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Nephrolithiasis
Cardiovascular Presentations
Abdominal aortic aneurysm
Acute coronary syndrome (NSTEMI)
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Acute decompensated heart failure
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Aortic dissection
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Respiratory Presentations
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Neurological Presentations
Bell's palsy
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Gastrointestinal Presentations
Acute appendicitis
Acute cholecystitis
Acute diverticulitis
Acute pancreatitis
Anal fissure
Choledocholithiasis and cholangitis
Clostridioides difficile colitis
Gastritis
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Incarcerated or strangulated hernia
Inflammatory bowel disease flare
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Perforated viscus
Small bowel obstruction
Upper GI hemorrhage
Genitourinary and Reproductive Presentations
Acute prostatitis
Acute urinary retention
Ectopic pregnancy
Epididymitis
Orchitis
Ovarian torsion
Paraphimosis
Pelvic inflammatory disease
Priapism
Pyelonephritis
Renal laceration
Ruptured ovarian cyst
Testicular torsion
Tubo-ovarian abscess
Urinary tract infection (uncomplicated)
Urolithiasis (renal colic)
Vaginal bleeding (non-pregnant)
Infectious Disease Presentations
Acute sinusitis
Acute tonsillitis
Acute upper respiratory infection
Animal bite
Bacterial meningitis
Cellulitis
Conjunctivitis (bacterial)
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Febrile neutropenia
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Hepatitis (acute)
Herpes zoster
HIV-related illness
Human bite
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Infectious mononucleosis
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Osteomyelitis
Otitis externa
Parasitic infection
Periorbital cellulitis
Peritonsillar abscess
Scabies
Sepsis
Septic arthritis
Spontaneous bacterial peritonitis
Tick-borne illness (Lyme disease)
Tinea infection
Tuberculosis
Viral exanthem
Wound infection
Trauma Presentations
Achilles tendon rupture
ACL and mceniscus tear
Ankle fracture
Ankle sprain
Burn
Calcaneus fracture
Cervical spine fracture
Clavicle fracture
Dental avulsion
Distal radius fracture
Drowning
Elbow fracture and dislocation
Electrical injury
Facial bone fracture
Facial laceration
Femur fracture
Fingertip amputation
Forearm fracture (radius and ulna)
Frostbite
Hand:finger laceration
Heat exhaustion
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Hip fracture
Humeral shaft fracture
Knee dislocation
Knee sprain
Lightning injury
Mandible fracture
Metacarpal fracture
Metatarsal fracture
Muscle strain
Nasal fracture
Non-accidental trauma
Orbital fracture
Patella fracture
Phalanx fracture (finger)
Proximal humerus fracture
Pulmonary contusion
Rib fracture
Rotator cuff tear (acute traumatic)
Scalp laceration
Scaphoid fracture
Shoulder dislocation
Skull fracture
Splenic laceration
Sternal fracture
Supracondylar pediatric fracture
Tendon laceration (hand:wrist)
Thoracic and lumbar spine fracture
Tibia:fibula fracture
Tibial plateau fracture
Toe fracture
Traumatic epistaxis
Traumatic hyphema
Toxicologic Presentations
Acetaminophen toxicity
Alcohol intoxication
Alcohol withdrawal
Anticholinergic toxicity
Anticoagulant overdose
Benzodiazepine overdose
Benzodiazepine:sedative overdose
Beta-blocker and calcium channel blocker toxicity
Carbon monoxide poisoning
Caustic ingestion
Digoxin toxicity
Drug eruption
Foreign body ingestion
Opioid intoxication
Opioid overdose
Opioid withdrawal
Organophosphate
Salicylate toxicity
Serotonin syndrome
Stimulant intoxication (cocaine, methamphetamine)
Tricyclic antidepressant overdose
Psychiatric Presentations
Acute anxiety
Acute psychosis
Agitation:behavioral emergency
Bipolar disorder
Conversion disorder
Major depressive episode
Neuroleptic malignant syndrome
Suicidal ideation and attempt
Musculoskeletal and Rheumatologic Presentations
Acute low back pain (mechanical)
Bursitis
Cervical radiculopathy
Costochondritis
Gout (acute)
Lumbar radiculopathy
Pseudogout
Tendinitis
Dermatology Presentations
Acute eczema (Eczema acute flare)
Allergic contact dermatitis
Erythema multiforme
Henoch-Schönlein purpura
Pressure injury
Psoriasis (acute flare)
Stevens-Johnson syndrome
Toxic epidermal necrolysis
Urticaria (acute)
Environmental and Exposure Presentations
Envenomation (snake, spider, insect)
High-altitude illness
Hypothermia
