Ch 38- Alt of Renal & Urinary Tract Fxn

• The chapter discusses alterations of renal and urinary tract function, focusing on UTIs and renal calculi.

UTIs

• UTIs involve inflammation of the urinary epithelium and are commonly caused by gut flora bacteria.
• Acute cystitis is the inflammation of the bladder, and is the most common site of a UTI.
• UTIs are classified by location or complicating factors like bladder inflammation (cystitis) or upper urinary tract inflammation (pyelonephritis).
• UTIs can occur anywhere along the urinary tract including the urethra, bladder, ureter, or kidney.
• Those at risk include:
• Premature newborns.
• Prepubertal children.
• Sexually active and pregnant women.
• Women treated with antibiotics.
• Spermicide users.
• Estrogen-deficient postmenopausal women.
• Individuals with indwelling catheters, diabetes, neurogenic bladder, or urinary tract obstruction.
• UTIs are more common in women due to their shorter urethra and its proximity to the anus, increasing bacterial contamination.
• Uncomplicated UTIs occur in individuals with a normally functioning urinary system and generally have mild symptoms without complications.
• Complicated UTIs develop when there is an abnormality in the urinary system or a health problem compromising host defenses (e.g., HIV, renal transplant, DM, or spinal cord injury).
• Recurrent UTIs are defined as 3 or more UTIs within 12 months.
• Relapse occurs within 2 weeks of original treatment with the same pathogen.
• Reinfection occurs more than 2 weeks after completing treatment with the same or a different pathogen.
• Protective urinary defense mechanisms include fimbriae, expression, sidophore production, and biofilm production, this maintains a sterile posterior urethra and bladder in healthy individuals.
• Bacteria are washed out during micturition.
• Low pH, high osmolality or urea, uromodulin, and uroepithelium secretions create a bactericidal effect and the ureterovesical junction prevents urine reflux.
• Periurethral mucus-secreting glands trap bacteria in women, while length and prostate secretions protect men.
• TLR4 recognizes pathogens, triggering neutrophil and macrophage recruitment, along with phagocytosis.
• Susceptibility to infection is influenced by the host's genetic ability to respond to the potential threat and the efficiency of bladder defenses, which can be influenced by Lewis blood group antigens.
• Asymptomatic bacteriuria is when bacteria is detected in the urine without an infection and intervention is only required for pregnant women.
• Common UTI "bugs" include Escherichia coli (80-85%), Staphylococcus saprophyticus (10%), and Schistosomiasis haematobium.
• Pathophysiology involves pathogens overcoming host defenses and rapidly reproducing, influenced by defense efficiency and pathogen virulence.
• Uropathic E. coli strains are the most common infecting microorganisms (80% to 85%).
• Bacterial contamination occurs via retrograde movement of gram-negative bacilli from the gut.
• E. coli produces siderophores for iron and expresses toxins.
• Virulence is enhanced through biofilm formation, common in catheter-associated UTIs.
• Uropathic E. coli uses type-1 fimbriae to bind to catheters and the uroepithelium, resisting flushing.
• Some women are genetically predisposed to E. coli attachment with pathogenic vaginal flora.
• Fungal pathogens, especially Candida, can colonize the urinary tract or catheters.

Complications

• Complications can occur alone or with pyelonephritis, prostatitis, or kidney stones.
• Urosepsis can cause septic shock in up to 40% of cases, which requires parenteral, broad-spectrum antibiotics, and may require hospitalization.
• Clinical manifestations are predominantly related to the host inflammatory response, including frequency, urgency, dysuria, and suprapubic or lower back pain.
• Bladder inflammation stimulates stretch receptors causing urgency and frequency and hematuria, cloudy and foul-smelling urine, and flank pain are also indicators of kidney problems.
• Some people with bacteriuria are asymptomatic, while others are abacteriuric but symptomatic.
• Older adults may have confusion or vague abdominal discomfort.
• Recurrent UTIs and concurrent illnesses increase morbidity and mortality risk.
• Diagnosis involves urine culture for symptomatic individuals with specific microorganisms and dipstick tests for leukocyte esterase or nitrite reductase in uncomplicated cases.

