chapter 61 medsurg 1

LEARNING OUTCOMES

• Designed to assist in:

  • Identifying key anatomical components of the renal and urinary systems.

  • Discussing the function of the renal and urinary systems.

  • Describing the procedure for completing a history and physical assessment.

  • Correlating relevant diagnostic examinations with renal and urinary system function.

  • Explaining nursing considerations for diagnostic studies relevant to renal and urinary system function.

  • Discussing changes in renal and urinary system function associated with aging.

KEY CONCEPTS

• Acid-Base Balance: Regulation of hydrogen ions in the blood to maintain pH.

• Caring: Essential in providing effective nursing care.

• Elimination: The process of waste removal from the body, primarily through urine.

• Fluid and Electrolytes: Management of body fluids and essential ions.

• Infection: Importance of preventing infections in the renal and urinary systems.

• Medication: Role of different medications in affecting renal function.

ESSENTIAL TERMS

• Afferent Arterioles: Blood vessels supplying blood to the glomeruli.

• Antidiuretic Hormone (ADH): Hormone regulating water absorption in the kidneys.

• Anuria: Producing less than 100 mL of urine per day.

• Bladder: Organ for storing urine.

• Bowman's Capsule: Surrounds the glomerulus, receiving filtered fluid.

• Bruit: An abnormal sound from blood flow in an artery.

• Collecting Tubule: Final part of nephron where urine is collected.

• Confinement: Ability to control urination.

• Creatinine: Waste product suggesting kidney function.

• Distal Convoluted Tubule (DCT): Kidney tubule involved in ion and fluid reabsorption.

• Dysuria: Painful urination.

• Efferent Arterioles: Blood vessels carrying blood away from the glomeruli.

• Glomerular Filtrate: Liquid filtered through the glomeruli.

• Glomerular Filtration Rate (GFR): Measure of kidney function.

• Glomerulus: Cluster of capillaries in the nephron.

• Kidneys: Organs that filter blood and produce urine.

• Loop of Henle: U-shaped section of the nephron involved in concentration of urine.

• Major Calyces: Larger chambers collecting urine from minor calyces.

• Micturition: The act of urinating.

• Minor Calyx: Small collection cup that receives urine from papillae.

• Nephron: Functional unit of the kidney that filters blood.

• Nocturia: Frequent urination at night.

• Oliguria: Decreased urine output of 100 to 400 mL per day.

• Papillae: Tips of the renal pyramids where urine is released.

• Polyuria: Excessive urine production.

CASE STUDY: EPISODE 1

• Patient: Reginald Jones, 72-year-old Black male.

• Complaints:

  • Recent weight gain.

  • Swelling in hands and feet.

  • Voiding small amounts of urine.

  • Fatigue.

• History:

  • Depression and borderline hypertension, untreated.

  • Last healthcare visit more than 2 years ago.

OVERVIEW OF ANATOMY AND PHYSIOLOGY

• Renal System: Composed of two kidneys.

• Urinary System: Composed of two ureters, bladder, and urethra.

• Functions:

  • Filtering blood to form urine.

  • Storage of urine in the bladder.

  • Passage of urine through ureters and urethra.

Kidney Functions

1. Excretion of Wastes: Removal of metabolic waste products.

2. Regulation of Fluid and Electrolyte Balance: Maintaining proper fluid levels and electrolyte concentrations.

3. Regulation of Acid-Base Balance: Maintaining blood pH.

4. Regulation of Blood Pressure: Involving hormones like renin.

5. Secretion of Erythropoietin: Stimulating RBC production.

6. Activation of Vitamin D: Essential for calcium absorption.

Renal Anatomy

• Kidney Structure:

  • Bean-shaped organs, located retroperitoneally.

  • Held in place by renal fascia.

  • Approximately 4-5 inches long, 2-3 inches wide.

  • Surrounded by renal capsule for protection.

Renal Circulation

• Blood Supply:

  • Receive 20-25% of cardiac output (1,200 mL/min).

  • Blood enters through renal artery, branches into segmental and interlobar arteries.

  • Afferent arterioles lead blood into glomeruli.

Microscopic Anatomy

• Nephrons:

  • 800,000 to 1.2 million in each kidney.

  • Two types: Cortical (80%) and Juxtamedullary (20%).

  • Components include glomerulus, Bowman's capsule, tubular system.

Renal Physiology

Urine Formation Processes:

1. Filtration: Blood filtering across glomeruli.

2. Reabsorption: Movement of water and solutes back into the blood.

3. Secretion: Movement of substances from blood into urine.

4. Concentration: Ensuring urine has the desired osmolarity.

Glomerular Filtration Rate (GFR)

• Normally 125 mL/min; indicative of kidney health.