Hematologic and Oncologic Presentations
Acute chest syndrome
Coagulopathy
Hyperviscosity syndrome
Sickle cell crisis (vaso-occlusive)
Symptomatic anemia
Thrombocytopenia (severe)
Tumor lysis syndrome
Pediatric-Specific Presentations
Bronchiolitis
Croup
Emergency delivery
Febrile seizure
Kawasaki disease
Neonatal jaundice
Neonatal sepsis
Nursemaid's elbow
Pediatric fever 0 to 28 days
Pediatric fever 29 to 60 days
Pediatric fever 61 to 90 days
Pyloric stenosis
Slipped capital femoral epiphysis
Intussusception
Endocrine and Metabolic Presentations
Adrenal crisis
Diabetic ketoacidosis
Hypercalcemia
Hyperosmolar hyperglycemic state
Hypertensive emergency
Hypertensive urgency
Hypoglycemia
Myasthenia gravis crisis
Myxedema coma
Severe hyperkalemia
Severe hyponatremia
Thyroid storm
ENT and Maxillofacial Presentations
Acute laryngitis
Acute otitis media
Acute pharyngitis
Cerumen impaction
Epistaxis (anterior)
Nasal foreign body
Otitis externa
Tympanic membrane perforation
Ophthalmologic Presentations
Acute angle-closure glaucoma
Central retinal artery occlusion
Chemical eye injury
Corneal abrasion
Corneal ulcer
Globe rupture
Ocular foreign body
Orbital cellulitis
Retinal detachment
Obstetric Presentations
Hyperemesis gravidarum
Painful vaginal bleeding in pregnancy
Placenta previa
Placental abruption
Preeclampsia:eclampsia
Preterm labor
Threatened:inevitable:incomplete abortion
Systemic and Miscellaneous Presentations
Anaphylaxis
Angioedema
Cannabis-induced hyperemesis
Nephrolithiasis
POCUS
Procedures
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ECG Guide
Back
Clinical Assessment Checklist
Browse categories and answer follow-up questions to refine your symptom profile.
Approach to the Critical Patient
Immediate priorities
Infected obstructing stone — urologic emergency
▶
Fever with obstructing stone on imaging
▶
Emergent urology consult regardless of pain control
Sepsis protocol activation
Sepsis physiology triggers
▶
SBP < 90 mmHg
MAP < 65 mmHg
Lactate >= 2 mmol/l
Altered mental status
If septic shock from obstructed infected kidney, emergent decompression
▶
Ureteral stent or percutaneous nephrostomy
Broad spectrum antibiotics within 1 hour
Monitoring and targets
Monitoring bundle
▶
Continuous cardiac monitor for tachyarrhythmia
▶
Tachycardia from pain versus sepsis differentiation
Hypotension detection
Urine output monitoring
▶
Anuria or oliguria suggests bilateral obstruction
Solitary or transplanted kidney at higher risk
Serial abdominal assessment
▶
Peritoneal signs absent in uncomplicated renal colic
If peritoneal signs present, consider alternative diagnosis
Vital sign thresholds
▶
Temperature > 37.8 C as infected stone red flag
▶
Obtain blood cultures prior to antibiotics
Urine culture and urinalysis
Escalate to resuscitation bay for hemodynamic instability
▶
Vasopressor initiation if hypotension unresponsive to fluids
ICU level care for urosepsis with shock
Key decision points
Critical branching questions
▶
Infected stone versus uncomplicated colic
▶
Fever + hydronephrosis = infected obstruction until proven otherwise
Pyuria alone does not confirm infection in stone patient
Alternative life threat must be excluded
▶
Abdominal aortic aneurysm in older patients with vascular risk
Ectopic pregnancy in reproductive-age women
Solitary kidney obstruction
▶
Lower threshold for emergent intervention
Urology consult immediate
AKI with obstructing stone
▶
Rising creatinine is indication for admission and decompression
Avoid nephrotoxic agents and contrast if creatinine elevated
History
Presentation pattern
Classic renal colic syndrome
▶
Acute colicky flank pain radiating to groin
▶
Waxing and waning corresponding to ureteral peristalsis
Sudden onset, often waking patient from sleep
Pain migration with stone descent
▶
Lower abdominal pain as stone approaches ureterovesical junction
Ipsilateral gonadal or urethral tip radiation
Associated symptoms
▶
Nausea and vomiting from shared splanchnic innervation
Urinary urgency and frequency with distal ureteral stones
Dysuria mimicking cystitis with stones near bladder
Alarm features
Red flag symptoms requiring urgent evaluation
▶
Fever or chills with flank pain
▶
Infected urolithiasis until proven otherwise
Rigors suggesting bacteremia
Anuria or markedly decreased urine output
▶
Bilateral obstruction
Obstruction of solitary or transplanted kidney
Pain unresponsive to IV analgesics
▶
Alternative diagnosis consideration
Surgical emergency evaluation
Hematuria absence does not exclude stones
▶
