Restrictive vs Liberal Perioperative Fluid Administration
Summary by Eric Brzozowski MD, 01.25.22
The RELIEF Trial
--> Patient selection = adults who had an increased risk of complications while undergoing major abdominal surgery that included a skin incision, an expected operative duration of at least 2 hours, and an expected hospital stay of at least 3 days. Surgical-risk criteria included an age of at least 70 years or the presence of heart disease, diabetes, renal impairment, or morbid obesity.
--> In patients at increased risk for complications while undergoing major abdominal surgery, a restrictive fluid regimen was not associated with a higher rate of disability-free survival than a liberal fluid regimen 1 year after surgery. However, the restrictive regimen was associated with a higher rate of acute kidney injury.
A Rational Approach to Perioperative Fluid Management
Background info
Liberal fluid resuscitation strategy typically consists of the formula:
Total Fluid Requirement = CVE+ Maintenance Rate + Fluid deficit + Surgical losses + Third space losses
CVE = Compensatory intravascular volume expansion (or venodilation and cardiac depression from anesthetic) which is typically 5-7 mL/kg
Fluid Deficit = NPO hrs x maintenance rate
Maintenance Rate = 4-2-1 rule for fluids (i.e. an 80 kg patient requires 120 mL/hr)
Third space losses: 0-2 mL/kg for minor procedures, 2-4 mL/kg for moderate procedures, and 4-8 mL/kg for large procedures.
Restrictive Fluid Management:
Replaces blood loss on a per mL basis (1:1 for colloid and 1.5:1 for crystalloid)
No replacement for “third space” losses
Administration of colloid bolus for signs of hypovolemia
Avoid fluid loading for preoperative deficit or neuraxial anesthesia
Replace sensible and insensible losses with 1-3 mL/kg
Paper
“A Rational Approach to Perioperative Fluid Management” A review article by Daniel Chappell, MD, Matthias Jacob, MD, Klaus Hoffmann-Kiefer, MD, Peter Conzen, MD, and Markus Rehm, MD
Overview:
The goal of this review is to discuss perioperative fluid management. In particular, the authors believe that a liberal fluid strategy is no longer supported by evidence. Additionally, hypervolemia may lead to morbidity and mortality. The authors recommend employing a restrictive (zero-balance or normovolemic) fluid strategy.
Key Points:
Excessive fluid administration or hypervolemia may result in complications including tissue edema, cardiopulmonary complications, renal failure, weight gain, anastomosis leak, coagulopathy, ileus, infection, and prolonged hospital stay
Perioperative weight gain from volume overload is linked to increased morbidity and mortality
Fluid boluses to reduce PONV may provide more benefit for minor and outpatient procedures.
“The majority of data does not support the existence of a third space… All other methods using various tracers, multiple sampling techniques, longer equilibration times, or analysis of kinetics contradict the existence of a fluid-consuming third space.”
As such, third space losses do not exist.
Preoperative fluid deficit from NPO status is likely small and does not require treating (unless clinically indicated based on confounding factors).
With crystalloid infusion, only 20% remains intravascular.
The authors recommend a restrictive fluid approach to resuscitation as outlined above. They prefer colloid solution when replacing blood loss.
Additional Reading: