Conventional vs Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubations: A Randomized Clinical Trial

Video laryngoscopy is increasingly used in routine tracheal intubation in the operating room, but evidence regarding its clinical outcomes remains inconclusive. In particular, the role of hyperangulated video laryngoscopes as first-choice devices has not been studied sufficiently.

To determine whether video laryngoscopy-regardless of blade geometry or manufacturer-provides superior first-pass success compared with direct laryngoscopy (DL) during routine tracheal intubations.

This 3-arm randomized clinical trial (Conventional vs Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubation [COVALENT]) was conducted at 6 academic or intermediate care centers in Germany and Austria between March 28, 2022, and February 17, 2025. Adults undergoing surgery under general anesthesia with the need for tracheal intubation were included in the trial. Adults undergoing surgery under any other form of anesthesia, those requiring nasal or planned fiberoptic intubation, and pregnant patients were excluded. Patients were sampled consecutively until trial staff capacity limits were met for any given day. Devices from different manufacturers were allowed to maximize generalizability. All data analyses followed a modified intention-to-treat approach.

Tracheal intubation as part of general anesthesia induction preceding surgery. Patients were randomly assigned (1:1:1) to DL, video laryngoscopy with Macintosh blade (VLM), or video laryngoscopy with a hyperangulated blade (VLH). All interventions were performed by the anesthesiologists assigned to their respective cases.

The primary outcome was first-pass intubation success rate. After the laryngoscope and tracheal tube were inserted into the patient's oral cavity, retrieval of either marked a failed intubation attempt. Successful intubation was defined as positive capnography. Differences between success rates were tested applying the z test for unpooled variance and reported as absolute differences with corresponding 95% CIs.

Of the 2532 patients (1426 males [56.3%]; mean [SD] age, 59.7 [15.4] years) randomly assigned to DL (n = 848), VLM (n = 841), or VLH (n = 843), 2423 (95.7%) were included in a modified intention-to-treat analysis. Both video laryngoscopy modalities were superior to DL regarding first-pass success (VLM: 82.9%, VLH: 87.6%, and DL: 78.2%; all P < .001). Unadjusted absolute risk differences for first-pass intubation success were 4.66 (95% CI, 4.45-4.78) percentage points for DL vs VLM, 9.34 (95% CI, 9.22-9.46) percentage points for DL vs VLH, and 4.68 (95% CI, 4.57-4.79) percentage points for VLM vs VLH. VLM and VLH compared with DL had faster intubation success after a failed first attempt (mean [SD] time to positive capnography, 146.6 [103.6] and 147.5 [98.9] seconds vs 170.3 [100.4] seconds; P = .008). There were fewer complications of lip or dental injuries or blood on the blade for VLH compared with VLM and DL (10.9% [11 of 101] vs 23.2% [32 of 138] and 24.1% [42 of 174]).

This randomized clinical trial of DL vs VLM and VLH found that video laryngoscopy significantly improved first-pass success during intubation in the operating room compared with DL. The findings support the use of video laryngoscopy as a new standard of care for routine airway management.

ClinicalTrials.gov Identifier: NCT05228288.