Elimination

This discussion is lifted from Ma'am Tuiza's presentation on Elimination Patterns (UE and FE). It will be supplemented with Kozier and Erb's Fundamentals of Nursing sometime soon.

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Urinary Elimination

Urinary elimination is the removal of waste from the body through the urinary system, via the urinary tract. Here’s a short review of the physiology of the urinary system:

1. Kidneys are the functional unit of the kidneys. It contains nephrons that filter the blood and removes metabolic wastes. The kidneys are the primary regulators of fluid and acid-base balance in the body. This filtered fluid from the kidneys is urine. They continue along the ureters, normally 10 to 12 inches, with its lower end connecting with the urinary bladder.
2. Bladder: the hollow, muscular organ that serves as a reservoir for urine. Its normal capacity is between 300 to 600 mL, stretching and contracting when voiding. The wall of the bladder is made of the detrusor muscle, which handles the expansion and contraction.
3. Urethra: the outlet starting from the bladder and ending at the urinary meatus (external opening). Females have a shorter urethra, only being ~1.5 inches as opposed to the male ~8 inches. This increases their susceptibility to UTIs.
4. Pelvic Floor Muscles: the pelvic floor muscles, unlike the smooth muscle of the bladder, is under voluntary control. These muscles are important in controlling urination (continence).
   • Factors that weaken these muscles include childbirth, pregnancy, chronic constipation, obesity/overweight, and aging (as well as decreases in estrogen at menopause).
5. Urination/Micturition: the urge to urinate begins once the stretch receptors of the bladder become distended, often at around 250 to 450 mL of urine. This transmits impulses to the spinal cord (S2 to S4 is the voiding reflex center of the spine). This relaxes the internal bladder sphincter, initiating the urge to void. Second, the external urethral sphincter muscle become relaxed when the time and place are appropriate for urination. Otherwise, the micturition reflex subsides until the bladder becomes more distended, and it repeats.
   • Voluntary control requires intact nerves that supply the bladder, urethra, cord, and brain, as well as the motor area of the cerebrum.\

Factors Affecting Voiding

Age	Developmental Milestone
3 months in-utero	Fetal kidneys begin to produce urine from the 11th to 12th week of gestation.
2 ½ years to 3 years	The child is able to perceive bladder fullness.
3 years	The child obtains daytime continence.
4 years to 5 years	The child obtains full urinary control.
Older adults	Decreased renal circulation from cardiac and vascular changes. Decreased bladder muscle tone, resulting in nocturia, incomplete bladder emptying (poses a risk for infection), and incontinence.

Psychosocial factors play a part in when an individual feels the urge to void. These include privacy, positioning, timing, and many others. Some individuals get the urge to pee when they hear running water, when they see others drinking, etc. Of course, being a physiologic function, physiologic factors also dictate the rate of production of urine:

1. Food and Fluid Intake: a high intake of fluids increase urine production, leading to more frequent urination.
   • Caffeine-containing drinks and foods act as diuretics.
   • High sodium content of a diet increases fluid retention.
2. Medications: diuretics are a class of medications that increase urine formation through various mechanisms. A common example of this is Furosemide, a loop diuretic that prevents the reabsorption of water and electrolytes from the tubules of the kidney and into the bloodstream. Similarly, there are anti-diuretic medications.
3. Muscle Tone: as micturition is a function of the detrusor muscle, its tone is important in being able to adequately and appropriately initiate voiding. In patients with a long-term need for in-dwelling/retention catheters, the continuous drainage of urine removes the cycle of stretching and contracting, which can negatively impact the detrusor muscle’s tone.
4. Pathology: the malfunctioning of any of the systems or structures related to the urinary system can increase and decrease urine output, or the filtering ability of the kidneys. These include renal failure, heart failure, shock, hypertension, urinary stones, prostatic hyperplasia, etc.
5. Surgical and Diagnostic Procedures: structures may be altered after procedures done to the urinary tract, such as urethral swelling after a cystoscopy.

Normal Urine Characteristics

Parameter	Reference Range	Abnormal	Considerations
Rate of Production (24 hours)	1,200 to 1,500 mL	<1,200 mL or if vastly greater than intake	Urinary output should be proportional to fluid intake.
Color and Clarity	Straw, amber, transparent	Dark amber, cloudy, dark orange, red, dark brown, mucous plugs, viscid/sticky, thick	Darker: concentration Clearer: dilution Pink/Red/Rusty/Brown: RBCs Cloudy: WBCs, bacteria, pus, prostatic fluid, sperm, vaginal drainage
Specific Gravity	1.010 to 1.025	<1.010 or >1.025	Elevations: concentration Depressions: dilution
pH	4.5 to 8	<5 or >8	Acidity: starvation, diarrhea, high protein diet, cranberries, freshly voided Alkalinity: alkalosis, UTI, fruit and vegetable diet
Odor	Faintly aromatic	Offensive	Musty: asparagus Fetid: infection Glucose: sweet
Glucose	(-)	(+)	Glucosuria begins at ~200 mg/dL, a high blood sugar level.
Ketone	(-)	(+)	Ketonuria: ketosis from fatty acid metabolism, often in patients with DM or starvation.
Blood	(-)	(+)	Hematuria: UTI, kidney disease, urinary tract bleeding
Sterility	(+) Microbes	(-) Microbes	Contamination from perineum during collection

