Perfect 🙌 let’s restart at the beginning and rebuild in the why / when / how style. I’ll do Slides 1–3 as
one chunk so you can see the flow.
Slides 1–3: Water Content, Fluid Compartments, Electrolytes
Slide 1 – Water Content of the Body
Core Concept (What)
Adults: 50–60% of body weight is water.
Older adults: 45–50% (↓ muscle, ↑ fat).
Men usually have ↑ % water than women (muscle vs fat ratio).
Lean muscle = water-rich; fat tissue = water-poor.
Why it matters
Patients with low baseline water (older adults, obese, women) → greater risk of dehydration
or overload with minor shifts.
Example: A frail elderly patient with pneumonia can get dangerously dehydrated in just 24 hours
of poor intake.
When to act
1 kg (2.2 lbs) = 1 liter of water.
A change of >2 lbs in 24 hrs = significant fluid shift.
Treatment / Medications
Deficit (hypovolemia):
o Oral fluids if mild.
o IV isotonic fluids (0.9% NS, LR) if moderate/severe.
o Blood products if hemorrhage.
Excess (hypervolemia):
o Loop diuretics (furosemide).
o Thiazides (hydrochlorothiazide).
o K⁺-sparing diuretics (spironolactone).
o Fluid & sodium restriction.
o Dialysis if renal failure.
,Nursing Interventions (How)
Daily weights = gold standard.
Strict I&O, urine output ≥30 mL/hr.
Assess mucous membranes, skin turgor, edema, lung sounds.
Teach patients:
o Older adults: drink regularly, don’t wait for thirst.
o HF/CKD: monitor weight daily, report >2 lbs in 24 hrs.
Slide 2 – Fluid Compartments of the Body
Core Concept (What)
Intracellular fluid (ICF): ~28 L (2/3 of total).
Extracellular fluid (ECF): ~14 L (1/3 of total).
o Interstitial fluid: ~10 L.
o Plasma: ~3 L.
o Transcellular: ~1 L (CSF, pleural, peritoneal, synovial).
Why it matters
Electrolyte distribution is compartment-specific:
o ICF: K⁺ (major cation), phosphate (major anion).
o ECF: Na⁺ (major cation), Cl⁻ (major anion).
Even small shifts between compartments → big neuro/cardiac effects.
When to act
ICF dehydration (hypernatremia): cells shrink → neuro changes (confusion, seizures).
ECF deficit (vomiting, bleeding): ↓ BP, tachycardia, poor perfusion.
Third spacing (burns, ascites): hypovolemia despite total body fluid overload.
Treatment / Medications
ICF deficit (cell dehydration): hypotonic fluids (0.45% NS, D5W).
ECF deficit (hypovolemia): isotonic fluids (0.9% NS, LR).
Third spacing (ascites/pleural effusion): paracentesis/thoracentesis, albumin infusion.
Nursing Interventions (How)
, Daily weights, strict I&O.
Monitor for edema vs dehydration.
Check labs: Na⁺, K⁺, Cl⁻, Mg²⁺, Ca²⁺, phosphate.
ECG monitoring for electrolyte shifts.
Teach patients: HF and liver patients should watch for swelling, rapid weight gain, SOB.
Slide 3 – Electrolyte Composition (ICF vs. ECF)
Core Concept (What)
ICF = K⁺, phosphate dominant.
ECF = Na⁺, Cl⁻ dominant.
Normal ranges:
o Na⁺: 136–145 mEq/L
o K⁺: 3.5–5.0 mEq/L
o Ca²⁺: 9–10.5 mg/dL
o Mg²⁺: 1.3–2.1 mEq/L
o Phosphate: 3.0–4.5 mg/dL
Why it matters
K⁺: critical for cardiac conduction.
Na⁺: major determinant of fluid balance and neuro function.
Ca²⁺/Mg²⁺/Phosphate: neuromuscular excitability, bone strength, clotting.
Even slight deviations can cause arrhythmias, seizures, tetany.
