Emergency Medicine · Medical Literature
Conventional vs Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubations: A Randomized Clinical Trial.
Abstract
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.
Clinical relevance
In adults undergoing routine tracheal intubation under general anesthesia in the perioperative setting, does video laryngoscopy—whether using a Macintosh-shaped blade (VLM) or a hyperangulated blade (VLH)—provide superior first-pass intubation success compared with conventional direct laryngoscopy (DL)? __SNAPSHOT__ {"studyDesign":"3-arm parallel-group randomized clinical trial (COVALENT), with a pre-specified hierarchical analysis testing non-inferiority first, then superiority","setting":"6 academic or intermediate care centers in Germany and Austria; March 2022 – February 2025","sampleSize":"n=2,532 randomized (DL: n=848; VLM: n=841; VLH: n=843); n=2,423 (95.7%) included in modified intention-to-treat analysis","population":"Adults undergoing surgery under general anesthesia requiring orotracheal intubation; mean age 59.7 years (SD 15.4); 56.3% male. Excluded: non-general anesthesia, nasal intubation, planned fiberoptic intubation, pregnant patients. Consecutive sampling on days when trial staff capacity permitted.","intervention":"Video laryngoscopy with a Macintosh-shaped blade (VLM) or video laryngoscopy with a hyperangulated blade (VLH) for tracheal intubation during anesthesia induction; devices from multiple manufacturers permitted to maximize generalizability","comparator":"Direct laryngoscopy with a Macintosh blade (DL), considered the prior standard of care","primaryOutcome":"First-pass intubation success rate, defined as positive capnography after a single laryngoscopy attempt; a failed attempt was defined by retrieval of either the laryngoscope or the endotracheal tube from the oral cavity before confirmed placement","followUp":"Not reported (procedural outcome; no extended follow-up duration specified in the abstract)","fundingSource":"Departmental funds, University Hospital Würzburg; supported by the German Society of Anaesthesiology and Intensive Care (GSAIC) Trials Group. No industry funding reported in the protocol publication; funding source for the 2026 results paper not fully reported in the available abstract."}
Key findings
Both video laryngoscopy modalities were statistically superior to direct laryngoscopy for first-pass intubation success. First-pass success rates were: VLH 87.6%, VLM 82.9%, and DL 78.2% (all pairwise comparisons P <.001). Unadjusted absolute risk differences were: DL vs. VLM: 4.66 percentage points (95% CI, 4.45–4.78); DL vs. VLH: 9.34 percentage points (95% CI, 9.22–9.46); VLM vs. VLH: 4.68 percentage points (95% CI, 4.57–4.79). NNT to achieve one additional first-pass success: approximately 21 for VLM vs. DL (calculated) and approximately 11 for VLH vs. DL (calculated). After a failed first attempt, both VLM and VLH were associated with faster time to successful intubation by capnography compared with DL (mean [SD]: VLM 146.6 [103.6] s, VLH 147.5 [98.9] s vs. DL 170.3 [100.4] s; P=.008). Regarding procedural safety among patients requiring more than one attempt, fewer lip or dental injuries or blood on blade were observed with VLH compared with VLM and DL (10.9% [11/101] vs. 23.2% [32/138] and 24.1% [42/174], respectively). Relative effect sizes (risk ratios, odds ratios) and confidence intervals for the injury outcome were not reported in the available abstract. No other specific adverse event frequencies are reported in the abstract.
Practice implications
The COVALENT trial establishes, in a large, multicenter, adequately powered perioperative RCT, that both Macintosh-type and hyperangulated video laryngoscopy are superior—not merely non-inferior—to direct laryngoscopy for first-pass intubation success in routine surgical patients under general anesthesia. The absolute benefit was modest for VLM (~4.7 percentage points; NNT ~21) and clinically more meaningful for VLH (~9.3 percentage points; NNT ~11). These findings are most applicable to adult surgical patients at academic and intermediate-care centers in the German-speaking European context, intubated by attending anesthesiologists. The trial does not establish the benefit of video laryngoscopy in critically ill patients (ED/ICU), pediatric populations, nasal intubation, anticipated difficult airways requiring fiberoptic technique, or in settings where operator video laryngoscopy experience is substantially lower than the trial centers. Importantly, the finding that VLH was associated with lower rates of lip/dental injuries and blood on the blade compared with DL and VLM among patients who required more than one attempt is hypothesis-generating but requires caution, as this was a secondary outcome from a subset of patients with failed first attempts, with no adjustment for multiplicity reported in the abstract. The trial supports transitioning to video laryngoscopy—particularly hyperangulated devices—as the routine first-line approach for perioperative orotracheal intubation in experienced anesthesiology settings. The absolute magnitude of benefit is statistically significant and directionally consistent with prior evidence (e.g., DEVICE trial in critically ill patients, JAMA 2024 OR cluster RCT), lending biological plausibility; however, the modest absolute gains for VLM must be weighed against device availability and cost in practice. Only the abstract is available for this summary, and full secondary outcome data, subgroup analyses, operator experience stratification, and adverse event details cannot be assessed. __LIMITATIONS__ Convenience/capacity-based sampling on trial days introduces a potential selection bias; patients intubated on non-trial days were excluded, which may limit representativeness,Blinding of the intubating clinician to device assignment was not possible by nature of the intervention; assessor and patient blinding status are not reported in the abstract,The consecutive sampling approach and restriction to days with available trial staff may systematically under-represent complex or emergency perioperative cases,Operator video laryngoscopy experience was not standardized and may vary significantly across the 6 centers, which could dilute or amplify the observed effects compared with centers where VL is still novel,Allowing devices from multiple manufacturers enhances generalizability but introduces device-level heterogeneity as an uncontrolled variable; specific manufacturer-level effects cannot be separated,The trial was conducted exclusively in Germany and Austria; generalizability to healthcare systems with different training paradigms, staffing models, or device availability is uncertain,The primary outcome (first-pass success confirmed by capnography) is a process/safety metric, not a long-term patient-centered outcome; the trial does not report downstream outcomes such as aspiration, hypoxemia events, ICU admission, or mortality,Secondary injury outcomes (lip/dental injury, blood on blade) were reported only in the subgroup of patients with failed first attempts, introducing selection bias for that comparison; no adjusted analysis is reported,The hierarchical testing procedure (non-inferiority then superiority) adds analytical rigor but the full statistical analysis plan details are not available from the abstract alone,Funding source for the 2026 results paper is not fully disclosed in the available abstract, though the protocol was funded by departmental and professional society funds (no industry funding disclosed in protocol) __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ The COVALENT trial demonstrates that both Macintosh-type and hyperangulated video laryngoscopy significantly improve first-pass intubation success over direct laryngoscopy in routine perioperative intubations, with the hyperangulated blade providing the largest absolute benefit (~9 percentage points; NNT ~11) and fewer procedural injuries on repeat attempts. These findings, from the largest dedicated perioperative RCT addressing this question, add strong confirmatory evidence supporting video laryngoscopy—particularly hyperangulated devices—as the preferred first-line technique for routine orotracheal intubation in experienced anesthesiology settings. Clinicians should consider institutional adoption of video laryngoscopy as the default perioperative airway device, while recognizing that absolute gains are modest for Macintosh-type VL and that generalizability to emergency, critical care, or low-resource settings requires separate consideration.