Urinary and Stool Elimination

• Lecture material is adapted from © 2022 Wolters Kluwer Health, Lippincott Williams & Wilkins
• Applied Pathophysiology: A Conceptual Approach to the Mechanisms of Disease
• Chapter 18: Altered Elimination
• Module 1: Altered Urinary Elimination
• Module 2: Altered Stool Elimination
• Dr. Romeo Batacan Jr.
• MPAT12001 Medical Pathophysiology Lecture Series

Altered Urinary Elimination

• Neural, vascular, muscular, and hormonal influences affect urinary elimination
• Urine's movement from production to exit must be patent and functional
• Altered motility: Reduced contraction of hollow structures
• Promotes stasis of filtrate in the renal tubules
• Promotes stasis of urine in the bladder which may facilitate bacteria growth and kidney infections
• Stasis leads to altered reabsorption and secretion
• Increased sodium concentration, low pH
• Cast formation, precipitation of urinary fluid components and obstruction
• Trapping of RBCs within casts leads to glomerulonephritis (inflammation of glomerulus)
• Trapping of epithelial cells within casts leads to acute tubular necrosis (sloughing of tubular cells)
• Trapping of WBCs within casts leads to pyelonephritis (kidney infection and inflammation)
• Altered neuromuscular function: the impaired neural control of urinary elimination and inappropriate muscle response in the renal tubules
• Impaired neural control involves neurons of the peripheral and central nervous systems
• Impaired neural control also incorporates neurotransmitter production and coordination of neural impulses from initiation to action
• Failure to provide an appropriate stimulus leads to a limited or absent ability to eliminate urine, which causes urinary retention
• Exaggerated response leads to premature release of urine, which causes urinary incontinence
• Altered perfusion can lead to decreased which is caused by excessive constriction of arterioles, inadequate vascular volume or an obstructed arterial supply (an embolism)
• Decreased oxygen delivery damages to renal structures due to the inability to meet metabolic demands
• Loss of functional tissue through necrosis will result in pain, bleeding, and/or obstruction in the venous system's branches
• Enhanced perfusion can lead to additional workload on the kidney and stress the organ system
• Altered patency or obstruction is characterized by buildup of pressure behind the blockage causing
• Blockage of urine flow
• Dilation of structures proximal to obstruction
• Injury to renal anatomy
• Causes of blockage include precipitation of substances in smaller lumen structures (casts etc.)
• Structural blockage: polyps or tumors
• Mechanical obstructions: urine precipitation, scar tissue, adhesions, inflammation
• Dilation of the structures proximal to the obstruction caused by stasis of urine, structural damage and/or infection
• Hydroureter is an accumulation of fluid in the urinary ureter caused by a complete ureteral obstruction
• Hydronephrosis results from increased hydrostatic pressure extending up to the renal pelvis and tubules
• This leads to impaired renal function, fluid escaping from the tubules into the surrounding capillary system, and impaired excretion of sodium, urea, and water
• Prolonged/severe pressure causes structural damage and impaired function

Manifestations of Altered Urinary Elimination

• Specific manifestations are related to the underlying pathology
• Include: altered urinary volume, altered urinary composition, bleeding, pain, general malaise, fever, and GI
• Proteinuria is protein in urine.
• Glucosuria is glucose in urine.
• Ketonuria is ketones in urine such as acetone, acetoacetic acid, beta-hydroxybutyric acid.
• Hematuria is RBCs in urine.
• Pyuria is WBCs in urine.
• Bacteriuria is bacteria in urine.
• Pain is a frequent symptom associated with altered renal and urinary function
• Stimulated by stretching and inflammation in the renal capsule (rather than kidney itself)
• Pain receptors in the renal capsule give a sensation of dull, persistent pain
• Pain receptors in the remaining parts of the urinary system produce intermittent and sharp pain
• Manifestations of urinary infection: lower and upper urinary tract (general malaise, anorexia, fever, nausea and vomitting
• Ascending infection leads to potential for renal structural damage that affects urine productivity
• Diagnosis of the cause and effect of altered elimination includes macroscopic and microscopic urinalysis
• Urinary Electrolytes: Normal values not standardized, but kidneys dynamically maintain electrolyte homeostasis in the plasma
• GFR and Creatinine Clearance will determine nephron function
• Anatomic and functional anomalies can be discovered through a range of radiographic diagnostic testings
• Intravenous pyelogram (IVP) is to visualize the kidneys, ureters, and bladder with the use of injected radiocontrast
• Voiding cystourethrogram (VCUG) is an X-ray examination of the bladder and urethra after catheter insertion
• Fluoroscopy is then used to determine ureteral reflux and bladder/urethra configuration during voiding
• In a renal angiogram contrast is injected into the real artery to diagnose renal artery stenosis or intrarenal vascular obstructions
• A renal ultrasound can determine the size of the kidney, hydroureter, cysts, and obstructions
• Renal artery flow can also be determined through a Doppler ultrasound
• Treatment options depend on the underlying cause
• Often associated with impaired regulation of fluid balance
• Administration of supplemental fluids to correct body fluid deficit
• Use of diuretics to correct body fluid excess

