4.3 Renal Diseases Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What percentage of adults aged 20 or greater in the US have chronic kidney disease?

Less than 5%

More than 10% (correct)

Approximately 5%

Approximately 20%

Which of the following is NOT a typical presenting symptom of early kidney disease?

Proteinuria

Hematuria

Asymptomatic state

Pain (correct)

Besides blood filtration, what other crucial function do kidneys perform?

Regulation of body temperature

Metabolism and excretion of compounds (correct)

Synthesis of digestive enzymes

Production of red blood cells

How do the kidneys contribute to overall bodily homeostasis?

By maintaining fluid, acid-base, and electrolyte balances (A) Signup and view all the answers

What is a common characteristic of nephrotic disorders relating to immune complexes?

Immune complex deposition is often found at or under epithelial cells. (D) Signup and view all the answers

Why is the renal medulla particularly susceptible to ischemic injury?

It is a low oxygen environment. (C) Signup and view all the answers

What is the initial filter of blood entering the kidney, and a prominent site for injury?

Glomerulus (A) Signup and view all the answers

What does the failure to adequately excrete urea manifest as, within the blood?

Progressive elevation of blood urea nitrogen (BUN) and serum creatinine (D) Signup and view all the answers

What is a common recommendation for sodium intake in patients with chronic kidney disease?

Limit intake to two grams a day or less (A) Signup and view all the answers

What is the most widely accepted definition of acute kidney injury based on serum creatinine levels?

A rise in serum creatinine of 0.3 mg/dL or more within 48 hours. (D) Signup and view all the answers

What is a potential life-threatening complication associated with advanced renal impairment?

Hyperkalemia (C) Signup and view all the answers

Which of the following is NOT typically a consequence of excessive sodium in the body?

Hypotension. (B) Signup and view all the answers

What is the primary cause of anemia in patients with chronic kidney disease?

Decreased production of erythropoietin (B) Signup and view all the answers

What does filtration across a glomerulus depend on?

The hydrostatic and oncotic pressures in the glomerular capillary and surrounding tubular lumen. (A) Signup and view all the answers

Which of the following characterizes acute glomerulonephritis?

Abrupt onset of hematuria and proteinuria with a reduced GFR (A) Signup and view all the answers

Which of the following best describes the pre-renal factor contributing to acute kidney injury in sepsis?

Renal hypoperfusion due to hypotension and low systemic vascular resistance. (B) Signup and view all the answers

What is a common consequence of acute tubular necrosis (ATN), regarding the cells of the renal tubules?

Sloughing of epithelial cells that make up the renal tubule. (A) Signup and view all the answers

What is a key characteristic of nephrotic syndrome?

Marked proteinuria, particularly albuminuria (A) Signup and view all the answers

What is one consequence of chronic kidney disease that contributes to further nephron destruction?

Increased glomerular filtration and hyperfiltration in remaining nephrons. (C) Signup and view all the answers

A patient with nephrotic syndrome may develop signs of intravascular volume depletion despite visible edema. Why?

Loss of proteins in the urine leading to decreased plasma oncotic pressure (B) Signup and view all the answers

Which of the following best describes the vascular theory behind acute tubular necrosis?

Decreased renal perfusion pressure from afferent arterial constriction and efferent arterial vasodilation. (C) Signup and view all the answers

Which electrolyte imbalance contributes to metabolic acidosis in chronic kidney disease?

Diminished capacity to excrete acid and generate base (A) Signup and view all the answers

Which of the following can be categorized as an intra-renal cause of acute kidney injury?

Rhabdomyolysis. (B) Signup and view all the answers

What percentage of renal stones contain calcium?

75% (A) Signup and view all the answers

What is the role of cytokines in the context of acute kidney injury due to sepsis?

They contribute to intrarenal inflammation, sclerosis and obstruction. (C) Signup and view all the answers

What is the typical cause of pain associated with renal stones?

Distention of the renal pelvis or renal capsule, caused by the stone obstructing the flow of urine (B) Signup and view all the answers

What are the early symptoms of kidney injury primarily related to?

Loss of the ability to excrete water, salt, and waste. (B) Signup and view all the answers

Which of the following laboratory abnormalities is manifested as a result of abnormal hemostasis in chronic kidney disease?

Prolonged bleeding time (B) Signup and view all the answers

What is a major consequence of retained nitrogenous products of protein metabolism in kidney disease?

Increased levels of nitrogen waste in the blood. (C) Signup and view all the answers

Which electrolyte is most commonly affected when the glomerular filtration rate (GFR) falls below 20ml/minute?

Metabolic acidosis (B) Signup and view all the answers

Which of the following is NOT a typical sign or symptom of chronic kidney disease?

Increased urine output (B) Signup and view all the answers

What does a patient with chronic kidney disease risk due to their reduced kidney function?

Increased risk of superimposed acute kidney injury (A) Signup and view all the answers

The diminished absorption of which electrolyte from the gut is a key factor in disorders of phosphate, calcium, and bone metabolism in chronic kidney disease?

Calcium (A) Signup and view all the answers

What describes how endogenous peptides contribute to kidney damage, as presented in the text?

They cause constriction of an already ischemic renal medulla, exacerbating the degree of hypoxic injury (C) Signup and view all the answers

What is the key factor determining intra capillary hydrostatic pressure?