Regulatory Functions

Water Balance

• Kidneys manage water levels to maintain homeostasis.

Diagnostic Studies

Blood Tests

• Common tests include serum creatinine, BUN, electrolytes.

Urine Tests

• Includes urinalysis, culture and sensitivity.

Nursing Implications

• Educate patients about tests, monitor results, and interpret abnormalities.

Age-Related Changes

• Decreased kidney size and nephron function, increased risk of UTIs, urinary incontinence, and issues related to the prostate gland in males.

LEARNING OUTCOMES

Designed to assist in:

• Identifying key anatomical components of the renal and urinary systems including the kidneys, ureters, bladder, and urethra, as well as their respective roles in urination and waste elimination.

• Discussing the multifaceted functions of the renal and urinary systems which include waste filtration, fluid regulation, electrolyte balance, and acid-base homeostasis.

• Describing the comprehensive procedure for completing a thorough history and physical assessment, focusing on patient interviews, physical examination techniques, and identifying pertinent medical histories.

• Correlating relevant diagnostic examinations such as blood tests, urine tests, and imaging studies with renal and urinary system function.

• Explaining nursing considerations for implementing and monitoring diagnostic studies relevant to renal and urinary system function, including patient preparation and post-test care.

• Discussing changes in renal and urinary system function associated with aging and how these changes impact overall health and nursing care planning.

KEY CONCEPTS

• Acid-Base Balance: Regulation of hydrogen ions in the blood to maintain pH within a narrow range, crucial for normal cellular functions.

• Caring: An essential component of effective nursing practice that fosters a healing environment and supports patients' emotional well-being.

• Elimination: The vital biological process of removing waste products from the body primarily through urine, which also serves as a marker for kidney and overall health.

• Fluid and Electrolytes: The management of body fluids and essential ions to ensure optimal physiological function and homeostasis.

• Infection: Understanding the importance of preventing infections, especially urinary tract infections (UTIs), in the renal and urinary systems to protect kidney function and overall health.

• Medication: Recognizing the role of various medications in affecting renal function, including nephrotoxic drugs that may compromise kidney health.

ESSENTIAL TERMS

• Afferent Arterioles: Blood vessels supplying blood to the glomeruli, crucial for maintaining glomerular filtration.

• Antidiuretic Hormone (ADH): Hormone primarily produced in the pituitary gland that regulates water absorption in the kidneys; its dysfunction can lead to disorders such as diabetes insipidus.

• Anuria: A clinical condition characterized by producing less than 100 mL of urine per day, often indicating severe underlying kidney dysfunction.

• Bladder: A hollow muscular organ that stores urine until it is excreted through the urethra, with a normal capacity of approximately 400-600 mL.

• Bowman's Capsule: A double-walled structure encasing the glomerulus that plays a critical role in the filtration process by collecting the filtrate from blood plasma.

• Bruit: An abnormal sound heard during auscultation due to turbulent blood flow in an artery, often indicative of vascular abnormalities.

• Collecting Tubule: The final section of the nephron where urine is concentrated and transported to the renal pelvis.

• Confinement: Refers to the ability to control urination, which can be affected by neurological and physiological factors.

• Creatinine: A chemical waste product produced by muscle metabolism, commonly used as a marker of kidney function; elevated levels may indicate impaired filtration.

• Distal Convoluted Tubule (DCT): A section of the nephron involved in the further reabsorption of ions and water, crucial for maintaining electrolyte balance.

• Dysuria: A symptom characterized by painful urination that often suggests infection or inflammation in the urinary tract.

• Efferent Arterioles: Blood vessels carrying blood away from the glomeruli, crucial in regulating filtration pressure in the kidneys.

• Glomerular Filtrate: The liquid that has passed through the glomerular membrane, containing water, ions, various solutes, and waste products.

• Glomerular Filtration Rate (GFR): The rate at which blood is filtered in the glomeruli, a key indicator of overall kidney health; normal GFR is typically around 125 mL/min.

• Glomerulus: A network of capillaries within the nephron where blood filtration begins, playing a central role in urine formation.

• Kidneys: Paired organs located retroperitoneally that filter blood, removing toxins and excess substances to produce urine.

• Loop of Henle: U-shaped section of the nephron involved in the concentration of urine by reabsorbing water and sodium ions.

• Major Calyces: Larger chambers that collect urine from the minor calyces; they funnel urine into the renal pelvis.

• Micturition: The physiological act of urination, involving complex neural and muscular activity.

• Minor Calyx: Small cup-like structure that receives urine from the papillae of the renal pyramids.

• Nephron: The functional unit of the kidney, responsible for the filtration of blood and formation of urine; each kidney contains approximately 800,000 to 1.2 million nephrons.

• Nocturia: A condition characterized by frequent urination during the night, which may disrupt sleep and indicate underlying health issues.

