Renal 2 ๐ซ Flashcards
What is the terminology change for microscopic or dipstick positive haematuria?
Non-visible haematuria
Previously known as microscopic or dipstick positive haematuria, now termed non-visible haematuria.
What is visible haematuria?
Macroscopic haematuria
Visible haematuria is the term now used for what was previously known as macroscopic haematuria.
What percentage of the population is affected by non-visible haematuria?
Approximately 2.5%
Non-visible haematuria is found in around 2.5% of the population.
List four causes of transient or spurious non-visible haematuria.
- Urinary tract infection
- Menstruation
- Vigorous exercise
- Sexual intercourse
Transient or spurious non-visible haematuria usually settles after about 3 days.
What are the causes of persistent non-visible haematuria?
- Cancer (bladder, renal, prostate)
- Stones
- Benign prostatic hyperplasia
- Prostatitis
- Urethritis (e.g., Chlamydia)
- Renal causes (IgA nephropathy, thin basement membrane disease)
Persistent non-visible haematuria requires further investigation.
What foods can cause spurious red/orange urine?
- Beetroot
- Rhubarb
These foods can lead to a false positive for blood in urine.
What is the test of choice for detecting haematuria?
Urine dipstick
Urine dipstick is the preferred method for detecting haematuria.
Define persistent non-visible haematuria.
Blood present in 2 out of 3 samples tested 2-3 weeks apart
This definition helps in identifying cases that require further investigation.
What are the NICE urgent cancer referral guidelines for patients aged 45 years or older?
- Unexplained visible haematuria without urinary tract infection
- Visible haematuria that persists or recurs after successful treatment of urinary tract infection
These guidelines were updated in 2015.
What is nephrotic syndrome characterized by?
- Proteinuria (> 3g/24hr)
- Hypoalbuminaemia (< 30g/L)
- Oedema
Nephrotic syndrome can arise from various glomerular diseases.
What are common primary causes of nephrotic syndrome?
- Minimal change disease
- Focal segmental glomerulosclerosis (FSGS)
- Membranous nephropathy
These are key primary causes of nephrotic syndrome.
List the secondary causes of nephrotic syndrome.
- Diabetes mellitus
- Systemic lupus erythematosus (SLE)
- Amyloidosis
- Infections (HIV, hepatitis B and C)
- Drugs (NSAIDs, gold therapy)
Secondary causes often relate to systemic diseases.
What is the pathophysiological mechanism of nephrotic syndrome?
Damage to the glomerular basement membrane and podocytes leading to increased permeability to proteins
This mechanism results in proteinuria, hypoalbuminaemia, and subsequent oedema.
What initial investigations are done for nephrotic syndrome?
- Urine dipstick for proteinuria
- MSU to exclude urinary tract infection
- Early morning urinary protein:creatinine ratio or albumin:creatinine ratio
- FBC and coagulation screen
- Urea and electrolytes
These investigations help in confirming the diagnosis.
What is the frequency of calcium oxalate stones?
40%
Calcium oxalate stones are the most common type of renal stone.
What are the clinical features of a urinary tract infection?
- Dysuria
- Urinary frequency
- Urinary urgency
- Cloudy/offensive smelling urine
- Lower abdominal pain
- Fever (typically low-grade)
- Malaise
Symptoms can vary in severity and presentation.
What is the role of urine dipstick in diagnosing UTI in women under 65 years?
Aid diagnosis
Urine dipsticks can help confirm UTI likelihood but should not be used in women over 65 years, men, or catheterised patients.
What is acute interstitial nephritis primarily caused by?
Drugs (most common cause), particularly antibiotics
Common drugs include penicillin, rifampicin, NSAIDs, allopurinol, and furosemide.
List symptoms associated with tubulointerstitial nephritis with uveitis (TINU).
- Fever
- Weight loss
- Painful, red eyes
TINU typically occurs in young females.
What are the three traditional classifications of acute kidney injury (AKI) causes?
- Prerenal
- Intrinsic
- Postrenal
These classifications help in identifying the underlying issues causing AKI.
What is a common prerenal cause of AKI?
Hypovolaemia secondary to diarrhoea/vomiting
Prerenal causes are often due to reduced blood flow to the kidneys.
What is a common intrinsic cause of AKI?
Acute tubular necrosis (ATN)
Intrinsic causes involve direct damage to the kidney tissue.
What is a postrenal cause of AKI?
Kidney stone in ureter or bladder
Postrenal causes relate to obstructions affecting urine flow from the kidneys.
What are the risk factors for AKI?
- Chronic kidney disease
- Other organ failure/chronic disease
- History of acute kidney injury
- Use of nephrotoxic drugs
- Age 65 years or over
- Oliguria
- Neurological or cognitive impairment
Identifying these risk factors can help in prevention strategies.