What is the appropriate management of acute scrotal edema in a patient with chronic kidney disease, including evaluation for testicular torsion versus volume overload?

Management of Acute Scrotal Edema in CKD Patients

Immediate Priority: Rule Out Testicular Torsion

The first and most critical step is to immediately exclude testicular torsion through clinical assessment and urgent Doppler ultrasound, as this surgical emergency requires intervention within 6-8 hours regardless of CKD status 1, 2.

Clinical Features Distinguishing Torsion from Volume Overload

Testicular torsion characteristics:

• Abrupt onset of severe unilateral scrotal pain (develops within minutes) 1, 3
• Pain NOT relieved by testicular elevation (negative Prehn sign) 1, 2
• Nausea and vomiting commonly present 1, 3
• Unilateral presentation with asymmetric findings 1

Volume overload characteristics:

• Bilateral, symmetric scrotal swelling 4
• Gradual onset over hours to days 4
• Minimal to no pain 2, 5
• Associated with generalized edema (legs, penis, periorbital) 4
• Worsens during the day, may improve at night when supine 4

Diagnostic Algorithm

Step 1: Urgent Doppler Ultrasound (Within 1 Hour)

Perform immediate scrotal Doppler ultrasound with the following protocol 1, 2:

• Grayscale examination for testicular homogeneity and "whirlpool sign" 1
• Color Doppler assessment comparing both testicles (use contralateral as internal control) 1, 3
• Power Doppler for enhanced sensitivity to low-flow states 1
• Spectral Doppler analysis of upper, mid, and lower poles 1

Critical pitfall: Doppler has a 30% false-negative rate in partial torsion—if clinical suspicion remains high despite normal flow, proceed directly to surgical exploration 1, 2.

Step 2: Interpretation of Ultrasound Findings

If decreased/absent testicular blood flow:

• Immediate urological consultation for surgical exploration 1, 2
• Do NOT delay surgery for additional imaging 1

If normal testicular perfusion with bilateral scrotal wall thickening:

• Proceed to evaluate for volume overload etiology 4, 5

Management of Volume Overload-Related Scrotal Edema in CKD

Identify the Mechanism of Fluid Retention

For patients on peritoneal dialysis, evaluate 4:

• Perform peritoneal equilibration test (PET) to assess ultrafiltration adequacy 4
• Obtain abdominal radiography to confirm catheter position 4
• Consider peritoneal scintigraphy if dialysate leak suspected 4

Two primary mechanisms in PD patients 4:

1. Catheter malfunction: Positional retention of dialysate due to catheter migration 4
2. Inadequate ultrafiltration: Imbalance between fluid removal and salt/water intake, often with high peritoneal transport status 4

Treatment Based on Mechanism

For catheter malposition with positional dialysate retention 4:

• Switch from CAPD to nocturnal peritoneal dialysis only (no daytime exchanges) 4
• This allows gravity-dependent drainage and improves ultrafiltration 4

For inadequate ultrafiltration with appropriate catheter position 4:

• Convert CAPD to continuous cycling peritoneal dialysis (CCPD) 4
• Add one daytime icodextrin exchange 4
• Strict dietary sodium restriction 4
• Consider increasing dialysis prescription if residual volume is high 4

For hemodialysis patients or non-dialysis CKD:

• Aggressive diuretic therapy (loop diuretics ± thiazides) targeting net negative fluid balance
• Sodium restriction to <2g/day
• Consider ultrafiltration if refractory to medical management
• Scrotal elevation and supportive garments for symptomatic relief

Alternative Diagnoses to Consider (After Excluding Torsion)

Acute idiopathic scrotal edema (AISE):

• Self-limiting condition with marked scrotal wall thickening 2, 5, 6
• Minimal pain, diagnosis of exclusion 2, 5
• Ultrasound shows increased peritesticular blood flow but normal testicular vascularity 2
• Treatment: Anti-inflammatory therapy, resolves within 24-48 hours 5, 6

Fournier's gangrene (life-threatening emergency):

• Rapidly progressive scrotal swelling with skin necrosis and systemic toxicity 7, 2
• Requires immediate surgical debridement and broad-spectrum antibiotics 7, 2
• Higher risk in CKD patients due to immunocompromised state 7

Epididymitis:

• Gradual onset, enlarged epididymis with increased blood flow on Doppler 1, 2
• Pain may be relieved by testicular elevation (positive Prehn sign) 2

Critical Clinical Pitfalls

• Never assume scrotal edema is simply volume overload without excluding torsion first—even bilateral edema can mask unilateral torsion 1, 2
• Do not delay surgical exploration for imaging if clinical suspicion for torsion is high—testicular salvage rates drop precipitously after 6 hours 1, 2
• Recognize that CKD patients may have blunted inflammatory responses, making clinical assessment more challenging 7
• In PD patients, proper PET interpretation is critical—high transport status with low ultrafiltration suggests inadequate dialysis prescription rather than catheter leak 4