bitemedicine - lecture (renal stones) slid
TRANSCRIPT
• Pathophysiology, clinical features, investigations, management, prognosis
• Provide important differential diagnoses
• Multi-step SBAs: for a full understanding of the patient journey
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Aims and objectives
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Which is a stone?
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Which is a stone?
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Which is a stone?
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Which is a stone?
History and examinationA 35-year-old male presents to the emergencydepartment with a two-hour history of severe,sudden-onset, right-sided flank pain radiating tohis groin. He has vomited once. He has no lowerurinary tract symptoms.
He has had a previous renal stone.
On examination, there is right flank tendernessbut no other findings.
ObservationsHR 120, BP 140/95, RR 24, SpO2 95%, Temp 37.3
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Case-based discussion: 1
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A 35-year-old male presents to the emergency department with a two-hourhistory of severe, sudden-onset, right-sided flank pain radiating to his groin.He has vomited once. He has no lower urinary tract symptoms.
He has had a previous renal stone.
Q1
What is your next step?
Case history
Oral dihydrocodeine
Urine dip
IV fluid bolus
Oral morphine
PR diclofenac
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Q2 Q3 Q4 Q5
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Explanations
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What is your next step?
Oral dihydrocodeineIn this context, opioids have a poorer analgesic effect and more side effects than NSAIDs
Urine dipShould be performed once symptomatic relief has been offered
IV fluid bolusTachycardia is likely due to pain and there are no features of dehydration on examination
Oral morphineIn this context, opioids have a poorer analgesic effect and more side effects than NSAIDs
PR diclofenacAs per BAUS guidelines, NSAIDs (diclofenac/ibuprofen) should be administered immediately after initial assessment
Q1 Q2 Q3 Q4 Q5
History and examinationA 35-year-old male presents to the emergencydepartment with a two-hour history of severe,sudden-onset, right-sided flank pain radiating tohis groin. He has vomited once. He has no lowerurinary tract symptoms.
He has had a previous renal stone.
On examination, there is right flank tendernessbut no other findings.
ObservationsHR 120, BP 140/95, RR 24, SpO2 95%, Temp 37.3
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Case-based discussion: 1
Definition• Nephrolithiasis is the presence of stones, or calculi, within the urinary tract
Epidemiology and general risk factors• Typically occurs in 30-60-year olds• Twice as common in males• Dehydration• Previous kidney stone(s)
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Introduction
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Basic anatomy
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Basic anatomy
Renal stone
Ureteric stone
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Renal stone
Calyceal stone
PUJ stone
Pelvic stone
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Ureteric stone
Ureteric stone
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VUJ stone
VUJ stone
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A 35-year-old male presents to the emergency department with a two-hourhistory of severe, sudden-onset, right-sided flank pain radiating to his groin.He has vomited once. He has no lower urinary tract symptoms.
He has had a previous renal stone.
Which of the following is the most likely site of obstruction in this patient?
Case history
As the ureter crosses over the coeliac trunk
As the ureter crosses over the uterine artery
Pelviureteric junction
As the ureter crosses anteriorly to the vas deferens
Spinoureteric junction
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Explanations
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Which of the following is the most likely site of obstruction in this patient?
As the ureter crosses over the coeliac trunkThe coeliac trunk arises at T12. The ureter begins at the level of the renal artery/vein (L1-2)
As the ureter crosses over the uterine arteryThe patient is male. Also, the ureter crosses under the uterine artery (water under the bridge)
Pelviureteric junctionOne of the most common sites of renal calculus obstruction
As the ureter crosses anteriorly to the vas deferensThe ureter crosses posteriorly to the vas deferens
Spinoureteric junctionThis does not exist
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Sites of obstruction
Pelviureteric junction (PUJ) of the renal pelvis and ureter
As the ureter enters the pelvis and crosses over the common iliac artery
At the vesicoureteric junction (VUJ) as the ureter enters the bladder
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Stone types
Composition
Calcium oxalate (75%)
Struvite (15%)Calcium phosphate (5%)
Uric acid (5%)
Cysteine (1%)
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Stone types: calcium oxalate
Composition
Calcium oxalate (75%)
Struvite (15%)Calcium phosphate (5%)
Uric acid (5%)
Cysteine (1%)
Risk factors and comments
Hypercalcaemia: e.g. hyperparathyroidism
Envelope-shapedRadio-opaque (less than calcium phosphate stones)
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Which is a stone?
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Stone types: struvite
Composition
Calcium oxalate (75%)
Struvite (15%)Calcium phosphate (5%)
Uric acid (5%)
Cysteine (1%)
Risk factors and comments
UTI with urease-producing organisms
Coffin-lid shaped and may cause staghorn calculiMildly radio-opaque
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Which is a stone?
