aDepartment of Critical Care Medicine, University of Alberta, Edmonton, Alberta, Canada

bDivision of Nephrology and Hypertension

cDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA

Correspondence to Oleksa G. Rewa, Department of Critical Care Medicine, University of Alberta, CSB 2-124 8440 112th St NW, Edmonton, Alberta T6G 2B7, Canada. Tel: +1 780 263 3280; fax: +1 780 492 1500; e-mail: [email protected]