CP

Fluid & Electrolyte Balance, Shock & Sodium Imbalance – Class Notes

Complete & Basic Metabolic Panels (CMP/BMP)

  • CMP = “Complete Metabolic Panel”; BMP = “Basic Metabolic Panel”
  • Ordered to evaluate fluid-electrolyte, renal, hepatic status
  • Common lab components frequently referenced
    • Electrolytes: Na^+, K^+, Cl^-, HCO_3^-
    • Renal: BUN, Creatinine, Specific Gravity
    • Glucose, Ca^{2+}, liver enzymes (CMP)

Homeostasis & Electrolyte Balance

  • Homeostasis = keeping internal environment stable
  • Heavily dependent on proper electrolyte concentration
  • Key regulatory systems
    • Kidneys (filter, reabsorb, excrete)
    • Endocrine (aldosterone, ADH, cortisol)
    • Respiratory (acid–base compensation)
  • Routes of electrolyte/fluid loss
    • Sweat, vomiting, diarrhea, NG suction, wounds/burns, diuretics (e.g., furosemide/Lasix – K^+ wasting)
    • Example given: heavy sweater or vomiting patient loses Na^+, K^+

Age-Related Considerations

  • Elderly lose skin elasticity & subcutaneous fat ➔ higher dehydration risk
  • Blunted thirst / taste / smell perceptions
  • Poly-pharmacy increases imbalance risk
  • Real-world image: older adult wearing 3 sweaters in summer ➔ sweating + dehydration

Hypovolemic Shock (Fluid Volume Deficit)

Etiology

  • Excessive fluid loss or blood loss: vomiting, diarrhea, NG suction, profuse sweating, burns, trauma (GSW, stab), diuretics

Diagnostics

  • CMP/BMP: ↓electrolytes, ↑BUN/Creatinine if renal hypoperfusion
  • CBC: H/H changes, platelets, WBC
  • Specific gravity: ↑ (>1.030) indicates concentrated urine / dehydration

Manifestations ("Signs & Symptoms")

  • Vital signs: Tachycardia (HR >100), Hypotension (SBP <90 or massive drop)
  • Orthostatic changes
  • ↓Skin turgor, dry mucous membranes, concentrated urine / oliguria (U/O <30\,\text{mL/hr})
  • Weight loss, thirst, flat neck veins (JVD)
  • Possible altered LOC, tachypnea to compensate, cool clammy skin

Nursing Management / Interventions

  • ABCs / Maslow: Airway first, then circulation
  • Vitals q15–q60 min; continuous pulse-ox (identify hypoxia <90\%)
  • Physical assessment: neuro, resp, peripheral perfusion
  • I&O, daily weights
  • Replace volume
    • Isotonic IV fluids (0.9% NS, LR)
    • Blood products / plasma if hemorrhage
  • Positioning
    • Severe hypotension with stable airway: Reverse Trendelenburg (feet elevated) to shunt blood centrally
    • Respiratory distress: High-Fowler’s + possible non-rebreather mask
  • Oxygen therapy as indicated (maintain SpO_2>94\%)
  • Monitor labs: BMP, CBC, lactate, ABGs

Hypervolemia (Fluid Volume Excess)

Causes / Risk Factors

  • Renal failure, CHF, cirrhosis, Cushing’s, high Na^+ intake, excessive IVF
  • Stress ➔ cortisol ➔ Na^+/water retention

Expected Findings

  • Vital signs: Hypertension, bounding pulse, tachycardia, tachypnea
  • Respiratory: crackles, cough, dyspnea, orthopnea
  • Peripheral & pitting edema (graded +1 to +4), weight gain (>2 lb/24 h ≈ 1 L fluid)
  • Distended neck veins (JVD)
  • Possibly seizures (cerebral edema)

Nursing Care

  • Daily weights; report gain >2 lb/24 h
  • Strict I&O; fluid restriction per MD order
  • Auscultate lungs; monitor SpO_2, work of breathing (nasal flaring, accessory muscles)
  • Diuretics as ordered (furosemide, spironolactone etc.)
  • Low-sodium diet: DASH (≤ 1500–2000\,\text{mg Na}^+/day)
  • Educate: label reading, edema monitoring, when to call provider
  • High-Fowler’s for dyspnea; possible oxygen
  • Inter-professional: PCP, nutritionist, PT/OT, respiratory therapist

