancy Anatomical abnormality of renal tract Hereditary disease e.g. polycystic kidney disease
Management of hypertension in adults (pharmacological)
ACE inhibitor or Angiotensin Receptor Blocker (<55 years)
Calcium channel blocker (>55 or black)
->Both if no effect
->+Diuretic
Add another diuretic or alpha blocker or beta blocker
Management of Cardiovascular risk - hypertension
Hypertension:
Treat systolic BP 140 or 130 if ACR >30g/g
RASi if ACR >30mg/g (diabetes) or 300mg/g (non-diabetes)
Consider <120 mmHg based on SPRINT
Management of Cardiovascular risk - Dyslipidemia
Lipid lowering with statins
Treat as per high risk population guidelines
Management of Cardiovascular risk - CKD specific
Phosphate Vascular calcification LVH Inflammation Vit D deficiency Sodium/water excess Electrolyte imbalance
Management of Cardiovascular risk - other than CKD, dylipidemia or hypertension
Address lifestyle
What causes anaemia in CKD
Iron deficiency
Liver produces Hepcidin
When kidney function is poor, the hepcidin builds up and inhibits iron absorption from the duodenum
Therefore iron levels are low
One of the first important things to do in CKD is get iron levels up, how would you do this
Not oral as cant absorb iron through the duodenum
IV iron + Erythropoietin
Examples of Renal Replacement Therapy
Haemodialysis
Peritoneal dialysis
Kidney transplant
Peritoneal dialysis - what is it
Involves infusing a sugary solution into the abdomen which draws off toxins
Transplanted kidneys
New kidneys not in same place as old kidneys (put lower down)
Put in iliac fossa
How do you assess volume/fluid status
Urine volume (not great for dialysis patients)
JVP
Stethoscope to listen to bottom of lungs (fluid in lungs, may be crackly)
Why do you see oedema more in the ankles
Oedema generally seen in ankles where hydrostatic pressure would be greater thus fluid is more likely to leak out despite similar oncotic pressure in the vessel
Hydrostatic pressure also increases when you’re fluid overloaded
Give examples of drugs that could be contraindicated in case of dehydration
ACE inhibitors ARBs Diuretics Metformin NSAIDs (vasoconstriction of small arteries entering kidney)
What can you give to treat dehydration
IV fluid
When would you give less fluid for dehydration
Renal impairment
Cardiac failure
