From the Journals

Worse outcomes with video laryngoscopy in ICU

View on the News

Video laryngoscopy creates blind spots

The results of this trial illustrate the fundamental problem with video laryngoscopy: It generates excellent views of the larynx but may not facilitate tracheal intubation.

The use of video laryngoscopy can lead to the creation of blind spots, both visual and cognitive. Because the lens of the laryngoscope is located at the tip of the device, the pharynx and hypopharynx are not visualized during video laryngoscopy. Manipulating the endotracheal tube into view therefore occurs within this blind spot, and this can be difficult depending on the patient’s pharyngeal anatomy. This phenomenon has been linked to higher rates of pharyngeal soft tissue injury and longer intubation times in patients undergoing video laryngoscopy as compared with direct laryngoscopy.

The view during video laryngoscopy can also create a cognitive blind spot: laryngoscopists may fail to abort a laryngoscopy attempt in a timely manner because they have such a clear view of the larynx.

Brian O’Gara, MD, and Daniel Talmor, MD, of Harvard University, Boston, and Samuel Brown, MD, MS, of the University of Utah School, Murray, Utah, made these comments in an accompanying editorial (JAMA. 2017 Feb 7; doi: 10.1001/jama.2016.21036) . None of the authors had relevant financial disclosures.



When used in intensive care units, video laryngoscopy did not improve the chances of successful intubation on the first try, compared with direct laryngoscopy, and was associated with a significantly higher risk of severe life-threatening complications, researchers reported.

In a multicenter, randomized trial of 371 patients, first-pass intubation rates did not differ significantly whether video or direct laryngoscopy was used, at 67.7% and 70.3%, respectively, Jean Baptiste Lascarrou, MD, of District Hospital Centre, La Roche-sur-Yon, France, and his associates wrote. Meanwhile, the combined rate of death, cardiac arrest, severe cardiovascular collapse, and hypoxemia was 9.5% with video laryngoscopy and just 2.8% with direct laryngoscopy, a significant difference (JAMA. 2017 Jan 24;317[5]:483-93).

“Improved glottis visualization with video laryngoscopy did not translate into a higher success rate for first-pass intubation, because tracheal catheterization under indirect vision was more difficult, in keeping with earlier data,” the researchers concluded. “Further studies are needed to assess the comparative effectiveness of these two strategies in different clinical settings and among operators with diverse skill levels.”

Intubation in the ICU carries an inherently high risk because patients are often acutely unstable, and the intubating clinician is usually a nonexpert, the investigators noted. At the same time, the procedure must be done quickly to prevent aspiration because patients usually have not fasted. Care bundles and training on simulators have improved safety, but ICU intubations remain riskier than those done in the operating room.

Observational studies and smaller trials in ICUs seemed to support video laryngoscopy over the Macintosh laryngoscope, but raised questions about intubation time and mortality, the investigators noted. To help resolve these issues, they randomly assigned adults needing orotracheal intubation at seven ICUs in France to either video or direct Macintosh laryngoscopy, and followed them for 28 days. Patients averaged 63 years of age, and 37% were women.

For both arms, residents performed the initial intubation attempt in about 80% of cases, and successful intubation usually took 3 minutes. Video laryngoscopy did not significantly increase the combined risk of esophageal intubation, aspiration, arrhythmia, or dental injury (5.4% versus 7.7% for direct laryngoscopy). But the only death in the study occurred after video laryngoscopy, and there were four cardiac arrests after video laryngoscopy and none after direct laryngoscopy, the researchers said. Furthermore, the rate of severe hypoxemia was nearly six times higher after video laryngoscopy than with direct laryngoscopy, and the rate of hypotension was twice as high.

The researchers did not identify predictors of life-threatening complications with video laryngoscopy, but hypothesized that being able to clearly visualize the glottis might create “a false impression of safety,” especially among nonexperts. “In addition, poorer alignment of the pharyngeal axis, laryngeal axis, and mouth opening despite good glottis visualization by video laryngoscopy can lead to mechanical upper airway obstruction and faster progression to hypoxemia,” they wrote.

Centre Hospitalier Département de la Vendée sponsored the study. Dr. Lascarrou reported having no relevant conflicts of interest. Four coinvestigators disclosed ties to Fisher & Paykel, LFB, Merck Sharp & Dohme, Astellas, Basilea Pharmaceutica. Gilead, Alexion, and Cubist. The remaining coinvestigators had no disclosures.

Next Article: