Renal impairment Flashcards
What is included in renal replacement therapy
Renal dialysis and renal transplant
What is end stage renal failure
A situation where renal function has diminished to such an extend that renal replacement therapy is required to sustain life
What is end stage renal failure also referred as
Renal failure
What is renal impairment
A situation where renal function is sub optimal but renal failure hasn’t been breached
What is compromised renal function
An all encompassing term covering renal impairment and renal failure
Patients with which medical condition have some degree of renal impairment
Diabetes mellitus or hypertension
How many people in the UK require renal replacement therapy (RRT)
640 per million
What is the number of patients requiring renal replacement therapy influenced by?
Factors such as:
- More men than women receive Renal replacement therapy
- Asian or Afro-Caribbean and living in the U.K., then you are 3-5x more likely to have RRT
How much of the nHS budget is taken up by renal replacement therapy
2% (but expected to rise to 3%)
How much cardiac output do the kidneys receive
Around 20%
Where is blood is filtered through the kidney and what does it form?
blood is filtered through around 2 million glomeruli to form the glomerular filtrate (~180 litres/day or 2ml/second)
Extensivley modified as it passes through the renal tubes to form ruin
What is the daily urine output for a healthy adult
Varies by typically between 750-2000ml
What are the kidneys responsible for
- Maintenance of water and electrolyte balance
- Excretion of water products
- Acid base balance and pH
- Endocrine functions
Do the homeostatic mechanisms of the kidney ever stop?
nope due to the dietary intake of food maintenance of the correct electrolyte and fluid balance always needed
What is the glomerular filtrate made up of
Water and electrolytes that need to be reclaimed for further use
What is the recovery of ion in the kidney essential fro
Recovery of water which follows ions as a consequence of osmotic gradients
What is water reabsorption in the kidneys facilitated by
Ions recovery
Increased secretion of the hormone vasopressin from the pituitary gland
Which ions are excreted into the nephron
H+ and K, are excreted into the nephron after the primary glomerular filtrate has formed
Kidneys are essential for the secretion of what waste products from the blood
- Urea
2. Creatinine
What is Urea
The main nitrogenous waste product formed during the normal turnover and metabolism of protein
What is Creatinine
It formed reatine as a by-product of normal muscle metabolism:
How much muscle mass is turned over by the average adult
1.0-1.5kg of muscle mass every day
What can happen to the secretion of waste in diminished renal function
The levels of plasma level urea and creatinine rise as the number of glomeruli effetely working reduces
What are biological processes critically dependent on
pH
What can slight changes in pH do to proteins
Can affect protein folding an function
How are hydrogen ions generated in the body
Primarily by the metabolism of sulphur containing amino acids
How do the kidneys maintain the correct acid base balance
Via the secretion of H+ and bicarbonate reabsorption
What is endocrine function
Gland that secrete hormones
What hormones do the kidneys produce
- erythropoietin
2. Renin
What is the role of erythropoietin
Up regulates the production of erythrocytes
What are erythrocytes
Red blood cells
What does renin act within
the renin-angiotensin-aldosterone pathway
What does renin stimulate
Release of angiotensin I which is converted to angiotensin II:
What is the significance of Angiotensin Converting Enzyme (ACE)-inhibitors
They reduce the conversion of angiotensin I to angiotensin II
What are Angiotensin Converting Enzyme (ACE)-inhibitors used in
The are a major class of drugs used in the management of hypertension, diabetic nephropathy, heart failure and following myocardial infarction;
What can be used in place of Angiotensin Converting Enzyme (ACE)-inhibitors
Angiotensin II receptor antagonists
What does Angiotensin do
Stimulates the release of aldosterone from the adrenal Cortex
What does aldosterone do
Promotes renal reabsorption of Na+ and consequently water to help raise blood pressure by increasing the circulating volume.
Which vitamin is the kidney responsible fro metabolising
Vitamin D
Why is vitamin D important
For normal bone turnover
How is vitamin D metabolised
Vitamin D undergoes 1-hydroxylation in the kidney to form 1,25- dihydroxycholecalciferol, which promotes Ca2+ absorption from the intestine;
What happens as Ca2+ levels fall
Phosphate levels rise
What happens fi vitamin D levels are reduces
Ca2+ levels fall
Phosphate levels rise
Increased release of Parathyroid Hormone
Where is the Parathyroid Hormone released from
The anterior pituitary gland
why is the Parathyroid Hormone released in response to falling vitamin D levels
in an attempt to correct blood Ca2+ concentrations.
What can happen is there’s chronic disruption of Ca2+ metabolism
Can result in renal bone disease
What are most cases of renal impairment and failure due to
- Diabetes mellitus
- Hypertension
- Congenital causes
List some Congenital causes of renal impairment and failure
- Autosomal Dominant Polycystic Kidney Disease
2. Alport’s syndrome.
How common is Autosomal Dominant Polycystic Kidney Disease
1 in 1000
What causes Autosomal Dominant Polycystic Kidney Disease
Dysfunction of the PKD1 and PKD2 genes results in formation of multiple renal cysts
How many patients with Autosomal Dominant Polycystic Kidney Disease develop end stage renal failure
Around 50% by the age of 55%
How many patients on renal replacement therapy have Autosomal Dominant Polycystic Kidney Disease
10%
Give examples of acquired causes of renal impairment and failure
- Diabetic Nephropathy
- Hypertension Nephropathy
- Renovascular disease
- Connective tissues diseases
- Infections such as HIV.
