Brazilian Journal of Anesthesiology
Brazilian Journal of Anesthesiology
Original Investigation

Preoperative fasting for the infusion of “yerba mate”: a randomized clinical trial with ultrasound evaluation of gastric contents

Jejum pré-operatório para infusão de erva- -mate: ensaio clínico randomizado com avaliação ultrassonográfica do conteúdo gástrico

Paola Alcarraz, Liliana Servente, Federico Kuster, Leticia Duarte, Mariela Garau, María Desirello, Lourdes Blanc, Nelson Bracesco, Anahi Perlas

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The traditional infusion of “yerba mate” is widely consumed in South America and exported to countries around the world. Although generally considered a “clear fluid”, there is no data to date on the gastric emptying time of yerba mate and safe preoperative fasting intervals. The objective of this study was to evaluate the gastric emptying time of a standardized infusion of yerba mate using bedside ultrasound and compare it with the time confirm of hot and cold tea.

This was a prospective, randomized crossover experimental study. Thirty healthy volunteers were evaluated after 8 hours of fasting for both fluids and solids. Gastric antral area and gastric volume were evaluated at baseline and every 20 minutes after drinking 300 mL of randomly assigned infusion of “yerba mate”, hot tea, or cold tea.

The mean gastric emptying time was: 69.7 ± 22.1 min, 63.1 ± 14.5 min, and 64.3 ± 23.5 min for the mate, hot tea, and cold tea respectively. No significant differences were found in emptying time among the infusion groups (p-value = 0.043). When same time measures were compared, the only significant difference detected was between hot teas and mate infusion at 20 minutes (p-value = 0.012)

Yerba mate infusion has a similar gastric emptying time to that of tea. All subject's gastric volume returned to baseline values by 100 minutes. It is reasonable to recommend a similar fasting period of 2 hours for mate infusion prior to elective surgery.


Gastric emptying;  Gastric contents;  Ultrasound measures;  Yerba mate;  Preoperative fasting  


Justificativa: A tradicional infusão de erva-mate é amplamente consumida na América do Sul e exportada para países de todo o mundo. Embora geralmente considerado um “fluido claro”, não há dados até o momento sobre o tempo de esvaziamento gástrico da erva-mate e intervalos seguros de jejum pré-operatório. O objetivo deste estudo foi avaliar o tempo de esvaziamento gástrico de uma infusão padronizada de erva-mate utilizando ultrassonografia à beira do leito e compará-lo com o tempo de confirmação do chá quente e frio. Métodos: Este foi um estudo experimental prospectivo, randomizado e cruzado. Trinta voluntários saudáveis foram avaliados após 8 horas de jejum para líquidos e sólidos. A área gástrica antral e o volume gástrico foram avaliados no início e a cada 20 minutos após a ingestão de 300 mL de infusão aleatoriamente designada de “erva-mate”, chá quente ou chá frio. Resultados: O tempo médio de esvaziamento gástrico foi: 69,7 ± 22,1 min, 63,1 ± 14,5 min e 64,3 ± 23,5 min para o mate, chá quente e chá frio, respectivamente. Não foram encontradas diferenças significativas no tempo de esvaziamento entre os grupos de infusão (valor de p = 0,043). Quando as medidas de mesmo tempo foram comparadas, a única diferença significativa detectada foi entre chás quentes e infusão de mate aos 20 minutos (valor de p = 0,012) Conclusão: A infusão de erva-mate tem um tempo de esvaziamento gástrico semelhante ao do chá. O volume gástrico de todos os indivíduos retornou aos valores basais em 100 minutos. É razoável recomendar um período de jejum semelhante de 2 horas para infusão de mate antes de cirurgia eletiva.