Up to 10% of confirmed stones have no hematuria
Risk factors and prior history
Personal stone history
▶
Prior stone episodes are strongest predictor of recurrence
▶
5-year recurrence rate 35 to 50% without treatment
Stone type and prior metabolic workup
Prior urologic procedures
▶
Stent or nephrostomy history
Lithotripsy or ureteroscopy prior episodes
Medical comorbidities
▶
Gout predisposes to uric acid stones
▶
Low urine pH environment
Hyperuricosuria
Hyperparathyroidism
▶
Hypercalcemia screen
Calcium stone formation
Inflammatory bowel disease and bariatric surgery
▶
Enteric hyperoxaluria with calcium oxalate stones
Increased intestinal oxalate absorption
Recurrent UTI history
▶
Struvite infection stone risk
Urease-producing organisms
Medication and supplement exposures
▶
Topiramate promoting calcium phosphate stones
▶
Carbonic anhydrase inhibition mechanism
Alkaline urine pH
High-dose vitamin C or calcium supplements not taken with meals
▶
Increased urinary oxalate with vitamin C
Timing-dependent calcium oxalate risk
Indinavir crystals in HIV-treated patients
▶
Radiolucent on CT
Drug crystallization mechanism
Epidemiological risk factors
Demographic and metabolic risk
▶
Male sex with narrowing gender gap
▶
Lifetime prevalence 13% men versus 7% women
Overall US population prevalence 8.8%
Obesity and metabolic syndrome
▶
Obesity OR up to 2.09 in women
Metabolic syndrome OR 1.77
Hypertension OR 1.61
Diabetes OR 1.55
Family history increases risk 3-fold
▶
55% of recurrent stone formers have positive family history
Hereditary cystinuria
Primary hyperoxaluria
Environmental factors
▶
Hot climate and occupational heat exposure
Low fluid intake and chronic dehydration
High sodium, animal protein, and fructose intake
Physical Exam
Vitals and general appearance
Stability snapshot
▶
Temperature
▶
Fever > 37.8 C as infected stone marker
High fever with rigors suggests bacteremia
Heart rate
▶
Tachycardia from pain versus sepsis differentiation
Persistent tachycardia after analgesia raises sepsis concern
Blood pressure
▶
Hypotension suggests septic shock
SBP < 90 mmHg triggers resuscitation
General appearance
▶
Patient writhing unable to find comfortable position
Distinguishes renal colic from peritonitis where patient lies still
Abdominal and urologic exam
Abdominal exam findings
▶
Costovertebral angle tenderness
▶
Ipsilateral CVA tenderness characteristic
Bilateral CVA tenderness raises alternative diagnosis concern
Abdominal tenderness
▶
Mild ipsilateral abdominal tenderness acceptable
Peritoneal signs absent in uncomplicated colic
Rebound and guarding suggest alternative diagnosis
Vascular assessment
▶
Palpation for pulsatile abdominal mass
AAA exclusion in older patients
Genitourinary exam
▶
Testicular exam in males
▶
Exclude testicular torsion
Scrotal tenderness or swelling
Pelvic exam in females when indicated
▶
Adnexal tenderness suggesting ovarian pathology
Cervical motion tenderness suggesting PID
PITFALLS
Diagnostic errors in renal colic presentation
▶
AAA misdiagnosed as renal colic
▶
Older male with vascular risk factors
Always palpate for pulsatile mass
Ectopic pregnancy missed
▶
All reproductive-age women require beta-hCG
Vaginal bleeding may be absent
Normal temperature does not exclude infected stone
▶
Immunosuppressed and older patients
Pyuria can occur with uninfected stones causing mucosal irritation
Differential Diagnosis
Life-threatening mimics
Cannot-miss diagnoses
▶
Abdominal aortic aneurysm
▶
ICD-10 I71.4
Pulsatile abdominal mass
Older patient with vascular risk factors and hypotension
Ectopic pregnancy
▶
ICD-10 O00.9
Positive beta-hCG in reproductive-age women
Adnexal tenderness or free fluid on ultrasound
Urosepsis from infected obstructing stone
▶
ICD-10 N20.1 with A41.9 association
Fever, hydronephrosis, sepsis physiology
Mortality risk without emergent decompression
Common mimics
Urinary tract pathology
▶
Pyelonephritis
▶
ICD-10 N10
Fever, pyuria, bacteriuria without stone on imaging
May coexist with stones
Renal infarction
▶
ICD-10 N28.0
Atrial fibrillation, age >= 70, elevated LDH >= 500 mmol/l
Absence of hematuria or pyuria with severe flank pain
Papillary necrosis
▶
Sickle cell disease, analgesic nephropathy, diabetes
Sloughed papilla may cause colic
Gastrointestinal causes
▶
Appendicitis
▶
ICD-10 K37
RLQ peritoneal signs, anorexia, migration of pain
Right-sided renal colic mimic
Diverticulitis
▶
ICD-10 K57.32
LLQ pain, fever, older patients
Left-sided stone mimic
Mesenteric ischemia
▶
ICD-10 K55.0
