Among patients suffering out-of-hospital cardiac arrest, laryngeal tube insertion was associated with significantly greater 72-hour survival compared with standard-of-care endotracheal intubation, researchers reported.
In a randomized clinical trial involving 3,000 cases and 27 emergency medical service (EMS) agencies, statistically significant associations with survival to hospital discharge and favorable neurological status at hospital discharge were also reported for the laryngeal tube intervention, according to Henry Wang, MD, of the University of Texas Health Science Center at Houston, and colleagues.
Rates of initial airway success were 90.3% with laryngeal tube insertion (LTI) and 51.6% with endotracheal intubation (ETI). Also, 72-hour survival was 18.3% in the LT group versus 15.4% in the ETI group (adjusted difference 2.9%, 95% CI 0.2%-5.6%, P=0.04), they wrote in JAMA.
“The trial demonstrated the effectiveness of the laryngeal tube-based strategy for advanced airway management in the out-of-hospital cardiac arrest setting,” Wang told MedPage Today. “Within the last 5 to 10 years, EMS agencies have increasingly used laryngeal tube insertion because it is simpler to perform, mostly to avoid distracting from other parts of resuscitation, like doing CPR chest compression. We have suspected that there are advantages to using laryngeal tube, but this has not previously been shown.”
In a second study in JAMA, U.K. researchers reported on the AIRWAYS-2 randomized clinical trial, which used of a different type of supraglottic airway device for advanced airway management, and found that it was not associated with favorable functional outcomes at 30 days in a comparison with ETI.
The cluster randomized clinical trial had 1,523 paramedics and 9,296 patients with out-of-hospital cardiac arrest. Jonathan R. Benger, MD, of the University of the West of England in Bristol, and colleagues reported that favorable functional outcome (modified Rankin Scale score in 0-3 range) at hospital discharge or after 30 days (if still hospitalized) occurred in 6.4% of patients in the supraglottic airway group versus 6.8% of patients in the tracheal intubation group. However, the difference was not statistically significant, they noted.
In an accompanying editorial, Lars W. Andersen, MD, PhD, MPH, of Aarhus University Hospital, Aarhus, Denmark, and colleagues, wrote that despite important limitations, the two trials, “provide important new evidence regarding airway managment in out-of-hospital cardiac arrest and again raise the important question of whether endotracheal intubation should be the preferred choice of airway management.”
“EMS personnel and physicans involved with protocol development for EMS systems in the United States, United Kingdom and similar settings with limited exposure to advanced airway management should reconsider the routine use of endotracheal intubation as the first-line strategy for airway management in out-of-hospital cardiac arrest,” they stated.
Wang’s group reported on the Pragmatic Airway Resuscitation Trial that included EMS agencies across a wide range of different practice settings in Birmingham, Alabama; Dallas-Fort Worth; Milwaukee; Pittsburgh; and Portland, Oregon.
The agencies were randomized to have their EMS personnel perform LTI or ETI on out-of-hospital cardiac arrest patients in need of an airway tube with crossover to the alternative strategy occurring at 3- to 5-month intervals during the trial.
The primary study outcome was 72-hour survival and secondary outcomes included return of spontaneous circulation, survival to hospital discharge, favorable neurological status at hospital discharge (Modified Rankin Scale score 3), and key adverse events.
A total of 3,000 patients were included in the primary analysis (median age 64; 60.9% men).
Secondary outcomes in the LTI group versus ETI group included:
- Return of spontaneous circulation: 27.9% versus 24.3% (adjusted difference 3.6%, 95% CI 0.3%-6.8%, P=0.03)
- Hospital survival: 10.8% versus 8.1% (adjusted difference 2.7%, 95% CI 0.6%-4.8%, P=0.01)
- Favorable neurological status at discharge: 7.1% versus 5.0% (adjusted difference 2.1%, 95% CI 0.3%-3.8%, P=0.02)
No significant differences were seen in oropharyngeal or hypo-pharyngeal injury (0.2% versus 0.3%), airway swelling (1.1% versus 1.0%), or pneumonia or pneumonitis (26.1% versus 22.3%), the authors reported.
Study limitations inherent in the cluster, cross-sectional design included imbalances in patient allocation, group baseline characteristics, and variations in within-cluster treatment effects, the researchers wrote.
Additional limitations included the comparison of the two airway management strategies in the EMS agencies without additional training or quality improvement monitoring. The influence of chest compression or ventilation quality was also not assessed and many elements of the trial were, by necessity, not blinded, they stated.
Andersen’s group noted that for most EMS personnel, out-of-hospital cardiac arrest is performed infrequently, suggesting an advantage for airway management strategies that are easier to learn and perform.
“Endotracheal intubation is a skill that needs practice to acquire and maintain,” they wrote, adding that alternative strategies even simpler than the ones examined in the two trials, such as bag-valve-mask ventilation, may result in similar or even better outcomes.