Urinary System & Fluid Balance: Key Misconceptions

Urinary Elimination: Chapter 38

• The components of the urinary system are explored

Kidney and Ureters

• The kidneys maintain the composition and volume of body fluids.
• Kidneys filter and excrete unneeded blood constituents, retaining those that are needed.
• The kidneys excrete waste product that takes the form of urine.
• Nephrons maintain and regulate fluid balance through selective reabsorption and secretion of water, electrolytes, and other substances.
• Urine from the nephrons empties into the kidneys.

Bladder

• The bladder consists of smooth muscle sac innervated by the autonomic nervous system (ANS).
• It serves as a temporary reservoir for urine.
• The bladder is composed of three layers of muscle tissue known as the detrusor muscle, including:
  • The inner longitudinal layer
  • The middle circular layer
  • The outer longitudinal layer
• The sphincter guards the opening between the urinary bladder and urethra.
• The urethra conveys urine from the bladder to the exterior of the body.

Urethra

• The urethra transports urine from the bladder to the outside of the body.

Kidney Functions & Influences on Urinary Elimination

• Nutrition affects urinary elimination, specifically dietary intake of foods and fluids.
• Changes in cognition increases the likelihood for complications in urinary elimination and can result in inability to obtain and maintain fluid and food intake.
• Cognition may also impact the ability to recognize elimination cues, leading to incontinence.
• Kidneys balance the body's water levels.
• Kidneys ensure appropriate blood pressure.
• Kidneys eliminate wastes like urea, uric acid, and toxins via urine.
• The Kidneys activates vitamin D, which helps the body absorb calcium.
• The kidneys maintain acid-base balance.
• Kidneys maintain electrolyte balance, which is critical for heart rhythm.
• The kidneys releases erythropoietin, which tells bone marrow to make red blood cells.
• Fluid/electrolytes & acid-base balance maintains homeostasis.
• Homeostasis relies on kidneys to retain or eliminate water and electrolytes.
• Changes in electrolyte balance influence neuromuscular transmission of smooth muscle, thus reducing or increasing muscle contractility.
• Muscle instability may result in ineffective urinary elimination and possible urine stasis, making the bladder a reservoir for bacteria.

Micturition (Voiding)

• Micturition, also known as voiding, means the process of emptying the bladder.
• Voiding is an involuntary act typically controlled later in life (after infancy).
• The urge to void starts when the bladder has about 150-250 ml of urine.
• A bladder that is no longer controlled by the brain because of disease or injury is called an autonomic bladder.
• An involuntary loss of bladder function is termed urinary incontinence.

The Act of Micturition

• The detrusor muscle contracts, internal sphincter relaxes, and urine enters the posterior urethra.
• Muscles of the perineum and external sphincter relax.
• The muscle of the abdominal wall contracts slightly.
• The Diaphragm lowers, and micturition occurs.
• In other words, the bladder distends, the voiding reflex is activated, the person has the urge to void, and voiding occurs.
• The bladder fills again and the process is repeated.

Voiding Frequency

• The frequency of voiding depends on the amount of urine produced.
• Infrequent urination patterns increase the risk for UTIs or kidney diseases.
• Urinary retention is when urine is produced normally, but not excreted completely.
• Urinary retention can be due to certain medications, post surgery, enlarged prostate, and/or vaginal prolapse.

Factors Affecting Urination

• Factors affecting urination include:
  • Developmental considerations in children and aging affect urinary continence
  • Food and fluid intake
  • Psychological variables like anxiety, embarrassment, stress, and cultural norms
  • Activity and muscle tone
  • Pathologic conditions
  • Medications

Developmental Considerations

• Toilet training typically occurs around 2 to 3 years of age, and enuresis may be present.
• Effects of aging include nocturia, increased frequency, urine retention and stasis, voluntary control affected by physical problems, and urge incontinence.

Food and Fluid Intake

• The kidneys aid in balancing fluid intake and output.
• Alcohol and caffeine act like diuretics.
• High sodium diets may decrease urine excretion.

Psychological Aspects

• Aspects can include anxiety, embarrassment, and culture.
• Stress can cause smaller excretion amounts, which leads to incomplete emptying.

Activity

• Regular activity promotes optimal urine production and elimination.
• Prolonged immobilization and catheter use decreases bladder and sphincter tone and can lead to poor urinary control and stasis.

