A randomized trial to assess the effect of cricoid displacing maneuver on the success rate of blind placement of double-lumen tube and Univent bronchial blocker

Background: Double lumen tube (DLT) and Univent are two commonly used lung isolation devices that often require bronchoscopy assistance. In order to facilitate blind placement for situations where bronchoscopy was unavailable, the cricoid displacing maneuver (CDM) was adopted. This study was designed to explore whether the CDM could improve the successful blind placement rate in left lung isolation esophageal surgeries. Methods: One hundred and twenty ASA 1-3 patients who received left lung isolation esophageal surgeries from October 2014 to February 2016 and October 2018 to January 2020 were enrolled in this single-centered prospective assessor-blinded randomized controlled trial. After anesthesia induction, patients were intubated either with DLT or Univent by applying the CDM, and the position of devices was checked by bronchoscopy. After turning into the right decubitus position, the devices were pulled back to the trachea, and placement was conducted once again. Successful placement rate for the first attempt, time needed for initial placement, malposition and reposition times by bronchoscopy during surgery, bronchus injury score, rank of lung isolation and postoperative anesthesia-related complications were recorded. Results: At supine position, the successful placement rates for the first attempt of DLT-CDM, DLT-control, Univent-CDM and Univent-Control were 100%, 76.7%, 96.7% and 66.7% respectively (DLT: P=0.016; Univent: P=0.003) while at right decubitus position were 86.7%, 66.7%, 93.3% and 66.7% (DLT: P=0.067; Univent: P=0.010). There was no significant difference in the time needed for successful intubation and no severe complications. Conclusions: The current study provided evidence that the CDM is an effective and safe blind endobronchial placement technique for left DLT and Univent. We suggest that CDM could be applied to the endobronchial placement of left DLT and Univent.