kidney disorders - renal 4 Flashcards
what is obstructive uropathy?
Obstructive uropathy is blockage of urinary flow
It can affect one or both kidneys depending on the level of obstruction
The obstruction may occur suddenly or develop slowly over days, weeks or even months
An “upper” obstruction i.e. ureter or above e.g. kidney stones
A “lower” obstruction i.e. ureter or below e.g. BPH
Obstruction to the kidneys can result in a condition called hydronephrosis which can cause renal failure.
what is hydronephrosis?
obstruction of urine flow (upper and lower)
Obstruction: urine backs eventually reaching the small tubes of the kidney and collecting in the renal pelvis
This results in swelling of the kidney and appear distended = hydronephrosis
how can infection in the kidney occur?
An infection may develop in the kidneys as the bacteria are not being flushed out
if both kidneys are obstructed what can it cause?
If both kidneys are obstructed it may lead to AKI or even CKD
what are the causes of obstructive uropathy? (children and young adults and older adults)
The most common causes of obstructive uropathy differ by age:
Children: structural abnormalities
Young adults: stones in the kidney, ureter or elsewhere in the urinary tract
Older adults: benign prostatic hyperplasia, prostate cancer, retroperitoneal or pelvic tumours and calculi
Other possible causes include:
Polyps in the ureter
Tumour in or near the ureter
Disorders of the muscles/nerves in the ureter or bladder
Formation of scar tissue in or around ureter
what is the symptoms of obstructive uropathy?
Depends on the cause, location and duration of the obstruction
If kidney distended, renal colic can develop
If obstruction related to BPH: hesitancy, frequency, nocturia, terminal dribbling or bladder discomfort occur (voiding and storage problems)
If a urinary tract infection has developed patients may have pus or blood in urine, fever and discomfort in the area of the bladder of kidneys
what is the diagnosis method for obstructive uropathy?
Imaging tests
- ultrasound of the bladder will tell us the volume of urine retained in the bladder. If
patient is in severe retention then a catheter will be inserted
- ultrasound of the kidneys will tell us if hydronephrosis is present
- CT scan can pick up renal stones
Endoscopy
- a camera can be used to examine the urethra, prostate, bladder, ureters or kidneys to
identify sites of obstruction
Blood and urine tests
- bloods may reveal high urea or creatinine levels - urine may reveal high WBCs
what is the treatment for obstructive uropathy?
Aim is to relieve the cause of the obstruction
BPH or prostate cancer: medications or surgery
Hydronephrosis: nephrostomy tube or ureteral stent
Renal calculi (stones): removal
what is renal calculi?
stone
Stones are common among middle-aged/older adults (aged 20-40)
More common amongst men (15% men and 5% women)
Vary in size
Staghorn!
Begin to form in a kidney and may enlarge in a ureter or the bladder
Kidney or ureteral or bladder stone
what are the types of renal calculi?
Calcium oxalate
- Most common (70%) - Made up of calcium and oxalate - Oxalate = waste product of food; sticks to calcium - Dehydration/high protein diet/high oxalate diet/medical conditions
Urate/uric acid stones
- Result of hyperuricaemia and/or when urine is too acidic - High protein diet but not the only cause
Cystine stones
- Made up of cystine (naturally occurring) - Rare - Genetic disorder that causes cysteine to leak from kidneys to urine
Infection stones
- AKA struvite stones - Made up of minerals e.g. magnesium, ammonium and phosphate - Happens when there is a urinary tract infection
what are the causes of stones?
May form if the urine is too saturated with salts or if the urine lacks the normal inhibitors for stone formation e.g. citrate Hyperparathyroidism Dehydration Renal tubular acidosis Diet high in animal-source protein or vitamin C Family history of stone formation Bariatric surgery Rarely drugs
what is the symptoms of stone?
Tiny stones may not cause any symptoms
Bladder stones may cause lower abdomen pain
Ureter or renal pelvis stones may cause back pain or renal colic
Nausea and vomiting
Sweating
Blood or a stone/piece of stone in the urine
Infection signs e.g. chills, fever, dysuria, cloudy urine, foul-smelling urine and abdominal swelling
what is the diagnosis methods for stones?
Symptoms (as above)
Urinalysis will pick up on the presence of blood or pus in the urine
X-ray not very accurate and will only pick up calcium stones
Intravenous urogram the dye will be able to determine the degree of blockage and the
location BUT risky due to the dye’s potential to worsen kidney failure or cause an allergic reaction. Not preferred
CT scan can locate the stone and indicate the degree to which the stone is blocking the urinary tract. Preferred.
what is the treatment for stones?
Manage the symptoms
- paracetamol is a safe option - NSAIDs or opioids but be careful of both due to potentially reduced renal function - anti-emetics e.g. cyclizine or metoclopramide
Remove the stones
- non-invasive removal - invasive removal
what are nin invasive management for stones?
Increase fluid intake (orally or IV) to encourage the smaller stones to be flush out
Alpha-adrenergic blockers e.g. tamsulosin can be used to relax the smooth muscle of the ureter and allow stones to pass
Penicillamine can be used to dissolve cystine stones
Extracorporeal shock wave lithotripsy (ESWL) use of sound waves to shatter the stones into tiny so that they can then be flushed out