Pathologic Conditions

• Pathologic conditions that may influence urination include infections or inflammation, calculi or tumors, hypertrophy of the prostate, cardiovascular and metabolic disorders, immobility and impaired communication, and cognitive changes.

• Diseases associated with renal problems are congenital urinary tract abnormalities, polycystic kidney disease, urinary tract infections, urinary calculi, hypertension, diabetes mellitus, gout, and connective tissue disorders.

AKI, CKD, & Renal Failure

• Acute kidney injury (AKI) is sudden kidney dysfunction within hours or days that is reversible if caught early.
• Chronic kidney disease (CKD) is a steady loss of kidney function that occurs over several months and/or years
• Renal failure is the inability of the kidneys to filter metabolic end products from the blood and regulate fluid, electrolyte, and pH balance.

Medications

• Drugs known for causing kidney damage are considered nephrotoxic drugs.
  • These drugs include diuretics, antibiotics, and analgesics.
• Cholinergics stimulate contraction of the detrusor muscle, producing urination.
• Anticholinergics treat incontinence by decreasing urgency and the production of urine, thus causing, urinary retention.
• Diuretics treat hypertension and prevent fluid reabsorption of water, as well as certain electrolytes.
• Antimuscarinic agents reduce involuntary detrusor contractions and increase bladder capacity, which may be useful for urgency, therefore treating, urinary incontinence
• Alpha Blockers prevent, treat, or improve BPH symptoms by relaxing the muscle of the prostate and bladder neck, allowing urine to flow more easily
• 5-alpha reductase inhibitors inhibit the production of DHT locally within the prostate gland, reducing prostate volume, improving lower urinary tract symptoms, increasing peak urinary flow, and decreasing the risk of acute urinary retention and need for surgical intervention.
• Topical estrogen may relieve atrophy of involved muscles in postmenopausal women, thereby treating urinary incontinence.
• Antidepressants can relax the bladder muscle while causing the smooth muscles at the bladder neck to contract, and treat mixed incontinence.
• Anticoagulants, diuretics, pyridium, antidepressants, and levodopa can change the urine color.

Nursing Process for Urinary Elimination

• The nursing process for urinary elimination includes assessment, diagnosis, planning, implementation, and evaluation.

Assessment

• Assessment requires the nurse to take a history of what brought the client in today.
• The history includes guidance from resources and the duration, severity, and possible factors to consider.
• The assessment also includes a physical exam.
• Findings correlate the history and assessment together for a formal diagnosis.
• Kidneys can be palpated.
• The urinary bladder can be palpated and percussed or a bedside scanner can be used.
• The urethral orifice is inspected for signs of infection, discharge, or odor.
• The skin is assessed for color, texture, turgor, and excretion of wastes.
• Urine is assessed for color, odor, clarity, and sediment.
• Measuring urinary output requires assessment of:
  • Continence
  • Incontinence
  • Indwelling catheter
• Additional assessment techniques require:
  • Routine urinalysis
  • Clean-catch or midstream specimen
  • Sterile specimen
  • Urinary diversion specimen
  • 24-hour specimens
• Collecting a urine specimen entails:
  • Fresh void
  • Clean catch
  • Sterile urine
  • 24-hour urine collection
• A urinalysis, culture, and/or sensitive study the urine more closely and is usually done in the lab.
• With these, the nurse assesses color, oder, turbidity, clarity, pH, specific gravity, and constituents.
• Important labs to consider include:
  • BUN: 8-20 mg/dL
  • Creatinine: 0.6-1.2 mg/dL (men), 0.4-1 mg/dL (women)
  • Specific Gravity: 1.015- 1.025

Diagnosis

• Diagnosis is achieved after the patient's urinary system and elimination patterns have been assessed.
• The nurse then collaborates with other nursing and healthcare professionals to discuss findings and adds that patient info to the health records.
• Potential problems may include urinary retention, stress incontinence, and urge incontinence in the form of UTIs.

Potential Testing

• Cystoscopy uses a scope to visually inspect the urethra, bladder, and ureteral orifices.
• Cystoscopy is used in cases of potential bladder infections, bladder cancer, and/or urinary tract stones.
• Intravenous pyelogram (IVP) uses IV contrast to evaluate renal function over time
• Retrograde Pyelogram uses contrast through a catheter to visualize the renal collecting system.
• A renal ultrasound helps visualize renal parenchyma (functional tissue) and renal blood vessels.
• Ultrasounds can also detect renal masses, infections, calculi, and malformed kidneys.
• Computed tomography is a more detailed scan than an x-ray.

