Minimizing Fasting Times

ERAS & Fasting Basics - Hunger Games Shift

• ERAS: Evidence-based, multimodal care to reduce surgical stress & hasten recovery.
• Traditional NPO: Prolonged fasting → dehydration, insulin resistance, patient distress.
• ERAS Goal: Minimize fasting for:
  • Better hydration, ↓PONV.
  • Improved insulin sensitivity.
  • Enhanced patient comfort.
• Key Pre-op Times:
  • Clear fluids: up to 2 hrs.
  • Light meal: 6 hrs.

⭐ ERAS protocols allow clear carbohydrate drinks up to 2 hours before surgery, reducing postoperative insulin resistance and improving patient comfort without increasing aspiration risk in most patients.

Current Fasting Rules - Sip, Sip, Hooray!

• ASA/ISA Consensus (Adults & Children):
  • Clear Fluids: 2 hours (water, no-pulp juice, black tea/coffee)
  • Breast Milk: 4 hours
  • Infant Formula / Non-human Milk: 6 hours
  • Light Meal (e.g., toast): 6 hours
  • Heavy/Fried Meal: 8 hours
• 📌 "2-4-6-8 Rule": Clear fluids → Breast milk → Formula/Light meal → Heavy meal.
• Oral medications: Typically with sips of water up to 1 hour pre-op.
• 

⭐ Preoperative oral carbohydrate drinks (e.g., maltodextrin) 2 hours before surgery can ↓PONV & ↓insulin resistance, improving patient comfort and recovery under ERAS protocols.

Physiology of Shorter Fasts - Gut Feelings & Gains

• Shorter Fasts: Physiological Wins
  • Maintains hydration & crucial liver glycogen stores.
  • Reduces surgical stress response, ↓ catabolism.
  • ↓ Insulin resistance: Pre-op carbs (e.g., maltodextrin 2-3 hours prior) prevent starvation-induced resistance.
  • Better glycemic control: Avoids fasting hypoglycemia & stress hyperglycemia.
  • ↑ Patient comfort: Significantly less hunger, thirst, anxiety.
  • ↓ PONV: Linked to better hydration & reduced ketosis.
  • Earlier gut function return: Gentle gut stimulation.
• Prolonged Fasts: Physiological Toll
  • Induces insulin resistance, mimics a starved state.
  • ↑ Protein breakdown, dehydration, electrolyte disturbances.

⭐ Allowing clear fluids up to 2 hours before surgery significantly reduces patient-reported thirst and anxiety, improving overall experience.

Fasting in Special Groups - Tricky Tummies & Alerts

Modify ERAS fasting for special groups. Balance aspiration risk vs. minimal fasting benefits.

• Diabetes Mellitus:
  • Risks: Hypo/hyperglycemia.
  • Mgmt: Monitor glucose. Adjust meds. Morning list preferred.
• GERD/Gastroparesis/Hiatus Hernia/Bowel Obstruction:
  • ↑ Aspiration risk.
  • Mgmt: PPI, H2 blockers, prokinetics. RSI. Solids >6-8h, clears >2-4h (case-by-case).
• Obesity (BMI >35 kg/m²):
  • ↑ Gastric volume & pressure.
  • Mgmt: ERAS often safe. Individualize. Consider RSI.
• Obstetrics:
  • Elective C-Section (non-laboring): ERAS (solids 6h, clears 2h).
  • Laboring/Emergency: Assume full stomach. NPO. RSI.
  • ⭐ > Parturients in active labor are always considered to have a full stomach.
• Emergency Surgery:
  • Assume full stomach. NPO. RSI mandatory.

Pre-Op Carb Drinks - Sweet Surge Strategy

• Goal: Transition from fasted to fed metabolic state before surgery.
• Key effect: ↓ postoperative insulin resistance.
• Protocol: 50g CHO (e.g., maltodextrin) in clear liquid.
  • Given 2 hours before anesthesia induction.
• Benefits: ↓ thirst, hunger, anxiety; ↓ PONV; preserves muscle.
• Improves patient comfort & glycemic control.

⭐ Preoperative CHO loading can reduce postoperative insulin resistance by up to 50%.

• Caution: Gastroparesis, severe reflux, emergency surgery.

High‑Yield Points - ⚡ Biggest Takeaways

• Clear fluids (water, pulp-free juice) allowed up to 2 hours before surgery.
• Solids (light meal) permitted up to 6 hours before surgery.
• Preoperative carbohydrate drinks (e.g., maltodextrin) 2 hours preoperatively reduce insulin resistance.
• Prolonged fasting offers no benefit; increases PONV and insulin resistance.
• Infants: breast milk 4 hours, formula 6 hours fasting.
• Goal: Enhance patient comfort, reduce catabolic state, improve glycemic control.