From the Department of Anesthesiology and Intensive Care Medicine, University Hospital Giessen and Marburg, Campus Marburg, Philipps-University Marburg, Germany (CG, CA, HW), Neonatology and Pediatric Intensive Care Medicine, Department of Pediatrics, Philipps-University, Marburg, Germany (NM), Paediatric Pulmonology, Department of Pediatrics, Philipps-University, Marburg, Germany (MB), Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, German Centre for Lung Research, Hannover, Germany (NS), Institute of Pathology, Philipps-University Marburg and University Hospital Marburg (UKGM), Universitaetsklinikum Marburg, Marburg, Germany (CW), Institute of Pathology, Agaplesion Diakonieklinikum Rotenburg Wümme gGmbH, Germany (IB)

Correspondence to Dr Christine Gaik, Department of Anaesthesiology and Intensive Care Medicine, University Hospital Marburg, Philipps-University Marburg, Baldingerstraße, 35033 Marburg, Germany. E-mail: [email protected]