Out-of-proportion pain in older patients
Vascular risk factors
Gynecologic causes
▶
Ovarian torsion
▶
ICD-10 N83.51
Most common alternative diagnosis in women on CT scan
Sudden onset pelvic pain with nausea
Ruptured ovarian cyst
▶
ICD-10 N83.20
Mid-cycle timing
Adnexal tenderness
Musculoskeletal pain
▶
Positional variation
Reproducible on palpation
No urinary symptoms
Laboratory Tests
Core emergency labs
Urinalysis
▶
Hematuria detection
▶
Sensitivity 90% for ureteral stones
Absence does not exclude stone in up to 10% of cases
Pyuria and bacteriuria
▶
Suggests concurrent infection
Urine culture required if present
Urine pH
▶
Low pH < 5.5 favors uric acid stones
High pH > 7.0 favors struvite or calcium phosphate stones
Basic metabolic panel
▶
Creatinine and GFR
▶
AKI assessment with obstructing stone
Baseline for contrast and medication dosing decisions
Solitary kidney identification
Calcium
▶
Hypercalcemia screen for hyperparathyroidism
Calcium > 2.6 mmol/l warrants further evaluation
Potassium and bicarbonate
▶
Electrolyte disturbance from vomiting
Renal tubular acidosis pattern
Infection and sepsis labs
CBC
▶
Leukocytosis as infection marker
▶
Mild WBC elevation may occur with pain alone
Marked leukocytosis with fever suggests infected stone
Neutrophilia with bandemia
▶
Bacterial infection pattern
Sepsis concern
Blood cultures
▶
Prior to antibiotics when infection suspected
▶
Two sets from separate sites
Gram-negative bacteremia common with urosepsis
Lactate
▶
>= 2 mmol/l as organ hypoperfusion marker
▶
Repeat in 2 to 4 hours if elevated
Lactate >= 4 mmol/l as septic shock marker
Urine culture
▶
Any fever or pyuria with stone
▶
Guides antibiotic de-escalation
Common organisms Escherichia coli and Klebsiella
Targeted labs
Beta-hCG
▶
All reproductive-age women without exclusion
▶
Ectopic pregnancy must be excluded
Quantitative for gestational age estimation if positive
Uric acid level
▶
Suspected uric acid stone
▶
Gout history or low urine pH
Hyperuricemia evaluation
Serum PTH
▶
If hypercalcemia identified
▶
Primary hyperparathyroidism evaluation
Not acute management but critical for workup initiation
Diagnostic Tests
Scoring Systems
STONE score for ureteral stone probability
▶
Five clinical variables
▶
Sex male = 2 points
Timing of pain onset < 6 hours = 3 points
Origin race non-black = 3 points
Nausea or vomiting = 1 point
Erythrocytes on dipstick = 3 points
Score interpretation
▶
Low 0 to 5 stone probability 8 to 10%
Moderate 6 to 9 stone probability 51 to 67%
High 10 to 13 stone probability 89%
Clinical utility
▶
ACEP Level B recommendation as decision support adjunct
STONE PLUS combines score with bedside ultrasound for improved accuracy
CLAD score for alternative urgent diagnosis
▶
Identifies patients needing CT to exclude surgical emergency
▶
Age > 50 years
Absence of prior stone history
Pain absence in flanks
Abnormal aortic diameter on ultrasound
High CLAD score warrants CT regardless of stone probability
MRI
MRI urinary tract
▶
Primary indication
▶
Pregnancy when ultrasound inconclusive
Radiation avoidance in young patients
Suspected soft tissue diagnosis not visible on CT
Performance characteristics
▶
Sensitivity 82% for urolithiasis
Lower than CT for small stones
Superior for soft tissue characterization
Protocol considerations
▶
No contrast required for stone detection
MR urography sequences
T2-weighted sequences identify hydronephrosis
Limitations
▶
Availability constraints in acute setting
Motion artifact risk
Poor small stone sensitivity
CT
Non-contrast CT abdomen and pelvis
▶
First-line imaging for suspected nephrolithiasis
▶
Sensitivity > 95% and specificity > 98% for urolithiasis
ICD-10 guided imaging indication N20.0 to N20.2
ACEP Level A recommendation
Low-dose CT protocol
▶
Pooled sensitivity 97% and specificity 95%
Radiation < 3 mSv versus 8 to 10 mSv standard protocol
Preferred in younger patients to reduce lifetime radiation exposure
Key CT findings
▶
Stone size and location determines management
Hydronephrosis grade
Perinephric stranding as obstruction severity marker
Tissue rim sign confirms ureteral location
Spontaneous passage prediction by size
▶
Stones <= 4 mm passage rate 80 to 98%
Stones 4 to 6 mm passage rate 59 to 80%
Stones 6 to 8 mm passage rate 48 to 60%
Stones > 8 mm passage rate < 40%
Alternative diagnoses detected
▶
Up to one-third of CT scans reveal non-stone diagnosis
Appendicitis, AAA, ovarian pathology identified
When CT may be deferred
▶
Young patient < 35 years with typical symptoms
