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Hydronephrosis: Treatment

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Grading (Guides Urgency and Approach)

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Principles of Management

1. Acuity — acute complete obstruction vs. chronic partial obstruction
2. Location of obstruction (ureteropelvic junction, ureter, ureterovesical junction, bladder outlet, urethra)
3. Laterality — unilateral (above the bladder) vs. bilateral (below the bladder level)
4. Cause — stone, stricture, BPH, malignancy, pregnancy, retroperitoneal fibrosis, etc.
5. Presence of infection — pyonephrosis is a urologic emergency
6. Renal function — split function on MAG3 renogram guides surgical vs. conservative approach

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I. Emergency Decompression (Immediate Priority)

Indications for Urgent Decompression

• Infected obstructive hydronephrosis (pyonephrosis) — fever + flank pain + internal echoes on ultrasound; prompt decompression is lifesaving
• Solitary kidney with obstruction
• Bilateral obstruction with rising creatinine / oliguria / AKI
• Electrolyte abnormalities (hyperkalemia, acidosis)
• Hemodynamic instability

Methods of Decompression

• First-line in most stable patients
• Placed cystoscopically under fluoroscopic guidance
• Internalized; allows the patient to go home
• Preferred when retrograde access is feasible

• Indicated when retrograde stenting fails or is contraindicated (e.g., sepsis with hemodynamic instability too great for general anesthesia, impassable ureteral obstruction due to stone, tumor, or stricture)
• A nephrostomy catheter is placed under fluoroscopic/ultrasound guidance through the renal parenchyma into the collecting system
• PCN can later be converted to internal antegrade stent drainage even if retrograde stenting had failed
• Whitaker test via the PCN tract can confirm functional obstruction (differential pressure >22 cm H₂O at 10 mL/min = moderate-to-severe obstruction)

"In a critically ill patient with electrolyte abnormalities and little or no urine output, nephrostomy tube placement is favored." — Campbell-Walsh-Wein Urology

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II. Cause-Specific Definitive Treatment

A. Urolithiasis (Most Common Acquired Cause)

• Extracorporeal Shock Wave Lithotripsy (ESWL) — for smaller stones (<2 cm), noninvasive
• Ureteroscopy (URS) + laser lithotripsy — ureterally located stones; direct endoscopic fragmentation
• Percutaneous Nephrolithotomy (PCNL) — large renal stones (>2 cm) or staghorn calculi

B. Ureteropelvic Junction (UPJ) Obstruction

• Symptomatic obstruction (flank pain, Dietl's crisis — pain with high fluid intake/diuretics)
• Associated urolithiasis
• Recurrent UTIs
• Deteriorating renal function on MAG3 renogram (T½ >20 min after furosemide)
• Split function <40% on the affected side

Relative contraindications to endoscopic management include lengthy strictures (>2 cm), severely impaired ipsilateral function (<25%), and the presence of an aberrant crossing vessel. — Hinman's Atlas of Urologic Surgery

C. Benign Prostatic Hyperplasia (BPH) / Bladder Outlet Obstruction

• Medical therapy: α-blockers (tamsulosin, alfuzosin), 5α-reductase inhibitors (finasteride, dutasteride)
• Surgical: TURP (transurethral resection of prostate), laser prostatectomy, or HoLEP for refractory cases
• Catheter drainage (urethral or suprapubic) for acute urinary retention

D. Ureteral Strictures (Iatrogenic, Radiation, Retroperitoneal Fibrosis)

• Endoscopic balloon dilation or incision for short strictures
• Ureteral reimplantation (distal strictures) — direct or with Psoas hitch / Boari flap
• Ureteroureterostomy (mid-ureteral, strictures <1 cm)
• Ileal ureter — for very long ureteral defects
• Nephrectomy — if split function <15% (non-functional kidney)

E. Malignant Obstruction (Cervical Ca, Prostate Ca, Retroperitoneal Lymphoma, Bladder Tumor)

• Ureteral stenting (JJ stent) or PCN for decompression while underlying malignancy is treated
• Metallic self-expanding ureteral stents for long-term palliation in malignant obstruction
• Definitive oncologic management (chemotherapy, radiation, surgery) per tumor type

