Overview
This lecture covers the physiology, factors, alterations, and nursing interventions related to urinary elimination, including normal vs. abnormal urine characteristics.
Learning Outcomes
- Describe the process of urination from urine formation to micturition.
- Identify factors influencing urinary elimination.
- List common causes of urinary problems.
- Distinguish normal and abnormal urine characteristics.
- Develop nursing diagnoses and desired outcomes for urinary elimination.
Physiology of Urinary Elimination
- Kidneys, ureters, bladder, and urethra comprise the urinary tract.
- Kidneys filter blood, remove wastes, and maintain fluid balance.
- Nephron is the kidney’s functional unit; urine forms in its tubules.
- Urine passes from kidneys via ureters to the bladder, exits through the urethra.
- Micturition is the process of emptying the bladder (urination/voiding).
- Adults feel the urge to void at 250–450 ml; children at 50–200 ml.
Factors Affecting Urinary Elimination
- Developmental stage: infants urinate frequently, control develops by age 2–5, bedwetting (enuresis) may occur in children.
- Older adults may have nocturnal frequency and incontinence.
- Psychosocial factors: privacy, time, and environment affect urination habits.
- Fluid and food intake: more fluid = more urine; alcohol/caffeine increase output, sodium causes retention.
- Medications: diuretics increase output, some drugs change urine color.
- Muscle tone: good tone enables full emptying; weakness may cause incontinence.
- Pathologic conditions: kidney disease, heart/circulatory disorders, stones, prostate enlargement affect urination.
- Surgical/diagnostic procedures: may cause retention, bleeding, or decreased urge.
Alterations in Urine Production and Elimination
- Polyuria: excessive urine output (>2L/day).
- Oliguria: low urine output (<500 ml/day).
- Anuria: absence of urine.
- Frequency: voiding >4–6 times/day.
- Nocturia: waking ≥2 times/night to void.
- Urgency: sudden strong desire to void.
- Dysuria: painful/difficult urination.
- Retention: inability to fully empty bladder.
- Incontinence: involuntary urine leakage—stress, urge, mixed, overflow types.
Urine Characteristics: Normal vs. Abnormal
- Amount: 1,200–1,500 ml/24 hr is normal.
- Color: normal is straw/amber & clear; abnormal includes dark, cloudy, red, or brown.
- Odor: faint aromatic is normal; strong/offensive may indicate infection or diet.
- Sterility: urine should be free of microorganisms.
- pH: normal 4.5–8; abnormal <4.5 or >8.
- Specific gravity: normal 1.010–1.025.
- Glucose, ketones, blood should NOT be present in normal urine.
Nursing Diagnoses & Interventions
- Common diagnoses: impaired urinary elimination, functional incontinence, overflow incontinence, reflex incontinence, disturbed body image.
- Interventions: increase oral fluid intake (1–2 liters/day), assist with toileting, encourage voiding every 2–4 hours.
- Prevent UTIs: drink water, void regularly, avoid irritants (soaps/bubble baths), wear cotton underwear, maintain hygiene.
Key Terms & Definitions
- Nephron — Functional unit of the kidney where urine forms.
- Micturition — The process of urinating.
- Enuresis — Involuntary urination in children.
- Polyuria — Excessive urine output.
- Oliguria — Low urine output.
- Anuria — No urine output.
- Nocturia — Frequent urination at night.
- Dysuria — Painful or difficult urination.
- Incontinence — Involuntary leakage of urine.
Action Items / Next Steps
- Review video/audio presentation on urinary system anatomy if not yet done.
- Read more about nursing diagnoses for urinary elimination issues.
- Answer the bonus question: What is the content in urine found to whiten teeth? (Submit via Hangouts with your section.)