Urinary System Notes

Creatine

• Creatine enhances the body's ability to regenerate ATP.
• It volumizes muscle cells, leading to increased size due to water entering the cells.
• Low muscle mass may indicate malnutrition or liver disease.
• Intervention: Increase animal protein in diet.
• Creatine Supplementation beneficial following vegetarian or vegan diet.

Creatinine

• High creatinine: Greater than 1.3.
• Signs and symptoms: Renal insufficiency or failure, itching, muscle cramps, nausea, vomiting, edema, nerve pain, and urination issues.
• Interventions: Increase fluids, manage diet, address kidney or liver issues.
• Indicates how well kidneys filter.

Blood Urea Nitrogen (BUN)

• Product made in the liver during protein breakdown.
• Kidneys filter out urea nitrogen, excreting it in urine.
• Used to assess kidney function and dehydration.
• Low value interventions: Educate on food restrictions, monitor intake/output, assess for fluid overload, assess dietary intake (especially protein), encourage nutrient-dense foods, assess for liver disease, and document changes.
• High values: Over 20, due to decreased renal excretion.

Urinary System Objectives

• Urinary Catheter and Nursing care is discussed.
• Math and lab values are on the exam.

Urinary Terms

• Normal Urine Output: 50-60 mL/hour (low end) with 1500 mL daily intake; aim for 2000 mL/day intake.
• Void: To empty the bladder.
• Micturition: Act of urinating.
• Anuria: Less than 100 mL urine output in 24 hours (e.g., congestive heart failure, kidney failure).
• Oliguria: Less than 400 mL urine output in 24 hours.
• Dysuria: Difficulty or painful urination, usually associated with irritated bladder, cystitis, or UTI.
• Pyuria: Pus or microorganisms in the urine.
• Enuresis: Involuntary loss of urine (incontinence, bedwetting in children).
• Nocturnal Enuresis: Bedwetting.
• Nocturia: Urinating more than once a night, associated with aging and pregnancy.

Historical Facts About Urination

• Hippocrates: Urine provides a window to the inside of the body.
• Urine can provide information about diet, hydration, overall health, and kidney function.
• Ancient methods of urine analysis: Smell, color, transparency, and taste.
• Ancient Egyptians and Indians: Diagnosed diabetes by the sweet taste of urine.
• Arabian physicians: Used a color wheel to diagnose diseases based on urine color.
• Middle Ages: "Piss prophets" diagnosed diseases based on urine color.
• Uromancy: Fortune telling based on urine characteristics (e.g., bubbles indicate wealth).
• Ancient Egypt (1350 BC): 70% accuracy in determining pregnancy by urinating on barley and wheat seeds.

Urine Composition and Regulation (Video Notes)

• Urination removes toxins and maintains water volume/blood pressure.
• Urine is analyzed for color, smell, clarity, and chemical composition to detect illnesses.
• Urine is typically 95% water, slightly acidic (pH ~6), and clear to dark yellow depending on hydration.
• Urine contains over 3,000 chemical compounds; concentration variations indicate body state.
• Cloudy urine with white blood cells indicates UTI.
• Sweet-smelling urine with glucose suggests diabetes.
• Pink urine (without recent beet consumption) indicates internal bleeding.
• Protein-filled urine suggests pregnancy, overexertion, high blood pressure, or heart failure.
• Urine production is influenced by blood volume and pressure.
• Glomerular Filtration Rate (GFR): Amount of blood passing through glomeruli per minute; kidneys regulate this rate.
• Increased blood pressure causes afferent arterioles to constrict, maintaining constant GFR.
• Caffeine and alcohol inhibit antidiuretic hormone (ADH) release, leading to increased urination and dehydration.
• ADH increases water reabsorption in collecting ducts by moving aquaporins to the apical side of cells.
• Ureters use peristalsis to move urine to the bladder, preventing backflow.
• Bladder stores urine; inner mucosa consists of transitional epithelium for expansion.
• Full bladder holds ~500 mL; maxes out around one liter; prolonged overdistension can lead to bursting (unlikely).
• Urine enters the urethra through the internal urethral sphincter (autonomic control).
• External urethral sphincter (skeletal muscle) is under voluntary control.
• Micturition: Bladder stretches, activating stretch receptors, sending nerve impulses to spinal cord and brain.
• Parasympathetic neurons are excited; sympathetic system is inhibited.
• Detrusor muscle contracts; internal urethral sphincter opens; external sphincter relaxes.
• Pons contains pontine storage area (inhibits urination) and pontine micturition center (promotes urination).

Urinary System Anatomy and Physiology

• Blood travels through kidneys every 30 minutes to filter waste, reabsorb water/electrolytes.
• Urine passes through ureters to the bladder, then out the urethra.
• Kidneys:
  • Located behind the gut, near the back.
  • Outer part (renal cortex) contains nephrons (functional units).
  • Nephrons contain glomeruli (filter) and tubules (reabsorb).
  • Primary functions: Filter waste, regulate blood pressure, reabsorb/excrete electrolytes/acids/bases.
  • Secondary functions: Erythropoietin (EPO) production, renin secretion (RAAS system), vitamin D activation.
• Ureters: Transport urine with peristalsis; one-way valve prevents backflow.
• Bladder: Stores urine; detrusor muscle contracts to facilitate urination; typical urge to void at 200-500 mL.
• Urethra: Transports urine from bladder to outside of the body.
• Women: Shorter urethra (1.5 inches), close to vagina/rectum, higher UTI risk.
• Men: Longer urethra (8 inches), passes through prostate.

