April 24, 2018

Are you floating your surgery patients?

Adapted from AAHA 2013 Fluid Therapy Guidelines

Monitor1The paradigm of “crystalloid fluids at 10 mL/kg/hr, with higher volumes for anesthesia-induced hypotension” is not evidence-based and should be reassessed. Those high fluid rates may actually lead to worsened outcomes, including increased body weight and lung water; decreased pulmonary function; coagulation deficits; reduced gut motility; reduced tissue oxygenation; increased infection rate; increased body weight; and positive fluid balance, with decreases in packed cell volume, total protein concentration, and body temperature.

When fluids are provided, continual monitoring of the assessment parameters is essential. The primary risk of providing excessive IV fluids in healthy patients is the potential for vascular overload. Current recommendations are to deliver, 10 mL/kg/hr to avoid adverse effects associated with hypervolemia, particularly in cats (due to their smaller blood volume), and all patients anticipated to be under general anesthesia for long periods of time. In the absence of evidence-based anesthesia fluid rates for animals, the authors suggest initially starting at 3 mL/kg/hr in cats and 5 mL/kg/hr in dogs. Preoperative volume loading of normovolemic patients is not recommended.