Preoperative fasting for the infusion of "yerba mate": a randomized clinical trial with ultrasound evaluation of gastric contents.
Level 2 - randomized trial
Individual randomized crossover trial in healthy volunteers
PubMed 35121062 · doi:10.1016/j.bjane.2021.12.010
What was done
A prospective, randomized crossover trial evaluated gastric emptying time in 30 healthy volunteers after an 8-hour fast for fluids and solids. Participants ingested 300 mL of a standardized yerba mate infusion, hot tea, or cold tea across sessions. Gastric antral area and gastric volume were measured via bedside ultrasound at baseline and every 20 minutes post-ingestion until clearance.
What was found
Mean gastric emptying time was 69.7 ± 22.1 minutes for yerba mate, 63.1 ± 14.5 minutes for hot tea, and 64.3 ± 23.5 minutes for cold tea (reported p = 0.043 across groups). The only significant pairwise difference was between hot tea and yerba mate at the 20-minute mark (p = 0.012). All participants returned to baseline gastric volume by 100 minutes.
Why it matters
This study provides physiological confirmation that yerba mate clears the stomach similarly to other clear fluids. The data support applying the standard 2-hour preoperative fasting interval for yerba mate prior to elective surgery.
Limits
The study was small (n = 30) and conducted exclusively in healthy volunteers, which may not represent surgical patients with delayed gastric emptying from diabetes, opioid use, gastrointestinal pathology, or preoperative stress. Blinding details were not reported in the abstract.
Cited by
- context Yerba mate improves digestion.
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