When to act
K⁺ <3.5 or >5.0 → high risk for arrhythmias, need immediate action.
Na⁺ <120 or >160 → risk of seizures/coma.
Ca²⁺ <9 or >10.5 → tetany vs sedation.
Mg²⁺ <1.3 or >2.1 → hyperreflexia vs lethargy.
Treatment / Medications
Na⁺ imbalances: IV fluids (hypo, iso, hypertonic), vasopressin antagonists.
K⁺ imbalances: supplements, insulin + glucose, Kayexalate, dialysis, IV calcium.
, Ca²⁺ imbalances: Ca supplements, vitamin D, bisphosphonates, calcitonin.
Mg²⁺ imbalances: Mg sulfate IV, calcium gluconate for toxicity.
Phosphate imbalances: phosphate binders (hyper), oral/IV phosphate (hypo).
Nursing Interventions (How)
Frequent electrolyte monitoring.
ECG monitoring for K⁺ and Ca²⁺ changes.
Neuro checks for Na⁺ and Ca²⁺ changes.
Teach patients dietary management:
o K⁺: bananas, oranges, spinach.
o Na⁺: avoid processed foods.
o Ca²⁺: dairy, greens.
o Phosphate restriction in CKD (avoid dairy, cola).
Perfect 🙌 let’s keep rolling! Here’s the why / when / how breakdown for Slides 4–5 (Diffusion &
Facilitated Diffusion).
Slide 4 – Diffusion
Core Concept (What)
Definition: Passive movement of molecules from high → low concentration across a permeable
membrane until equilibrium is reached.
No energy required.
Example: O₂ and CO₂ exchange in alveoli.
Why it matters
Diffusion is the basis of gas exchange and electrolyte balance.
If diffusion is impaired → tissues can’t get oxygen or rid CO₂ → hypoxemia, hypercapnia.
Common in conditions where the alveolar-capillary membrane is thickened (e.g., pneumonia,
pulmonary edema, ARDS).
When to act
When a patient shows signs of poor diffusion:
one chunk so you can see the flow.
Slides 1–3: Water Content, Fluid Compartments, Electrolytes
Slide 1 – Water Content of the Body
Core Concept (What)
Adults: 50–60% of body weight is water.
Older adults: 45–50% (↓ muscle, ↑ fat).
Men usually have ↑ % water than women (muscle vs fat ratio).
Lean muscle = water-rich; fat tissue = water-poor.
Why it matters
Patients with low baseline water (older adults, obese, women) → greater risk of dehydration
or overload with minor shifts.
Example: A frail elderly patient with pneumonia can get dangerously dehydrated in just 24 hours
of poor intake.
When to act
1 kg (2.2 lbs) = 1 liter of water.
A change of >2 lbs in 24 hrs = significant fluid shift.
Treatment / Medications
Deficit (hypovolemia):
o Oral fluids if mild.
o IV isotonic fluids (0.9% NS, LR) if moderate/severe.
o Blood products if hemorrhage.
Excess (hypervolemia):
o Loop diuretics (furosemide).
o Thiazides (hydrochlorothiazide).
o K⁺-sparing diuretics (spironolactone).
o Fluid & sodium restriction.
o Dialysis if renal failure.
,Nursing Interventions (How)
Daily weights = gold standard.
Strict I&O, urine output ≥30 mL/hr.
Assess mucous membranes, skin turgor, edema, lung sounds.
Teach patients:
o Older adults: drink regularly, don’t wait for thirst.
o HF/CKD: monitor weight daily, report >2 lbs in 24 hrs.
Slide 2 – Fluid Compartments of the Body
Core Concept (What)
Intracellular fluid (ICF): ~28 L (2/3 of total).
Extracellular fluid (ECF): ~14 L (1/3 of total).
o Interstitial fluid: ~10 L.
o Plasma: ~3 L.
o Transcellular: ~1 L (CSF, pleural, peritoneal, synovial).
