Acute Kidney Injury (Post-renal)MANAGEMENT

GENITOURINARY AND REPRODUCTIVE PRESENTATIONS · 12 SECTIONS

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579 items

☷ Legend

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Cardiovascular Presentations71▾

Respiratory Presentations52▾

Neurological Presentations83▾

Gastrointestinal Presentations74▾

Genitourinary and Reproductive Presentations48▾

Acute Kidney Injury (ATN)Acute Kidney Injury (Post-renal)Acute Kidney Injury (Pre-renal)Amniotic Fluid Embolism Balanitis Bladder Rupture Breast Abscess Cystitis Dialysis access complications Ectopic pregnancy Epididymitis Glomerulonephritis Hematuria (gross)Hydrocele Interstitial Cystitis Mastitis Mittelschmerz Nephrolithiasis Nephrotic Syndrome Flare Nutcracker Syndrome Orchitis Ovarian Cyst Rupture Ovarian hyperstimulation syndrome Ovarian torsion Paraphimosis Pelvic Congestion Syndrome Pelvic Inflammatory Disease (PID)Peritoneal dialysis peritonitis Phimosis Priapism Prostatitis Pyelonephritis Renal laceration Renal transplant complications and rejection Ruptured ovarian cyst Testicular torsion Torsion of Appendix Testis Tubo-ovarian abscess Ureteral Rupture Urethritis Urinary Retention Urinary tract infection (uncomplicated)Urolithiasis (renal colic)Vaginal bleeding (non-pregnant)Vaginitis (Bacterial)Vaginitis (Candidal)Varicocele Vulvovaginal Hematoma

