Reply to: Optic nerve sheath diameter measurement in hypoxic ischaemic brain injury after cardiac arrest. (May 2019) - Cardim, Danilo; Griesdale, Donald E.; Ainslie, Philip N.; Robba, Chiara; Calviello, Leanne; Czosnyka, Marek; Smielewski, Peter; Sekhon, Mypinder S.