Enhanced Recovery After Surgery (ERAS)

• ERAS was initially developed for colon resection surgery. However, with the positive results, this technique is being used for many disciplines.
• Nonsteroidal anti-inflammatories, acetaminophen, gabapentinoids, NMDA antagonists, alpha-2-agonists, and sodium and calcium channel blocking agents are at the center of multimodal anesthesia. A multimodal approach may be a more effective pain control strategy, potentially decreasing the complications associated with suboptimal pain control, such as pneumonia, deep venous thrombosis, and postoperative cognitive dysfunction.
• A multimodal approach may decrease the use of opioids and associated side effects (e.g., delirium, and respiratory depression), tolerance, and diversion.
• The preoperative goal for ERAS is to arrive in the operating room in a euvolemic state.
  • Historically, patients are NPO from at least midnight until after surgery. This obviously leads to hypovolemia and metabolic demand.
• ERAS implements a carbohydrate drink 2 hours prior to surgery and eliminates the mechanical bowel preparation. This helps to maintain glucose levels, reduce thirst and hunger, and provide anxiolysis. Also, the patients may not experience as significant of a drop after induction as normal.
• Traditionally, the NPO deficit as well as maintenance fluids, third space loss, and blood loss is replaced with crystalloid and sometimes colloids according to the 4-2-1 calculation. The volumes calculated can be highly subjective and liberal infusion of fluids can have detrimental effects.
• Goal-directed fluid therapy (GDFT) aims for individual end-points to support oxygen transport balance. This helps improve outcomes for surgical patients because they can tolerate the metabolic and hemodynamic insults.
  • GDFT protocols begin with baseline vitals and a target. A small fluid bolus of 250- 500 mL is given IV to assess its effect on the Frank-Starling curve.
  • The differentiation between preload dependence and preload independence is vital to ascertain. Preload independence shows that a bolus of fluid does not help hemodynamic parameters. This can be due to a weak heart and result in edema.