Hematuria confirmed on urinalysis
Prior confirmed stone history with identical presentation
Pain relief with analgesics and no alarm features
Ultrasound
Renal and bladder ultrasound
▶
Indications
▶
First-line in pregnancy
Pediatric patients to minimize radiation
Initial study in young patients with typical presentation
ACR appropriateness criteria supports ultrasound first approach
Performance characteristics
▶
Sensitivity 45 to 67% for stone detection
Specificity 94 to 97%
High sensitivity 88 to 95% for hydronephrosis detection
Key findings
▶
Hydronephrosis grade I to IV
Intraluminal stone with acoustic shadowing
Ureteral jet assessment via Doppler
Limitations
▶
Poor visualization of ureteral stones especially mid-ureter
Operator dependent
Bowel gas interference
Point of care ultrasound role
▶
STONE PLUS study supports POCUS combined with clinical score
Hydronephrosis detection guides triage and CT decision
ACEP Level B recommendation for POCUS in renal colic
Disposition
Admission indications
Mandatory admission criteria
▶
Infected obstructing stone
▶
Any fever with hydronephrosis
Urosepsis or septic shock
Emergent decompression required
Acute kidney injury
▶
Rising creatinine with obstructing stone
Obstruction of solitary or transplanted kidney
Bilateral ureteral obstruction
Intractable symptoms
▶
Pain uncontrolled despite IV analgesics
Persistent vomiting preventing oral intake
Large stones with high-grade obstruction
▶
Stone > 10 mm unlikely to pass spontaneously
High-grade hydronephrosis with pain
ICU indications
Critical care level
▶
Septic shock from urosepsis
▶
Vasopressor requirement
Persistent lactate elevation despite resuscitation
Multi-organ dysfunction
▶
AKI with hemodynamic instability
Altered mental status with sepsis
Discharge criteria
Copy
Safe discharge requirements
▶
Pain controlled with oral analgesics
▶
Tolerating oral medications and fluids
No persistent vomiting
No infection signs
▶
Afebrile
No pyuria requiring culture result
Renal function stable
▶
No AKI or baseline creatinine
Normal or mild hydronephrosis
Stone characteristics favorable
▶
Stone <= 10 mm
Distal location preferred for MET candidacy
Urology consultation triggers
Urgent urology consult indications
▶
All infected obstructing stones
▶
Emergent decompression decision
Stent versus nephrostomy tube selection
Stone > 10 mm or unlikely to pass
▶
Ureteroscopy or SWL planning
Outpatient versus inpatient decision
Solitary kidney with obstruction
▶
Lower threshold for intervention
Renal function preservation priority
Recurrent stone formers
▶
Metabolic evaluation planning
24-hour urine collection scheduling post-acute phase
Follow up planning
Copy
Outpatient follow-up requirements
▶
Repeat imaging within 14 days
▶
CT or ultrasound to assess stone position
Hydronephrosis resolution
Trial of passage duration
▶
4 to 6 weeks for conservative management
Urology follow-up if no passage by 4 weeks
Metabolic evaluation timing
▶
24-hour urine collection 3 or more weeks after passage
Reserved for recurrent stone formers
Not in the acute setting
Treatment
Acute analgesia
NSAIDs — first-line analgesia
▶
Ketorolac IV
▶
15 to 30 mg IV
Preferred first-line agent per EAU and AUA guidelines
Reduces ureteral smooth muscle spasm
Avoid in AKI, GI bleeding history, allergy
Ibuprofen PO when tolerated
▶
600 to 800 mg PO every 6 to 8 hours
Transition from IV ketorolac
Maximum 3200 mg per day
Combination analgesia superior to monotherapy
▶
NSAID plus opioid superior to either alone
ACEP Level B recommendation
Opioid analgesia — second-line
▶
Morphine IV
▶
0.1 mg/kg IV titrated to effect
Reassess pain at 15 to 30 minutes
Nausea common, antiemetic co-administration
Hydromorphone IV
▶
0.015 mg/kg IV for moderate to severe pain
Titrate every 15 minutes
Preferred in morphine-intolerant patients
IV lidocaine as alternative
▶
1.5 mg/kg IV over 10 minutes
Opioid-sparing analgesic option
Cardiac monitoring required during infusion
Antiemetics
Nausea and vomiting management
▶
Ondansetron IV
▶
4 mg IV over 2 to 5 minutes
First-line antiemetic
QT prolongation risk at high doses
Metoclopramide IV
▶
10 mg IV over 15 minutes
Alternative when ondansetron unavailable
Extrapyramidal side effect monitoring
Medical expulsive therapy
Tamsulosin for stone passage facilitation
▶
Tamsulosin 0.4 mg PO daily
▶
Distal ureteral stones 5 to 10 mm
Relaxes ureteral smooth muscle via alpha-1 blockade
Continue for duration of trial of passage up to 4 to 6 weeks
Evidence and indications
▶
Benefit demonstrated for stones > 5 mm in distal ureter
