Presentation of diseases of the kidneys and ureters Flashcards
What is a surgical sieve?
The surgical sieve is a thought process in medicine. It is a typical example of how to organise a structured examination answer for medical students and physicians when they are challenged with a question. It is also a way of constructing answers to questions from patients and their relatives in a logical manner e.g. mnemonics
How can renal disease present?
- Pain
- Pyrexia (fever)
- Haematuria
- Proteinuria
- Pyuria - pus in urine
- Mass on palpation
- Renal failure
What is the definition of proteinuria?
a. Presence of protein in urine b. Presence of albumin in urine c. Urinary protein excretion >1mg/day d. Urinary protein excretion >150mg/day e. Urinary protein excretion >15g/day
d. Urinary protein excretion >150mg/day
How many types of haematuria are there?
a. One b. Two c. Three d. Four e. Five
b. Two – microscopic and gross
c. Three – microscopic, gross and dipstick
The definition of microscopic haematuria is:
a. ≥1 red blood cells per high power field b. ≥2 red blood cells per high power field c. ≥3 red blood cells per high power field d. ≥4 red blood cells per high power field e. ≥5 red blood cells per high power field
between 3 and 5 is acceptable (this lecture said c)
Define oliguria
• Oliguria: Urine output <0.5ml/kg/hour
Define anuria (absolute and relative)
Anuria:
Absolute anuria - No urine output
Relative anuria - <100ml/24 hours
Describe polyuria
• Polyuria: Urine output >3L/24 hours
Describe nocturia
• Nocturia: Waking up at night ≥1 occasion to micturate
Describe nocturnal polyuria
• Nocturnal polyuria: Nocturnal urine output >1/3 of total urine output in 24 hours
Describe the RIFLE staging of acute kidney injury severity
o Risk - Increase in serum creatinine level (1.5x) or decrease in GFR by 25%, or UO <0.5 mL/kg/h for 6 hours
o Injury - Increase in serum creatinine level (2.0x) or decrease in GFR by 50%, or UO <0.5 mL/kg/h for 12 hours
o Failure - Increase in serum creatinine level (3.0x), or decrease in GFR by 75%, or serum creatinine level >355μmol/L with acute increase of >44μmol/L; or UO <0.3 mL/kg/h for 24 hours, or anuria for 12 hours
o Loss - Persistent ARF or complete loss of kidney function >4 weeks
o End-stage kidney disease - complete loss of kidney function >3 months
How can chronic renal failure present?
- Asymptomatic (found on blood and urine testing)
- Tiredness
- Anaemia
- Oedema
- High blood pressure
- Bone pain due to renal bone disease
- Pruritus (in advanced renal failure)
- Nausea/vomiting (in advanced renal failure)
- Dyspnoea (in advanced renal failure)
- Pericarditis (in advanced renal failure)
- Neuropathy (in advanced renal failure)
- Coma (untreated advanced renal failure)
How does advanced chronic renal failure present?
- Pruritus (in advanced renal failure)
- Nausea/vomiting (in advanced renal failure)
- Dyspnoea (in advanced renal failure)
- Pericarditis (in advanced renal failure)
- Neuropathy (in advanced renal failure)
- Coma (untreated advanced renal failure)
How does ureteric disease present?
- Pain (eg. renal colic from stones)
- Pyrexia
- Haematuria
- Palpable mass (ie. hydronephrosis)
- Renal failure (only if bilateral obstruction or single functioning kidney)
How can bladder diseases present?
• Pain (suprapubic)
• Pyrexia
• Haematuria
• Lower urinary tract symptoms (LUTS):
- Storage LUTS (i.e. frequency, nocturia, urgency, urge incontinence)
- Voiding LUTS (i.e. poor flow, intermittency, terminal dribbling) – due to underactive bladder
- Incontinence (stress, urge, mixed, overflow, neurogenic, dribbling, etc.)