Infectious Disease Presentations148▾

Trauma Presentations89▾

Toxicologic Presentations80▾

Psychiatric Presentations26▾

Musculoskeletal and Rheumatologic Presentations96▾

Dermatology Presentations23▾

Environmental and Exposure Presentations27▾

Hematologic and Oncologic Presentations36▾

Pediatric-Specific Presentations19▾

Endocrine and Metabolic Presentations45▾

ENT and Maxillofacial Presentations27▾

Ophthalmologic Presentations19▾

Obstetric Presentations23▾

Systemic and Miscellaneous Presentations17▾

01Approach to the Critical Patient/attcp53

Immediate priorities

›Life threats in obstructive AKI

›Severe hyperkalemia

›K+ > 6.0 mmol/l

›ECG changes peaked T waves to widened QRS

›Obstructed infected system

›Fever plus hydronephrosis

›Urosepsis is a urologic emergency

›Severe metabolic acidosis

›Serum bicarbonate low

›pH < 7.1 threshold for bicarbonate therapy

›Uremic emergencies

›Encephalopathy

›Pericarditis

›Time critical actions

›Bladder catheter for suspected outlet obstruction

›Immediate diagnostic and therapeutic for lower tract cause

›Decompresses retained urine volume

›If fever plus hydronephrosis, emergent decompression

›Percutaneous nephrostomy

›Retrograde ureteric stent

›Treat hyperkalemia before definitive imaging if unstable

›Calcium gluconate for membrane stabilization

›Insulin dextrose to shift potassium

Monitoring and targets

›Monitoring bundle

›Cardiac monitor if hyperkalemia suspected

›Continuous rhythm during shifting therapy

02History/hx73

Onset and urinary pattern

›Urine output trajectory

›Acute anuria

›Suggests complete bilateral or outlet obstruction

›Until proven otherwise assume obstruction

›Alternating polyuria and oliguria

›Pathognomonic for intermittent obstruction

›Prompts upper tract evaluation

›Oliguria

›Output below 0.5 ml/kg/hr

›Overlaps with prerenal pattern

›Lower urinary tract symptoms

›Hesitancy and weak stream

›Suggests bladder outlet obstruction

›BPH as common cause

›Frequency and nocturia

›Incomplete emptying

›Overflow incontinence

›Suprapubic fullness

›Distended bladder sensation

›Relief after catheterization

Pain and associated symptoms

›Pain pattern

›Flank pain unilateral or bilateral

›Capsular distension from hydronephrosis

›CVA region discomfort

›Colicky pain radiating to groin

›Ureteral calculus pattern

03Physical Exam/exam44

Vitals and volume status

›Vital sign clues

›Fever

›Infected obstructed system

›Urosepsis concern

›Hypertension

›Volume overload from anuria

›Pain mediated

›Tachycardia

›Sepsis

›Pain or hypovolemia

›Volume assessment

›Overload findings

›JVD and peripheral edema

›Pulmonary crackles

›Depletion findings

›Dry mucous membranes

›Poor skin turgor suggesting prerenal overlap

Abdominal and urologic exam

›Abdominal findings

›Suprapubic distension

›Palpable bladder

›Dullness to percussion

›Flank tenderness

›CVA tenderness

›Hydronephrosis correlate

›Palpable kidney or mass

›Massive hydronephrosis

04Differential Diagnosis/ddx44

By category of AKI

›Post-renal obstructive causes

›Bladder outlet obstruction

›BPH ICD-10 N40.1

›Urethral stricture ICD-10 N35.9

›Ureteric obstruction

›Calculus ICD-10 N20.1

›Malignant compression

›Obstructive uropathy with hydronephrosis

›ICD-10 N13.4 hydroureter

›ICD-10 N13.2 hydronephrosis with obstruction

›Prerenal AKI mimics

›Hypovolemia

›FENa < 1 percent

›Responds to volume resuscitation

›Cardiorenal and hepatorenal

›No hydronephrosis

›Low fractional excretion

›Intrinsic renal causes

›Acute tubular necrosis

›Muddy brown casts

›FENa > 1 percent

›Acute interstitial nephritis

›WBC casts and eosinophiluria

›Drug exposure

›Glomerulonephritis

›RBC casts

›Proteinuria and hematuria

05Laboratory Tests/lt54

Renal and electrolyte panel

›Basic metabolic profile

›Creatinine

›Elevated and rising

›Compare to baseline value

›Potassium

›Hyperkalemia from impaired excretion

›K+ > 5.5 mmol/l triggers ECG

›Bicarbonate

›Metabolic acidosis

›Anion gap assessment

›BUN to creatinine ratio

›May exceed 20 to 1 early

›Overlaps with prerenal pattern

›Mineral and supportive labs

›Calcium and phosphorus

›Hyperphosphatemia

›Hypocalcemia in advanced AKI

›Complete blood count

›Leukocytosis with infection

›Anemia of chronic disease or malignancy

Urine studies

›Urinalysis

›Bland sediment common in obstruction

›Distinguishes from intrinsic causes

›No casts typically

›Hematuria

›Stones or malignancy

06Diagnostic Tests/dt69

Scoring Systems

›KDIGO AKI staging

›Stage 1

›Creatinine 1.5 to 1.9 times baseline

›Urine output < 0.5 ml/kg/hr for 6 to 12 hours

›Stage 2

›Creatinine 2.0 to 2.9 times baseline

›Urine output < 0.5 ml/kg/hr for >= 12 hours

›Stage 3

›Creatinine >= 3.0 times baseline or initiation of dialysis

›Anuria for >= 12 hours

›Prognostic considerations

›Stage 3 AKI predicts progression

›Independent predictor of ESKD

›Worse long-term outcome

›Duration of obstruction

›Recovery inversely related to duration

›Early relief favors reversibility

MRI

›MR urography role

›Limited acute utility

›Availability and time constraints

›Reserved for problem solving

›Indications

›Contrast allergy precluding CT urography

›Characterize retroperitoneal mass or fibrosis

›Advantages

›No ionizing radiation

