Urinary System - Level 1 Flashcards
Definition of bacteriuria?
o presence of bacteria in the urine. This may be symptomatic or asymptomatic. Asymptomatic bacteriuria should be confirmed by two consecutive urine samples
Definition of UTI?
o presence of characteristic symptoms and significant bacteriuria from kidneys to bladder
o >105 (cfu/ml)
Types of UTI?
o Lower UTI = infection of the bladder (cystitis)
o Upper UTI = infection of kidney and ureters (acute pyelonephritis)
Classifications of UTI?
o Uncomplicated – normal renal tract/function
o Complicated – abnormal renal tract, obstruction, decreased renal function, immunocompromised
Epidemiology of UTIs?
- Incidence is 5% in UK
- More common in females due to short urethra
- 40% have genitourinary anomalies
Risk factors of UTIs?
o Women o Sexual intercourse o Catheter o Abnormality of renal tract o Antibiotic use o Pregnancy o Immunocompromise o Diabetes Mellitus o Spermide
Causative organisms of UTIs?
o E. coli in 90% of cases
o Proteus (present under prepuce)
o Klebsiella
o Enterococcus faecalis
o Saprophytic staphylococci (young women)
o Pseudomonas (may indicate structural damage in urinary tract)
Symptoms of lower UTIs?
o Dysuria o Frequency o Urgency o Haematuria o Suprapubic discomfort o Burning o Cloudy urine with offensive smell
Investigations in lower UTI?
- Urine dipstick MSU
o Leukocytes and nitrites, haematuria and proteinuria - Urine M, C&S
o Male, child under 16, pregnant, very ill
o May show leukocytes, RBC commonly seen, renal pathology if crystals or granular casts found - Renal USS (KUB)
o If recurrent or complicated - Bloods
o FBC, U&Es, CRP, cultures if unwell
Management of lower UTI - referral?
- Referral to hospital if sepsis suspected
Management of lower UTI - general advice?
o Paracetamol for pain
o Hygiene: clean perineum front to back
o Increase fluid intake
o Voiding after intercourse
Management of lower UTI - in non-pregnant women?
o Back-up antibiotic or immediate prescription, depending on clinical picture
Back-up prescription should be used if no improvement in 48 hours of taking antibiotic or worsens
Management of lower UTI - non-pregnant women - antibiotics - first & second choice?
First Choice
• Nitrofurantoin (if eGFR>45) 100mg MR BD for 3 days
• Trimethoprim 200mg BD for 3 days
Second Choice (worsening UTI on first choice for >48 hours) • Nitrofurantoin (if eGFR>45 and not first choice) 100mg MR BD for 3 days • Pivmecillinam 400mg initial dose then 200mg TDS for 3 days • Fosfomycin 3g single dose sachet
Management of lower UTI - pregnant women, men and children - investigations?
Midstream urine for M, C & S in pregnant women, men and children <16
Management of lower UTI - antibiotics children <16 years old - under 3 months?
• Under 3 months – refer to paediatric specialist
Management of lower UTI - antibiotics children <16 years old - over 3 months?
o First Choice
Nitrofurantoin (if eGFR>45) for 3 days
Trimethoprim for 3 days
o Second choice
Nitrofurantoin (if eGFR>45) for 3 days
Amoxicillin for 3 days
Cefalexin for 3 days
Management of lower UTI - antibiotics men first choice?
o Nitrofurantoin (if eGFR>45) 100mg MR BD for 7 days o Trimethoprim 200mg BD for 7 days
Follow up in 48 hours
If not working consider alternative diagnosis
Management of lower UTI - antibiotics - pregnant women - first & second choice?
• First choice o Nitrofurantoin (if eGFR >45) 100mg MR BDS for 7 days
Second choice
o Amoxicillin (only if cultures results available) 500mg TDS for 7 days
o Cefalexin 500mg BDS for 7 days
Management of lower UTI - antibiotics - in asymptomatic bacteriuria?
• Nitrofurantoin, amoxicillin or cefalexin
Management of lower UTI - catheterised patients - general management?
o Remove catheter or changing as soon as possible if been in place for >7 days
o Obtain urine sample via sampling port
Management of lower UTI - catheterised patients - non-pregnant women and men >16 - antibiotics if lower symptoms?
o First choice
Nitrofurantoin, trimethoprim, amoxicillin (only if cultures available)
o Second choice
Pivmecillinam
Management of lower UTI - catheterised patients - non-pregnant women and men >16 - antibiotics if upper symptoms?
o First choice
Cefalexin, ciprofloxacin, co-amoxiclav, trimethoprim
o First choice IV
Co-amoxiclav, cefuroxime, ceftriaxone, gentamicin, amikacin
Management of lower UTI - catheterised patients - pregnant women - antibiotics?
