What type and rate of intravenous (IV) fluids are appropriate for administration?

IV Fluid Administration: Type and Rate

For initial fluid resuscitation, administer isotonic crystalloid (Lactated Ringer's or normal saline) at 20 mL/kg as rapid boluses, with reassessment after each bolus to guide further administration. 1

Initial Fluid Resuscitation

Type of Fluid

• First-line choice: Balanced crystalloids such as Lactated Ringer's solution
  • Better acid-base profile
  • Lower risk of hyperchloremic metabolic acidosis
  • Reduced risk of acute kidney injury 2
• Alternative: Normal saline (0.9% NaCl)
  • Use with caution as high volumes (>5000 mL) may cause hyperchloremic acidosis 2

Initial Bolus Administration

• Administer 20 mL/kg of isotonic crystalloid as a rapid bolus 1
• Use push method or rapid infusion device (pressure bag) 1
• For septic shock, severe malaria, or dengue shock syndrome, initial fluid bolus of 20 mL/kg is recommended 1

Reassessment and Subsequent Management

After Initial Bolus

• Reassess patient after each bolus for:
  • Clinical response (perfusion, vital signs)
  • Signs of fluid overload:
    • Increased work of breathing
    • Rales/crackles
    • Gallop rhythm
    • Hepatomegaly 1

Subsequent Fluid Administration

• If no signs of fluid overload and continued shock:

  • Continue with additional 20 mL/kg boluses
  • Patients commonly require 40-60 mL/kg in the first hour
  • Up to 200 mL/kg may be needed in the first hour in severe cases 1

• If signs of fluid overload develop:

  • Stop fluid boluses
  • Consider inotropic support 1

Special Considerations

Vascular Access

• Establish intravenous access rapidly
• If reliable venous access cannot be obtained within minutes, establish intraosseous access 1

Monitoring During Fluid Administration

• Continuous assessment of:
  • Heart rate
  • Blood pressure
  • Capillary refill (target ≤2 seconds)
  • Urine output (target >1 mL/kg/h)
  • Mental status
  • Oxygen saturation 1

Hypotension Management

• If hypotension persists despite adequate fluid resuscitation:
  • Consider starting vasopressors
  • For peripheral administration (while establishing central access):
    • Low-dose dopamine or epinephrine through a second peripheral IV/IO catheter
  • For central administration:
    • Dopamine, epinephrine, or norepinephrine based on hemodynamic state 1

Maintenance Fluids

• After resuscitation, transition to maintenance fluids
• Consider D10%-containing isotonic IV solution at maintenance rates to prevent hypoglycemia 1

Common Pitfalls to Avoid

1. Inadequate initial resuscitation: Don't underestimate fluid needs in shock states
2. Failure to reassess: Always reassess after each bolus to guide further therapy
3. Delayed vasopressor initiation: Consider early vasopressor support if fluid resuscitation doesn't restore adequate perfusion
4. Overlooking fluid overload: Watch carefully for signs of fluid overload, especially in patients with cardiac or pulmonary compromise
5. Using non-crystalloid fluids as first line: There is insufficient evidence to support routine use of colloids over crystalloids for initial resuscitation 1

By following this approach to IV fluid administration, you can effectively restore intravascular volume while minimizing the risks of inadequate resuscitation or fluid overload.