Exam 3 patho: Renal Disorders

Kidney function

filter and reabsorbs → maintain pH and fluid balance

Kidney Structure – Nephron

• Glomerulus

• Proximal convoluted tubule

• Loop of Henle

• Distil convoluted tubule

• Collecting tubule

Maintenance via…

Lab tests to assess renal function

• BUN

• Creatinine

• BUN/Cr ratio

• GFR

• Urinalysis

BUN test and high vs low BUN

A blood test that measures the amount of urea nitrogen in the blood

• Urea nitrogen is a waste product produced when your liver breaks down protein

• High BUN: May indicate kidney problems, dehydration, or a high-protein die

• Low BUN: May be due to liver damage, malnutrition, or overhydration

Purpose of creatinine test

Creatinine is a product of muscle metabolism, and higher levels in the blood indicates that the kidneys are not functioning well bc they are not filtering out the creatinine

• True indicator of kidney function

GFR (Glomerular Filtration Rate)

the volume of blood filtered by the kidneys per minute, indicating their ability to remove waste products

Urinalysis

Measures:

• Specific gravity

• Casts

• Presence of proteins

Specific Gravity of Urine

measure of the concentration of dissolved particles in urine, reflecting the kidney's ability to concentrate or dilute urine

• Higher SG indicates more particles in the urine, signaling that someone has kidney disease

Age related changes due to renal cells not working as efficiently

• Decreased GFR

• Tubular transport under stress less efficient

• Drug elimination decreases —> toxic reactions

• Renal activation of Vit. D

Causes of Glomerular Disease

• Immunologic

• Non immunologic

• Hereditary mechanisms

Immunologic conditions that cause Glomerular Disease (2)

• Post Streptococcal Glomerulonephritis

• Systemic Lupus Erythematous Glomerulonephritis

Nonimmunologic conditions that cause Glomerular Disease

• Diabetes

• Hypertension

• Drug/Chemical Toxicity

Hereditary condition that causes Glomerular Disease

Alport Syndrome

• type of progressive kidney disease

What is the result of glomerulus disease?

Ineffective filtering

What is the most common side effect of glomerular disease that helps with diagnosis?

• Oliguria

3 types of glomerular damage

• Proliferative

• Sclerotic

• Membranous

Proliferative glomerular damage

Number of cells increase

• Describes the hypercellular inflammatory process involving infiltrating leukocytes or WBCs & proliferation of glomerular cells

Sclerotic glomerular damage

Increaed amount of extracellular material

Membranous glomerular damage

Increase in thickness of glomerular capillary

• abnormal thickening of the glomerular basement membrane

Systemic disease glom disease (4)

• Systemic Lupus Erythematosus Glomerulonephritis

  • Long term

• Hypertensive Glomerular Disease

  • Makes filtration difficult

  • Less BF to glomerulus —> decrease in GMR —> not enough BF to cells —> cells atrophy

• Sclerotic changes to renal arterioles & small arteries

• Diabetic Glomerulonephritis

Diabetic Glomerulosclerosis

• Lots of buildup and thickening of the meninges matrix, which affect filtration. This reduces the SA of filtration, leading to decreased filtration

• high glucose in BS? will cause sugars to be pulled into the BS

  • Pores open up, allowing albumin to leak out into the urine filtrate — protein in urine

  • The nephron will try to pull back the albumin, which puts a lot strain on the kidneys

  • End up with microalbuminuria

Microalbuminuria Disease

a condition characterized by the presence of small amounts of albumin in the urine

• a key indicator of early diabetic nephropathy

Acute infection of glomerulonephritis — Group A beta hemolytic streptococci

an immune-mediated inflammatory response triggered by a streptococcal infection

• Antigen-Antibody are now in the kidneys and causes the kidneys to inflame

Symptoms of Acute Post Infectious Glomerulonephritis

• Inflammation = decreased BF —> causes decreased GFR

• Can lead to scarring

• Capillary permeability will increase

  • Allows for RBCs to leak out into the urine — dark urine

• Other proteins leak out of kidney into urine

• Na+ and H2O retention that is not being filtered

‣ Swelling as a result

• Isotemia

Isotemia

medical condition characterized by abnormally high levels of nitrogen-containing compounds, like urea and creatinine, in the blood

• Increase BUN and creatinine bc it’s not filtered out

What is Acute Pyelonephritis and why does it occur?

• Bacterial infection of kidney parenchyma and renal pelvis

• Occurs after a UTI

  • The infection went up the ureters into the kidney

Risk factors for acute pyelonephritis

• Anything that can lead to a UTI, such as:

  • Pregnant women

  • Inserting anything in body (e.g. catheter)

  • Obstruction of outflow of urine

    • When urine sits it will collect more organisms and cause infection

Symptoms of acute pyelonephritis

• Kidney inflammation

• Fever

• Chills

Acute pyelonephritis can lead to _____ of the kidneys, eventually leading to…

• Scarring of the kidneys because it is acute

• Can lead to chronic pyelonephritis

Chronic Pyelonephritis

Persistent/recurring infection and scarring

• chronic obstruction prevents elimination of bacteria

Chronic obstruction (pyelonephritis) leads to… (3 steps)

1. Progressive inflammation and fibrosis of interstitial spaces btwn tubules

2. Tubule destruction

3. Leads to impaired ability to concentrate urine —> may develop CKD

What can occur because of tubule scarring?

• Acid-base balance is off

• Impairs ability to filter blood

• Polyuria

  • Can lead to hyperkalemia

Drug related nephropathies — substances can damage kidneys by…(4)

• Decreasing blood flow

• Obstructing urine flow

• Direct damage to tubulointerstitial structures

• Illicit drug abuse

When administering drugs to someone with nephropathies, you must be mindful of… (3)

• Age

• Existing renal function

• Hydration

Symptoms of obstructive kidney disorders

• Recurrent UTI

• Pain

• Urine output

  • oliguria, polyuria, nocturia

Most common cause of OKD

Nephrothilitis or kidney stones

Supersaturation of salt in urine results in:

Crystalize to form large crystals

High or low pH can cause…

Kidney stones

• obstruct the urethra and they cannot pee

Types of kidney stones

• Calcium

• Struvite

• Uric acid

• Cystine

Calcium kidney stone

• Most common

Renal calculi (kidney stones) cascade of events (formation is not definite)

1. Supersaturation of one or more salts in urine

2. Precipitation of salts from liquid to solid state

3. Growth through crystallization or aggregation

Calcium stones

Large amounts in BS will filter out and end up in urine and create stones

Struvite stones — “staghorn” stones

• Cause: bacteria (urease enzyme)

  • Produce ammonia ions

  • Increase phosphate levels in urine

• Produces large stones

Uric acid stones

Cystine stones

Due to a genetic disorder

• Childhood kidney stones

Clinical manifestations of kidney stones

• Severe pain

• Nausea/vomiting

• Hematuria can occur

kidney stones pain renal colic and non-renal colic

• Renal colic: stabbing pain

• Non-colicky: dull pain but still very painful

Treatments for kidney stones

• Pain relief

• Stones pass spontaneously

• Large stones and struvite stones require lithrotripsy or surgery