Urinary Elimination Process

• 200-400 mL urine in bladder -> signal to brain -> detrusor muscle contraction -> internal sphincter relaxes (involuntarily) -> external sphincter relaxes (consciously).
• Characteristics of Urine
  • Color: Yellow (pale if hydrated)
  • Smell: Aromatic (ammonia-like if standing)
  • Odor changes: Asparagus and Brussels sprouts
  • Color changes: Beets
• Specific Gravity: 1.005-1.030 (density relative to water, solutes cause heaviness)
• Urine Color Indications (not tested on):
  • Blue: Bacterial infections or medications
  • Dark brown: Liver disease
  • Cloudy: UTI
  • Red/pink: Kidney stones, blood, or beets
  • Clear: Overhydration

Fluid Intake and Output

• Intake should closely match output.
• Intake: Feeding tube, water, IVs.
• Output: Urine, liquid stool, vomit.
• Insensible water loss: ~900 mL (sweat, breathing, metabolism).
• Adult Urine Output:
  • Low end: 50-60 mL/hour.
  • Anuria: <100 mL/24 hours.
  • Oliguria: <400 mL/24 hours.
  • Polyuria: Excessive urine, clear with low specific gravity.
• Daily Intake: 1500-2000 mL.
• Infants: >1 mL/kg/hour.
• Adults: 5-6 voids/day.
• Less output at night due to ADH secretion.

Assessing Hydration Status

• Measure intake and output.
• Assess skin turgor and mucous membranes.
• Monitor blood pressure.
• Evaluate pulse (rapid and weak indicates dehydration).
• Observe for edema.
• Track weight changes.
• Auscultate lungs for crackles.

Focused Urinary Assessment Questions

• Normal pattern: Frequency of urination per day.
• Habits: Water intake, types of fluids (caffeine, alcohol).
• Urinary diversion/catheter: Presence and functionality.
• Incontinence: Occurrence and type.
• Urine description: Color, smell, difficulty urinating (dysuria, pyuria).
• Lifestyle questions: Constipation, nocturia.
• Occupation: Holding urine due to job demands.
• Surgery: Urinary system/pelvic area surgeries.
• Other conditions: Obesity, diabetes.
• Difficulty starting/stopping stream: Prostate issues.
• Family history: Kidney stones, kidney disease.
• Medications: Anticholinergics, nephrotoxic drugs, diuretics.
• Children: Toilet training, accidents, bedwetting.

Developmental Considerations

• Newborns have immature kidneys with poor water reabsorption, leading to frequent urination (up to 25 times/day).
• Target output for newborns/infants/small children is >1 mL/kg/hour.
• Toilet Training
  • Typically occurs between 18 months and 3 years.
  • Boys usually later than girls.
  • Normal until 7 yo.
  • Requires recognition of need to pee, control of external sphincter, communication, and ability to remove clothes.
• Older Adults
  • Nephrons decrease with age, reducing bladder functionality.
  • Bladder elasticity decreases.
  • Nocturia is common.
  • Increased risk of retention, frequency, and leakage (though not normal).
  • ADH production decreases.

Factors Affecting Urination

• Diet
  • Caffeine: Diuretic, bladder irritant.
  • Alcohol: Impairs ADH release.
  • Salt: Promotes water retention.
• Activity
  • Hot weather promotes perspiration and respiration
• Psychological Factors
  • Privacy/dignity: Shuttered bladder
  • Time:
    • Lack of time -> Retention
• Sociocultural Factors
  • May not want to ask for help to bathroom.
• Medications
  • Diuretics: Increase urine output.
  • Anticholinergics: Benadryl.
  • Be aware of decreased kidney function in elderly people for medications.
• Pathological Conditions
  • Kidney stones: Obstruction.
  • Prostate issues: Benign prostatic hyperplasia (BPH), enlarged prostate.
  • Infection: UTI.
  • Fever: Increased insensible loss.
• Indirect Causes
• Constipation: Pressure on bladder.
  • Neurogenic bladder: Lack of sensation of need to urinate (spinal nerve injuries).
  • Cardiovascular Problems: Congestive heart failure, blood pressure issues.

Urinary Tests and Specimen Collection

• General Guidelines
  • Explain procedure to patient.
  • Provide peri wipes.
  • Instruct on proper cleaning technique before collecting specimen.
    • Females: Front to back.
    • Males: Pull foreskin back (if uncircumcised), clean urinary meatus down.
  • A routine urinalysis (UA) is not sterile; sample can be collected from a “sassy hat”.
  • For infants, use a collection bag.
  • For midstream collection:
• Instruct patient to start urinating, stop midstream, collect sample, then finish.
• Sterile Sample from a Catheter
  • Clamp the tubing to allow urine to collect (remove clamp within 30 minutes).
  • Clean the collection port with antiseptic for at least 15 seconds.
  • Use a non-needle syringe to withdraw urine.
  • Empty a catheter drainage bag, remove any securement devices.
  • Deflate the catheter balloon completely before removal.
  • Twenty-four Hour Urine Specimen
    * Discard the first void, collect all urine for 24 hours, and save the last void.