How do we initiate intravenous (IV) fluid therapy?

Initiating Intravenous Fluid Therapy

Begin with a rapid bolus of 500-1000 mL of isotonic crystalloid (0.9% normal saline or balanced crystalloid solution such as Ringer's Lactate or Plasmalyte) over less than 15 minutes, then reassess the patient's hemodynamic response before administering additional fluid. 1

Initial Fluid Selection

Crystalloid Choice

• Use balanced crystalloid solutions (Ringer's Lactate, Plasmalyte) as first-line therapy in most critically ill patients, as they prevent hyperchloremic metabolic acidosis and may reduce vasopressor requirements compared to 0.9% saline 1, 2
• 0.9% normal saline is acceptable as an alternative, but should be limited to a maximum of 1-1.5 liters to avoid hyperchloremia and potential renal dysfunction 1
• Avoid Ringer's Lactate in patients with severe head trauma due to its hypotonic nature (osmolarity <280 mOsm/L), which can worsen cerebral edema 1

Initial Bolus Volume

• Administer 500-1000 mL crystalloid over <15 minutes as the initial bolus in adults 1
• For septic shock specifically, give 30 mL/kg crystalloid over 3 hours (approximately 2 liters for a 70 kg patient) 1
• In children with septic shock, administer 20 mL/kg boluses, repeating up to 60 mL/kg in the first 2 hours based on response 1
• For anaphylaxis, use 1-2 liters of normal saline rapidly (5-10 mL/kg in first 5 minutes for adults), with potential need for up to 30 mL/kg in children within the first hour 1

Reassessment After Each Bolus

Signs of Adequate Response

• Look for ≥10% increase in systolic/mean arterial pressure 1
• Monitor for ≥10% reduction in heart rate 1
• Assess improvement in mental status, peripheral perfusion (capillary refill time), and urine output 1

When to Continue Fluids

• Repeat 500 mL boluses if hypotension persists (systolic BP <90 mmHg) and signs of poor perfusion continue, with reassessment after each bolus 1
• Continue fluid administration until hemodynamic endpoints are achieved within 6 hours of recognizing sepsis 1
• Target lactate normalization if elevated (>4 mmol/L indicates tissue hypoperfusion) 1

When to Stop Fluids

• Immediately stop if no improvement in tissue perfusion occurs after a bolus 1
• Halt fluid administration if signs of volume overload develop: increased jugular venous pressure, new or worsening pulmonary crackles/rales, decreasing oxygen saturation, or peripheral edema 1
• In patients with cardiac failure history, monitor closely for fluid intolerance and reduce infusion rate if overload signs appear 1

Special Considerations by Clinical Scenario

Hemorrhagic Shock

• Limit crystalloid to 1-2 liters maximum before transitioning to packed red blood cells in patients with severe anemia and ongoing hemorrhage 3
• Use permissive hypotension strategy targeting systolic BP 80-90 mmHg to avoid dislodging clots, except in patients with head trauma or chronic hypertension who require MAP ≥80 mmHg 1, 3
• Add norepinephrine if systolic BP remains <80 mmHg despite 1-2 liters of crystalloid 3, 4

Septic Shock with Refractory Hypotension

• After 2-2.5 liters of crystalloid without adequate response, seek senior help and consider early vasopressor support rather than continuing aggressive fluid resuscitation 1
• Initiate norepinephrine to target MAP 65 mmHg if fluid-resistant shock persists 1, 3

Meningococcal Disease in Children

• Administer up to 60 mL/kg as three boluses of 20 mL/kg with reassessment after each 1
• Fluid resuscitation in excess of 60 mL/kg plus inotropic support is often required 1
• Arrange early intensive care consultation if repeated fluid boluses are needed, as inotropic and ventilatory support may be required 1

Route of Administration

• Establish intravenous access via large peripheral vein as first choice 1
• Use intraosseous access if IV access cannot be rapidly obtained, but only if running freely and for ≤24 hours 1
• Consider central venous access or surgical cut-down if peripheral access fails 1
• Avoid oral rehydration in septic patients—no data support its efficacy or safety in sepsis 1

Common Pitfalls to Avoid

• Do not delay fluid resuscitation to obtain lactate measurements in patients with clear signs of shock (hypotension, poor perfusion, altered mental status) 1
• Do not use colloids (hydroxyethyl starch, gelatin) as first-line therapy due to adverse effects on hemostasis and potential renal harm 1
• Do not use hypertonic saline (3% or 7.5%) for hemorrhagic shock resuscitation, as it provides no mortality benefit 1
• Avoid aggressive crystalloid resuscitation beyond 2 liters in hemorrhagic shock, as it worsens coagulopathy through dilution of clotting factors 3
• Never leave a septic patient unattended—ensure continuous observation and frequent clinical reassessment 1