Oesophageal intubation can cause death. Selective intubation can induce a poor ventilation, hypoxemia, atelectasis etc… It's not rare in paediatric intubation. The prevalence of malposition of endotracheal tube is 30 to 40% in babies and infants less than 1 year old. Currently doctors try to detect malposition of intra-tracheal tube by auscultation and capnograms and chest radiography is needed to confirm it. The Chest X ray is the gold standard.