HD 1 - Patients with chronic renal disease Flashcards
Where is Vitamin D and EPO made?
Kidneys
What is the GFR in renal function per day and per min?
Per day –> 180L
Per min –> 125ml
How many litres of urine passed per day?
1.5L
How can you measure renal function?
Measure serum creatinine with a blood test
What is the entering and exiting arterioles of the glomerulus?
Entering is efferent arteriole and leaving is afferent arteriole
In the kidney was are the structures in the nephron after the glomerulus?
Bowmans capsule, proximal convoluted tubules, loop of henle, distal convoluted tubules, collecting duct, urine
What is filtered through the glomerulus from the blood?
Water, electrolytes, glucose, amino acids, creatinine
What happens to the number of nephrons when age increases or premature babies, and what condition does this cause in the body?
Decreased number, causing high BP later in life
Where in the nephron does the most absorption occue?
Proximal convoluted tubule
What occurs in the loop of henle?
Absorption of water
What are the 3 glomerular filtration barriers?
Filtration slits in epithelial cells of bowmans capsule
Glomerular basement membrane
Fenestrated capillary endothelium
Define GFR?
GFR is the sum of filtration rates in all functioning nephrons
How is GFR measured?
Creatinine clearance
Plasma creatinine concentration
Estimation Equation e.g. Cockroft - Gault, MDRD
How does creatinine travel through glomerulus?
Flows freely
Where is creatinine secreted in the nephron?
Secreted by tubules
How does creatinine arise in the body?
From metabolism of creatinine in skeletal muscles and in dietary meat intake
Where is 15% of urinary creatine derived?
Tubular secretion by proximal convoluted tubule
What is the equation of creatine clearance?
What are the limitations of this?
Urine creatinine conc. X Urine vol. / Plasma creatinine conc.
Incomplete urine collection.
Increased creatinine secretion from tubule in renal impairment.
What are the normal values of creatinine clearance in Males and Females per minute?
M –> 120 +/- 25 ml/min
F –> 95 +/- 20ml/min
If there is increased creatinine, what happens to the GFR levels? When would this most likely to be found?
Large decrease
In kidney injury = Need dialysis
What cases would the GFR be measured?
Those at risk of kidney problems, such as diabetes, stroke, ischaemic heart disease, peripheral vascular disease. Pt.s taking diuretics/ACEIs, family history of renal problems.
What is the GFR in stage 1 chronic kidney disease?
90+
What is the GFR in stage 2 chronic kidney disease?
60-89
What is the GFR in stage 3 chronic kidney disease?
30-59
What is the GFR in stage 4 chronic kidney disease?
15-29
What is the GFR in stage 5 chronic kidney disease?
<15
What are the symptoms of stage 1 chronic kidney disease? What treatment would be provided?
Normal function but urine/structural abnormalities/genetic trait point to kidney disease
Tx: Observe, control BP
What are the symptoms of stage 2 chronic kidney disease? What treatment would be provided?
Mildly decreased kidney function and other findings point to kidney disease
Tx: Observe, control BP and address risk factors
What are the symptoms of stage 3 chronic kidney disease? What treatment would be provided?
Moderately decreased kidney function Patient asymptomatic Creatinine marginally raised Hypertensive Decreased EPO, therefore anaemic Decreased vitamin D, therefore Ca may be low
Tx: Observe, control BP, address risk factors, modify drug doses and avoid nephrotoxins.
Blood thinners/diuretics/phosphate binders
What are the symptoms of stage 4 chronic kidney disease? What treatment would be provided?
Severely decreased kidney function
Tired, pale, not unwell
Creatinine 250-600umol/L
Tx: Plan for end-stage renal failure
Dietary restriction, phosphate binders, vit. D supplements and EPO
Take antihypertensive drugs and diuretics
Decrease doses for renally excreted drugs
What are the symptoms of stage 5 chronic kidney disease? What treatment would be provided?
End-stage kidney failure Serum creatinine >700 Pale, tired and unwell Anorexia, nauseas, vomiting, uraemia factor, itch Confused Fluid retention and oedema
Tx: Dialysis and transplant
What are the creatinine and GFR in people with increased muscles?
Creatine higher, therefore GFR higher
What are the causes of chronic renal failure?
Diabetes - most common, and mainly type 2
What is the survival rare of type 1 DM patient on dialysis?
5 year survival rate in 50%
What alterations need to be made when prescribing in chronic renal failure?
Altered rate of elimination of renally excreted drugs = may accumulate e.g. opiates
Altered protein binding = reduced binding of acidic drugs such as phenytoin and increased binding of basic drugs e.g. lignocaine
Nephrotoxic drugs may worsen renal function e.g. gentamicin, NSAID’s
Define uraemia?
Urea levels which build up in kidney disease, stop platelets working and increase bruising
What are the effects of uraemia on the body?
