Percutaneous dilatational tracheostomy (PDT), especially single-step dilatational tracheostomy (sd-PDT), is now frequently preferred to surgical tracheostomy. Occasionally, it needs a second dilation maneuver .Dissection of the deep cervical fascia during PDT, known as reformative PDT (re-PDT), may facilitate the procedure. This study was designed to compare re-PDT with sd-PDT in ICU patients

Percutaneous dilatational tracheostomy (PDT) is a popular airway management technique in the intensive care unit (ICU).Occasionally the first dilation may be challenging when using Ciaglia and colleagues' method, and a second dilation may be needed to insert the tracheostomy tube. In these circumstances, potentially life-threatening complications, such as hemorrhage and hypoxia, may arise. The investigators found the reasons for difficulty in achieving smooth dilation of the stoma.The investigators compared the traditional method with the improved method.

Inclusion Criteria:

• age ≥18 years;
• requirement for long-term mechanical ventilation;
• failure of weaning from mechanical ventilation.

Exclusion Criteria:

• age <18 years;
• pre-existing infection at the tracheostomy site;
• pre-existing malignancy at the tracheostomy site;
• difficulty in identifying the anatomic landmarks;
• unstable cervical spine fracture;
• international normalized ratio (INR) >2;
• platelet count <50 000 mm3.