Altered Stool Elimination

• Impaired large intestine function alters final steps of water and electrolytes retrieved from stool
• Alos alters the absortion of vitamins produced by intestinal bacterial flora
• Stool elimination is the forward movement of stool and the propelling of intestinal contents towards and out the anus
• Motility determines the rate that fecal matter passes through for evacuation
• Increased motility leads to diarrhea that causes shortened transit time
• Impairs nutrition, prevents adequate nutrient and water absorption, and enhances loss of water and electrolytes
• Decreased motility which causes slowed, increased transit time, prolongs the storage time leading to enhanced fluid loss
• Bacterial intestinal flora influences include
• Promoting motility: Lactobacillus acidophilus, Bifidobacterium bifidum
• Inhibits motility: Escherichia coli
• The altered neuromuscular function is the impaired neural control on stool elimation which causes perstalsis of the gastrointestinal tract
• Impaired neural control involves coordination of neural impulses of the peripheral and central nervous systemas as well the ability for neurotransmitters to be produced and available
• Failure to provide an appropriate stimulus causes the body to lose the ability to eliminate stool and increased the risk of impaction
• Exageratted response can lead to unexpectedly passing stool and could lead to bowel incontinence
• Impaired neuromuscular function can leas to a loss of propulsive activity
• Reduced propulsive activiy leads to harder tools
• Enhanced neuromuscular function involves excerise to promote bowel elimination
• Alered perfusion from ischemia is typically manifested by pain and bowel dysfunction
• Includes altered local circulation of clots, pressure from a space ocupying mass and erosion of blood vessels supplying the perfusion to the small instesine
• If the person has altered global circulation blood is redistributed away from the digestive system to the vital organs
• Excessive demands are a product of infection
• Appendicitis is a common infection of the Gastrointestional system that is caused by trapped fecal matter, trapping bacteria that the body is unable to empty
• From this the the person's appendix swells which is called acute inflammation which also can cause the squeezing off of venous damage
• If the appendix ruptures the feces with bacteria can cause peritonitis

Altered Elimination: Bowel Obstruction

• Space-occupying lesions block the intestinal lumen, either partially or totally and are common
• Tumors, polyps, and impacted feces prevent excretion
• Non-space occupying lesions can include herniations, adhesions, volvulus, and intussusceptions
• Bowel obstruction is associated with fluid and as accumulation
• Displayed through abdominal distention which causes pain
• Major effects: abdominal distention, loss of fluids and electrolytes (vomiting), gas and fluid accumulation, further distention causing pain, ischemia and necrosis, perforation, sepsis
• A space-occupying lesion impairs the capacity for venous return causes fluid to leak into the peritoneum

General Manifestations of Altered Bowel Elimination

• Altered bowel sounds: can auscultate to measure how active the small instentine is
• Check quality, locotion and frequencey
• Check if it indicates peristoltic function (ex. if motility increases this implies diarrhe)
• The Abdomen should be soft when palpated relatic to body size
• Abdominal size can increase.
• Trapping of gas > hardening and tightening of the abdomen
• Gaseous byproducts of digestion (Flatus) are passed normally
• Altered volume and characteristics of stool
• Diarrhea means that stool is loose and water
• In contrast constipation if lack of bowel activity
• You can tell what disese the is by noting color changes
• Bright red blood around stool can indicate hemorrhoids or bleeding in the lower intestines
• A light stool (absence of bile) indicates an issue in the liver (hepatitis, malabsorption syndromes)
• Black Stool (melena) indicates bleeding in the upper GI system
• Altered stool texture
• Watery, hard, stringy, fatty, foul odour
• Pain is a characteristic of intestinal disorders
• Can can mechanical inflammatory or ischemic to the body
• Anorexia means one has a loss of appetite, nausua, and vomitting
• It is general and you cannot determine a certain condtion
• Abdominal distention can be increased by
• Increased pressure due to fluid in stool in the intestinens
• Increase production of gas
• Fever: infection
• peritonitis (inflammation of the peritoneal membrane

Diagnosis of Altered Elimination

• Stool analysis: Can microscopically analyse bacteria or parasites
• Fat contnent means there may or may not be a malabsorbtion
• Occult is blood that is too small to be seen (use Guaiac test)
• Take sample an apply a chemical solution
• Color change (blue) indicates presence/absence of blood
• Barium enema diagnosis can mechanically analyse the obstruction
• Colon and Rectal anatomy are inspected with the aid of contast with a Barium in the anus
• With a radiograph you can inspect for any diverticultites such as alterations in motility, obstruction
• Sigmoidoscopy insert a flexible tube into the anus as well as the rectum
• colonoscopy is when the entire colon is inspected by a flexable tube

Treatment of Altered Bowel Elimination

• Diarrhea: excessive Gl elimination (must use andtidiarrhoel drugs to diminish fluid loss)
• 1. Slowing the passage of stool through the intestine
• Antimotility agents: Water is then removed from fecal matter
• 2. Diarrhoea-Causng factors and moved out of the stool (Adsorbents)
• 3. Decreasing the Secretion of FLuids into the Intestines
  • (Antibiotics can remove inflamitary response that decrease the flueid movements into intestianls contents Bulk-forming agents are used to absorb the fluid-causing liquid contents Constipation is not having sufficient GI elimination must do the following Must incoporate Excerise with a high amount of fiber and adequate amounts of fluid intake To assist additonal aids and stool softeners must be used In addition stool softener also promote more water intake with causing stimulant efffects Enema fluid injection: fluid injection into lower bowel through the rectum If there are obstructive abmoralites (must perform surgica removal) To fix Alterations (must have assistive devices or bowel training

Questions cover urinary and stool elimination, focusing on consequences of reduced contraction, stasis, neuromuscular function, and impaired organ function. Also addresses the impact of altered intestinal motility and neural responses.