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Stone types: calcium phosphate
Risk factors and comments
Hypercalcaemia: e.g. hyperparathyroidism
Type 1 and 3 renal tubular acidosisVery radio-opaque
Composition
Calcium oxalate (75%)
Struvite (15%)Calcium phosphate (5%)
Uric acid (5%)
Cysteine (1%)
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Stone types: uric acid
Risk factors and comments
Purine metabolism: gout and malignancy
Rhomboid-shapedRadiolucent
Composition
Calcium oxalate (75%)
Struvite (15%)Calcium phosphate (5%)
Uric acid (5%)
Cysteine (1%)
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Stone types: cysteine
Composition
Calcium oxalate (75%)
Struvite (15%)Calcium phosphate (5%)
Uric acid (5%)
Cysteine (1%)
Risk factors and comments
Cystinuria
Hexagonal-shaped and semi-opaqueMay cause multiple stones
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Other risk factors
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A 35-year-old male presents to the emergency department with a two-hourhistory of severe, sudden-onset, right-sided flank pain radiating to his groin.He has vomited once. He has no lower urinary tract symptoms.
He has had a previous renal stone.
Q2
Which of the following would be a red flag feature in this patient?
Case history
Vomiting
Haematuria
Renal-angle tenderness
Fever
Tachycardia
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Explanations
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Which of the following would be a red flag feature in this patient?
VomitingThis is common secondary to severe pain
HaematuriaAlthough haematuria is usually microscopic, macroscopic haematuria may be present
Renal-angle tendernessFlank or ‘renal-angle’ tenderness may be present with a renal stone and alone is not worrying
FeverThis is very concerning and may suggest urosepsis or pyelonephritis
TachycardiaOften present due to severe pain
Q2 Q3Q1 Q4 Q5
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Clinical features
Symptoms SignsAcute, severe ‘loin-to-groin’ pain Flank or renal-angle tenderness
Nausea and vomiting Hypotension and tachycardia: suggests urosepsis
Urinary urgency/frequency
Haematuria: usually microscopic
Fever: suggests superimposed infection
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Important differential diagnoses
Differential diagnosis CommentsAAA rupture • Sudden onset abdominal pain radiating to back
• Haemodynamic instability• Cardiovascular risk factors present
Acute appendicitis • Peri-umbilical à RIF pain and low-grade fever• Less acute onset
Ectopic pregnancy • Women of child-bearing age• Missed menstrual period• Vaginal spotting and cervical motion tenderness
Pyelonephritis • LUTS: dysuria, frequency, hesitancy• Fever• Less acute onset
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A 35-year-old male presents to the emergency department with a two-hourhistory of severe, sudden-onset, right-sided flank pain radiating to his groin.He has vomited once. He has no lower urinary tract symptoms.
He has had a previous renal stone. Pain has settled with diclofenac andurine dip is +++ blood. Observations are now normal.
What is your imaging of choice in this patient?
Case history
Non-contrast CT KUB
Renal tract ultrasound
MRI abdomen and pelvis
Contrast CT KUB
CT abdomen and pelvis
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Explanations
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What is your imaging of choice in this patient?
Non-contrast CT KUBConsidered gold-standard by BAUS (97% sensitivity and 95% specificity)
Renal tract ultrasoundPerformed if radiation must be avoided or in a subset of known stone formers
MRI abdomen and pelvisNot performed
Contrast CT KUBA CT KUB is a non-contrast procedure
CT abdomen and pelvisA CT is required but should be performed using a KUB protocol
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InvestigationsBedside• Urinalysis: microscopic haematuria
Bloods• FBC: WBC may be elevated, but if significantly may suggest superimposed infection• CRP: elevated• U&Es: deranged renal function suggests hydronephrosis• Bone profile: elevated calcium may suggest hyperparathyroidism• Blood cultures: if >38°C or features of sepsis• Coagulation profile: if percutaneous intervention is planned
Primary imaging• Non-contrast CT KUB: gold-standard and within 14 hours of admission at the latest
Imaging to consider• Renal tract ultrasound and/or X-ray KUB: may suffice if a known stone former, particularly if CT
KUB performed in the last 3 months (BAUS guidelines)
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A 35-year-old male presents to the emergency department with a two-hourhistory of severe, sudden-onset, right-sided flank pain radiating to his groin.He has vomited once.
Pain has settled with diclofenac and urine dip is +++ blood. Observations arenow normal. CT KUB: 15 mm right-sided mid-ureteric stone.
What is your first-line definitive management option?
Case history
Tamsulosin expulsive therapy
Ureteroscopy
Shockwave lithotripsy
Watchful waiting
Antibiotics and ureteric stenting
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Explanations
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What is your first-line definitive management option?
