Primary Purpose: To investigate the incidence and risk factors related to the appearance of tracheal phlegmon in patients undergoing percutaneous tracheostomy. Participant Population/Primary Condition: Patients admitted to Intensive Care Main Questions Aims to Answer: 1. \- What are the risk factors associated with the development of tracheal phlegmon percutaneous tracheostomy? 2. \- How does the appearance of tracheal phlegmon impact intensive care stay, hospital stay, mortality, and Health-related quality of life? Participants will be followed up after undergoing tracheostomy for 7 days to identify eventual phlegmons. At the two-year follow-up, the health-related quality of life will be assessed