What are the guidelines for fluid bolus administration in adults and pediatric (paeds) patients with shock?

Fluid Bolus Administration in Shock

Pediatric Patients

For children with shock, administer 20 mL/kg boluses of isotonic crystalloid (normal saline or lactated Ringer's) rapidly over 5-10 minutes, with immediate reassessment after each bolus and repeat dosing up to 60 mL/kg in the first hour if perfusion does not normalize. 1, 2

Initial Resuscitation

• Fluid type: Use isotonic crystalloid solutions (normal saline or lactated Ringer's solution) as first-line therapy 1, 2
• Bolus volume: Administer 20 mL/kg as a rapid push or via pressure bag 1
• Administration speed: Give each bolus over 5-10 minutes in children 1, 2
• Repeat dosing: Children commonly require 40-60 mL/kg in the first hour, and may need up to 200 mL/kg total if signs of fluid overload are absent 1

Vascular Access Strategy

• Establish intravenous or intraosseous access immediately 1
• If reliable venous access cannot be obtained within minutes, place intraosseous access without delay 1
• Consider peripheral inotrope infusion (low-dose dopamine or epinephrine) through a second peripheral IV/IO while establishing central access if shock persists after initial fluid 1

Monitoring During Resuscitation

Stop or slow fluid administration when any of the following occur:

• Development of hepatomegaly 1
• New or worsening pulmonary rales/crackles 1
• Gallop rhythm on cardiac auscultation 1
• Increased work of breathing 1
• Decreased oxygen saturation 1

Therapeutic Endpoints

Target the following clinical parameters 1:

• Capillary refill ≤2 seconds
• Normal heart rate for age
• Warm extremities with strong peripheral pulses equal to central pulses
• Urine output >1 mL/kg/hour
• Normal mental status
• Normal blood pressure for age

Special Populations

• Septic shock: Use 20 mL/kg boluses with reassessment; isotonic crystalloid and 5% albumin are equally effective 1
• Severe malaria with profound anemia: Administer fluid boluses cautiously and consider blood transfusion instead 1
• Dengue shock syndrome: Use 20 mL/kg boluses with careful reassessment 1
• Severe febrile illness WITHOUT shock: Avoid routine bolus fluids; use maintenance fluids only with frequent reassessment 1

Vasopressor Initiation

If shock persists after 40-60 mL/kg of fluid resuscitation 1:

• Begin central epinephrine (0.05-0.3 μg/kg/min) for cold shock with poor perfusion
• Begin central norepinephrine for warm shock with vasodilation
• Consider peripheral vasopressor via second IV/IO while establishing central access

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Adult Patients

For adults with shock, administer 500-1000 mL boluses of isotonic crystalloid over 15-30 minutes, targeting 30 mL/kg within the first 3 hours, with continuous reassessment for fluid responsiveness and signs of overload. 1, 3

Initial Resuscitation

• Fluid type: Isotonic crystalloid solutions (lactated Ringer's preferred over normal saline) 1, 3
• Bolus volume: 500-1000 mL per bolus 1, 3
• Administration speed: Over 15-30 minutes 1
• Target volume: 30 mL/kg within the first 3 hours 1

Fluid Responsiveness Assessment

Evaluate response to each bolus by monitoring 1, 3:

• ≥10% increase in systolic or mean arterial pressure
• ≥10% reduction in heart rate
• Improvement in mental status
• Improved peripheral perfusion (capillary refill <2 seconds, warm extremities)
• Increased urine output

Important caveat: Blood pressure response does not reliably predict cardiac output improvement; up to 67% of patients may be mean arterial pressure-nonresponders despite adequate cardiac index response, and vice versa 4, 5

When to Stop or Limit Fluids

Discontinue or reduce fluid administration when 1, 3:

• No improvement in tissue perfusion occurs despite repeated boluses
• Signs of fluid overload develop: pulmonary crackles, increased jugular venous pressure, hepatomegaly
• Patient has received adequate volume (30 mL/kg) without response
• Limited access to mechanical ventilation exists (use more restrictive approach) 1

Vasopressor Initiation

Begin vasopressors when 1:

• Mean arterial pressure remains <65 mmHg after initial fluid resuscitation (typically after 30 mL/kg)
• Signs of persistent tissue hypoperfusion continue despite adequate fluid
• Norepinephrine is the first-line vasopressor 1
• Consider higher MAP targets (>65 mmHg) in patients with chronic hypertension 1

Resource-Limited Settings

In settings with limited mechanical ventilation or vasopressor access 1:

• Use more cautious fluid administration after initial boluses
• Balance adequate intravascular filling against risk of pulmonary edema
• Monitor closely for respiratory deterioration
• Consider earlier vasopressor initiation if available

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Critical Pitfalls to Avoid

• Do not use hypotonic fluids for shock resuscitation in any age group 1, 2
• Do not rely solely on blood pressure to guide fluid therapy; assess perfusion parameters comprehensively 4, 5
• Do not continue aggressive fluid resuscitation without reassessing for fluid overload after each bolus 1
• Do not use etomidate for intubation in pediatric septic shock due to increased mortality 1
• Do not delay vasopressor initiation in fluid-refractory shock; begin after 40-60 mL/kg in children or 30 mL/kg in adults 1
• Do not assume mean arterial pressure response equals improved cardiac output; the correlation is poor and unpredictable 4, 5