NCLEX Review Guide: Hydronephrosis

Definition & Causes

• Hydronephrosis is the distention of the renal pelvis and calyces caused by obstruction of urine flow from the kidney, leading to progressive kidney damage if untreated.
• Common causes include kidney stones, tumors, enlarged prostate, urethral strictures, and congenital abnormalities that block normal urine drainage.
• Can be unilateral or bilateral, with bilateral hydronephrosis being more serious and potentially life-threatening.

Clinical Manifestations

• Severe flank pain that may radiate to the groin, often described as colicky or constant depending on the degree of obstruction.
• Nausea, vomiting, and decreased urine output (oliguria) or complete absence of urine (anuria) in bilateral cases.
• Signs of infection including fever, chills, and cloudy, foul-smelling urine if concurrent UTI is present.
• Hypertension may develop due to activation of the renin-angiotensin system from decreased renal perfusion.

Diagnostic Tests

• Ultrasound is the initial imaging study of choice as it's non-invasive and can quickly identify kidney dilation without contrast.
• CT scan provides detailed visualization of the obstruction location and cause, while IVP shows kidney function and drainage patterns.
• Laboratory studies include BUN, creatinine, electrolytes to assess kidney function and urinalysis to detect infection or blood.

Treatment Interventions

1. Immediate relief of obstruction through nephrostomy tube placement, ureteral stent insertion, or surgical removal of the cause
2. Pain management with analgesics, avoiding NSAIDs if kidney function is compromised
3. Antibiotic therapy if infection is present, with culture-guided selection when possible
4. Fluid management to maintain adequate hydration while preventing fluid overload

Priority Nursing Interventions

• Monitor urine output hourly and report output less than 30 mL/hr, as this indicates worsening obstruction or kidney dysfunction.
• Assess pain using 0-10 scale and administer prescribed analgesics, positioning patient for comfort (usually side-lying on affected side).
• Monitor vital signs for signs of sepsis including fever, tachycardia, hypotension, and altered mental status.
• Maintain strict intake and output records, daily weights, and monitor for signs of fluid overload or dehydration.

Patient Teaching

• Educate about signs of infection (fever, chills, burning urination) and when to seek immediate medical attention.
• Emphasize importance of adequate fluid intake (2-3 L/day unless contraindicated) to prevent stone formation and maintain kidney function.
• Teach proper care of nephrostomy tube or ureteral stent if present, including keeping drainage bag below kidney level and monitoring for displacement.

Key Laboratory Values to Remember

• Normal creatinine: 0.6-1.2 mg/dL - elevation indicates kidney dysfunction
• Normal BUN: 10-20 mg/dL - rises with decreased kidney function
• BUN:Creatinine ratio >20:1 suggests dehydration or obstruction