No demonstrated benefit for stones < 5 mm
AUA guideline supports MET for distal stones > 5 mm
Not recommended agents
▶
Nifedipine no longer recommended for MET
Aggressive IV hydration does not accelerate stone passage
Urosepsis and infected stone treatment
Antibiotic therapy for infected urolithiasis
▶
Empiric gram-negative coverage
▶
Piperacillin-tazobactam 4.5 g IV every 6 hours
Ceftriaxone 2 g IV daily for non-severe illness
Adjust based on local resistance patterns
Fluoroquinolone alternative
▶
Ciprofloxacin 400 mg IV every 12 hours
Only if local resistance < 10%
Oral transition when clinically stable
Duration of antibiotics
▶
7 to 14 days total depending on source control
Extend if bacteremia documented
De-escalate per culture and sensitivity results
Emergent decompression
▶
Ureteral stent placement
▶
Retrograde approach under anesthesia
Drainage while awaiting definitive stone treatment
Percutaneous nephrostomy tube
▶
Antegrade drainage under ultrasound or fluoroscopic guidance
Preferred when anatomy precludes retrograde stenting
Interventional radiology or urology performed
Interventional stone treatment
Ureteroscopy with laser lithotripsy
▶
Indications
▶
Stones > 10 mm
Stone not expected to pass with MET
Failed trial of passage
Higher stone-free rates
▶
Preferred for distal ureteral stones
Stone-free rate > 90% for ureteral stones
Post-procedure care
▶
Ureteral stent typically placed
Stent removal in 2 to 4 weeks
Shock wave lithotripsy
▶
Indications
▶
Renal stones < 20 mm
Proximal ureteral stones
Lower morbidity than ureteroscopy
Contraindications
▶
Pregnancy
Coagulopathy
Obstruction distal to stone
Aortic aneurysm
Stone-free rates
▶
Lower than ureteroscopy for ureteral stones
Repeat sessions may be required
Percutaneous nephrolithotomy
▶
Indications
▶
Large renal stones > 20 mm
Staghorn calculi
Stones not accessible by ureteroscopy
Higher complication rate
▶
Bleeding risk
Requires general anesthesia
Prolonged recovery
Recurrence prevention pharmacotherapy
Thiazide diuretics for hypercalciuria
▶
Chlorthalidone 25 mg PO daily
▶
First-line for recurrent calcium stones with hypercalciuria
Reduces urinary calcium excretion
Monitor potassium
Hydrochlorothiazide 50 mg PO daily
▶
Alternative thiazide option
AUA guideline recommendation
Indapamide 2.5 mg PO daily
▶
Alternative with lower metabolic side effects
Potassium citrate
▶
Indication
▶
Hypocitraturia
Uric acid stones
Cystine stones
Distal renal tubular acidosis
Dosing
▶
30 to 60 mEq PO divided twice to three times daily
Alkalinizes urine pH target > 6.0 for uric acid
Citrate inhibits calcium oxalate crystallization
Allopurinol for hyperuricosuria
▶
Indication
▶
Hyperuricosuria with calcium oxalate stones and normocalciuria
Uric acid stone formers
Dosing
▶
100 to 300 mg PO daily
Start low and titrate
Monitor renal function and CBC
Special Populations
Pregnancy
Pregnancy-specific considerations
▶
Prevalence and presentation
▶
Incidence 1 in 200 to 1500 pregnancies
Ureteroscopy and colic most common in second trimester
Physiologic hydronephrosis of pregnancy complicates interpretation
Imaging approach in pregnancy
▶
Renal ultrasound first-line
Non-contrast MRI if ultrasound inconclusive
CT as last resort when benefits outweigh fetal radiation risk
ACR appropriateness criteria supports this hierarchy
Analgesic safety in pregnancy
▶
Acetaminophen preferred first-line for mild to moderate pain
NSAIDs limited to second trimester only with caution
Avoid NSAIDs in third trimester due to premature ductus closure
Opioids short-term use with neonatal monitoring if near term
Antibiotic safety
▶
Beta-lactams safe throughout pregnancy
Cephalexin or ceftriaxone for UTI and pyelonephritis
Avoid fluoroquinolones and tetracyclines
MET in pregnancy
▶
Tamsulosin not established as safe in pregnancy
Avoid MET unless risk-benefit clearly favorable
Interventional management
▶
Ureteral stent under local anesthesia feasible
Stent requires more frequent exchanges due to encrustation
Ureteroscopy can be performed safely in second trimester
Fetal monitoring during and after procedures
Geriatric
Older adult features
▶
Atypical presentation risk
▶
Reduced pain perception may minimize reported severity
Confusion or functional decline as primary presentation
Afebrile infected stones more common in immunosenescence
Comorbidity burden
▶
Anticoagulation affects interventional planning
Renal insufficiency at baseline
Cardiovascular disease limits contrast use
Medication considerations
▶
