Renal Pathologies (CKD) Flashcards
(34 cards)
*Structure of the kidney*
What are some end-products of kidney excretion?
Water, carbon dioxide, urea and other acid waste products
What hormone controls the permeability of the collecting ducts?
Antidiuretic hormone (ADH)
What two main structures does the nephron have?
Glomerulus
Tubule
Roughly explain the funtion of both the glomerulus and tubule?
Glomerulus:
- Water and other soluable molecules filter from the blood through the glomerular capillaries to the Bowman’s capsule
- Large molecules such as proteins and RBCs cannot pass through and therefore remain in the blood
- The filtrate leaves the glomerulus and flows into the renal tubule
Tubule:
- The collecting tubule recieves fluid from the distal convoluted tubules
- Water leaves the collecting ducts via osmosis
- The permeability of the collecting ducts to water is controlled by ADH
What are some functions of the kidney?
- Excretion of waste products from metabolism
- Homeostasis of fluid and blood pressure
- Homeostasis of electrolytes (sodium, potassium, calcium and phosphate)
- Production of hormones
Roughly how much urine does somone producte a day?
1-2L
Through what process are water, minerals and other substances converved? Where does this occur?
Through what process is urea and other waste products eliminated?
Selective reabsorption - renal tubules
Filtration
What 3 hormones does the kidney produce and release?
Renin (blood pressure regulation)
Erythropoietin (stimulates production of RBCs)
Activated form of vitamin D
What is acute renal failure? What are the indicators?
The sudden and complete loss of ability of the kidneys to remove waste usually marked by
- decreased glomerular filtration rate (GFR)
- Increased concentrations of blood urea nitrogen and creatinine
- Urine output of <400ml/day
- Hyperkalemia (increased potassium levels)
- Sodium retention
What are the 3 categories of acute renal failure and how to they occur?
- Prerenal - Sudden and severe blood pressure drop or interupption of blood flow to kidneys
- Intrarenal - Direct damage to the kidneys by inflammation, toxins, drugs or reduced blood supply.
- Postrenal - sudden obstruction of urine flow due to enlarged prostate, kidney stones, bladder tumour or other injury
What are the risk factors for acute renal failure?
- Older age
- Preexisting injury or medical condition
- Diabetes
- Hypertension
Liver disease
- Heart failure
- Genetic disorders
What are the symptoms for acute renal failure?
- Decreased urination
- Blood in urine
- Nausea/vomiting
- High blood pressure
- Loss of appetite
- Swollen hands and feet
Through what 4 stages does acute renal failure progress through?
- Initiation phase
- Oliguric phase
- Diuretic phase
- Recovery phase
What are some clinical manifestations that occur from acute renal failure?
- Critically ill & lethargic patient
- Decreased urine production
- Dark coloured urine
- Foamy urine
- Frequent urination during the night
- Azotemia
What is chronic kidney disease (CKD)? How is it characterised?
Rapidly progressive deterioration/loss of renal function in which the body’s ability to maintain metabolic, fluid and electrolyte balance fails resulting in uremia or azotemia.
Characterised by a slow irreversible impairment of renal excretory and regulatory function.
Final stage CKD is called end-stage renal disease (ESRD)
What is the aetiology of CKD?
- chronic glomerulonephritis (inflammation of glomeruli)
- long term infection (chronic pyelo-nephritis, tuberculosis)
- Nephrotoxic agents
Autoimmune disorders (systemic lupus erythematosus causing lupus nephritis & leroderma)
- Kidney stones
What are the risk factors for CKD?
- Diabetes
- High blood pressure (hypertension)
- >60 years
What are some prevention suggestions for CKD?
- Blood pressure control
- Blood glucose control (especially diabetics)
- Abstain from smoking
- Weight loss if overweight/obese
- Reduce sodium intake
- Physical activity
What are some common complications associated with CKD?
- Fluid and sodium retention
Dyslipidaemia
- High serum potassium (hyperkalaemia) and/or high serum urea (uraemia)
- Mineral/bone disorders
- Protein energy wasting
- Anaemia
- Metabolic acidosis
In stages, what is the pathophysiology of CKD?
What are some of the characteristics?
PATHOPHYSIOLOGY
- Due to aetiology factors, renal function begins to decline.
- Progressive nephron damage (nephrons unable to function or recover)
- Decreased glomerular function rate (GFR)
- Remaining nephrons undero changes to compensate for damaged nephrons
- Compensatory excretion continues by kidneys, GFR continues to diminish
- Filtration of concentrated blood by remaining nephrons
- Progressed damage of nephrons results in hypertrophy
- Urine usually contains abnormal protein, RBC and WBC levels
- Increase in serum creatinine, blood urea nitrogen (BUN), urea and other nitrogenous waste
- Further nephron damage (~80-90%)
- Chronic renal failure
CHARACTERISTICS
- Reduced renal reserve - loss of ~50% of nephron function, no outward symptoms, early/silent stage. This stage is often not diagnosed.
- Renal insufficiency - loss of ~75% nephron function. Some symptoms of mild renal failure present.
- Anaemia & inability to concentrate urine - BUN and creatinine levels are elevated. Patients at risk of further damage by infection, dehydration, drugs.
What % of nephron loss does CKD become ESRD?
~90% nephron loss
What are the characteristics of ESRD?
- BUN and creatinine levels are always elevated
- Patients may make urine but waste products are not filtered out
- Uremia (urea/toxins in the blood) present with chronic renal failure
- Dialysis/kidney transplant required to survive