Electrolyte Imbalance Overview

  • Focus for exam: Na^+, K^+, Ca^{2+}, Mg^{2+} (no phosphate/chloride testing)
  • Normal urine output: \ge 30\,\text{mL/hr}

Sodium (Na^+) Imbalances

  • Normal serum range 136-145\,\text{mEq/L}
  • Functions: skeletal muscle contraction, cardiac contraction, nerve impulse transmission, water distribution

Hyponatremia (Na^+ <136)

Causes / Risk Factors

  • Excessive sweating, diuretics, NG suction, burns, GI loss (vomit/diarrhea), NPO status, renal disease

Clinical Manifestations

  • Neuro: confusion, irritability, restlessness, headache, seizures, coma
  • Muscular: muscle twitching, weakness, ↓/absent deep tendon reflexes (DTRs)
  • CV: tachycardia, orthostatic hypotension
  • GI/renal: dry sticky mucosa, oliguria

Nursing Interventions

  • Seizure Precautions
    • Padded side rails, bed low & locked, suction & O2 at bedside
    • Side-lying (lateral) during event, protect head, loosen clothing, time & characterize seizure
  • Replace Na^+
    • PO salty foods/broth if mild & GI tolerates
    • IV hypertonic saline (3% NaCl) for severe cases – INFUSE slowly to avoid cerebral edema
  • Monitor neuro status q2–q4 h; BMP; I&O; daily weights
  • Patient education: moderate Na^+ intake, recognize confusion, hydrate appropriately, med review (diuretics)

Hypernatremia (Na^+ >145) (lecture introduced but details to be continued next class)

  • Etiology preview: renal disease, Cushing’s, DI, excessive Na^+ intake
  • Anticipated S/S: hypotension? (instructor paused – will clarify), neuro changes, thirst

Positioning & Respiratory Support Scenarios

  • High-Fowler’s optimizes lung expansion for SOB
  • Non-rebreather mask for acute hypoxia (higher FiO_2 than nasal cannula)
  • Reverse Trendelenburg to improve venous return when BP critically low with stable airway

Diuretics & Medications Mentioned

  • Furosemide (Lasix) – loop, K^+ wasting
  • Spironolactone – K^+ sparing (implied)
  • Sodium polystyrene sulfonate (Kayexalate) for hyperkalemia (discussed in documentation example)

Documentation & Legal Emphasis

  • “If it isn’t documented, it wasn’t done.”
  • Critical labs (e.g., K^+ 7.8) must be reported to provider immediately; document notification & orders transcribed/executed
  • Example case: failure to chart diabetes education ➔ patient died, nurses/hospital sued

Nursing Process & Patient Education Principles

  • Use Maslow’s hierarchy to prioritize (ABC)
  • Assess learner needs (age, literacy, dyslexia) ➔ adapt teaching (visuals, return demo)
  • Always evaluate patient understanding and document education

Quick Reference Values & Nuggets

  • Urine specific gravity normal 1.005–1.030; ↑ = dehydration
  • Daily weight gain >2\,\text{lb}/24 h ≈ 1\,\text{L} fluid
  • Normal urine output: \ge 30\,\text{mL/hr} (≈ 0.5\,\text{mL/kg/hr})
  • Tachycardia = HR >100 bpm (textbook)
  • Severe hypotension example: 70/30\,\text{mmHg}

Real-World & Metaphor Examples Incorporated

  • Elder in coat on hot day ➔ sweating ➔ dehydration ➔ hypovolemic risk
  • “Bowling-ball” ascites visual for cirrhosis fluid excess
  • NG suction pressure 80–120\,\text{mmHg} (FYI – not tested)

Study Tips Given by Instructor

  • Highlight ATI handouts; focus on “expected findings” & “nursing care” tables
  • Content taught = content tested (“no surprises”)
  • Read ahead; fast-paced class

What’s Next (upcoming sessions)

  • Finish Hypernatremia, Hyper/Hypo-kalemia, ‑calcemia, ‑magnesemia
  • Begin Respiratory module: Asthma, TB, etc.