Black or white coffee before anaesthesia?: A randomised crossover trial

Area of Science:

• Anesthesiology
• Gastroenterology
• Medical Imaging

Background:

• Current preoperative fasting guidelines often classify coffee with milk as a solid food.
• Limited evidence exists regarding the impact of milk in coffee on gastric volume 2 hours before anesthesia.

Purpose of the Study:

• To compare gastric volume in healthy volunteers after consuming coffee with and without added milk using MRI.
• To assess the safety and efficacy of liberalizing preoperative fasting guidelines for hot beverages.

Main Methods:

• A randomized crossover trial involving 32 healthy volunteers.
• Participants underwent MRI scans to measure gastric volume after ingesting coffee with 0%, 20%, or 50% full-fat milk.
• A noninferiority study design with a predefined limit of 12 ml was employed.

Main Results:

• Mean gastric volumes were 27.8 ml (black coffee), 17.9 ml (20% milk), and 20.6 ml (50% milk).
• Adding 20% milk significantly decreased gastric volume (-10.0 ml).
• Adding 50% milk insignificantly decreased gastric volume (-7.2 ml).

Conclusions:

• Adding up to 50% milk to coffee does not significantly increase gastric volume 2 hours prior to anesthesia.
• These findings support a more liberal approach to preoperative fasting policies regarding milk in hot drinks.