- First choice oral – cefalexin
* First choice IV - cefuroxime
Management of lower UTI - catheterised patients - children <16 - antibiotics?
Under 3 months – refer to paediatrics
Over 3 months
o First choice oral
Trimethoprim, amoxicillin, cefalexin, co-amoxiclav
o First choice IV
Co-amoxiclav, cefuroxime, ceftriaxone, gentamicin, amikacin
Management of recurrent UTIs - definiton of recurrent?
at least 2 episodes within 6 months, or 3 or more within 12 months
Management of recurrent UTIs - when to refer?
Men >16
People with recurrent upper UTI
People with recurrent lower UTI when underlying cause unknown
Pregnant women
Management of recurrent UTIs - general measures?
Non-pregnant women may wish to try D-mannose or cranberry products
Avoid douching
Wipe from front to back after defaecation
Avoid delay in post-coital urination
Hydration important
Management of recurrent UTIs - antibiotic prophylaxis - men and pregnant women?
First choice
o Trimethoprim 200mg when exposed to trigger or 100mg at night
o Nitrofurantoin 100mg when exposed to trigger or 50mg at night
Second choice
o Amoxicillin 500mg when exposed to trigger or 250mg at night
o Cefalexin 500mg when exposed to trigger or 125mg at night
• Review in 6 months
Management of recurrent UTIs - antibiotic prophylaxis - non-pregnant women?
- Vaginal oestrogen (estriol cream) for postmenopausal women with recurrent UTI if behavioural and personal hygiene measures are not effective
- Can consider single-dose antibiotic prophylaxis or daily antibiotic prophylaxis if needed
When to refer lower UTI to specialist - in women?
Recurrent lower UTI when cause unknown
When to refer lower UTI to specialist - in men?
Ongoing symptoms despite antibiotic treatment
Suspected bladder outlet obstruction, Hx of pyelonephritis, urinary calculi or previous GU surgery
Recurrent episodes of UTI (2 or more in 6 months)
Further investigations needed in children with UTI - When to arrange US of UT?
During acute infection in all children with atypical infection:
• Poor urine flow, abdominal/bladder mass, raised creatinine, sepsis, failure to respond to antibiotics within 48 hours, non-E.coli organism
During acute infection if child <6 months with recurrent UTI
Within 6 weeks if child >6 months with recurrent UTI
Within 6 weeks if <6 months with first-time UTI that responds to treatment
Further investigations needed in children with UTI - other tests needed and when?
o Dimercaptosuccinic acid scintigraphy (DMSA) carried out within 4-6 months of acute infection if:
All children <3 years with atypical or recurrent UTI
All children >3 years or over with recurrent UTIs
Definition of recurrent UTI in children?
- 2 or more UTI with acute pyelonephritis or,
- 1 episode of acute pyelonephritis + one or more lower UTI with cystitis or,
- 3 or more UTI with cystitis
When referred to secondary care for UTI - what further tests can be performed?
o US KUB
o CT KUB
o Cystoscopy
o Urodynamic studies
Risk factors for pyelonephritis?
o Women o Sexual intercourse o Catheter o Abnormality of renal tract o Antibiotic use o Pregnancy o Immunocompromise o Diabetes Mellitus o Spermide
Causative organisms of pyelonephritis?
o E. coli in 90% of cases
o Proteus (present under prepuce)
o Klebsiella
o Enterococcus faecalis
o Saprophytic staphylococci (young women)
o Pseudomonas (may indicate structural damage in urinary tract)
Symptoms of acute pyelonephritis?
o UTI symptoms (dysuria, frequency, urgency) o Malaise o Fever o Loin pain +/- back pain o Vomiting o Rigors
Investigations in pyelonephritis?
- Urine dipstick MSU
o Leukocytes and nitrites, haematuria and proteinuria - Urine M, C&S
o Obtain before starting antibiotics
When to refer to hospital - with suspected pyelonephritis?
o Septic signs
o Significantly dehydrated or unable to take oral fluids
o Pregnant
o Structural or functional abnormality of GU tract
o Immunosuppression
o Diabetes
Management of pyelonephritis - general measures?