• Recurrent UTIs
• Chronic urinary retention (due to bladder underactivity)
• Urinary leak from vagina (i.e. vesico-vaginal fistula)
• Pneumaturia (i.e. colo-vesical fistula) - gas in urine
1What is the risk of bladder cancer in a patient who presents with frank haematuria?
a. 10-15% b. 15-20% c. 20-25% d. 25-30% e. 30-35%
C. 25-30%
What is the risk of renal cancer in a patient who presents with frank haematuria?
a. 0-0.5% b. 0.5-1.0% c. 5-10% d. 10-20% e. 20-25%
b. 0.5-1.0%
Why is the bladder an unreliable witness?
Lower urinary tract symptoms (LUTS) (i.e. voiding LUTS, storage LUTS, incontinence, polyuria, etc.) can have multitude of causes all at different levels and not just the bladder e.g. systemic causes, spinal lesions
What can cause supra-pontine lesions leading to LUTs?
stroke, Alzheimer’s, Parkinson’s
What can cause infra-pontine supra-sacral lesions leading to LUTs?
spinal cord injury, disc prolapse, spina bifida
What can cause infra-sacral lesions leading to LUTs?
multiple sclerosis, diabetes, cauda equina compression, surgery to retroperitoneum
What systemic conditions can cause lower urinary tract symptoms?
chronic renal failure, cardiac failure, diabetes mellitus, diabetes insipidus
Where is the micturition centre?
Pons
What spinal segments are responsible for the micturition reflex
Sacral segments S2-S4 (micturition reflex):
o Relaxation of internal urethral sphincter (autonomic - sympathetic)
o Relaxation of external urethral sphincter (somatic)
o Contraction of detrusor muscle (autonomic – parasympathetic)
How can bladder outflow tract disease present?
• Pain (suprapubic or perineal) • Pyrexia • Haematuria • Lower urinary tract symptoms (LUTS) - Voiding LUTS (i.e. hesitancy, intermittency, poor flow, terminal dribbling, incomplete bladder emptying) due to Bladder Outflow Obstruction (BOO) - Overflow incontinence (high-pressure chronic urinary retention) - Stress urinary incontinence • Recurrent UTIs • Acute urinary retention • Chronic urinary retention
Define Acute urinary retention
- Defined as ‘painful inability to void with a palpable and percussible bladder’
- Residuals vary from 500ml to >1 litre depending on time lag in seeking medical attention; usually <1L
What can cause acute urinary retention?
- Main risk factor is benign prostatic obstruction (BPO) but can also occur independently of BPO (eg. UTI, urethral stricture, alcohol excess, post-operative causes, acute surgical or medical problems)
- For those with BPO, can occur spontaneously (i.e. natural progression of BPO) or triggered by an unrelated event (eg. constipation, alcohol excess, post-operative causes, urological procedure)
How is acute urinary retention treated?
Immediate treatment is catheterisation (either urethral or suprapubic)
If due to BPE and no renal failure, start alpha blocker immediately and remove catheter in 2 days (60% will void successfully); if fail to void, recatheterise and organise transurethral resection of prostate (TURP; after 6 weeks)
What is the main risk factor for acute urinary retention?
benign prostatic obstruction (BPO)
What are some complications associated with acute urinary retention?
UTI, post-decompression haematuria, pathological diuresis, renal failure, electrolyte abnormalities
Define chronic urinary retention
- Defined as ‘painless, palpable and percussible bladder after voiding’
- Patients often able to void but with residuals ranging from 400ml to >2 litres depending on stage of condition (i.e. wide spectrum)
What is the main cause of chronic urinary retention?
Main aetiological factor is detrusor underactivity which can be primary (i.e. primary bladder failure) or secondary (i.e. due to longstanding BOO, such as BPO or urethral stricture)
How do those with chronic urinary retention present?
Presents as LUTS or complications (e.g. UTI, bladder stones, overflow incontinence, post-renal or obstructive renal failure) or incidental finding
What can occur with severe chronic urinary retention?
Overflow incontinence and renal failure occur at severe end of spectrum, when bladder capacity is reached and bladder pressure is in excess of 25cm water (i.e. chronic high-pressure urinary retention)
How is chronic urinary retention treated?
- Asymptomatic patients with low residuals do not necessarily need treatment
- Patients with symptoms or complications need treatment (but no role for medical therapy!)
