Urologic Problems

Terminology

  • Nephro: Refers to the kidney.

  • Renal: Pertaining to, or belonging to the kidneys.

  • Nephrology: The study of the kidneys.

  • Urology: The study of the urinary tract.

  • Lithos: Translates to stone.

  • Calculi: Denotes something accidental that does not belong in the body (stone).

Important Medical Terms

  • Hematuria: The presence of blood in urine.

  • Azotemia: A condition characterized by high nitrogen levels in the blood.

  • Oliguria: A condition where urine production is less than 0.5 ml/kg/hr. Indicative of decreased renal function.

  • Proteinuria: The presence of elevated protein in urine, often signifying kidney injury.

  • Glomerular Filtration Rate (GFR): A measure of kidney function. GFR quantifies the flow rate of filtered fluid through the kidney.

Obstructive Urologic Disorders

Important Factors for Obstruction Evaluation

  • Degree of obstruction.

  • Location of the obstruction.

  • Duration of the obstruction.

  • Timing of the obstruction.

Locations of Obstructions

  • Renal Pelvis:

    • Causes: renal calculi (kidney stones), trauma.

  • Ureter:

    • Causes: renal calculi, pregnancy, tumors, trauma.

  • Bladder and Urethra:

    • Causes: bladder cancer, neurogenic bladder, prostatic hyperplasia, prostate cancer, urethral strictures, trauma.

Complications of Obstruction

  • Stasis of urine flow: Can lead to significant consequences.

  • Multiple complications may arise due to prolonged obstruction.

  • Back-up Pressure: Elevated pressure in urinary tract.

  • Hydroureter: Dilation of the ureter due to urine accumulation.

  • Hydronephrosis: Swelling of a kidney due to a build-up of urine as a result of obstruction.

  • Post-renal kidney failure: Decline in kidney function due to obstruction.

Hydroureter and Hydronephrosis

  • Hydronephrosis can be classified as follows:

    • Normal

    • Mild

    • Moderate

    • Severe

  • Illustration provided:

    • Representation of mild to severe hydronephrosis.

Nephrolithiasis (Kidney Stones)

  • Definition: Clumps of crystals that aggregate in the urinary tract, commonly known as kidney stones, formed from salts and minerals when urine becomes oversaturated.

Risk Factors for Nephrolithiasis

  • Sex: More prevalent in men.

  • Age: Typically occurs in individuals in their 20s to 30s.

  • Race: Higher incidence in white populations.

  • Family History: Genetic predisposition may play a role.

  • Congenital Defect: Structural abnormalities affecting the urinary tract.

  • Weather: Potential influence of climate (e.g., hot/dry climates).

  • Obesity: Increased body weight as a contributing factor.

Etiology of Nephrolithiasis

  • Defined by crystallized solutes within the urine, which depend on various factors:

    • Individual risk factors (e.g., diet, genetics).

    • Characteristics of the urine (e.g., diet, medications).

    • Type of stone formation.

Pathogenesis of Nephrolithiasis

  • Urine is comprised of a solvent (water) and solutes (dissolved particles).

  • Problem: Occurs when urine is supersaturated with solutes such as calcium oxalate and uric acid.

  • Crystals initiate formation within the nephron.

  • Factors enhancing crystal formation:

    • Dehydration: Reduced fluid intake leading to concentrated urine.

    • Immobility/Sedentary Lifestyle: Lack of movement may predispose individuals to stone formation.

Types of Kidney Stones

  • Cystine Stones

  • Calcium Stones

  • Uric Acid Stones

  • Struvite Stones

Staghorn Calculus

  • A specific type of renal stone that takes the shape of the renal pelvis and can fill the renal collecting system.

Clinical Manifestations of Nephrolithiasis

  • Acute renal colic symptoms are significant indicators prompting emergency medical visits:

    • Pain: Location and radiation need to be assessed.

    • Spasms: Characterized as intermittent and sharp.

    • Accompanying symptoms include:

    • Nausea/Vomiting (N/V)

    • Diaphoresis (excessive sweating)

    • Increased heart rate (↑HR)

    • Increased respiration rate (↑RR)

    • Hematuria: Presence of blood in urine.

