Presentation on theme: "Chapter 25 Disorders of Renal Function"— Presentation transcript:
1 Chapter 25 Disorders of Renal Function Essentials of Pathophysiology Chapter 25 Disorders of Renal Function
2 Pre lecture quiz true/false The kidneys do not begin to develop until the 12th week of gestation and start to function approximately 6 weeks later.There is just a single theory that applies to kidney stone formation.Most uncomplicated urinary tract infections (UTIs) are caused by Escherichia coli.Upper urinary tract infections differ from those of lower urinary tract infections in that they incite an acute inflammatory response with marked systemic manifestations of infection.Catheter-associated bacteriuria remains the most frequent cause of gram-negative septicemia in hospitalized patients.FT
3 Pre lecture quizAutosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder that primarily affects the kidneys, resulting in the formation of fluid-filled __________ in both kidneys with the threat of progression to chronic renal failure.____________ refers to urine-filled dilatation of the renal pelvis and calices associated with progressive atrophy of the kidney due to obstruction of the outflow of urine.Most kidney stones are composed of __________.Nephrotic syndrome is associated with increased glomerular permeability to the plasma __________, resulting in generalized edema.The __________ phenomenon, the process by which the urine released from the bladder washes out the bacteria out of the urethra, aids in maintaining the sterility of the urine formed in the kidneys and found in the bladder.calciumHydronephrosisproteinsacswashout
4 Cystic and Obstructive Disorders Cystic disease of the kidneySimple and acquired renal cystsMedullary cystic diseaseAutosomal dominant polycystic kidney diseaseObstructive disordersHydronephrosisRenal calculi
5 Consequences of Dilation of Renal Tubules or Tract Expansion of the kidney with urine (hydronephrosis)Increased pressure inside the renal capsuleCompartment syndrome compresses blood vessels inside kidneyRenal ischemiaStasis of urineRisk of infectionStones
7 QuestionTell whether the following statement is true or false. Hydronephrosis is categorized as a disorder of glomerular function.
8 AnswerFalse Rationale: Hydronephrosis is caused by a urinary obstruction, so it is considered an obstructive disorder. The glomerulus is not involved.
9 Renal CalculiSaturation theory: urine is supersaturated with stone componentsMatrix theory: organic materials act as a nidus for stone formationInhibitor theory: a deficiency of substances that inhibit stone formationFour types of kidney stones:Calcium stones (i.e., oxalate or phosphate)Magnesium ammonium phosphate stonesUric acid stonesCystine stones
11 Urinary Tract Infections Bacteria usually enter through the urethraHost defenses include:Washout phenomenonProtective mucusLocal immune responses and IgANormal bacterial flora
12 Scenario: Mr. K is paraplegic. When in the hospital, he had a catheter Now he has a high fever and complains of joint and back painHe has pyuria and reports urgencyBUN is 78 mg/dL (Normal 8-20 mg/dL)PCR is 4.7 mg/dL (Normal mg/dL)Question:What complication are you most worried about? Why?
13 QuestionTell whether the following statement is true or false: Urinary tract infections (UTIs) are usually caused by a virus.
14 AnswerFalse Rationale: UTIs are most often caused by bacteria that enter through the urethra (most common) or the bloodstream.
15 Structure of the Glomerulus Glomerular capillaries and Bowman’s capsule are both made of epithelial cells sitting on a basement membraneThey are so tightly attached to each other that they share one basement membraneThe epithelial cells of Bowman’s capsule stand up from the basement membrane on foot processes, leaving pores between the feet for filtrationUrineEpithelial cellFoot processesBasement membraneBlood in capillary
16 Immune Damage to the Glomerulus Antibodies to glomerular proteinsCirculating immune complexes lodge in glomerulus
17 Glomerular Damage Proliferative: number of cells increase Sclerotic: amount of extracellular matrix increasesMembranous: thickness of glomerular capillary wall increasesAll can decrease the efficiency of filtrationAllow blood cells, lipids, or proteins to pass into the urine
18 Disorders of Glomerular Function Nephritic syndromesProliferative inflammatory responseNephrotic syndromeIncreased permeability of glomerulusMixed nephritic and nephrotic responsesChronic glomerulonephritisGlomerular lesions associated with systemic disease
19 Proliferative inflammatory response Nephritic SyndromesProliferative inflammatory responseRAA pathway activated; hypertensionInflammatory process damages the capillary wallRed blood cells escape into the urineHematuria with red cell castsHemodynamic changes decrease the GFRAzotemia (presence of nitrogenous wastes in the blood), oliguria
20 Nephrotic Syndrome Other proteins lost in urine: Immunoglobulins and complement immune suppressionClotting and anticlotting proteins thrombosisProteins that carry other blood components imbalances in blood components; altered drug dosages
21 QuestionTell whether the following statement is true or false: Nephritic syndromes are characterized by blood in the urine.
22 AnswerTrue Nephritic syndromes decrease the permeability of the glomerular capillary membrane, which results in hematuria, HTN, oliguria, and ↓ GFR.
23 Scenario: She has severe edema and frothy, cola-colored urine A woman has diabetes mellitusShe has severe edema and frothy, cola-colored urineShe has difficulty breathing, with crackles in both lungsShe just finished a course of antibiotics for strep throatShe is also taking corticosteroids for lupus-related arthritisQuestion:What are three reasons for her renal problems?
24 Scenario (cont.)A woman has diabetes mellitus and lupus and recently had strep throat.She has severe edema and frothy, cola-colored urineQuestion:The doctor says the only way to determine what has caused her glomerular disease is a renal biopsy. Why?
25 Scenario (cont.) Urinalysis show that she is producing: Urine with 500 mg protein/ dayContains blood and RBC castsHigh level of K+Blood tests show:HypoalbuminemiaSlightly decreased K+She has borderline hypertensionQuestion:Does she have nephritic syndrome or nephrotic syndrome?