- Cancers
- Iatrogenic such as drug use
Name the leading cause of renal failure
Diabetes mellitus
How many patients on dialysis have Diabetes mellitus
20-50%
Name the 2 types of Diabetes mellitus
Type 1 and 2
When does Diabetic Nephropathy reach its peak in type one diabetics
15 years following diagnosis of type 1 diabetes
Does everyone with type 2 diabetes develop Diabetic Nephropathy
No varies with race
How many caucasians with type 2 diabetes go on to develop Diabetic Nephropathy
25%
How many Asian Indians with type 2 diabetes go on to develop Diabetic Nephropathy
50%
How many African-caribbeans with type 2 diabetes go on to develop Diabetic Nephropathy
50%
How common is hypotension in diabetes
30-50% of those with type 1
20% of those in type 2
What is Renovascular disease
Atherosclerosis of the renal arteries
List connective tissue disease that can lead to renal impairment and failure
Systemic lupus erythematosis
Which cancers can lead to renal impairment and failures
lymphomas, myeloma and carcinomas.
List some clinical features of renal impairment and failure
- Acute renal failure
- Chronic renal failure
- renal Osteodystrophy
What can renal impaireent and failure be assocated with
- Cardiovascular disease
- Anaemia
- Abnormalities of coagulation
- Renal bone disease
- Malnutrition
- Tissue oedema
- Impairment of the immune system
- Malignancy
- Sexual dysfunction and pregnancy
- Mental health problems
What is acute renal failure
It is the abrupt loss of normal renal functions
Give examples of some abnormal renal functions
- Oliguria
- Retention of nitrogenous waste (urea) and creatine
- Loss of normal electrolyte, water and pH homeostasis
What is Oliguria characterised as
Urine volume of <400ml/day
List the key features of acute renal failure
- Loss of normal electrolyte and fluid homeostasis
2. Metabolic acidosis
What happens to the kidney is acute renal failure
They lose their ability to excrete or conserve electrolytes in an appropriate way with associated disruption of fluid balance
What can happen as a result of the loss of normal electrolyte and fluid homeostasis
Hyperkalaemia (high levels of K+) can result in arrhythmias
what causes metabolic acidosis
The kidneys losing their ability to maintain a normal acid base mechanism
Is acidosis fatal
It is associate with a high morbidity and mortality
is acute renal failure fatal
It has a high mortally rate 35-80%
What is the relationship between cardiovascular disease and chronic renal failure
Cardiovascular disease is 3-5 times more common in those with chronic renal failure than without
What does cardiovascular disease with renal failure include
- Coronary heart disease
2. Heart failure
Why might the pathology of cardiovascular disease be different in a patient with renal failure
may relate to high urea levels:
- Uraemic vasculopathy
- Uraemic cardiomyopathy
Why is anaemia clinically important in chronic renal failure
- Patients are tired, lethargic, breathless, limited exercise tolerance, muscle fatigue
- Reduced oxygen carriage in anaemia can contribute to symptomatic cardiovascular disease
- The oral manifestations of anaemia may be the first clinical signs of undiagnosed anaemia
Talk through the origin of anaemia in chronic renal failure
- Diminished production and function of erythropoietin
- Anaemia of chronic disease
- Inappropriate haemolysis of erythrocytes;
- Blood loss via the gastrointestinal tract when there is prolonged bleeding
What can chronic renal failure be associated with in terms of coagulation
- Prolonged bleeding
2. Prothrombotic states
What does prolonged bleeding in chronic renal patients relate to
Abnormal platelet funciton
Why is normal platelet function essential
For clot formation
Why with Prothrombotic States be related to
- Altered endothelial cell function
2. Altered coagulation factor production and function
What effect can chronic renal failure have on bone
Can impact bone metabolism resulting in bone that turns over too rapidly or too slowly
Describe the bone in renal Osteodystrophy
- Poor quality
- Prone to fracture
- metastatic calcification in soft tissue
What is metastatic calcification
inappropriate calcification; nothing to do with cancer
Which hormone is affected in renal Osteodystrophy
Excess parathyroid hormone released leading to secondary hyperparathyroidism.
What can Osteoporosis be marked by
1 .Long term use of systemic corticosteroids
2. Following renal transplant
What is tissue oedema in chronic renal failure related to
- Reduces plasma protein concentration
2. An increase int eh total sodium ion content
Describe urine in health
Very little protein present
When urine testing talk through A significant findings
Detection of proteinuria (protein in the urine)
What can proteinuria suggest
Damage to the glomeruli
What can damage to the glomeruli result in
- High levels of protein in the urine
- Low levels of protein in the blood
- Dyslipidaemia
What is the most common cause of proteinuria
Diabetic nephropathy
What can chronic protein loss in urine lead to
Reduced osmotic pressure in the blood leading to excess fluid leaving the capillaries and being retained in the tissues
tissue oedema
What can and excess total body Na+ result in
- Fluid retention
- tissue oedema
- Hypertension.