Esvaziamento gástrico; Conteúdo gástrico; Medidas de ultrassom; Erva mate; Jejum pré-operatório


1 A Lienhart, Y Auroy, F Pequignot, et al. Survey of anesthesia-related mortality in France Anesthesiology, 105 (2006), pp. 1087-1097

2 GP Pimenta, JE de Aguilar-Nascimento Prolonged preoperative fasting in elective surgical patients Nutr Clin Pract, 29 (2014), pp. 22-28

3 JL Apfelbaum, RA Caplan, RT Connis, et al. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures Anesthesiology, 114 (2017), pp. 495-511

4 JL Apfelbaum, RA Caplan, RT Connis, et al. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures Anesthesiology, 126 (2017), pp. 376-393

5 I Smith, P Kranke, I Murat, A Smith, G O'Sullivan, E Sreide, B in't Veld Perioperative fasting in adults and children Eur J Anaesthesiol, 28 (2011), pp. 556-569

6 GE Vist, RJ Maughan The effect of osmolality and carbohydrate content on the rate of gastric emptying of liquids in man J Physiology, 486 (1995), pp. 523-531

7 Encuesta STEP, OPS 2007, Ministerio de Salud Pública, Uruguay:

8 Bastos D, Fornari A, Queiroz Y, Torres E. Bioactive compounds content of chimarrão infusions related to the moisture of yerba mate (Ilex Paraguariensis) Leaves brazilian archives of biology and technology. 2006;49:399-404.

9 Filip R, Ferraro G, Bandoni A, et al. Chapter: 5 Mate (Ilex paraguariensis) Recent advances in phytochemistry. 2009,000-000 ISBN: 978-81-308-0309-8 Editor: Filippo Imperato.

10 N Bracesco, AG Sánchez, V Contreras, T Menini, A Gugliucci Recent advances on Ilex paraguariensis research: minireview J Ethnopharmacol, 136 (2011), pp. 378-384

11 N Bracesco, M Dell, A Rocha, et al. Ilex paraguariensis extracts prevent peroxide damage to biomolecules: a study on DNA double strand breaks in Saccharomyces cerevisiae and human low-density lipoprotein J Altern Complemen Med, 3 (2003), pp. 379-387

12 N Bracesco, V Sosa, L Blanc, et al. Analysis of radioprotection and antimutagenic effects of Ilex paraguariensis infusion and its component rutin Braz J Med Biol Res, 51 (9) (2018)

13 A Falconi, M Gutierrez, L Benedetto, J Abin-Carriquiri, N Bracesco, P Torterolo Waking-promoting action of yerba mate (Ilex paraguariensis) Sleep Science, 6 (2013), pp. 9-15

14 N Bracesco Ilex Paraguariensis as a Healthy food supplement for the future world Biomed J Sci Tech Res, 16 (1) (2019)

15 A Perlas, VW Chan, CM Lupu, et al. Ultrasound assessment of gastric content and volume Anesthesiology, 111 (2009), pp. 82-89

16 L Bolondi, M Bortolotti, V Santi, et al. Measurement of gastric emptying time by real-time ultrasonography Gastroenterology, 89 (1985), pp. 752-759

17 A Perlas, N Mitsakakis, L Liu, et al. Validation of a mathematical model for ultrasound assessment of gastric volume by gastroscopic examination Anesth Analg, 116 (2013), pp. 357-363

18 R1 Kruisselbrink, C Arzola, R Endersby, et al. Intra- and interrater reliability of ultrasound assessment of gastric volume Anesthesiology, 121 (2014), pp. 46-51

19 D Loomis, K Guyton, Y Grosse, et al. Carcinogenicity of drinking coffee, mate, and very hot beverages. International Agency for Research on Cancer Monograph Working Group Lancet Oncology, 17 (2016), pp. 877-878

20 T Okabe, H Terashima, A Sakamoto Determinants of liquid gastric emptying: comparisons between milk and isocalorically adjusted clear fluids Br J Anaesth, 114 (2015), pp. 77-82

21 B Mendes, C Claudino, W de Brito, et al. Ultrasound dynamics of gastric content volumes after the ingestion of coconut water or a meat sandwich. A randomized controlled crossover study in healthy volunteers Rev Bras Anestesiol, 68 (2018), pp. 584-590

22 P Van de Putte, A Perlas Evaluación ecográfica del contenido y volumen gástrico H. J Anaesth., 113 (2014), pp. 12-22

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