Dr. de Graaff is an anesthesiologist with a special interest in pediatric anesthesia. He is specialized in providing anesthesia services for the most vulnerable patients, newborns and infants. He is particularly interested in locoregional anesthetic techniques and has created many clinical anesthesia and postoperative pain management protocols, both locally and nationally, in collaboration with other specialists.

Dr. de Graaff is an active clinical researcher. He is particularly interested in improving perioperative care for children using studies of what happened before, during, and after surgery. He has been involved with numerous international research projects, like NECTARINE, MPOG, PeDi-Registry, NIRS, and isoelectric EEG events in infants. He has also developed reference values for blood pressure in children during anesthesia, which are online (Reference values for blood pressure during anesthesia in children & Blood pressures during neonates' first week of life). He is dedicated to combining clinical observations with research questions, and vice versa.

Dr. de Graaff has written over 120 peer-reviewed papers in international peer-reviewed journals, including British Journal of Anaesthesia, Anesthesiology, and Lancet. He is an editor for the European Journal of Anesthesiology, Pediatric Anesthesia, and the Journal of Medical Systems, and he completes ad-hoc reviews for other international scientific journals.

Dr. de Graaff was president of the European Society for Paediatric Anaesthesiology (ESPA) from 2022 to 2023 and honorary secretary from 2016 to 2021. He has served on the Scientific Committee since 2015.