Why it matters
Electrolyte distribution is compartment-specific:
o ICF: K⁺ (major cation), phosphate (major anion).
o ECF: Na⁺ (major cation), Cl⁻ (major anion).
Even small shifts between compartments → big neuro/cardiac effects.
When to act
ICF dehydration (hypernatremia): cells shrink → neuro changes (confusion, seizures).
ECF deficit (vomiting, bleeding): ↓ BP, tachycardia, poor perfusion.
Third spacing (burns, ascites): hypovolemia despite total body fluid overload.
Treatment / Medications
ICF deficit (cell dehydration): hypotonic fluids (0.45% NS, D5W).
ECF deficit (hypovolemia): isotonic fluids (0.9% NS, LR).
Third spacing (ascites/pleural effusion): paracentesis/thoracentesis, albumin infusion.
Nursing Interventions (How)
, Daily weights, strict I&O.
Monitor for edema vs dehydration.
Check labs: Na⁺, K⁺, Cl⁻, Mg²⁺, Ca²⁺, phosphate.
ECG monitoring for electrolyte shifts.
Teach patients: HF and liver patients should watch for swelling, rapid weight gain, SOB.
Slide 3 – Electrolyte Composition (ICF vs. ECF)
Core Concept (What)
ICF = K⁺, phosphate dominant.
ECF = Na⁺, Cl⁻ dominant.
Normal ranges:
o Na⁺: 136–145 mEq/L
o K⁺: 3.5–5.0 mEq/L
o Ca²⁺: 9–10.5 mg/dL
o Mg²⁺: 1.3–2.1 mEq/L
o Phosphate: 3.0–4.5 mg/dL
Why it matters
K⁺: critical for cardiac conduction.
Na⁺: major determinant of fluid balance and neuro function.
Ca²⁺/Mg²⁺/Phosphate: neuromuscular excitability, bone strength, clotting.
Even slight deviations can cause arrhythmias, seizures, tetany.
When to act
K⁺ <3.5 or >5.0 → high risk for arrhythmias, need immediate action.
Na⁺ <120 or >160 → risk of seizures/coma.
Ca²⁺ <9 or >10.5 → tetany vs sedation.
Mg²⁺ <1.3 or >2.1 → hyperreflexia vs lethargy.
Treatment / Medications
Na⁺ imbalances: IV fluids (hypo, iso, hypertonic), vasopressin antagonists.
K⁺ imbalances: supplements, insulin + glucose, Kayexalate, dialysis, IV calcium.
, Ca²⁺ imbalances: Ca supplements, vitamin D, bisphosphonates, calcitonin.
Mg²⁺ imbalances: Mg sulfate IV, calcium gluconate for toxicity.
Phosphate imbalances: phosphate binders (hyper), oral/IV phosphate (hypo).
Nursing Interventions (How)
Frequent electrolyte monitoring.
ECG monitoring for K⁺ and Ca²⁺ changes.
Neuro checks for Na⁺ and Ca²⁺ changes.
Teach patients dietary management:
o K⁺: bananas, oranges, spinach.
o Na⁺: avoid processed foods.
o Ca²⁺: dairy, greens.
o Phosphate restriction in CKD (avoid dairy, cola).
Perfect 🙌 let’s keep rolling! Here’s the why / when / how breakdown for Slides 4–5 (Diffusion &
Facilitated Diffusion).
Slide 4 – Diffusion
Core Concept (What)
Definition: Passive movement of molecules from high → low concentration across a permeable
membrane until equilibrium is reached.
No energy required.
Example: O₂ and CO₂ exchange in alveoli.
Why it matters
Diffusion is the basis of gas exchange and electrolyte balance.
If diffusion is impaired → tissues can’t get oxygen or rid CO₂ → hypoxemia, hypercapnia.
Common in conditions where the alveolar-capillary membrane is thickened (e.g., pneumonia,
pulmonary edema, ARDS).
When to act
When a patient shows signs of poor diffusion:
