chronic kidney Flashcards
when do we define the issue as chronic kidney disease ?
Repeated kidney injury with supportive care within 3 MONTHS
Chronic vs acute renal failure ?
Acute renal failure :
Abrupt onset
Potentially reversible
Chronic renal failure CRF :
Progrsses at least 3 months ( We dont always wait 3 months if the evidence is present )
permanent non reversible damage to nephrons
how do we define chronic kidney disease ?
1- Urinary albumin excretion of 30 mg/day or more
2- Estimated glomerular filtration rate less than 60 mm for 3 months or more
3- Association of eGFR less than 60 , albuminuria , urine sediment abnormalities and renal tubular disorders defines CKD at 2 months
how do we stage CKD?
Established through the measurement of GFR
done via injecting insuline as well ASSESSING PLASMA CREATININE LEVELS from blood sample and taking 24 hours urine sample
Plasma creatinine and 24 hour urine test are both very critical lab tests that need to be taken for patients suspected to have CKD
theres a specific formula for calculating GFR on the basis of age and body weight
at risk patients include those with GFR below 110 mL/Min normal is around 120-125
Stage 2 : considered mild may need follow up and investigations ( GFR 60-89 )
Stage 3 : the patients is in bad situation involving irreversible kidney damage , needs full diagnosis and aggressive treatment HOWEVER CAN STILL LIVE WITHOUT DIALYSIS OR RENAL TRANSPLANT UNDER CONSERVATIVE MANAGEMENT (30-60 )
stage 4 and 5 ( 15-30 OR LESS THAN 15 ) : REQUIRES RENAL DIALYSIS
what other ways we use to measure disease severity?
concentration of albumin being excreted (albuminuria )
general rule level of albumin in urine must not exceed 30 mg/day
The A3 stage of albuminuria ( more than 300 mg/day ) reflects severely- impaired kidney
its important to incorporate both parafmeters ( GFR and albuminuria ) in staging of CKD
we can use ultrasound as well
what are the risk factors of CKD?
Diabetes –> MOST COMMON CAUSE OF ESRD(30%)
Hypertension –> 23% of cases
Glomerulonephritis 10% cases
polycystic kidney disease - 5% of cases (autosomal dominant renal disease )
Rapidly progressive GN ( vasculitis ) 2% cases
Chronic intoxication ( aflatoxin , mercury )
Renovascular disease
Drugs
what is the aeitology of chronic kidney disease?
1- Episodes of ARF usually acute tubular necrosis often lead to eventually to CRF
2- Over time, combination of acute renal insults are additive and lead CRF
describe analgesic nephropathy ?
drug induced renal failure
Associated with a use of NSAIDS
Slow progression
Polyuria is the most common early symtpoms
Macroscopic hematuria / papillary necrosis
Chronic interstitial nephritis , renal papillary necrosis , renal calcification
it is interstitial disease = show RBCS and WBCS casts may also eosinophils
clinical features of chronic kidney failure?
Uremia syndrome :
Earthy look
Fever malaise
anorexia and nausea
Mild neural dysfunction
Uremic pruritus
Bones aches and cramps
Neuropathy
describe hypertension causing problems ?
Renin aldosterone angiotensin
Atherosclerotic changes in LVH
about 30% of end stage renal disease ESRD is related to hypertension
Overall risk of CRF with creatinine more than 2. mg is 2X in fives with hypertension
how does CRF cause anemia?
reduced erythropoietin production by kidney
bone marrow depression
Occur when creatinine rises to 2.5-3 mg
Anemia management : HCT goal = 33%
how does CRF causes acidosis?
Defect in renal generation of HCO3 as well retention of NOVOLATILE ACIDS
acidosis caused by hyperchloremia narrow anion gap acidosis
When GFR 40 ml then decrease NH4 excretion adds to metabolic acidosis
When GFR reaches less than 30 = Urinary phosphate buffers decline and acidosis worsens
Bone CaCO3 being to act as the buffer and bone lesions results –> RENAL OSTEODYSTROPHY
what comes with renal osteodystrophy?
Low vitamind D, hypocalcemia ( cuz kidney cant convert vitamind D to active form )
Secondary hyperparathyroidism ( cuz low calcium )
Bone demenralization
Bone resorption, osteodystrophy
Phosphate retention ( when calcium becomes low , phosphate increases )
how does hyperkalemia happen in CRF?
Tubular K secretion is decreased
Aldosterone mediated ( PRIMARY CAUSE )—> kidney cant excrete potassium
Catabolism, hemolysis
How does hyponatremia happen in CRF?
cannot conserve Na when GFR less than 25 and FeNa rises with falling GFR
natriuretic peptide
treatment of hyperkalemia?
calcium gluconate
Insulin glucose
Kayexalate
Mg instead of Ca in patients digoxin
Bicarbonate in severe acidosis
Dialysis
main focus here is to shift potassium ions from ECF itno ICF
what is the management of CRF?
Reversal of underlying disease
Avoid/treat acute insults
Slow progression of nephropathy
Minimise complications
Prepare physically and mentally for renal replacement therapy
whati s the management of complications ?
Erythropoietin
Sodium bicarbonate
Calcium based phosphate binders
Vitamin D supplementation
Statins
anti-hypertensies : ACE I, ARBS
what are 2 different forms of dialysis ?
Hemodialysis –> From blood
Peritoneal dialysis : Peritoneal surface : intraabdominal and membranous vasculature utilized here for the exhcange of electrolyes and removal of metabolites
dialysis can be either lifelong or over 3 months until kidney disease resolves
what are the common indications for RRT?
renal replacement therapy :
Acidosis ( Metabolic )
Electrolytes ( Hyperkalemia )
Ingestion of drugs/ischemia
Overload ( Fluid )
Uremia
An arteriovenous AV fistula is commonly established for long term dialysis this involves surgically connecting an artery and vein to enhance blood flow during dialysis as vein alone have low pressure and flow making them unsuitable for dialysis
what are the indications for RRT in CKD?
pericarditis or pleuritis ( Urgent indications )
Progressive uremic encephalopathy or neuropathy with signs such as confusion , asterixis , myoclonus, wrist or foot drop, severe cases seizures ( Urgent indication )
Clinically significant bleeding diathesia attributable to uremia ( urgent indication )
Fluid overload refractory to diuretics
Hypertension poorly responsive to antihypertensive medications
Persistent metabolic disturbances that are refractory to medical therapy these include , hyperkalemia, hyponatremia, metabolic acidosis, hypercalcemia, hypocalcemia, hyperphosphoshatemia
Persistent nausea and vomiting
evidence of malnutrition
describe peritoneal dialysis
Catheter is passed over the peritoneal cavity
intra abdominally and fluid moves into the abdomen by the action of gravity
Exchange is facilitated by peritoneal membrane after which waste is collected by another catheter
describe renal transplant?
Living and cadaveric donors
Predialysis : obtain a dry weight free of excess fluids and toxins
More prerparation time from a living donor vs cadeveric transplant withing 36 hours of procurement
Delay may increase ATN
pre transplant immunotherapy : Iv METHYLPREDINSOLONE SODIUM SUCCINATE , CYCLOSPORINE, AZATHIOPRIN