07Disposition/dispo34

Level of care

›Admission indications

›Obstruction requiring intervention

›Upper tract obstruction needing drainage

›Failed bedside decompression

›Metabolic emergency

›Hyperkalemia

›Severe acidosis or uremia

›Infected obstructed system

›Urosepsis

›Pyonephrosis

›ICU indications

›Septic shock

›Vasopressor requirement

›Rising lactate despite resuscitation

›Emergent dialysis need

›Refractory hyperkalemia

›Refractory volume overload

›Post-obstructive diuresis instability

›Massive output with hypovolemia

›Severe electrolyte shifts

Discharge and follow up

›Discharge criteria

›Outlet obstruction relieved

›Foley in place draining well

›Stable creatinine trend

›No metabolic emergency

›Normal potassium

08Treatment/t86

Initial stabilization

›Resuscitation basics

›IV access and cardiac monitor

›Monitor if hyperkalemia suspected

›Continuous rhythm during treatment

›Cautious fluids until obstruction relieved

›Avoid aggressive IV fluids pre-decompression

›Reassess after relief of obstruction

›Diuretics not effective for obstruction

›Do not use to treat post-renal AKI

›They do not relieve mechanical obstruction

Relieve obstruction

›Lower tract obstruction

›Foley catheter insertion

›Diagnostic and therapeutic

›Decompresses bladder outlet obstruction

›If unable to pass Foley, urology

›Coude catheter attempt

›Suprapubic catheter placement

›Upper tract obstruction

›Percutaneous nephrostomy

›Interventional radiology placement

›Preferred when infected or unstable

›Retrograde ureteric stent

›Cystoscopic placement by urology

›Alternative for select stone disease

›If fever plus obstruction, emergent decompression

›Obstructed infected system is an emergency

09Special Populations/sp39

Pregnancy

›Pregnancy considerations

›Physiologic hydronephrosis

›Right greater than left

›Distinguish from true obstruction

›Imaging approach

›Ultrasound first line

›Avoid CT and contrast when possible

›Obstructing stone management

›Ureteric stent or nephrostomy preferred over surgery

›Urology and obstetrics co-management

›Medication safety

›Beta lactams preferred for infection

›Avoid fluoroquinolones and aminoglycosides when alternatives exist

Geriatric

›Older adult features

›BPH and malignancy predominate

›Prostatic hypertrophy most common cause

›Prostate and pelvic cancers

›Atypical presentation

›Delirium as presenting feature

›Blunted pain perception

›Medication burden

›Anticholinergics precipitate retention

›Renal dose all agents

›Higher baseline CKD

›Worse recovery potential

›Independent predictor of ESKD

10Background/b51

Epidemiology

›Burden and frequency

›Proportion of all AKI

›Post-renal accounts for about 2 to 5 percent

›Often reversible with timely relief

›AKI within obstructive uropathy

›AKI present in 78 percent in a large cohort

›Common reason for admission

›Progression to ESKD

›ESKD rate 4.4 to 6.8 percent in non-malignant obstruction

›Higher with stage 3 AKI and preexisting CKD

›Etiologic distribution

›Most common causes in adults

›Prostatic hypertrophy most common overall

›Malignancy and nephrolithiasis

›Sex differences

›Male predominance from prostatic disease

›Female pelvic malignancy contribution

Pathophysiology

›Mechanism of injury

›Increased intratubular pressure

›Back pressure transmitted to nephron

›Reduced glomerular filtration

›Phases of obstruction

›Early functional impairment is reversible

›Prolonged obstruction causes structural injury

›Post-obstructive diuresis

›Tubular dysfunction and solute load

11Patient Discharge Instructions/pdi20

copy discharge instructions

›Home care after obstruction relief

›Keep urinary catheter draining and below bladder level

›Empty and clean the drainage bag as instructed

›Drink fluids as advised by your clinician

›Take prostate or stone medications exactly as prescribed

›Return to ER warning signs

›No urine draining from the catheter

›Fever or chills

›Severe flank or belly pain

›Blood or clots blocking the catheter

›Confusion or severe drowsiness

›Nausea and vomiting with inability to keep fluids down

›Follow up

›Urology appointment for catheter removal or trial of void

›Bloodwork to recheck kidney function as scheduled

›Imaging follow up if the cause is not yet resolved

›Self-care tips

›Wash hands before handling the catheter

›Watch for and report any leaking around the catheter

›Avoid pulling or kinking the tubing

12References/r12

Guidelines and key sources

›Guideline sources

›ACR Appropriateness Criteria Renal Failure imaging

›KDIGO clinical practice guideline for acute kidney injury

›CIRSE Standards of Practice on nephrostomy and ureteric stent placement

›Evidence summaries

›Point-of-care ultrasound accuracy for obstructive cause in AKI

›Cochrane review on diuretics for preventing and treating AKI

›Cohort data on AKI and long-term outcomes in obstructive uropathy

›Coding standards

›ICD-10 N13.2 hydronephrosis with renal and ureteral calculous obstruction

›ICD-10 N17.9 acute kidney failure unspecified

›SNOMED CT obstructive uropathy disorder concept

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Reviewed by SymptomDx Medical Team · Last reviewed August 18, 2026

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