Paracetamol for pain
Increase fluid intake
Seek medical advice if worsens or does not improve within 48 hours, or person systemically unwell
o Midstream urine sample for M, C & S
Management of pyelonephritis - antibiotics - non-pregnant women and men - oral antibiotics?
o Oral cefalexin 500mg BD/TD for 7-10 days
o Oral ciprofloxacin 500mg BD for 7 days
o If culture results known:
Oral Co-amoxiclav 500/125mg TDS for 7-10 days
Oral trimethoprim 200mg BD for 14 days
Management of pyelonephritis - antibiotics - non-pregnant women and men - IV antibiotics?
o Ceftriaxone o Cefuroxime o Ciprofloxacin o Gentamicin o Amikacin o Co-amoxiclav (in combination or if culture results known)
Management of pyelonephritis - antibiotics - pregnant women - oral antibiotics?
o Cefalexin 500mg BD/TD for 7-10 days
Management of pyelonephritis - antibiotics - pregnant women - IV antibiotics?
o Cefuroxime 750mg to 1.5g TDS/QDS
Management of pyelonephritis - antibiotics - children <16 - oral antibiotics?
• Under 3 months – refer to paediatric specialist
Over 3 months
Cefalexin
Co-amoxiclav (only if culture results available and sensitive)
Management of pyelonephritis - antibiotics - children <16 - IV antibiotics?
Co-amoxiclav (only in combination or if culture result known) Cefuroxime Ceftriaxone Gentamicin Amikacin
When to review antibiotics in acute pyelonephritis?
o Review antibiotics at 48 hours if IV and when cultures available
Definition of acute urinary retention?
- Inability to voluntarily urinate
Mechanism of acute urinary retention?
o Increased resistence to flow
o Inappropriate detrusor muscle innervation
o Bladder over-distention
o Drugs
Epidemiology of acute urinary retention?
- Medical emergency, abrupt development of inability to pass urine
- Common 0.3%
- Men 10x
Causes of acute urinary retention - anatomical?
BPH (most common) Urethral strictures Prostate carcinoma Prostate haematoma Urethral stone Foreign body Urinary stent occlusion Constipation Meatal stenosis
Causes of acute urinary retention - functional?
Neurogenic bladder MS, Parkinsons, Alzheimer’s, cauda equina syndrome SCI CVA Tumour Spinal anaesthesia Alcohol Pain UTI Acute prostatitis (E.coli, proteus)
Causes of acute urinary retention - drugs?
Anticholinergics, antihistamines, amphetamines, morphine, hyoscine, TCAs
Symptoms of acute urinary retention?
o Severe pain
o Unable to pass urine
o Previous episodes
Signs of acute urinary retention?
Tender, distended bladder – dull to percuss above pubic symphysis
Initial investigations of acute urinary retention?
Rule out cauda equina
Bladder US scan
Calculates bladder volume
DRE of prostate – after catheterisation
Check anal tone, prostatic size, nodules, tenderness and exclude faecal impaction
Urinalysis - MSU
Bloods – FBC, U&E, glucose
Investigations to perform on ward of acute urinary retention?
o Renal US if any renal impairment
Immediate management of acute urinary retention?
o Catheterisation immediately
Document post-catheterisation residual volume, type of catheter (14/16G)
o Alpha-blocker given before catheter (tamsulosin)
Subsequent management of acute urinary retention?
o Treat cause
If BPH – tamsulosin with finasteride as an adjunct can be used
o Trial without catheter (TWOC) in men with BPH
Follow up of acute urinary retention?
o If secondary to BPH, constipation, UTI with no previous UT symptoms – no follow up
o Referral to urology clinic
Complications of acute urinary retention?
- UTIs
- AKI
- Post-retention diuresis, haematuria
Physiology of potassium?
- Potassium is mostly intracellular and thus serum potassium is poor indicator of total potassium
- Concentrations of H and K tend to vary together
- Insulin and catecholamines stimulate K into cells via Na/K/ATPase pump
Normal values of potassium?
- Normal values – 3.5-5mmol/L
Classifications of hyperkalaemia?
o Mild 5.5-6mmol/L
o Moderate 6.1-6.9mmol/L
o Severe >7.0mmol/L
Causes of hyperkalaemia?
o Spurious – Haemolysed sample
o Decreased renal excretion – AKI, CKD, K+ sparing diuretics
o Hypoaldosteronism – Addison’s disease, NSAIDs, ACEi
o Cell injury – Crush injury, rhabdomyolysis, burns, incompatible blood transfusion
o K+ cellular shifts – Metabolic acidosis, suxamethonium
Symptoms of hyperkalaemia?
o Muscle weakness/cramps
o Paraesthesia
o Focal neurological deficits
o Fast, irregular pulse with palpitations
ECG changes of hyperkalaemia?
o Peaked (tall, tented) T waves
o Small, flat P waves
o Widening QRS complexes (becomes sinusoidal)
o VF
When to treat hyperkalaemia immediately?