F. Pregnancy-Associated Hydronephrosis

• Usually mild and physiological; managed conservatively
• Symptomatic cases: lateral decubitus positioning (left side), hydration
• Rarely requires stenting or PCN (reserved for symptomatic nephrolithiasis or pyonephrosis)

G. Neurogenic Bladder

• Clean intermittent catheterization (CIC)
• Anticholinergics (oxybutynin, solifenacin) for overactive bladder
• Botulinum toxin injection into detrusor
• Surgical: augmentation cystoplasty, urinary diversion

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III. Pediatric and Antenatal Hydronephrosis

• Most antenatally detected hydronephrosis resolves spontaneously
• Continuous antibiotic prophylaxis (CAP) reduces febrile UTI risk in high-grade antenatal hydronephrosis (SFU grade III/IV), especially with ureteral dilation ≥7 mm, VUR, or UVJ obstruction
• VCUG indicated in neonatal period if renal insufficiency or bladder outlet obstruction is suspected
• Functional assessment with DMSA scan at 4–6 weeks; MAG3 renogram for outflow obstruction
• Pyeloplasty for UPJO with worsening function, recurrent pain, or UTIs

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IV. Post-Obstructive Diuresis

• Mechanism: accumulated urea (osmotic), impaired tubular concentrating ability, ANP elevation
• Monitor fluid and electrolyte status closely
• Replace urine output volume 50–75% with IV fluids (0.45% NaCl) to avoid volume depletion while allowing gradual diuresis to clear retained solutes

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V. Monitoring After Treatment

• Serial renal ultrasound to assess resolution of dilation
• MAG3 renogram at 4–6 weeks post-intervention to confirm drainage improvement
• Serum creatinine/BUN to monitor renal recovery
• Urine culture (treat any UTI promptly — obstructed, infected systems are dangerous)

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• Sabiston Textbook of Surgery, 20e — UPJ Obstruction and Ureteral Reconstruction
• Campbell-Walsh-Wein Urology, 12e — Hydronephrosis and Obstruction
• Hinman's Atlas of Urologic Surgery — Antegrade Endopyelotomy & Laparoscopic Pyeloplasty
• Smith and Tanagho's General Urology, 19e — Percutaneous Catheter Placement
• Robbins & Kumar Basic Pathology — Pathogenesis of Hydronephrosis
• Comprehensive Clinical Nephrology, 7e — Ultrasound Grading

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Urinary Tract Infection (UTI): Treatment

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Classification (Determines Treatment)

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Common Pathogens

• E. coli (80% of community-acquired UTI)
• Staphylococcus saprophyticus (young sexually active women)
• Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis
• Pseudomonas aeruginosa, Enterobacter — hospital-acquired/complicated/catheter-associated

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I. Uncomplicated Cystitis (Women)

First-Line Agents

Second-Line Agents (use only when first-line agents are not feasible)

• Fluoroquinolones (ciprofloxacin 250 mg BID × 3 days; levofloxacin 250 mg × 3 days) — NOT first-line for uncomplicated cystitis due to adverse effects (tendinopathy, CNS effects) and resistance promotion
• Beta-lactams (cephalexin 500 mg BID × 5–7 days; amoxicillin-clavulanate 500 mg BID × 5–7 days) — inferior cure rates; use when no alternatives

"Fluoroquinolones such as ciprofloxacin or levofloxacin should not be used as first-line agents for empirical treatment of uncomplicated UTIs. Instead, they should be reserved for patients who have failed or have contraindications to first-line antibiotics." — Rosen's Emergency Medicine

Symptomatic Relief

• Phenazopyridine (Pyridium) 200 mg TID for 1–2 days — urinary analgesic; relieves dysuria; warn patients of orange-red urine discoloration; not an antibiotic

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II. Acute Uncomplicated Pyelonephritis

Outpatient (Mild–Moderate, Patient Can Tolerate Oral Intake)