What is renal dialysis associated with in terms of sexual health
- Reduced levels of testosterone and erectile dysfunction
2. Amenorrhoea
What can childhood developed chronic liver failure present as
Impact on:
- Physical growth and development
- Education
- Development of social skills
How can we diagnose and monitor renal impairment and failure
- Urea, creatine and electrolysis levels
- Urine volumes
- Urine microscopy
- Blood tests
- Imaging
- Renal biopsy
Name the most widely used test for Renal function
urea, creatinine and electrolyte LEVELS
Renal impairment can have a profound effect on drug what?
- Pharmacokinetics
2. Pharmacodynamics
How can drug Pharmacokinetics be affected by Renal impairment
- Active drugs and/or their active metabolites will accumulate with potentially adverse effects,
- The activity of some drugs is influenced by their degree of protein binding, which can be changed in renal impairment.
How can drug Pharmacodynamics be affected by Renal impairment
The sensitivity of the target tissues to specific drugs may be either increased or decreased with potentially adverse effects.
Which drugs used in dentistry should we be cautious of prescribing to patients with renal failure
- Aspirin and NSAIDs;
- Opioid analgesic drugs including compound preparations
- Amoxicillin, ampicillin and related drugs;
- Cefalexin and related drugs;
- Flucloxacillin;
- Tetracyclines;
- Fluconazole and related drugs;
- Acyclovir.
What are the symptoms of renal impairment
Initially asymptomatic
What are the aims of management fro renal failure
- Limit an y further renal damage
- Improve renal function
- introduce renal replacement therapy
How can we manage renal failure
- Low protein diet
- Management of hypertension
- Suppression of the immune system
- Management of Dyslipidaemia
How can we manage hypertension in kidney failure
By using ACE inhibitors
What does renal replacement therapy include
- Dialysis
2. Human kidney transplant
Name the 2 types of dialysis
- Haemodialysi;
2. Peritoneal dialysis
How many times do patients need to undergo Haemodialysi
3 times a week each sessionlastign several hours
What does dialysis involve
Movement of solutes and water across a semi permeable membrane
Talk through the diffusion that occurs when on dialysis
small molecules such as urea (60 Daltons) pass across the membrane (removed from the blood),
larger molecules such as albumin (60,000 Daltons) do not so are retained in the blood
Which drug is used in conjunction with a dialysis machine
Heparin
Why is heparin giving to patients on dialysis
To prevent blood clotting triggers by the dialysis machine
Name some complications associated with renal replacement therapy
- accelerated atherosclerosis, hypertension and anaemia:
2. Increased risk of blood borne viruses
Name an alternative to haemodialysis
Peritoneal Dialysis
What is the advantage of peritoneal Dialysis
Can be done at home
What happens in peritoneal Dialysis
- A catheter is inserted into the peritoneal cavity
- Dialysis fluid is introduced into the peritoneal cavity
- The peritoneum acts as the dialysis membrane;
Talk through the typical regime of Peritoneal Dialysis
is to introduce and drain 2 litres of dialysis fluid on four occasions within a 24 hour period
Name a common complication of peritoneal Dialysis
Peritoneal infection
Which has a higher survival rate peritoneal Dialysis or haemodialysis
Both have a similar survival rate
What is the preferred option for end stage renal failure
Renal tranplantation
Where can donor kidneys come from for kidney transplantation
- Deceased donors
2. Living donors (more common in UK)
How can we reduce the risks of complications for a kidney transplant
Matching of the donor ro the recipient
List some complications and outcomes of kidney transplantation
- Graft loss
- Cardiovascular disease
- Hypertension
- Dyslipidaemia;
- Diabetes mellitus;
- Obesity;
- Metabolic bone disease;
- Anaemia, leucopenia or thrombocytopenia;
- Post-transplant cancers – related to immunosuppression:
What is the percentage fo graft survival 1 year post op
90%
What is the percentage fo graft survival 5 year post op
80%
Name the 2 major cases of graft loss
- Chronic allograft nephropathy
2. Death, usually due to cardiovascular disease with a functioning transplanted kidney.
What risk assessment do we carry our fro our patients who have renal disease
- Identify underlying cause
- Known or unknown blood Bourne virus infection risk
- Past, current or planned treatment
- Patient complaint
How can dentists contribute to the diagnosis of renal impairment
1, Oral manifestations leading to new diagnosis of diabetes
- Oral manifestation of anaemia
- Increased propensity for infection such as oral candidiasis
- Uraemic stomatitis
What is Uraemic stomatitis characterised by
- Unpleasant taste and breath that smells of ammonia;
2. A thick grey pseudomembrane overlying areas of oral mucosa that may be ulcerated.
