title: Real-time ultrasound-guided percutaneous dilatational tracheostomy: a feasibility study.
abstract: BACKGROUND
  Ultrasound (US) performed prior to percutaneous tracheostomy (PT) may be useful in avoiding injury to pretracheal vascular structures and in avoiding high placement of the tube. Bedside real-time US guidance with visualization of needle path is routinely utilized for other procedures such as central venous catheterization, and may enhance the safety and accuracy of PT without causing airway occlusion or hypercarbia. Our objective was to demonstrate that PT performed under real-time US guidance with visualization of needle path during tracheal puncture is feasible, including in patients with features that increase the technical difficulty of PT.
  
  
  METHODS
  Mechanically ventilated patients with acute brain injury requiring tracheostomy underwent US guided PT. The orotracheal tube was withdrawn using direct laryngoscopy. The trachea was punctured under real-time US guidance (with visualization of the needle path) while using the acoustic shadows of the cricoid and the tracheal rings to identify the level of puncture. After guidewire passage the site and level of entry was verified using the bronchoscope, which was then withdrawn. Following dilatation and tube placement, placement in the airway was confirmed using auscultation and the "lung sliding" sign on US. Bronchoscopy and chest X-ray were then performed to identify any complications.
  
  
  RESULTS
  Thirteen patients successfully underwent US guided PT. Three patients were morbidly obese, two were in cervical spine precautions and one had a previous tracheostomy. In all 13 patients bronchoscopy confirmed that guidewire entry was through the anterior wall and between the first and fifth tracheal rings. There was no case of tube misplacement, pneumothorax, posterior wall injury, significant bleeding or other complication during the procedure.
  
  
  CONCLUSIONS
  Percutaneous tracheostomy performed under real-time ultrasound guidance is feasible and appears accurate and safe, including in patients with morbid obesity and cervical spine precautions. Larger studies are required to further define the safety and relative benefits of this technique.
  
  
  BACKGROUND
  UMIN Clinical Trials Registry, UMIN000005023.
authors.affiliation: Department of Neurosurgery and Neurology, University of Michigan Health System, 3552 Taubman Health Care Center, 1500 E, Medical Center Dr, SPC 5338, Ann Arbor, MI 48109-5338, USA. vrajajee@yahoo.com
authors.forename: Venkatakrishna
authors.initials: V
authors.lastname: Rajajee
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fletcher
authors.forename: Lauryn R
authors.initials: LR
authors.lastname: Rochlen
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Jacobs
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid; D011446:Prospective Studies; D014132:Trachea / Q000000981:diagnostic imaging* / Q000601:surgery; D014139:Tracheostomy / Q000009:adverse effects / Q000379:methods*; D018084:Ultrasonography, Interventional / Q000379:methods*; D055815:Young Adult