Prolonged bleeding time
Normal platelet count but disturbed platelet function
Therefore, check not on aspirin or clopidogrel
If patient has uraemia in chronic renal failure, how is the bleeding time improved?
Dialysis or increased haematocrit (with EPO)
What are the effects of chronic renal failure on the body?
Severe metabolic acidosis + hyperkalaemia + hypocalcaemia = increase cardiac instability (kidney gets rid of potassium)
Salt and water retention = peripheral and pulmonary oedema
Cramps, tremor, twitches, restless legs & hormonal imbalance
What is the treatment programme of patient on dialysis of ESRF (haemodialysis)?
In hospital 3x/week for 4hr periods
How is dialysis of ESRF (haemodialysis) placed in patient?
Via a tunnelled intrajugular neckline or arm arteriovenous fistula (connect A and V)
What takes place during dialysis of ESRF (haemodialysis)?
Fully anticoagulated with heparin for each treatment
Fluid removal as well as biochemical correction (NB fluid and diet restricted)
What happen if haematoma arises in an arteriovenous fistula, and patient needs dialysis?
Might render AVF unsuitable for effective dialysis or too painful to use
Check biochemistry – might require dialysis line whilst AVF rested +/- treated
What is the vascular access for dialysis is patient has infection risk?
Temporary Line (‘Vascath’) (LHS) - High infection risk Tunnelled Lines (‘Tesio’) (RHS) - Cuffs aims to reduce infection
What happens to body function if in acidaemia?
What is the treatment?
DANGER: impacts cellular and cardiac function
Tx: Na bicarbonate offers a bridge until dialysis available
o NB: Care if fluid overloaded (increased Na+ = increased Extracellular fluid)
o NB: Care if already hypocalcaemic (increased pH = decreased Ca2+)
At what point is the body considered to be in acidaemia state?
pH <7.2
HCO3- <16mmol/L
Another cause is lactic acidosis/ DKA/ Poisoning
Pericardial effusion can occur following pericarditis, what can this lead to?
Cardiac tamponade (Beck’s triad)
What can decrease risk of pericardial bleeding in dialysis?
Avoid anticoagulation
What are the advantages and disadvantages of dialysis treatment of ESRF - CAPD (continuous ambulatory peritoneal dialysis)?
+ Continuous ambulatory
+ Gentle, effective
+ Good biochemical control
+ No anticoagulation
- peritonitis
- weight gain with glucose as osmotic agent
- peritoneal membrane failure with time
What are the complications of uraemia and dialysis?
- Hypotension, cramp
- Anaemia
- Vascular calcification
- Increased risk of heart disease
- Amyloidosis as a consequence of beta-2-microglobulin accumulation - carpal tunnel, joints
Why does infection arise during dialysis and chronic renal failure? How can this be managed?
Natural increased risk with dialysis - 20% dialysis deaths
Immunosuppressed due to uraemia and malnutrition
Defective phagocyte function
Managed by: adjusting antibiotic doses
Do immunosuppressed/ transplant/ dialysis/ chronic renal failure patients need antibiotic prophylaxis for dental tx, if so what tx?
NO, only if also have prosthetic heart valve or other endocarditis risk
• E.g. amoxycillin 3g 1-hour pre procedure or IV Vancomycin and gentamicin for HD pts, clindamycin for tx pts who are penicillin allergic
What are the drug treatments for immunosuppression for renal transplants?
- Prednisolone
- Azathioprine = inhibits purine synthesis and so DNA synthesis = Lymphocytes and neutrophils more sensitive than other proliferating cells
- MMF or mycophenolate mofetil = more selective inhibition of purine synthesis, blocks proliferating lymphocytes only
What are the drug treatments for general transplant immunosuppression?
- Cyclosporin A or Neoral = calcineurin inhibitor which blocks activation of T cells and so of cytokines such as IL-2
- FK506 or tacrolimus = similar mode of action but more potent
- Side effect of gum hypertrophy
What is the function of sirolimus?
Inhibits response to cytokines
Potent non calcineurin inhibiting immunosuppressant
Has similar structure to tacrolimus and binds to cytosolic receptors (immunophilins)
Whats another name for sirolimus?
Rapamycin
What are the side effects of sirolimus?
Hyperlipidaemia
Delayed wound healing
Stomatitis
What are the main dental risks associated with chronic renal failure?
Gum hypertrophy and caries
How does oral facial digital syndrome affect males and females?
X-linked dominant disorder, lethal in males
Females may have cysts (also liver cysts), indistinguishable from those in autosomal dominant polycystic kidney disease
Both show extra renal manifestations
What are the cranio-facial abnormalities and oral manifestation of oral facial digital syndrome?
Facial milia –> small bumps (cysts) on skin surface
Cleft palate
Dental abnormalities
Bifid and lobulated tongue
What are the limb and skeletal abnormalities of oral facial digital syndrome?
Brachydactyly –> shortened fingers and toes
Syndactyly –> 2/more digits fused together
Clinodactyly –> curved digits