Treatment

• Identify and treat risk factors like urinary tract obstruction.
• Urine culture and sensitivity testing should be done before antibiotic therapy.
• Clinical symptoms can be relieved while bacteria are still present. Treatment can last 3 to 5 days commonly or 7 to 14 days for complicated UTIs.
• Follow-up urine cultures are required 1 week post-treatment, then monthly for 3 months and recurrent infections require repeat cultures every 3 to 4 months for one year.
• UTIs are effectively treated with a short course of antibiotics.

Childhood UTIs

• In childhood, UTIs are defined as the colonization of a pathogen anywhere along the urinary tract, commonly caused by bacteria, especially E. coli accounting for approximately 80% of infections.
• Higher risk in uncircumcised males, infants with renal abnormalities, and sexually active adolescent girls.
• UTIs in Females are commonly due to perineal bacteria ascending the urethra.
• Women that have genetically-controlled blood group antigens on uroepithelial cells which act as receptors for bacterial attachment.
• Individual susceptibility, bacterial virulence, anatomy, and genetics affect disease severity and recurrent UTIs impacts approximately 20-30% of children.
• The low pH from acidic urine defends the urinary tract from infection.
• Educate families about signs and symptoms of UTIs to allow for early identification and treatment.
• Incontinence in a previously dry child is a very common assessment finding in children
• Symptoms may be nonspecific, making it difficult to differentiate bladder from kidney infections based on symptoms alone.
• Infants may develop fever, vomiting, diarrhea, or jaundice and some children may only have a fever of undetermined origin.
• Acute pyelonephritis is associated with chills, fever, flank or abdominal pain, and enlarged kidneys from edema.
• Asymptomatic, chronic pyelonephritis occurs
• Diagnosis includes urine culture before antimicrobial treatment and urinalysis revealing pyuria, nitrites, and hematuria.
• Ultrasound, voiding cystourethrography, radionuclide cystography, or CT scans are all methods that may be necessary to rule out obstructions.
• UTI relief in one to two days with sterile urine is usually seen through a two to four day course of oral antibiotics for uncomplicated UTIs.
• Extended treatment may be necessary with recurrent UTI's.
• If a child responds to therapy no repeat cultures are needed, however support of constipation and adequate fluid intake are some methods of treatment.

Renal Calculi

• Prophylactic medications may be perscribed and surgical correction may be required with vesicoureteral reflux.
• A mass of crystals, protein, or stone is the most common cause of urinary tract obstructions in children with stones located unilaterally.
• Prevalence of stones is 8.8 percent with a 30-40% recurrence rate in 10-15 years.
• Risk is influenced by age, race, sex, geographic location, seasonal factors, fluid intake, diet, occupation, and genetic predisposition with kidney stones developing around 50 years of age.
• Kidney stones increase cardiovascular risk.
• Urinary calculi are classified according to the salts that make up the stones with calcium oxalate or phosphate being most common (70-85 percent).
• Struvite is magnesium, ammonium, and phosphate (1 to 5 percent)
• Uric acid is accounted for between 5-10 percent.
• Calculi classification depends on location and size, with staghorn calculi filling the minor major calyces and nonstaghorn filling the ureter.
• Cystine and Xanthene are less common stone elements.
• Salt concentration factors lead to calculi formation requiring salt for formation and supersaturation in fluid.

Renal calculus

• Formation involves precipitation of salts, stone inhibitors, and relates to urine super saturation through saturation of + and - ions forming into a crystal.
• Precipitation influenced by pH resulting in increased alkaline risk of calcium phosphate and acidic increase of uric acid leading to cystine excretion.
• Crystal growth is interrupted when potassium rate citrate, uromodulin, pyrophosphate, and magnesium overwhelm and reduce precipitation
• Stones with the size of less than 5 can spontaneously move by about 50 percent.

Types of Stones

• Calcium creates urolithiasis from the factors of genetic and environmental impacts.
• Those with idiopathic calcium oxalate have stones that form in supersaturated urine from interstitial sites.
• Hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia, alkaline urine with mild renal tubular acidosis and growth deficiency increase stone formation is associated.
• Hyperparathyroidism and bone demineralization increase risk due to hypercalciuria.
• Struvite stones contain magnesium ammonium phosphate causing bacteria branch from alkaline urine with a highest risk in women due to UTIs with staghorn calculus growth coming near pelvicaliceal
• Uric acid results from endogenous purine synthesis and consumption resulting excessive excretion and acidic urine being a primary risk and cause.
• Cystine and xanthene are amino acids that result due to genetic disorders,

Clinical Manifestations

• Pain ranges from moderate to severe, originating in posterior hypochondrium caused by renal pelvis obstruction spreading down the ureter with lower urination resulting from ureter obstruction.
• Pain may be nausea with blood in present.
• History can diagnose underlying contributing factors such as diet or UTIs combined with physical assessment and imaging from labs such as pH and calcium.
• X-rays, ultrasounds, pyelography, CT-scans, and MRIs may be required for imaging.

