Are complex carbohydrates recommended when providing carb-loaded beverages prior to colorectal surgery?

Complex Carbohydrates Are Recommended for Preoperative Carbohydrate Loading in Colorectal Surgery

Yes, complex carbohydrates (primarily maltodextrins) should be used when providing carbohydrate-loaded beverages prior to colorectal surgery, not simple carbohydrates.

Carbohydrate Type Recommendations

• Preoperative carbohydrate drinks should contain complex carbohydrates, specifically maltodextrins at a concentration of approximately 12.5%, to achieve optimal metabolic benefits 1
• The standard recommended dose is 400ml of a 12.5% complex carbohydrate solution (primarily maltodextrins) administered 2-3 hours before anesthesia induction 1
• An additional 800ml dose the evening before surgery is also recommended as part of the complete protocol 1

Benefits of Complex Carbohydrate Loading

• Complex carbohydrate loading helps patients undergo surgery in a metabolically fed state, reducing postoperative insulin resistance by more than 50% 1, 2
• Preoperative complex carbohydrate administration results in:
  • Reduced preoperative thirst, hunger, and anxiety 1
  • Decreased postoperative protein breakdown and better-maintained lean body mass and muscle strength 1
  • Lower insulin requirements and less hyperglycemia compared to placebo 1
  • Potentially shorter hospital stays (meta-analysis data shows approximately one day shorter stay in major abdominal surgery) 1, 3

Why Complex vs. Simple Carbohydrates

• Complex carbohydrates (maltodextrins) provide more sustained energy release and better metabolic benefits than simple sugars 4
• A 2018 study demonstrated that complex carbohydrate/maltodextrin solutions resulted in significantly less glycemic variability (7.6% vs 21.4%) compared to simple carbohydrate drinks in colorectal surgery patients 4
• Lower glycemic variability is associated with fewer postoperative complications 4

Administration Protocol

• Clear fluids containing complex carbohydrates can be safely given up to 2 hours before anesthesia induction 1
• The standard protocol involves:
  • 800ml (containing 100g carbohydrates) the evening before surgery
  • 400ml (containing 50g carbohydrates) 2-3 hours before anesthesia 1, 2
• This protocol applies to most patients, including those with uncomplicated type-2 diabetes and obese patients 1

Special Considerations

• Patients with delayed gastric emptying (e.g., those with diabetic neuropathy or gastrointestinal motility disorders) require special consideration 1
• Emergency surgery patients should remain fasted according to standard protocols 1
• While carbohydrate drinks can be given to patients with well-controlled diabetes along with their normal medication, the evidence for this practice is still limited 1

Implementation Considerations

• A U.S. survey found that 87.2% of hospitals with colorectal ERAS programs administer preoperative carbohydrate drinks 5
• Surprisingly, about one-third of programs incorrectly use simple carbohydrate drinks for patients with diabetes, which may lead to greater glycemic variability 5, 4
• The ERAS Society strongly recommends preoperative carbohydrate drinks as part of the standard protocol for elective colorectal surgery 1

Pitfalls to Avoid

• Using simple carbohydrate beverages (like sports drinks) instead of complex carbohydrate solutions can lead to greater glycemic variability and potentially more complications 5, 4
• Failing to adhere to proper timing (2-3 hours before anesthesia) may reduce the metabolic benefits 1
• Omitting the evening dose (800ml) reduces the overall effectiveness of the carbohydrate loading protocol 1