1 Department of Anesthesiology, Amsterdam University Medical Centers, Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. p.schober@amsterdamumc.nl.
2 Department of Anesthesiology, Amsterdam University Medical Centers, Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.