About the Authors

Chris Martini

Affiliation Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands

Monique van Velzen

Affiliation Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands

Asbjørn Drewes

Affiliation Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark

Leon Aarts

Affiliation Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands

Albert Dahan

Affiliation Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands

Marieke Niesters

m.niesters@lumc.nl

Affiliation Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands

Competing Interests

A. Dahan and A. Drewes received speaker fees from Grünenthal GmbH. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: CM A. Dahan A. Drewes LA MN. Performed the experiments: CM AD MN. Analyzed the data: MN AD. Contributed reagents/materials/analysis tools: LA. Wrote the paper: A. Dahan MN MvV CM A. Drewes LA.