(>6.5 or >6 with ECG changes needs immediate treatment
Management of hyperkalaemia - immediate drug management?
o 10mL 10% calcium gluconate IVI to stabilise cardiac membrane (up to 30ml if no improvement in ECG)
o 10U soluble insulin (Actrarapid) in 50mL 50% glucose given over 5-15 minutes
o 5mg NEB Salbutamol, repeated once as necessary
o Calcium Resonium 15g orally every 6-8 hours (removes K from GI tract)
Co-prescribe with lactulose
o Review potassium intake, medications
o Contact renal team – may need dialysis if intractable
Definition of hypokalaemia?
- Potassium <2.5 needs urgent treatment but any value under 3.5 considered hypokalaemic
- Hypokalaemia exacerbates digoxin toxicity
Causes of hypokalaemia?
o Diuretics o D&V o Cushing’s/Steroids/ACTH o Alkalosis o Conn’s syndrome o Renal tubular failure o Pyloric stenosis o Intestinal fistula
Symptoms and signs of hypokalaemia?
o Muscle weakness o Hypotonia o Hyporeflexia o Cramps o Tetany o Palpitations o Light-headedness o Constipatio
ECG changes of hypokalaemia?
o Small/Inverted T waves
o Prominent U waves (after T wave)
o Long PR interval
o Depressed ST segments
Management of hypokalaemia - mild?
Oral K+ supplement (Sando K tablets) and U&Es daily
Management of hypokalaemia - severe?
IV potassium (normal max rate if 10mmol/hr but if severe 20mmol/h) and ensure continuous cardiac monitoring
Physiology of sodium regulation?
- Sodium controlled by aldosterone on DCT and collecting duct to increase Na reabsorption from urine
- Natriuretic peptides ANP, BNP, CNP reduce resorption from DCT and inhibit renin
- Derangement can occur with hypervolaemia, euvolaemia, hypovolaemia
Normal range of sodium?
- Normal ranges – 135-145mmol/L
Causes of hypernatraemia?
o Diabetes insipidus (lack of ADH or renal response)
o Fluid loss without replacement – Diarrhoea, vomiting
o Osmotic diuretics (mannitol, isosorbide)
o Hypertonic saline
o Cushing’s syndrome
Symptoms and signs of hypernatraemia?
o Lethargy, thirst, weakness, irritability, confusion and coma
o Signs of dehydration
Blood tests of hypernatraemia?
o High Na, PCV, albumin, urea
Management of hypernatraemia?
o Water orally if possible
o If hypovolaemia, 0.9% saline to correct
o Dextrose 5% IV (1L/6h) guided by urine output and serum Na (check every 2-3 hours)
Complications of hypernatraemia?
o Seizures
o Cerebral/subdural haemorrhages
o Dural sinus thrombosis
o Cerebral oedema
Causes of hyponatraemia - if dehydrated?
High urine Na – Addison’s disease, renal failure, diuretic excess, osmolar diuresis
Low urine Na – Diarrhoea, vomiting, burns, small bowel obstruction, CF
Causes of hyponatraemia - if not dehydrated?
Oedematous – Nephrotic syndrome, cardiac failure, liver failure, renal failure
Not oedematous – SIADH, water overload, hypothyroidism, glucocorticoid insufficiency
Symptoms of hyponatraemia?
Anorexia, nausea, malaise, headache, irritability, confusion, weakness and seizures
Management of hyponatraemia - acute (<24 hours)?
Assess volume status
Urine osmolarity
<100 - primary polydipsia or low solute intake
>100 and urine sodium >30 & hypovolaemic - vomiting, Addison’s, diuretics, salt wasting
>100 and urine sodium >30 & euvolaemic - SIADH, secondary adrenal insufficiency, hypothyroid, diuretics
>100 and urine sodium <30 - heart failure, liver failure, nephrotic syndrome, D&V
Mild
If hypervolaemic - fluid restriction
If hypovolaemic - 0.9% saline IV slowly
• Rapid change can lead to central pontine myelinolysis
Na <120mmol/L associated with risk of cerebral herniation
In emergency consider hypertonic saline (1.8/3%)
Management of hyponatraemia - chronic?
Slowly increase Na <10mmol/L per day
Treat cause
May need hypertonic saline
Definition of hyponatraemia?
Mild hyponatraemia — serum sodium 130–135 mmol/L.
Moderate hyponatraemia — serum sodium 125–129 mmol/L.
Severe hyponatraemia — serum sodium less than 125 mmol/L.
Classes of hyponatraemia?
Acute — hyponatraemia duration for less than 48 hours.
Chronic — hyponatraemia duration for 48 hours or more
Complications of hyponatraemia?
Life-threatening if severe and/or of acute onset
Swelling of brain cells, cerebral oedema and raised intracranial pressure can lead to seizures, coma, or cardio-respiratory arrest
Increased mortality and longer hospital admission
Chronic hyponatraemia can cause falls, gait disturbances, concentration and cognitive deficits
