What is restricted fluid resuscitation?

Restricted Fluid Resuscitation: Definition and Clinical Application

Restricted fluid resuscitation is a strategy that limits the volume of fluids administered during resuscitation to achieve lower-than-normal blood pressure targets, with the goal of reducing complications associated with aggressive fluid administration while maintaining adequate tissue perfusion.

Definition and Key Principles

• Restricted fluid resuscitation (also called permissive hypotension) involves administering limited volumes of fluid to achieve a target systolic blood pressure of 80-90 mmHg or mean arterial pressure of 50-60 mmHg until bleeding is controlled 1
• This approach contrasts with traditional aggressive fluid resuscitation that aims to restore normal blood pressure (normotension) 1
• The strategy is based on evidence that aggressive fluid administration may worsen outcomes by exacerbating bleeding, disrupting coagulation, and increasing mortality 1, 2

Clinical Applications

Trauma and Hemorrhagic Shock

• In trauma patients without traumatic brain injury (TBI), restricted fluid resuscitation is recommended until major bleeding has been controlled 1
• The European guideline on management of major bleeding recommends a target systolic blood pressure of 80-90 mmHg using a restricted volume replacement strategy 1
• This approach has been shown to decrease mortality compared to traditional aggressive fluid resuscitation in trauma patients 1

Septic Shock

• In septic shock, the evidence for restricted fluid resuscitation is less definitive but emerging 3
• Initial fluid boluses are still recommended for septic shock, but subsequent fluid administration should be more cautious 1
• The CLASSIC trial demonstrated that a protocol restricting resuscitation fluid after initial resuscitation successfully reduced fluid volumes in ICU patients with septic shock 3

Gastrointestinal Bleeding

• For non-variceal upper GI bleeding, evidence is insufficient to make a definitive recommendation regarding restrictive fluid resuscitation 1
• The primary goal is to stop bleeding while minimizing hemodynamic compromise 1

Contraindications and Special Considerations

• Restricted fluid resuscitation is contraindicated in patients with traumatic brain injury (TBI) or spinal injuries 1
• For patients with severe TBI (GCS ≤8), a mean arterial pressure ≥80 mmHg should be maintained 1
• This approach should be used cautiously in elderly patients and those with chronic arterial hypertension 1
• In pediatric patients with septic shock, fluid boluses must be administered cautiously, especially in those with profound anemia and malaria 1

Implementation Approach

• Initial fluid boluses should be given to improve tissue perfusion 1
• Positive response to fluid loading can be assessed by: 10% increase in systolic/mean arterial blood pressure, 10% reduction in heart rate, and/or improvement in mental state, peripheral perfusion, or urine output 1
• Fluid resuscitation should be stopped when no improvement in tissue perfusion occurs in response to volume loading 1
• If restricted volume replacement doesn't achieve target blood pressure, noradrenaline is recommended as an adjunct to maintain arterial pressure 1

Potential Benefits

• Reduced blood loss in trauma patients with active bleeding 2, 4
• Prevention of dilutional coagulopathy 4
• Decreased risk of fluid overload and pulmonary complications 1
• Potentially reduced mortality in trauma patients 1, 2
• In septic shock, potential reduction in worsening of acute kidney injury 3

Type of Fluid

• Crystalloid solutions (particularly balanced crystalloids) are recommended as first-line fluid for resuscitation 1
• Colloids have not shown survival benefit over crystalloids and are more expensive 1
• Use of colloids should be restricted due to adverse effects on hemostasis 1

Common Pitfalls and Caveats

• Failure to recognize when restricted fluid resuscitation is contraindicated (TBI, spinal injuries) 1
• Inadequate monitoring of tissue perfusion during restricted fluid resuscitation 1
• Development of crepitations indicates fluid overload or impaired cardiac function 1
• The strategy must be balanced with the need to maintain adequate tissue perfusion 1, 4
• Current evidence has limitations, including small sample sizes and methodological weaknesses in many studies 1