NSAID caution with reduced GFR
Avoid NSAIDs if GFR < 30 ml/min
Opioid dose reduction with frailty
Fall risk with opioids and tamsulosin
AAA mimicry highest risk in older patients
▶
Bedside aortic ultrasound prior to assuming stone diagnosis
Pulsatile mass palpation mandatory
Disposition bias toward admission
▶
Limited home support
Frailty and fall risk
Greater risk of decompensation
Pediatrics
Pediatric differences
▶
Epidemiologic trends
▶
Increasing prevalence in children linked to obesity and diet
Metabolic disorders proportionally more common
JAMA Pediatrics 2015 review of current trends
Presentation differences
▶
Younger children may present with vague abdominal pain
Older children similar to adult flank colic pattern
Nausea and vomiting prominent
Imaging preference
▶
Ultrasound first to minimize radiation
Low-dose CT if ultrasound inconclusive and clinical concern high
MRI in selected cases to avoid radiation
Metabolic evaluation priority
▶
Higher yield of underlying metabolic disorder than adults
Cystinuria, primary hyperoxaluria, RTA evaluation
24-hour urine collection after acute episode
Analgesia dosing
▶
Ketorolac 0.5 mg/kg IV maximum 15 mg per dose
Morphine 0.1 mg/kg IV titrated every 15 to 30 minutes
Ondansetron 0.15 mg/kg IV maximum 4 mg
MET in children
▶
Tamsulosin 0.2 to 0.4 mg PO daily off-label use
Limited evidence in pediatric population
Cochrane review 2017 notes limited pediatric data
Prevention in pediatric patients
▶
Fluid intake targets age and weight based
Dietary modification counseling for family
Avoid dietary oxalate restriction unless hyperoxaluria confirmed
Background
Epidemiology
Prevalence and incidence
▶
US population prevalence 8.8% of adults
▶
Lifetime prevalence 13% in men
Lifetime prevalence 7% in women
Gender gap narrowing with obesity epidemic
Recurrence rates
▶
5-year recurrence rate 35 to 50% without treatment
Recurrence rate reduced to < 15% with preventive therapy
Strongest recurrence predictor is prior stone history
Stone type distribution
▶
Calcium oxalate 70 to 80% of stones
Calcium phosphate 5 to 10%
Uric acid 5 to 10%
Struvite 5 to 15%
Cystine < 1%
Associated conditions prevalence
▶
Metabolic syndrome association OR 1.77
Hypertension OR 1.61
Diabetes OR 1.55
Dyslipidemia OR 1.59
Pathophysiology
Stone formation mechanisms
▶
Supersaturation principle
▶
Urine supersaturation with stone-forming salts drives crystallization
Supersaturation depends on urinary concentration of constituents
Inhibitors of crystallization include citrate, magnesium, and Tamm-Horsfall protein
Calcium oxalate stone formation
▶
Hypercalciuria most common metabolic abnormality
Hyperoxaluria from dietary or enteric sources
Hypocitraturia permits crystal growth
Uric acid stone formation
▶
Low urine pH < 5.5 critical factor
Hyperuricosuria from purine excess
Dehydration and concentrated urine
Struvite stone formation
▶
Urease-producing organisms raise urine pH
Common organisms Proteus, Klebsiella, Pseudomonas
Staghorn calculi development risk
Cystine stone formation
▶
Autosomal recessive cystinuria
Impaired renal tubular reabsorption of cystine
Recurrent stone formation beginning in childhood
Obstruction and injury mechanism
▶
Ureteral obstruction sequence
▶
Initial ureteral peristalsis increase causes colic
Hydrostatic pressure elevation with prolonged obstruction
GFR reduction proportional to obstruction duration
Infection in obstructed kidney
▶
Impaired drainage promotes bacterial proliferation
Bacteremia risk from mucosal disruption
Pyonephrosis and abscess formation risk
Therapeutic Considerations
Analgesia strategy principles
▶
NSAIDs mechanism superiority in renal colic
▶
Reduce prostaglandin-mediated ureteral spasm
Decrease GFR transiently reducing ureteral wall tension
EAU and AUA endorse NSAIDs as first-line agents
Opioid role as adjunct not replacement
▶
Combination with NSAIDs superior to monotherapy
ACEP Level B recommendation for combination therapy
Aggressive IV hydration not evidence based
▶
Does not accelerate stone passage
Nifedipine not recommended for MET per current guidelines
MET evidence base
▶
Tamsulosin mechanism and evidence
▶
Alpha-1A receptor blockade in distal ureter
Demonstrated benefit for stones 5 to 10 mm
Cochrane review supports MET for larger distal stones
Conservative management timeframe
▶
4 to 6 week trial appropriate for stones <= 10 mm
Interval imaging to assess position and obstruction
Stone prevention evidence
▶
Fluid intake most evidence-based intervention
▶
Goal urine output >= 2 to 2.5 L per day