Pharmacology for Nephrolithiasis

  • Acute Pain Management:

    • IV Narcotics such as Morphine or Hydromorphone.

    • NSAIDs may also be utilized.

    • IV fluids: Administration to promote hydration.

  • Preventive Medications:

    • Calcium stones: Thiazide diuretics.

    • Struvite stones: Antibiotics are recommended to treat the underlying causes.

    • Urate stones: Allopurinol is recommended (related to gout treatment).

Protective Mechanisms of the Urinary System

  • pH of urine: Generally acidic, inhibiting bacterial growth.

  • Presence of urea: Contributes to the antibacterial properties of urine.

  • Sex-specific factors:

    • Men: Prostatic secretions contribute to lower UTI rates.

    • Women: Urethral gland secretions provide some protection.

  • Urine flow: Unidirectional flow helps prevent infection.

  • One-way valve: Located at the ureteral attachment to the bladder to prevent backflow.

  • Immune response: Urinary tract is lined with epithelial and immune cells which defend against infections.

UTI Risk Factors

  • Catheterization: Particularly leads to catheter-associated urinary tract infections (CAUTIs).

  • Sex: Females are more prone due to anatomical differences.

  • Perineal Irritation: Such as from feminine hygiene products or douching.

  • Age: Increased risk in elderly populations.

  • Institutionalization: Nursing home residents have up to 50% prevalence of bacteriuria.

  • Pregnancy: Hormonal changes and anatomical alterations increase susceptibility.

  • Sexual Activity: Specific behaviors increase UTI incidence.

  • Spermicide Use: Devices like diaphragms or certain condoms increase risk.

  • Immobility: Increases risk due to stagnant urine.

  • Incontinence: Can lead to increased exposure to pathogens.

  • Poor personal hygiene: Elevates risk factors for UTIs.

Pathogenesis of UTIs

  • Ascending Pattern: UTIs commonly progress from contamination of the perineum to the urethra, leading to cystitis (bladder infection) and potentially ascending to the ureters and kidneys (pyelonephritis).

Clinical Manifestations of Lower UTI

  • Urethritis:

    • Symptoms include dysuria (painful urination).

    • Most common presentation can be asymptomatic.

  • Cystitis:

    • Symptoms include frequency, urgency, suprapubic discomfort, dysuria, and possible hematuria.

Clinical Manifestations of Upper UTI

  • Sudden Onset: Symptoms present include fever and chills.

  • CVA Tenderness: Costovertebral angle tenderness is an important physical exam sign.

  • Progression of symptoms:

    • Lower UTI symptoms (such as dysuria) may accompany N/V and anorexia.

Complication: Sepsis from UTI

  • Definition: Severe systemic response to UTI, can be life-threatening.

  • High-risk populations:

    • Elderly patients.

    • Diabetics.

    • Immunosuppressed individuals.

  • Prognosis: High mortality is associated with untreated sepsis.

  • Treatment: Key focuses include source control, administration of antibiotics, following cultures, and providing supportive care.

Atypical UTI Presentations

In Children

  • Signs may include fever, irritability, poor feeding, vomiting, diarrhea, and generally ill appearance.

  • Query if the child is verbal to assess symptoms more accurately.

In the Elderly

  • Symptoms of UTI may present as:

    • Anxiety.

    • Confusion.

    • Lethargy.

    • Anorexia.

    • History of falls may be exacerbated by UTI symptoms.

Treatment Regimens for UTI

  • Antibiotics for community-acquired infections:

    • Options include single-dose, short-course (3 days), or conventional therapy (7-14 days), depending on presenting factors such as:

    • Site of infection (upper vs. lower UTI).

    • Presence of complications.

    • Pregnancy status.

    • Culture and sensitivity results.

Specific Medication: Bactrim

  • Also known as Septra or Sulfatrim (a sulfa drug).

  • Mechanism of Action: Inhibits synthesis of folate in bacteria, preventing DNA and protein synthesis.

  • Metabolism: Processed by the liver involving cytochrome P450 enzymes, then excreted in urine.

  • Uses: Effective for treating uncomplicated UTIs and provides coverage for MRSA infections.

  • Side Effects: Possible nausea/vomiting and increased photosensitivity (sunburn risk).

  • Pregnancy Safety: Generally safe for use after the first trimester.