The blood flow into and out of the glomerular capillary (C) Signup and view all the answers

How does decreased renal perfusion contribute to hypertension in chronic kidney disease?

By increasing renin production (C) Signup and view all the answers

Which of the following is a consequence of the kidneys' excretory failure related to electrolyte imbalances?

Increased intracellular sodium and water and decreased intracellular potassium. (B) Signup and view all the answers

What is the typical timeframe for chronic glomerulonephritis progresses to end-stage renal disease in some patients?

Up to 20 years after the initial discovery (B) Signup and view all the answers

Study Notes

Renal Diseases

Prevalence: Over 10% of adults aged 20+ in the US have chronic kidney disease, with many experiencing acute kidney injury. Treatable forms exist to slow disease progression.
Etiology: Common causes include diabetes, hypertension, and autoimmune disorders (like lupus).
Presentation: Typically asymptomatic until advanced failure, as kidneys lack pain receptors. Pain may occur if the ureter or renal capsule is involved.
Kidney Function: Kidneys filter blood, metabolize substances, excrete waste, regulate fluid/electrolyte balance, and maintain homeostasis.

Types of Renal Disease

Categorization: Classified by site of lesion (e.g., tubular interstitial disease), factors leading to the disease (e.g., infectious or toxic glomerular diseases), or clinical presentation (e.g., proteinuria, hematuria).
Nephrotic Disorders: Often present with immune complex deposition under epithelial cells, affecting foot processes, basement membranes, and potentially causing structural changes.
Kidney Regions Affected: The glomerulus (initial filter), renal medulla (low oxygen environment), & overall hemodynamics (blood flow) are key areas susceptible to injury.

Acute Kidney Injury (AKI)

Definition: Rapid deterioration of renal function, characterized by nitrogen waste accumulation (e.g., elevated blood urea nitrogen, serum creatinine), and/or decreased urine output (<0.5 mL/kg/hour for 6+ hours).
Causes (Pre-renal, Intra-renal, Post-renal): Various, including blood flow issues (hypoperfusion, hypotension), inflammatory diseases, toxic effects (amino glycosides, antibiotics, rhabdomyolysis), and urinary tract obstructions (intrinsic or extrinsic). Sepsis is a prominent cause with both pre and intra renal components.
Pathophysiology: Deterioration affects filtration, leading to toxin buildup and electrolyte imbalances (sodium, potassium).
Consequences: Volume/fluid imbalances (edema, hypertension, heart failure), electrolyte/acid-base disturbances, and potential life-threatening complications arise from the build-up of toxins.

Chronic Kidney Disease (CKD)

Etiology: Primarily caused by diabetes and hypertension, leading to nephron loss and irreversible damage. This causes an elevated burden on remaining nephrons, contributing to further damage.
Progression: Irreversible loss of nephrons, elevated glomerular filtration rates, hyperfiltration in remaining nephrons, and resulting hypertension, fibrosis, and scarring accelerate nephron destruction.
Clinical Effects: Waste products (e.g., nitrogen) build-up, hormonal imbalances, fluid/electrolyte imbalances (sodium, potassium, acid/base), cardiovascular complications, bone disorders (calcium, phosphorus), anemia, and impaired blood clotting (hemostasis).

CKD Specific Imbalances

Sodium & Water: Moderate retention typically occurs without obvious signs but excessive sodium intake worsens fluid retention, contributing to heart failure, hypertension. Restrict sodium intake (≤2 grams/day).
Potassium (Hyperkalemia): Potentially life-threatening complication, initially compensated through mechanisms that can be impaired by drugs, leading to dangerous imbalances.
Acid-Base (Metabolic Acidosis): Decreased capacity to excrete acid, leading to an imbalance. Treatable with sodium bicarbonate, but patients are susceptible to severe acidosis; (diarrhea, ketoacidosis).
Bone Metabolism: Diminished calcium absorption, increased parathyroid hormone, and vitamin D metabolism issues alongside phosphorus retention and acidosis cause bone reabsorption.
Cardiovascular Issues: Hypertension commonly occurs due to salt/fluid overload, leading to an increased incidence of cardiovascular disease, and is the leading cause of death for CKD patients.

Glomerulonephritis

Types: Acute (sudden hematuria/proteinuria, reduced GFR, often associated with infections, e.g., Group A streptococci), chronic (persistent abnormalities, gradual decline in renal function, and eventual ESRD), and nephrotic syndrome (significant proteinuria, edema).
Pathophysiology: Immune-related damage to glomeruli, varying in extent and cause, with potential genetic predisposition and environmental triggers. Antibodies and microscopic examinations assist in classification.
Consequences: Leakage of blood cells and proteins, fluid/salt retention leading to edema, hypertension and hypoalbuminemia.

Renal Stones

Presentation: Flank pain that may radiate, microscopic or macroscopic hematuria (blood in urine); possible obstruction, decreased/absent urine production.
Composition: Primarily calcium. Causes include idiopathic hypercalciuria (high calcium in urine).
Contributing Factors: Dehydration, high protein/sodium diets.
Complications: Obstruction complications include hydro-nephrosis, and possible permanent renal damage, infection or abscess, repeated stones contributing to hypertension due to obstructed kidney.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores various aspects of renal diseases, including their prevalence, etiology, and classification. It covers the function of kidneys and highlights critical types of renal disorders along with their symptoms and causes. Test your knowledge on how kidney diseases are categorized and their implications for health.