Planning

• The planning stage prioritizes expected outcomes.
• For example " the patient will empty the bladder completely at regular intervals” or “the patient will report ease of voiding".

Implementation

• Implementation interventions focus on maintaining and promoting normal urinary patterns, improving/controlling urinary incontinence, preventing problems from bladder catheterization, and assisting with care of urinary diversions

Promoting Urinary Elimination

• Should produce urine output about equal to fluid intake
• Maintain fluid and electrolyte balance
• Empty the bladder completely at regular intervals
• Report is of voiding
• Maintain skin integrity
• Demonstrate appropriate self-care behaviors

Caring for Patients: UTI

• The most common cause of systemic infections in the older population.
• Females are the vulnerable gender
• Diagnosis is achieved through nursing history, physical exam, and labs.
• Treatment may consist of antibiotics, water intake, and more frequent voiding practices.

Caring for Patients: Incontinence

• Incontinence involves transient episodes and could indicate a treatable illness or temporary issue.
• There are different types of incontinence, including stress, urge, mixed, overflow, functional, reflex, and total incontinence.
• Assessment requires:
  • Assessing the environmental factors for potential barriers
  • Assessing whether the patient is able to safely use or access a commode
  • Assessing dietary habits
  • Assessing voiding patterns via a diary
  • Assessing postvoid residual with a bladder ultrasound
• The nursing interventions are:
  • Urethral catheter insertion and care for patients with an indwelling catheter
  • Caring for a patient with a urologic stent
  • Caring for a patient with a urinary diversion
  • Caring for a patient receiving dialysis

Reasons for Catheterization

• Relieving urinary retention
• Obtaining a sterile urine specimen when a client is unable to void voluntarily
• Accurate measurement of urinary output in critically ill clients
• Assisting in healing open sacral or perineal wounds in incontinent clients
• Emptying the bladder before, during, or after select surgical procedures and before certain diagnostic examinations.
• Providing improved comfort for end-of-life care
• Prolonged client immobilization (potentially unstable thoracic or lumbar spine, multiple traumatic injuries)

Types of Catheters

• Types include intermittent urethral catheters, indwelling urethral catheters, and suprapubic catheters
• Straight catheters are for one time use
• Indwelling catheters stay in for a period of time
• Suprapubic insertions involve a surgical incision for continuous drainage

Indwelling & Intermittent Urinary Catheter Insertion

• In indwelling:
  • Prepare a sterile field
  • Cleanse the female or male meatus appropriately.
  • Grasp firmly the catheter, insert without touching the meatus, and advance the catheter once the urine is visualized.
  • Do male and female, inflate a ballon
  • Ensure it in right position
  • Secure by tubing
• Intermittent:
  • Scan to verify and prepare sterile instruments
  • Cleanse meatus using sterile process.
  • Once done, allow for urination to drainage back
  • Remove and clean area.

Three-Way Catheter: Irrigation

• Provides way to irrigate bladder
• Balloon inflated to stay in

Caring for Patients: Urologic Stent

• Allows for urine passing in the event of a blockage and prevents swelling of the ureter.
• Urologic stents can be temporary (ureters) or permanent (urethra).
• They are typically placed during surgery or cystoscopy procedures and requires monitoring urine output for color, consistency, and odor.

Urostomy

• A stoma (lleal conduit) is formed with a piece of the ileum and creates a pouch that makes up the ileal, single, or double condui, and the continent urinary conduit that drains the urine.
• There also could be cutaneous ureterostomy & continent urinary diversion

Caring for Patients: Dialysis

• Dialysis is used for severely decreased or total kidney function loss.
• It filters waste and extra electrolytes mechanically, including hemodialysis and peritoneal dialysis (PD).
• When vascular access is required, assessment requires palpating the skin and listening to the AVF, AVF, graft.

Evaluation

• Continuous nursing process
• Questions the nurses should reflect on:
  • Has the patient showed a positive or negative outcome during the care?
  • Were individualized goals met for the patient?
  • Are there any adjustments needing to be made?

Explore common misconceptions about the urinary system and fluid balance. Understand the effects of cognitive changes, electrolyte imbalances, and mobility on urinary function. Learn about bladder capacity and the role of nephrons and the detrusor muscle.