Practice of adjunctive treatments in critically ill COVID–19 patients—rational for the multicenter observational PRoAcT-COVID study in The Netherlands

Christel M. A. Valk, Pien Swart, Leonoor S. Boers, Michela Botta, Lieuwe D. J. Bos, Marcelo Gama de Abreu, Liselotte Hol, Markus W. Hollmann, Janneke Horn, Ignacio Martin-Loeches, Guido Mazzinari, Sheila N. Myatra, Sunny G. Nijbroek, Neeltje M. Rosenberg, Willemke Stilma, Anissa M. Tsonas, Ward H. van der Ven, Ary Serpa Neto, Marcus J. Schultz, Frederique Paulus, for the PRoAcT-COVID collaborative group