Med Trauma Week 1 practice quiz

Pathophysiology Overview

• Pathophysiology examines how diseases and injuries alter bodily functions.
• Pathology involves studying cell and tissue changes due to disease.
• Physiology focuses on normal biological functions of living organisms.
• Essential for healthcare practitioners, particularly in pre-hospital settings.

Human Biology Fundamentals

• The human body consists of organ systems, with cells being the basic unit.
• Four tissue types:
  • Connective: Supports and binds tissues (e.g., bone, blood).
  • Epithelial: Covers/lines organs (e.g., skin, respiratory/GI tracts).
  • Muscle: Comprises skeletal, smooth, and cardiac tissues.
  • Nervous: Facilitates signal transmission to/from body parts.
• Cellular respiration converts glucose and oxygen into ATP, yielding CO2 and water.

Homeostasis

• Homeostasis is the stable internal environment necessary for health.
• Disease arises when homeostasis cannot be maintained.
• Paramedics must identify changes in homeostasis, administer rapid treatments, and ensure appropriate transport.

Fluid & Electrolyte Regulation

• Body fluids account for 60% of adult total body weight:
  • Intracellular Fluid (ICF): 66% of body water.
  • Extracellular Fluid (ECF): 33%; includes Intravenous Fluid (IVF) and Interstitial Fluid (ISF).
• Electrolytes maintain electrical gradients for nerve and muscle function.

Fluid Movement Mechanisms

• Cell membranes are semi-permeable; they allow certain substances to pass (e.g., water) while restricting others (e.g., hormones).
• Diffusion: Movement of molecules from high to low concentration without energy.
• Osmosis: Specifically refers to water diffusion.
• Facilitated diffusion: Passive transport needing transmembrane proteins (e.g., glucose entry).
• Active transport: Energy-dependent movement (e.g., Na/K pump).

Tonicity of Solutions

• Isotonic: No net water movement; cell volume remains the same.
• Hypertonic: Net water movement out of the cell leads to cell shrinkage.
• Hypotonic: Net water movement into the cell results in cell swelling.
• Ontario paramedics use isotonic fluids (e.g., Normal Saline) for treatment.

Role of the Kidneys & Hormones

• Antidiuretic hormone (ADH): Released when water volume is low; stimulates water retention in kidneys.
• Renin-Angiotensin-Aldosterone System (RAAS): Regulates blood pressure and fluid balance through vasoconstriction and sodium reabsorption.
• Atrial Natriuretic Hormone (ANH): Released when blood volume is high; reduces sodium reabsorption and opposes ADH/RAAS.

Dehydration

• Defined as a reduction in total body water volume, primarily affecting ECF first.
• Causes cellular dehydration due to osmotic gradients between ECF and ICF.
• Homeostasis management systems include thirst mechanism, ADH release, RAAS activation, and sympathetic nervous system response.

Assessment of Dehydration

• Identify causes such as heat stroke, physical exhaustion, and gastrointestinal losses.
• Assess clinical manifestations: level of awareness, skin turgor, heart rate, respiratory rate.
• Utilize tools like Glasgow Coma Scale (GCS) to evaluate consciousness levels.

Clinical Manifestations of Fluid Regulation

• Fluid overload can lead to edema in different areas: ascites, peripheral and pulmonary edema.
• Dehydration manifests as decreased skin turgor, thirst, lethargy, and increased vital signs (HR, RR, BP).

Consequences of Dehydration

• Electrolyte imbalances arise, affecting sodium and potassium levels.
• Hypernatremia and hypokalemia can disrupt Na/K pump function, impacting nerve/muscle signals.
• Severe dehydration leads to cellular inefficiencies and potential shock states due to hypoperfusion.
• Acidosis may occur from inadequate oxygen delivery and increased lactic acid production.

Environmental Emergencies

• Address exposure to temperature extremes, leading to conditions like heat exhaustion (temperature ≥40°C).
• Actively cool patients using wet sheets or cold packs for heat stroke.

Pre-Hospital Management of Dehydration

• Ensure patent airways and adequate oxygenation; prepare for potential seizures.
• Administer IV isotonic fluids (e.g., normal saline) for hydration.
• Rapidly transport patients from inhospitable environments, removing excess clothing and providing active cooling.