Lecture Review: Chapter Three

Overview

• Focus on key facts, particularly bolded and underlined areas.

Kidneys and Homeostasis

• Functions: Maintain homeostasis, regulate fluid volume, electrolytes, acid-base balance.
• Secretions:
  • Renin: Blood pressure regulation.
  • Erythropoietin: Stimulate blood cell production.
  • Calcitriol: Active form of Vitamin D for bone health.

Urine Flow in the Kidney

• Functional Unit: Nephron.
• Pathway:
  • Blood enters via nephron -> glomerulus -> Bowman's capsule -> proximal tubule -> loop of Henle -> distal tubule -> collecting ducts -> exits as urine.
• Reabsorption: Glucose, amino acids, sodium chloride, calcium, bicarbonate.
  • Sodium is crucial for reabsorption.

Renal Failure

• Challenges: Decreased kidney function affects fluid/electrolyte balance and excretion.
• Causes: Often an underlying pathology.
• Goals: Maintain kidney flow for adequate urine output.
• Drug Safety: Monitor nephrotoxic drugs (e.g., NSAIDs, ACE inhibitors).
• Testing: Urinalysis, creatinine, imaging, renal biopsy.
  • GFR: Best marker for renal function.

Types of Renal Failure

• Acute: Find underlying causes (e.g., heart failure, dehydration).
• Chronic: Often from diabetes or chronic hypertension.
• Drugs: Nephrotoxic drugs are high-risk.

Diuretics

• Purpose: Increase urine flow, decrease blood volume.
• Types:
  • Loop Diuretics: Most effective, act on loop of Henle (e.g., Furosemide).
  • Thiazides: Act on distal tubule, treat hypertension (e.g., Hydrochlorothiazide).
  • Potassium-sparing: Spare potassium, prevent excessive loss.
• Patient Education: Monitor potassium levels, dietary advice.

Body Fluid Compartments

• Fluid Exchange: Sodium controls water movement across compartments.
• Osmolality: Water moves from low to high osmolality areas.
• IV Solutions:
  • Hypertonic: High sodium content.
  • Isotonic: No fluid shift.
  • Hypotonic: Water moves to interstitial space.

Fluid Balance Regulation

• Mechanisms: Thirst controlled by osmoreceptors.
• Hormones: Renin-Angiotensin-Aldosterone mechanism and ADH.

Acid-Base Balance

• Balance: Constant adjustment needed, especially with underlying diseases.
• Definitions:
  • Acidosis: pH < 7.35
  • Alkalosis: pH > 7.45
• Causes: Excessive sodium bicarbonate or diuretics.

Hypertension

• Classification: Pre-hypertension, Stage 1 begins at 140/90.
• Factors: Cardiac output, peripheral resistance.
• Drugs:
  • ACE Inhibitors: Block vasoconstriction.
  • Calcium Channel Blockers: Dilate vessels.
• Lifestyle: Diet, alcohol, sodium, activity.

Heart Failure

• Side Effects:
  • Left-sided: Blood backs into lungs.
  • Right-sided: Blood backs into peripheral system.

Shock and Treatments

• Types: Anaphylactic, cardiogenic, hypovolemic, neurogenic, septic.
• Goal: Reperfusion, increase fluid volume.
• Medications:
  • Norepinephrine: Post-fluid resuscitation.
  • Inotropic Drugs: Based on need.

Anemia and Treatment

• Medications:
  • Epoetin Alpha: Stimulate RBC production.
  • Filgrastim: Increase neutrophil production.
  • Feros sulfate: Treat iron deficiency.
• Education: Monitor for side effects, dietary advice.

Anti-platelet and Anticoagulant Drugs

• Examples:
  • Clopidogrel (Plavix): Inhibit platelet action.
  • Heparin: Safe for pregnancy.
• Risks: Monitor for bleeding, dietary considerations.

These notes cover key concepts necessary for understanding the functions and management of the renal system, fluid balance, hypertension, heart failure, shock, and anemia treatments. Please review the highlighted sections for deeper understanding and clarification.