Treatment

• Manage the pain, promote stone and passage, promote the size of stones already formed and prevent new stones from forming.
• Managing the pain may require increasing fluid intake, adjusting pH like citrate and decreasing substances with a ureteroscopy or laser to help decrease the stones.
• Impaction with infection may require emergency decompression and antibiotics.
• Fluid should be increased 2.5L a day while avoiding soft drinks and limit sodium intake.
• Dextrin intake should maintain a dietary 1000 – 1200 mg a day.
• Common underlying risk factors are generally obstruction such as reflux and stones with most causes being found in women.
• E. coli, proteus, and Pseudomonas are some of the microorganisms associated with acute pyelonephritis often coming after a urethral placement.
• Organisms that split the urea can make an alkaline increasing chances of stone formulation.
• Spread infection along ascending ureters that disseminate into the blood stream with medullary infiltration neutrophils causing inflammation with the most acute symptoms.
• Non specific symptoms present, but diagnosis comes from clinical signs, urine cultures that may include WBC.
• Required blood comes from urinary tract imaging.
• Two to three weeks of anitbiotics and treatment with more followed up cultures and a more surgically made intravenous.

Chronic

• Scarring may result due to other drugs and kidney stones through the obstruction and prevent elimination causing progressive inflammation atrophy and lower concentration.
• Minimal symptoms include progression of renal failure relating to salt conserevation and dehydration.
• Related treatment relieves the obstruction
• Inflamed and fibrosis comes from the interstitial space with minimal early symptoms.
• Defined as inflammation of the most common UTI with acute relating to morphology that shows redness and hemorrhage.

Cystitis

• In acute causes the most common microoganism are E. coli that colonizes and binds from the ureter that is pushed upstream with symptoms shown to increase morbidly.
• Diagnosis has over or equal to 10000.
• Complicated infections in early treatment may require several months long term.
• Unpleasant pain, pressure, discomfort from less than 6 months duration is called interstitial cystitis more typically found in women from their autoimmune causing nerve inflammation that causes bladder inflammation increasing sensitivity through inflammation that affects wall of the bladder.
• APF blockage increases sensation with a lot of urination and sleep deprivation.
• Diagnosis requires physical and exam and urine analysis with no effectiveness in treatment without surgery and Botox may be required.
• Infants often experience vomiting and diarrhea with fever to incontinence may show pain and urinary urgency.
• Goodpasture syndrome is a subtype associated with nephrotic syndrome is and extra capillary pulmonary illness rapidly resulting in bleeding lungs in antibodies from attack.
• Immune cells attack collagen with IgG from capillary basement that effects renal tubulars with a rapidly progressive process affecting younger men Fatigue is experienced quickly that may be from rapid progression through kidneys that result form blood.

Goodpasture syndrome

• Urinalysis will often test high with presence of antibodies with a need on biopsy.
• Treat with plasma with kidney to prevent immune attacks that are quickly progressive with lesions.
• Causes blood loss with low blood cells.

Nephrotic syndrome

• Nephrotic Syndrome causes excretion of 3.5g of protein in the urine when injury and filtrates damage occur.
• Minimal change glomerulonephritis leads to a familial effect from damage through capillary loss.
• Serum album decreases and fat increases through a restrcitions of albumin due to the body's inability to retain and keep with liver losing binding and function with calcium and kidney.
• Treat with restriction from diuretics and spironolactone in the absence of injury protein is damaged through blood as glomeruli increases damage.
• In the urine proteinuria is not as severe due to the damage with endothelial cells often having a related blood loss.
• Rapidly progressive post streptococcis increases progression through a loss blood and cast where protein comes.
• Immunousuppresive are the medical for glomeruli.