ACP and AUA guideline Class I recommendation
Dietary calcium paradox
▶
Low dietary calcium increases urinary oxalate and stone risk
Normal dietary calcium 1000 to 1200 mg per day recommended
Calcium supplements without meals increase risk
Pharmacotherapy reserved for dietary failure
▶
Stone type and 24-hour urine results guide agent selection
AUA medical management guideline 2014 framework
Patient Discharge Instructions
copy discharge instructions
Copy
Kidney stone home care instructions
▶
Strain all urine with a stone strainer
▶
Catch any passed stone for laboratory analysis
Stone type guides future prevention
Fluid intake goals
▶
Drink enough fluids to produce pale yellow or clear urine
Aim for at least 2 to 2.5 litres of fluid per day
Water is preferred over sugary or carbonated drinks
Pain management at home
▶
Take prescribed ibuprofen or naproxen as directed with food
Take tamsulosin as prescribed to help the stone pass
Pain may come and go as the stone moves
Activity
▶
Light activity is safe and may help stone passage
Avoid strenuous activity if pain is severe
Warning signs to return to ER
▶
Fever or chills
▶
Temperature above 38 C is an emergency
May signal infected stone requiring urgent drainage
Inability to urinate
▶
No urine output for 8 hours
Suggests complete obstruction
Worsening or uncontrolled pain
▶
Pain not relieved by prescribed medications
Return immediately for IV pain management
Persistent vomiting
▶
Unable to keep fluids or medications down
Dehydration risk
Blood in urine that worsens significantly
▶
Some blood in urine is expected
Heavy bleeding or clots should prompt ER visit
Dietary advice
▶
Increase fluid intake starting today
▶
Avoid concentrated dark yellow urine
Track fluid intake if needed
Normal calcium diet recommended
▶
Do not restrict dairy unless specifically instructed
Avoid calcium supplements between meals
Reduce salt and animal protein intake
▶
Limit processed foods high in sodium
Limit red meat to recommended daily allowances
Follow-up instructions
▶
Urology appointment within 1 to 2 weeks
▶
Bring any stone caught in strainer to appointment
Bring imaging results
Repeat imaging in 14 days if stone has not passed
▶
To confirm stone position and kidney drainage
Metabolic workup for recurrent stone formers
▶
24-hour urine collection arranged after stone passes
Discuss at follow-up appointment
References
Guidelines and key sources
Primary guidelines
▶
AUA Medical Management of Kidney Stones Guideline 2014
▶
Pearle MS et al. Journal of Urology 2014
Framework for metabolic evaluation and prevention pharmacotherapy
EAU Guidelines on Urolithiasis 2025
▶
Skolarikos A et al. European Urology 2025
Diagnosis and interventional treatment recommendations
ACP Guideline on Recurrent Nephrolithiasis Prevention 2014
▶
Qaseem A et al. Annals of Internal Medicine 2014
Dietary and pharmacologic prevention strategies
ACR Appropriateness Criteria Flank Pain Urolithiasis 2023
▶
Gupta RT et al. Journal of American College of Radiology 2023
Imaging algorithm for acute flank pain
Key clinical studies
Landmark evidence
▶
STONE score derivation and validation
▶
Moore CL et al. BMJ 2014
Clinical prediction rule for ureteral stone probability
STONE PLUS study
▶
Daniels B et al. Annals of Emergency Medicine 2016
STONE score combined with POCUS improves accuracy
Nephrolithiasis ED evaluation and management review
▶
Gottlieb M, Long B, Koyfman A. American Journal of Emergency Medicine 2018
Comprehensive ED management review
Infected urolithiasis emergency management
▶
Yoo MJ et al. American Journal of Emergency Medicine 2024
Urosepsis recognition and emergent decompression
Recurrent nephrolithiasis prevention systematic review
▶
Asher GN et al. Annals of Internal Medicine 2026
Adults and children prevention strategies
Acute renal colic from ureteral calculus
▶
Teichman JM. NEJM 2004
Classic review of pathophysiology and management
Pediatric nephrolithiasis trends
▶
Hernandez JD et al. JAMA Pediatrics 2015
Current trends evaluation and management in children
Coding references
ICD-10 coding
▶
Kidney stone without hydronephrosis
▶
N20.0 calculus of kidney
N20.1 calculus of ureter
N20.2 calculus of kidney with calculus of ureter
Complications
▶
N13.2 hydronephrosis with renal and ureteral calculous obstruction
A41.9 sepsis unspecified organism for urosepsis
SNOMED CT nephrolithiasis disorder concept 95570007
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.
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