• Fluoroquinolones are first-line for pyelonephritis (excellent tissue/blood penetration)
• If local fluoroquinolone resistance >10%: give initial parenteral dose (ceftriaxone 1 g IV/IM) then 10–14 days oral cephalosporin
• Nitrofurantoin and fosfomycin are contraindicated for pyelonephritis — they do not achieve adequate renal tissue/blood levels

Inpatient (Severe, Vomiting, Sepsis Signs, Inability to Tolerate PO)

2025 IDSA Update: For cUTI with clinical improvement on appropriate antibiotics, shorter courses are supported — 5–7 days fluoroquinolone or 7 days non-fluoroquinolone (vs. traditional 10–14 days). However, shorter durations are not appropriate for patients with indwelling catheters, severe sepsis, significant immunocompromise, renal abscesses, CKD, complete obstruction, or recent urologic procedures.

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III. Complicated UTI (cUTI)

2025 IDSA Four-Step Framework for Empiric Therapy:

1. Assess severity — Is the patient septic?
2. Review patient-specific risk factors for resistant organisms (recent antibiotics, healthcare exposure, prior ESBL/MDR infection, travel)
3. Consider allergies and drug interactions
4. Consult local antibiogram (mandatory if septic)

Empiric Antibiotic Choices for cUTI

IV-to-Oral Switch

• Acceptable once patient is clinically improving and can tolerate oral intake
• Preferred oral step-down: Fluoroquinolones or TMP-SMX (high bioavailability)
• Oral beta-lactams: acceptable if susceptible and adequate serum/urinary concentrations expected; duration may need to extend to 10–14 days

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IV. Catheter-Associated UTI (CAUTI)

• Remove or replace catheter before collecting culture and initiating antibiotics
• Treat only if symptomatic (fever, rigors, altered mental status, flank pain, suprapubic tenderness) — asymptomatic bacteriuria with a catheter should not be treated
• Antibiotic choice: same as cUTI, guided by culture results
• Duration: 7 days if prompt clinical response; 10–14 days if delayed response

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V. UTI in Men

• All UTIs in men are considered complicated (rule out prostatitis, epididymo-orchitis, structural abnormality)
• Treat for 7–14 days (7 days if no immunocompromise or complications per recent evidence)
• If prostatitis suspected: TMP-SMX or fluoroquinolone for 14 days (fluoroquinolones preferred for prostate tissue penetration)
• Refer to urology for recurrent UTI, hematuria, or suspicion of prostatic involvement

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VI. UTI in Pregnancy

• Screen all pregnant women with urine culture at 12–16 weeks (USPSTF Grade A)
• Treat asymptomatic bacteriuria — up to 30% will develop pyelonephritis if untreated
• Safe agents in pregnancy:
  • Cephalexin 500 mg BID × 3–7 days
  • Nitrofurantoin 100 mg BID × 3–7 days (avoid at term/third trimester — risk of neonatal hemolysis)
  • Amoxicillin 500 mg TID × 7 days
  • TMP-SMX (avoid in first trimester [neural tube defects] and third trimester [kernicterus])
• Pyelonephritis in pregnancy → admit for IV ceftriaxone 1 g daily; follow-up culture post-treatment mandatory

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VII. Recurrent UTI (Women)

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VIII. Resistant Organisms — Special Agents

For Pseudomonas UTI: "Urinary catheters, stents, or stones should be removed if possible. In general, 7 to 10 days of antibiotic treatment will suffice." — Goldman-Cecil Medicine

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IX. When to Admit

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Quick Reference: Treatment Duration Summary

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• Rosen's Emergency Medicine, 9e — Uncomplicated & Complex UTI Treatment
• Tintinalli's Emergency Medicine, 9e — UTI Classification, Complicated UTI Tables
• Goldman-Cecil Medicine, 26e — Pseudomonas UTI, ESBL/CRE Treatment
• Comprehensive Clinical Nephrology, 7e — UTI Classification
• 2025 IDSA Guideline on Complicated UTI — Four-step framework, shorter duration evidence, BALANCE trial