Initial IV Fluid Dosing
For initial resuscitation in hypovolemic patients, administer 10-20 mL/kg of isotonic crystalloid as a bolus, with repeated doses based on clinical response. 1
Fluid Type Selection
Isotonic crystalloid solutions are the first-line choice for initial resuscitation. 1, 2
Balanced crystalloid solutions (Ringer's Lactate or Plasmalyte) are preferred over 0.9% normal saline, particularly when large volumes are anticipated, as they maintain better acid-base balance and may reduce mortality. 2
Isotonic saline remains acceptable for initial boluses but should be avoided in patients with traumatic brain injury or when large volumes are needed due to hyperchloremic acidosis risk. 1
Synthetic colloids should be avoided due to increased risk of renal failure and coagulopathy. 2, 3
Albumin may be considered as second-line therapy only in refractory shock requiring large crystalloid volumes, but offers no mortality benefit and is significantly more expensive. 1, 2
Initial Bolus Dosing
The standard initial fluid bolus is 10-20 mL/kg administered rapidly. 1
For pediatric patients, this translates to 10-20 mL/kg per bolus. 1
For adult septic shock, at least 30 mL/kg should be given within the first 3 hours. 2
Fluid challenges should be given as discrete boluses (250-1000 mL in adults) rather than continuous infusion to allow assessment of response. 1
Reassessment and Repeat Dosing
After each bolus, reassess hemodynamic status before administering additional fluid. 2
Evaluate heart rate, blood pressure, capillary refill, skin temperature, urine output, and mental status. 1, 2
Target mean arterial pressure ≥65 mmHg in patients requiring vasopressors. 2
Monitor lactate levels and aim for normalization as a marker of adequate tissue perfusion. 2
Repeat 10-20 mL/kg boluses based on clinical response, but stop if no improvement occurs or signs of fluid overload develop. 1
Special Populations and Contexts
Sepsis/Septic Shock
- More aggressive initial resuscitation is warranted, with up to 60 mL/kg in the first 2 hours in some protocols. 1
- When large volumes are required (>40-60 mL/kg), synthetic colloids may be considered for their longer intravascular duration, though crystalloids remain preferred. 1
Traumatic Brain Injury
- Permissive hypotension is contraindicated—maintain adequate perfusion pressure to ensure cerebral oxygenation. 1
- Hypertonic saline may be beneficial for focal neurological signs due to osmotic effects. 2
Hemorrhagic Shock
- Restrictive fluid strategy is preferred until hemorrhage control is achieved in penetrating trauma without TBI. 1
- Target systolic BP 80-90 mmHg (MAP 50-65 mmHg) until definitive hemorrhage control, then normalize. 1
- This approach does NOT apply to elderly patients, those with chronic hypertension, or patients with TBI. 1
Adrenal Insufficiency
- Strongly consider a concomitant 20 mL/kg fluid bolus of D5NS or D10NS during the first hour when treating suspected adrenal crisis. 1
Critical Pitfalls to Avoid
Do not continue fluid administration without reassessment—both inadequate and excessive fluid cause harm. 2, 4
Avoid fluid overload, which increases mortality, pulmonary edema, and abdominal compartment syndrome. 1, 2
Pre-hospital administration of >1,500 mL is associated with increased mortality in trauma patients with systolic BP ≥60 mmHg. 1
Do not use static measures like CVP alone to guide fluid therapy—dynamic variables (pulse pressure variation, passive leg raise response) better predict fluid responsiveness. 2
Hypotonic solutions are contraindicated in cerebral edema or patients at risk for increased intracranial pressure. 1