Altered Urinary Characteristics

Abnormality	Description
Polyuria	Excessive urine production.
Oliguria	Diminished urine production at <30 mL/hr or <500 mL/day.
Anuria	Halted urine production.
Urinary Frequency	Decreased urination interval, voiding 4 to 6 times a day. This may be caused by UTI and pregnancy, among other things.
Urinary Urgency	A sudden and strong desire to void, even without a full bladder. This may be caused by psychologic stress, urethral irritation, poor external sphincter control, and unstable bladder contractions.
Nocturia	Voiding two or more times at night.
Urinary Hesitancy	A delay or difficult in initiating voiding, often associated with dysuria.
Dysuria	Painful or difficult voiding
Enuresis	Bedwetting, normally found in children and older adults. Nocturnal enuresis affects boys more often than girls.
Urinary Incontinence	Involuntary or uncontrolled urine leakage. It may be caused by various factors, and their nature dictates the type of incontinence produced.
Stress Incontinence	Increased pressure, especially with weakened pelvic floor muscles, can cause urine to leak. Examples include coughing and sneezing.
Urge Incontinence	Involuntary contraction of the bladder muscles.
Overflow Incontinence	Blockage of the urethra results in urinary retention, which eventually fills the bladder and causes it to overflow, surpassing the pressure of the obstruction. This may be caused by prostatic hyperplasia.
Neurogenic Incontinence	Disturbed nervous system functions create faulty control of the bladder muscles
Urinary Retention	A condition where impaired voiding can result in urine accumulation in the bladder, resulting in distention and potential overflow incontinence. This is found in cases of prostatic hyperplasia and surgery.

Related Nursing Interventions

1. Promoting Fluid Intake: A normal daily intake averaging 1,500 mL is adequate for most adult clients. Fluid restrictions are common in those with kidney failure or heart failure to prevent fluid overload and edema.
2. Maintaining Normal Voiding Habits: patients should void immediately after feeling the urge to do so. Privacy is provided, and bedpans (if being used) should also be warmed to promote comfort.
   • For patients having difficulty with urination, the urge can be stimulated with the sound of running water, increasing fluid intake, and ambulation. If still unsuccessful, the use of a catheter may be ordered by a physician.
3. Assisting with Toileting: bathrooms should be equipped with accessible call signals to call for help if needed. Clients should be reminded to utilize handrails for safety.
4. Preventing Urinary Tract Infection: urinary tract infections are among the most common infections worldwide, particularly in women. Many preventive measures can be applied:
   • Fluid intake: eight 8-ounce glasses of water should be drank per day.
   • Frequent voiding should be practiced. Ignoring urges when unnecessary is conducive to bacterial growth. Immediately after intercourse, voiding is suggested.
   • Harsh soaps, bubble baths, powders, or sprays should be avoided for use in the perineal area.
   • Avoid tight clothing that can irritate the urethra. Additionally, cotton underclothes are better than nylon underclothes when it comes to perineal moisture.
   • Women wipe the perineal area front to back. The most common causative agent implicated in urinary tract infections is Escherichia coli, a microbe found within the intestinal tract.
5. Kegel Exercises/Pelvic Floor Muscle Exercises: exercises that are used to strengthen the pelvic floor muscles. This involves tightening the anal sphincter, as if to control the passing of gas, and tightening of the vagina and urethra as if the stop urine during flow. These can be performed anytime, anywhere, sitting or standing.
6. Maintaining Skin Integrity: assess the skin for breakdown. The patient’s bed linens should be maintained clean and dry. If necessary, barriers or ointments can be used to protect the skin.
   • An incontinence drawsheet should be used for patients with incontinence.

Urinary Catheterization

A catheter may be introduced into the urinary bladder to facilitate urination when indicated. This can be done intermittently via a straight catheter, or continuously, via an indwelling or retention catheter. Depending on the function required, there are several types of catheters used: (I honestly have no clue who or what “Robinson” refers to. Apparently, it’s not even the name of an inventor.)

