Mark Nelligan BCS Flashcards
(150 cards)
Classification of CKD
see slide 5 of 2- progressive kidney disease lecture
Define rapid deterioration of renal function
Rapid deterioration defined as a fall in GFR of
> 5mLs/min/1.73m2 in 1 year
or
> 10mLs/min/1.73m2 in 5 years
Cause of deterioration of kidneys
- Lose adaptability
- Fail to excrete fluid load promptly
3.Fail to reduce urine volume in hypovolaemia promptly = DEHYDRATION Haemorrhage Hypotension Surgery Reduced Cardiac Output Sepsis
- Nephrotoxicity (NSAID’s, IV Contrast, etc)
- Worse in Diseased Kidneys
- Reduced Ability to Recover
Ist line Mx of HTN to prevent renal failure
- Angiotensin blockade (unless CI) eg. hyperkalaemia
2. Then move to ACE or CCB
1st line Mx of diabetic neuropathy (CHECK THIS WITH GREY BOOK AND NICE)
- Control HTN (130/80)
Tx of acidosis and justification
Sodium biocarbonate
Reduces Hyperkalaemia
Reduces Calcium Loss from Bone
Improves Catabolic State
Tx of hyperphosphatemia and justification
- Deranged Calcium, VitD, PTH
Normal Serum Phosphate
Reduces Renal Osteodystrophy
Reduces Calcium Loss from Bone
Improves Catabolic State
Dietary modifications in renal failure
- Protein Restriction 0.8 g/kg/day
- Avoid Ultra-Low Protein
- Calorie Supplements
No-Added Salt
- Sodium 60-90 mmol/day, Sodium Chloride 3.5-5 g/day
Reduced Protein
- Chronic Renal Failure 0.8 g/day
- Haemodialysis/CAPD 1.2 g/day
Reduced Phosphate
- <1000 mg/day
Low-Potassium Diet
- Potassium 40 mmol/day
Options or end stage renal failure
- End of life care
- Transplanatation
- Haemodialysis
- Peritoneal dialysis
What does dialysis `achieve
- Removes nitrogenous wastes/toxins
- Corrects electrolytes
- Removes water
- Corrects acid base abnormalities
Difference between dialysis and haemofiltration
Haemofiltration Blood is filtered across
a highly permeable membrane, allowing
movement of large and small solutes by
convection at almost the same rate. The
ultrafi ltrate is replaced with an equal volume
of fl uid, so there is less haemodynamic
instability. It is used in critically ill patients
for this reason, but is impractical as longterm
RRT, as it takes much longer than HD to
achieve the same clearance.
Haemodialysis removes solutes by diffusion. As such, it is relatively inefficient for solutes of high molecular weight as clearance by diffusion is inversely related to the molecular weight of the solute.
Haemofiltration removes solutes by convection. As such, efficiency remains more constant for all solutes able to cross the semi-permeable membrane.
The choice between haemodialysis and haemofiltration can be difficult. Points in favour of haemofiltration include:
better control of blood pressure
less risk of hyperlipidaemia
Those in favour of haemodialysis:
less expensive
technically easier
toxicity of molecules of high molecular weight has yet to be demonstrated
haemofiltration can only reduce, not normalise, the concentration of larger solutes
Advantages of haemodialysis
Good Clearance of small molecules
Very Efficient and Adjustable
Patient Freedom between Sessions
Does not cause Domestic Strain (Centre HD)
Acceptable to Patients
Disadvantage of haemodialysis
Expensive, Labour-Intensive, Capital-Intensive
Vascular Access
Intermittent Fluid Overload
Haemodynamic Instability during Dialysis
Restricted Fluid Intake
Poor Clearance of Phosphate
Poor Clearance of Middle Molecules
Malnutrition
Restrictive Diet
Types of peritoneal dialysis
- Diffusion of Chemicals – ‘Dialysis’
- Concentration Gradient In Both Directions - Osmotic Gradient (hypertonic glucose) - Endothelial Membrane with larger pores - ‘Middle Molecules’
- Convection of Chemicals – ‘Ultrafiltration’
- Transmembrane Hydrostatic Pressure does not exist
- Convection - Solvent Drag
- Endothelial Membrane with larger pores
- Middle Molecules’
Advantages of peritoneal dialysis
Preserves Residual Renal Function (8 ml/min virtual GFR)
Haemodynamically Stable, less challenging
Better Clearance of Middle Molecules
No Potassium Restriction
Liberal Diet
Lesser/No Fluid Restriction
Home-Based, No Travelling, More ‘Own’ time
Bloodless, Painless
Disadvantages of peritoneal dialysis
Self-Administered or Dependent on Trained Helper
Peritonitis and its Complications
Sclerosing Peritonitis
Often Chronic Fluid Overload
Poor Clearance of Phosphate
Obesity
Technique Failure after a few years
How is kidney function measured
MDRD equations gives eGFR
Causes of end stage renal failure
Diabetic Nephropathy
Glomerulonephritis
Idiopathic
Systemic (SLE, Vasculitis, Blood Dyscrasia, other)
Hypertension
Adult Polycystic Kidney Disease
Reno-Vascular Disease
Vesico-Ureteric Reflux Nephropathy and Congenital Renal Malformations CAKUT (‘Chronic Pyelonephritis’)
Other Hereditary Renal Diseases
Uremia related CV risk factors
- increased ECF
- Calcification
- PTH
- Anaemia
- ROS
- Malnutrition
- Pulse pressure
- TG’s and LP remnants
- Thrombogenic factors
Haemostatic Fx of the kidney
Fluid Balance & Euvolaemia
Excretion of Metabolic ByProducts
Degradation of Metabolic ByProducts, Peptides
Regulation of Chemical Composition of Plasma/ECF
Maintenance of Normal Osmolality
Acid-Base Balance
Hormonal Fx of the kidney
HORMONAL
- Endocrine
- Renin secretion
- Erythropoietin (HIF, Peritubular Cells)
- 1-α Hydroxylation of 25(OH)VitD3 - Paracrine
- Angiotensin II production
- Prostaglandin (PGI2, PGE2)
Haemostatic pathogenesis in renal failure
Accumulation of ‘Middle Molecules’ – ‘Uraemia’
Accumulation of Metabolic ByProducts (potassium,
phosphate, urate, oxalate, urea, creatinine)
Electrolyte Abnormalities
Acidosis
Oedema (Peripheral/Pulmonary) or Dehydration
Hyperlipidaemia
Compications of chronic renal failure
CKD1
No complications
CKD2
Increased CVD
CKD3
Increased CVD; Bone disease - raised PTH
CKD4
CVD, Anaemia, Bone disease - low Ca, high PO4
CKD5
CVD, Anaemia, Bone disease, Pruritus, Bleeding, Malnutrition
Symptoms of chronic renal failure
- Uraemic Muddy Colour:‘Urochrome’
- Severe Hypertension: Cardiac Failure, Headache, cerebrovascular Events,
- Fluid Overload : Peripheral Oedema, Ascites
- Pulmonary Oedema: Dyspnoea, Orthopnoea
- Hyperkalaemia: Cardiac Arrest, Diarrhoea,Peripheral Paralysis
- Diarrhoea, Vomiting: Gastritis, Hypermotility
- Peripheral Neuropathy :‘Middle Molecules’
- Encephalopathy, Coma: ‘Middle Molecules’, Urea