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REHYDRATION AND IV FLUIDS (Nursing)

REHYDRATION

  • Oral hydration options: water, sports drinks
  • Pediatric dosing (oral): 50-100\;\mathrm{mL/kg} \text{ over } 4\;\mathrm{hours}
    • This can also be viewed as an hourly rate of \frac{50-100}{4} = 12.5-25\;\mathrm{mL/kg/hour}
  • Intravenous (IV) fluids are used when oral intake is contraindicated
  • Nursing roles during rehydration:
    • Monitor intake and output (I&O)
    • Monitor urine specific gravity
    • Monitor relevant lab values

IV FLUIDS - CRYSTALLOIDS

  • Crystalloid solutions are IV fluids composed of small dissolved particles that dissociate in solution
  • Common crystalloids include:
    • Isotonic solutions: \text{NS} = 0.9\%\;\mathrm{NaCl}, \; \text{LR} (Lactated Ringer's), \; \text{D5W}
    • Hypotonic solutions: 0.45\%\;\mathrm{NaCl}
    • Hypertonic solutions: 3\%\;\mathrm{NaCl}, \; \mathrm{D10W}, \; \mathrm{D5NS}
  • Hypotonic solution: moves water into cells
    • Example: 0.45\%\;\mathrm{NaCl}
    • Effect: expands intracellular fluid (ICF)
  • Isotonic solutions: expand extracellular fluid (ECF) and replace losses
    • Examples: NS, LR, D5W
  • Hypertonic solutions: draw water out of cells; used to treat hyponatremia or to expand ECF in specific contexts
    • Examples: 3\%\;\mathrm{NaCl}, \; \mathrm{D10W}, \; \mathrm{D5NS}

IV FLUIDS - COLLOIDS

  • Colloid solutions stay in the vascular space longer and elevate oncotic (osmotic) pressure
  • Common colloids:
    • Albumin
    • Dextran
    • Hetastarch
  • Indications for colloids (in general):
    • Hypovolemic shock
    • Edema management
    • Trauma resuscitation contexts
  • Key benefits: help maintain vascular volume by drawing fluid into the intravascular space
  • Risks associated with colloids:
    • Allergic reactions
    • Bleeding tendency
    • Renal failure risk

NURSING ROLES

  • Assess and monitor fluid/electrolyte status
  • Interpret laboratory results related to fluids and electrolytes
  • Ensure safe administration of fluids and medications
  • Educate patients and families about hydration, fluid choices, and ongoing monitoring

SPECIAL POPULATIONS

  • Older adults:
    • Reduced thirst sensation
    • Altered renal function
    • Increased medication-related risks
  • Infants and children:
    • Higher body water percentage
    • Higher metabolic rate
    • Higher fluid losses

HYPERVOLUME (HYPERVOLEMIA)

  • Rehydration considerations can apply in contexts of fluid excess prevention
  • Oral hydration guidance remains the same when used appropriately, with monitoring
  • IV crystalloid choices for management should consider volume status and goals
  • Nursing roles in hypervolemia include close monitoring of I&O, weight changes, edema, lung sounds, and vitals

HYPOVOLEMIA

  • Hypovolemia refers to reduced intravascular volume
  • Management focuses on restoring circulating volume with appropriate fluids (crystalloids or colloids) based on severity and cause
  • Nursing roles emphasize frequent assessment of vitals, capillary refill, mucous membranes, skin turgor, urine output, and electrolyte balances

KEY CONCEPTS AND CONNECTIONS

  • Fluid compartments and distributions:
    • ICF: intracellular fluid
    • ECF: extracellular fluid (intravascular and interstitial)
    • Crystalloids vs colloids act differently on these compartments
  • Osmotic principles:
    • Isotonic solutions expand ECF without shifting water between compartments
    • Hypotonic solutions move water into cells (risk of cellular swelling)
    • Hypertonic solutions draw water out of cells (risk of cellular dehydration)
  • Clinical indications for solution choice:
    • Hypovolemic shock or trauma may require rapid volume expansion
    • Hyponatremia may be treated with hypertonic solutions in certain circumstances
    • Colloids can be used when rapid intravascular volume expansion is needed, but with specific risks in mind
  • Practical implications:
    • Monitoring: vital signs, I&O, weight, edema, lung sounds, urine output, urine specific gravity, and relevant labs
    • Safety: avoid unnecessary fluid overload, monitor for allergic reactions or renal impact with colloids

SUMMARY OF DULY NOTED POINTS

  • Rehydration strategies include both oral and IV approaches depending on tolerance and contraindications
  • Dosing for pediatric oral rehydration is specifically 50-100 mL/kg over 4 hours, which translates to 12.5-25 mL/kg/hour
  • Crystalloids are categorized as hypotonic, isotonic, and hypertonic, with distinct effects on fluid distribution and clinical use cases
  • Colloids act by staying in vasculature and increasing oncotic pressure; used in selected scenarios but carry notable risks
  • Nursing roles focus on assessment, interpretation of labs, safe administration, and patient education
  • Special populations (older adults and children) require adjusted consideration due to physiologic differences
  • The material covers both hypovolemia and hypervolemia contexts and emphasizes monitoring and appropriate fluid selection