1. Robinson one-way catheter, also known as a straight catheter. It contains one lumen that facilitates the drainage of urine. This type of catheter is used for:
   • Specimen gathering
   • Residual urine measurement
   • Relief of bladder distention
   • Empty the bladder completely prior to surgery
2. Robinson two-way catheter, also known as an indwelling catheter or a Foley catheter named after its designer, Frederic Foley. Any catheter with a balloon may be called a Foley catheter. It contains two lumens, one which facilitates the drainage of urine, and the other that connects to a balloon at the tip of the catheter. This balloon is inflated through the lumen to anchor the catheter in place. This type of catheter is used for:
   • Relief of urinary retention or bladder outlet obstruction
   • For selected surgical procedures, especially for measuring intake and output.
   • These are also used for those who are critically ill (for measuring accurate intake and output), at end-of-life care (for comfort), who have urinary retention, who have incontinence (especially if a perineal wound is present), who have had surgery (urologic surgery, caesarean section), and are immobilized.
3. Coude two-way catheter: “Coude” refers to a curved tip. The structure of the catheter is the same as a Robinson two-way catheter, but the curved tip allows the catheter to be maneuvered past obstructions or an enlarged prostate.
4. Robinson three-way catheter: the two lumens are the same as before, but a third lumen is added to serve as a channel for irrigation post-surgery.

Catheter-Associated Urinary Tract Infections (CAUTIs)

Catheters produce a large percentage of healthcare-associated infections, with the risk of urinary tract infections increasing for every day a catheter is retained. A CAUTI Care Bundle is set in place and aims to reduce these occurrences. Additionally, these considerations should be held:

• Avoid any unnecessary use of an indwelling catheter. As soon as indicated, its removal should be ordered and carried out.
• Insert and remove the catheter while maintaining strict asepsis. The catheterization kit is prepared in a sterile kit.
• Avoid disconnecting the catheter from the drainage tubing.

Other considerations for setting up a catheter and urine collection bag include:

1. Examine and measure the urine. In some cases, only 750 mL to 1,000 mL of urine is to be collected at one time. Check with the agency for specific policies.
2. Hang the bag below the level of the bladder. It is normally hung on the side of the bed. Any tubing connected to the catheter should not hang below the bag.
3. Urine specimens are collected if needed. A straight catheter is used, allowing 20 mL to 30 mL to flow into the bottle without contact to prevent contamination. An indwelling catheter can also be used, but only initially upon insertion.
4. Restore the voiding cycle: a few days prior to removing the catheter, continuous drainage is stopped to allow the smooth muscles of the bladder to resume their function. To do this, the catheter is clamped for 2 to 4 hours, then released, the clamped again, simulating a voiding cycle.
5. Sizing and Length: the catheter is inserted until urine flows, at somewhere around 6 to 9 inches for men with a Fr. 16 to Fr. 18 lumen catheter, and 3 to 4 inches for women with a Fr. 12 to Fr. 14 lumen catheter.

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Fecal Elimination

Fecal elimination is the removal of waste from the body through the digestive system, via the gastrointestinal tract. Here’s a short review of the physiology of the digestive system:

1. Colon: the large intestine, which is generally about 50 to 60 inches long. Its main functions are the absorption of water and nutrients, fecal elimination, and mucoid protection of the intestinal wall. The colon terminates at the rectum, where any remaining products of digestion is feces or stool.
2. Rectum: a pouch with vertical folds, that expand to retain feces. This connects to the anal canal, which has to sphincters: the internal sphincter acts involuntarily, while the external sphincter is controlled voluntarily. The internal sphincter reacts to the defecation reflex, but the external sphincter can be used to inhibit the reflex. The urge to defecate normally disappears soon after inhibition, and resurfaces in a few hours.

Factors Affecting Defecation

Development

Stool Characteristics

Parameter	Normal	Abnormal
Color	Brown (Adult), Yellow (Infant)	Clay, white, black, tarry, red, pale, orange, green
Consistency	Formed, soft, semi-solid, moist	Hard, dry
Shape	Cylindrical (same as the contour of the rectum)	Narrow, pencil-shaped stool
Amount	Varies with diet
Odor	Aromatic, affected by ingested food	Pungent
Constituents	Small amounts of undigested roughage, sloughed dead bacteria and epithelial cells, fats, and proteins.	Pus, parasites, blood, large quantities of fat, and foreign objects

These abnormalities have the following potential (common) causes:

1. Color:
   • Clay/White: absence of bile, potentially from bile obstruction. Diagnosis is through a barium enema.
   • Black/Tarry: (1) normal from iron intake, (2) upper gastrointestinal bleeding, or (3) diets high in red meat and dark green vegetables.
   • Red: lower gastrointestinal bleeding
   • Pale: (1) malabsorption of fats, (2) diet high in milk and low in meat.
   • Orange/Green: intestinal infection
2. Consistency: hard, dry stool can be a result of dehydration or a lack of fiber in the diet.
3. Shape: narrow, pencil-shaped stool can be a result of obstruction conditions.
4. Amount: N/A
5. Odor: a foul or pungent smell results from infection or the presence of blood.
6. Constituents: pus (infection), parasites (parasitic infection), blood (bleeding), large amounts of fat (malabsorption), and foreign objects.