- Immediate treatment is catheterisation (either urethral or suprapubic initially, followed by clean intermittent catheterization (CISC) if appropriate)
What are some complications associated with chronic urinary retention?
• Complications: UTI, post-decompression haematuria, pathological diuresis, electrolyte abnormalities (hyponatraemia, hyperkalaemia, metabolic acidosis), persistent renal dysfunction due to acute tubular necrosis
Describe the 2 types of diuresis seen in those with high pressure chronic urinary retention
- Physiological (usually <200ml/hour)
* Pathological (usually >200ml/hour) – very dangerous
How is pathological diuresis in those with high pressure chronic urinary retention treated?
- Pathological diuresis features: urine output >200ml/hr + postural hypotension (systolic differential >20mm Hg between lying and standing) + weight loss + electrolyte abnormalities
- Manage with iv fluids (total input = 90% of output) and monitor closely; liaise with renal team
- Subsequent treatment is with either long term urethral or suprapubic catheter, CISC or TURP if due to BPE
What evidence is needed to diagnose a UTI?
Microbiological evidence: Bacterial count of 104 cfu/ml from MSSU specimen with no more than two species of microorganisms
Symptoms/signs: At least one of the following: Fever >38ºC; loin/flank pain or tenderness; suprapubic pain or tenderness; urinary frequency; urinary urgency; dysuria
What are the two types of UTI?
o Uncomplicated UTIs (young sexually active females only with clear relation to sexual activity)
o Complicated UTIs (everyone else!)
Which type of UTI must always be investigated?
Complicated UTI
How can we differentiate between complicated and uncomplicated UTI cases?
o Age
o Sexual activity (females)
o Gender
o Co-morbidities (e.g. immunosuppression, renal failure, medications)
o Abnormal renal tract (e.g. stones, renal outflow obstruction, BOO, horseshoe kidney, VU reflux, renal scarring, bladder tumour)
o Foreign body (e.g. catheter, ureteric stent)
o Type of organisms (E. coli, Staph. saprophyticus, Klebsiella, Proteus, Pseudomonas, Staph aureus)
What organisms are commonly associated with UTIs?
E. coli, Staph. saprophyticus Klebsiella Proteus Pseudomonas Staph aureus
How can UTIs present?
o Bladder (cystitis) o Prostate (prostatitis) o Kidney (pyelonephritis) o Testis (orchitis)
What are some complications of UTIs?
o Infective: sepsis (esp. pyelonephritis), perinephric abscess
o Renal failure (scarring)
o Bladder malignancy (squamous cell carcinoma)
o Acute urinary retention
o Frank haematuria
o Bladder or renal stones
How are UTIs investigated?
o MSSU/CSU
o Lower tract: flow studies, residual bladder scan, cystoscopy
o Upper tract: USS kidneys, IVU/CT-KUB, MAG-3 renogram, DMSA scan
How are UTIs treated?
o Appropriate antibiotic therapy (type? duration? route?)
o Treat complications and cause
List some emergencies related to urinary tract diseases
- Acute renal failure
- Sepsis due to UTI +/- upper or lower urinary tract obstruction
- Renal colic - pain associated with urinary stones blocking urinary tract
- Severe haematuria causing haemorrhagic shock
- Metastatic disease causing metabolic derangements (eg. hypercalcaemia from bony metastases), spinal cord compression from vertebral metastases, etc.
- Acute urinary retention
- Chronic high-pressure urinary retention
- Iatrogenic injury/Trauma to upper or lower urinary tracts, penis and testis
- Testicular torsion
- Paraphimosis - urologic emergency in which the retracted foreskin of an uncircumcised male cannot be returned to its normal anatomic position.
- Priapism – prolonged erection of penis
The following are features of acute urinary retention except:
a. Painful b. Palpable bladder c. Inability to urinate d. Bladder volume >800ml e. Percussible bladder
d. Bladder volume >800ml
Can occur with volume around 500ml-1000ml
The following organisms are commonly associated with urinary tract infections except:
a. E. coli b. Klebsiella species c. Proteus species d. Chlamydia trachomatis e. Pseudomonas aeruginosa
d. Chlamydia trachomatis