• Oliguria: A reduced urine output of 100 to 400 mL per day, suggesting potential renal impairment.

• Papillae: The tips of the renal pyramids where urine passes into the minor calyces for collection.

• Polyuria: The production of excessive urine, often indicative of uncontrolled diabetes or other endocrine disorders.

CASE STUDY: EPISODE 1

Patient: Reginald Jones, 72-year-old Black male.Complaints:

• Recent weight gain apparent in the abdomen and extremities.

• Noticeable swelling in hands and feet, possibly indicating fluid retention.

• Voiding small amounts of urine, suggesting potential oliguria.

• Persistent fatigue possibly linked to kidney dysfunction or related metabolic issues.History:

• Previous medical history includes depression and borderline hypertension, untreated, which may complicate his renal status.

• Last healthcare visit over 2 years ago, indicating a lack of regular health maintenance and follow-up.

OVERVIEW OF ANATOMY AND PHYSIOLOGY

Renal System:

Composed of two kidneys, which play a crucial role in maintaining homeostasis by filtering blood to remove waste products and excess substances.

Urinary System:

Includes two ureters, a bladder, and urethra, providing a pathway for waste excretion.

Functions:

• Filtering blood to form urine, thereby removing metabolic by-products.

• Storage of urine in the bladder until elimination.

• Passage of urine through ureters and out of the body via the urethra.

Kidney Functions

• Excretion of Wastes: Critical for preventing the accumulation of toxic substances in the blood.

• Regulation of Fluid and Electrolyte Balance: Involves adjusting sodium, potassium, and water levels to support cardiovascular health.

• Regulation of Acid-Base Balance: Provides mechanisms for maintaining blood pH within a narrow range, vital for physiological functions.

• Regulation of Blood Pressure: Through the secretion of hormones like renin, influencing fluid balance and vascular resistance.

• Secretion of Erythropoietin: Stimulates the bone marrow to produce red blood cells in response to hypoxia or anemia.

• Activation of Vitamin D: Required for calcium and phosphate absorption, essential for maintaining bone health.

Renal Anatomy

Kidney Structure:

• Shape and Location: Bean-shaped organs located retroperitoneally, meaning they are positioned behind the peritoneal cavity.

• Size: Approximately 4-5 inches long and 2-3 inches wide, with variations based on age and individual physiology.

• Support and Protection: Held in place by renal fascia and surrounded by a renal capsule that provides cushioning.

Renal Circulation

Blood Supply:

• Perfusion: Kidneys receive 20-25% of cardiac output (approximately 1,200 mL/min), vital for effective filtration.

• Blood Pathway: Blood enters through the renal artery, which branches into segmental and interlobar arteries before reaching the afferent arterioles leading into glomeruli.

Microscopic Anatomy

Nephrons:

• Quantity: Each kidney contains between 800,000 to 1.2 million nephrons, which are the functional units of the kidney.

• Types of Nephrons: Two types are present—cortical nephrons (80%) that are located primarily in the renal cortex and juxtamedullary nephrons (20%) that extend into the medulla.

• Components: Each nephron includes a glomerulus, Bowman's capsule, and a tubular system, harmoniously working together for filtration and absorption.

Renal Physiology

Urine Formation Processes:

• Filtration: The first step occurs in the glomeruli, where blood plasma is filtered to form the glomerular filtrate.

• Reabsorption: Water and essential solutes are selectively reabsorbed back into the bloodstream to maintain homeostasis.

• Secretion: Harmful substances are moved from the blood back into the tubular fluid (urine) for elimination.

• Concentration: Adjusting water and solute reabsorption to ensure urine has the desired osmolarity and is appropriately concentrated.

Glomerular Filtration Rate (GFR)

• Indicator of Kidney Health: Normatively at 125 mL/min, with lower rates suggesting impaired kidney function, necessitating clinical evaluation.

Regulatory Functions

Water Balance

• The kidneys are essential for managing water levels to ensure homeostasis, adjusting reabsorption based on hydration status and hormonal control.

Diagnostic Studies

Blood Tests

• Common diagnostic tests include serum creatinine, blood urea nitrogen (BUN), and electrolyte levels, critical for assessing renal function and metabolism.

Urine Tests

• Including urinalysis and culture and sensitivity tests, these help diagnose infections, assess kidney health, and monitor metabolic disorders.

Nursing Implications

• It is critical to educate patients about the purpose of diagnostic tests, monitor results attentively, and interpret abnormalities in the context of their overall health.

Age-Related Changes

• Acknowledge decreased kidney size and nephron function with aging, increased susceptibility to urinary tract infections, urinary incontinence, and prostate-related issues in males, necessitating tailored nursing care plans for older adults.