Tamsulosin expulsive therapyConsidered in <10 mm distal ureteric stones (NICE). BAUS do not recommend routine use
UreteroscopyGenerally first-line surgical management for 10-20 mm ureteric stones (NICE)
Shockwave lithotripsyConsidered in the management of 5-10 mm ureteric and renal stones (EUA/NICE)
Watchful waitingAppropriate for < 5 mm ureteric and renal stones (EUA/NICE)
Antibiotics and ureteric stenting Performed for sepsis/anuria in an obstructed kidney (urological emergency)
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The golden points when referring a stone patient to urology
1. Basic details (name/DOB etc.)2. A brief background
3. Known stone-former?4. Severity of pain/vomiting and response to medication
5. Presence of fever or features of sepsis6. Renal function
7. CT KUB: stone size, location and evidence of hydronephrosis
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Management
First line• IV fluids and anti-emetics (as required)• Analgesia: an NSAID by any route is first-line (NICE)
Conservative or medical management• Watchful waiting: ureteric and renal stones <5 mm usually pass spontaneously• Medical expulsive therapy: (distal) ureteric stones 5-10 mm (controversial)
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Extracorporeal shock wave lithotripsy (ESWL)
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Ureteroscopy (URS)
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Percutaneous nephrolithotomy (PCNL)
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Surgical management: EUA and NICEKey:
ESWL: extracorporeal shock wave lithotripsy
URS: ureteroscopy
PCNL: percutaneous nephrolithotomy
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Percutaneous nephrostomy
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Ureteric stenting
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Surgical management: EUA and BAUS
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Complications and prognosis
System Complication
Urological • Hydronephrosis• Urosepsis
Procedure-related • Ureteric injury• Bleeding• Sepsis• ESWL haematoma
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Top-decile question
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Explanations
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Which of the following stones would NOT be visible on a non-contrast CT KUB?
Prednisolone-induced stonesNot a recognized condition
Maraviroc-induced stonesThis is an entry inhibitor (HIV medication) and that is not usually associated with stones
Type 3 renal tubular acidosis-induced stonesThis causes calcium phosphate stones which are visible on CT KUB
Indinavir-induced stonesA protease inhibitor (HIV medication) characteristically linked with radiolucent stones
Raltegravir-induced stonesThis is an integrase inhibitor (HIV medication) that is not usually associated with stones
Q1
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Recap
• Renal vs ureteric stones
• There are numerous types of stones with specific risk factors
• Renal colic has a characteristic presentation, but important differentials must always be excluded
• All patients need a urine dip, basic bloods and most will have a non-contrast CT KUB
• Most patients can be managed conservatively
• Surgical options include ESWL, URS, PCNL, nephrostomy and stent insertion
• Patients with features of infection require immediate investigation and management
• Lifetime recurrence is remarkably high
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References
Slide 3 and 22: • Mikael Häggström, M.D. - Author info - Reusing images / CC0. https://commons.wikimedia.org/wiki/File:Spiculated_kidney_stone.jpg• Uploader1977 / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://commons.wikimedia.org/wiki/File:The_Puffer_Fish.jpg
Slide 4:• Mikael Häggström, M.D. - Author info - Reusing images / CC0. https://commons.wikimedia.org/wiki/File:Spiculated_kidney_stone.jpg• Jolanta Dyr / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0).
https://commons.wikimedia.org/wiki/File:020613_Interior_of_Manor_in_Pilaszk%C3%B3w_-_14.jpg
Slide 5:• Father.Jack from Coventry, UK / CC BY (https://creativecommons.org/licenses/by/2.0).
https://commons.wikimedia.org/wiki/File:Dough_balls_(1028134868).jpg• Jacek Proszyk / CC0. https://commons.wikimedia.org/wiki/File:Kidney_stone_4mm_05.jpg
Slide 6 and 40:• Willis Lam / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0).
https://commons.wikimedia.org/wiki/File:Burger_King_Chicken_Nuggets_(15423233415).jpg• RJHall / Public domain. https://commons.wikimedia.org/wiki/File:Kidney_stone_fragments.png
Slides 12, 13, 15, 19, 40, 43: Jordi March i Nogué [1] / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://commons.wikimedia.org/wiki/File:Urinary_system.svg
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References
Slide 14: Piotr Michał Jaworski; PioM EN DE PL / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/). https://commons.wikimedia.org/wiki/File:KidneyStructures.svg
Slide 16: DBCLS 統合TV / CC BY (https://creativecommons.org/licenses/by/4.0). https://commons.wikimedia.org/wiki/File:201405_bladder.png
Slide 21: Nevit Dilmen / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://commons.wikimedia.org/wiki/File:Radiology_1300236_cr.jpg
Slide 23: © Nevit Dilmen / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://commons.wikimedia.org/wiki/File:Staghorn_Kidney_Stone_08779.jpg
Slide 24: • Prefeitura de Olinda / CC BY (https://creativecommons.org/licenses/by/2.0).
https://commons.wikimedia.org/wiki/File:3%C2%BA_Festival_da_Tapioca_(1%C2%BA_Dia)_5.jpg• Joel Mills / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/). https://commons.wikimedia.org/wiki/File:Struvite_stones.JPG
Slide 26: © Nevit Dilmen / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_ALP02_nevit.jpg
Slide 31: Shutterstock basic license
Slide 44: Unknown author / Public domain. https://commons.wikimedia.org/wiki/File:N01224_H_nephrostomy.jpg
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References
Slide 45:• Hildpeyi at the English Wikipedia / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/).
https://commons.wikimedia.org/wiki/File:Ureteral_stent.jpg• Lucien Monfils / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). https://commons.wikimedia.org/wiki/File:DoubleJ.jpg
•
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