Supraglottic Airway or Tracheal Intubation for Out of Hospital Cardiac Arrest

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The Pre-brief

Rescue 18 is dispatched to a 44-year-old man with active CPR in progress by bystanders. When the crew of Rescue 18 arrive on scene they find a few bystanders doing chest compressions with an AED attached to the patient. They say downtime has only been 7 minutes and they all witnessed him collapse. CPR was started immediately and an AED was attached within moments. 2 shocks have already been delivered. The lead medic looks to his partner and signals him to go to an advanced airway while he prepares the monitor. The airway roll pack is opened but which advance airway is ideal; a supraglottic i-gel or a directly visualized endotracheal tube?

The authors of the AIRWAY-2 Trial, published in 2018, looked at whether a supraglottic i-gel vs an endotracheal tube improved modified Rankin Scores. They found that there was no difference in the modified Rankin Score at hospital discharge or 30 days but this new paper published September 2020 looked at outcomes at 3 and 6 months after out-of-hospital cardiac arrest (OHCA).

The Paper

JR, Lazaroo MJ, Clout M, et al. Randomized Trial of the i-gel Supraglottic Airway Device Versus Tracheal Intubation During Out of Hospital Cardiac Arrest (AIRWAYS-2): Patient Outcomes at Three and Six Months [published online ahead of print, 2020 Sep 30]. Resuscitation. 2020;S0300-9572(20)30490-1. doi:10.1016/j.resuscitation.2020.09.026. PMID: 33010371.

What did they do?

This is a cluster randomized control trial that evaluated the use of either an SGA device or TI for OHCA. 4 EMS agencies in England enlisted 759 paramedics to utilize i-gel SGA devices and 764 paramedics to utilize traditional oral intubation. The original AIRWAYS-2 paper published in 2018, looked at the immediate results of a modified Rankin Score at hospital discharge or 30 days after OHCA. This newly published paper asked survivors to complete questionnaires at 3 and 6 months. Outcomes were analyzed using regression methods.

Inclusion Criteria:

  • 18 years of age or older
  • Non-traumatic OHCA
  • Attended by a paramedic participating in the trial who was either the first or second paramedics to arrive at the patient’s side
  • Resuscitation commenced or continued by paramedics or EMS personnel

Exclusion Criteria:

  • Detained in the prison system
  • Previously recruited in trial
  • Resuscitation deemed inappropriate
  • Advanced airway already in place when a paramedic participating in the trial arrived at the patient’s side
  • Know to be already enrolled in another pre-hospital RCT
  • Patient mouth opening <2cm

What were the outcomes?

“767/9296 (8.3%) enrolled patients survived to 30 days/hospital discharge and 317/767 survivors (41.3%) consented and were followed-up to six months. No significant differences were found between the two treatment groups in the primary outcome measure (mRS score: 3 months: odds ratio (OR) for good recovery (i-gel/TI, OR) 0.89, 95% CI 0.69-1.14; 6 months OR 0.91, 95% CI 0.71-1.16). EQ-5D-5L scores were also similar between groups and sensitivity analyses did not alter the findings.”

What were the limitations?

  • Relatively few survivors in the study
  • Reliance on participants willingness to complete and return questionnaires
  • Only 41.3% of survivors were followed for 6 months
  • More paramedics allocated to i-gel than allocated to use TI
    • These paramedics were volunteers, thus limiting the generalizability of the results

The Authors’ Conclusions

“Longer-term follow-up confirmed the results of the AIRWAYS-2 primary analysis. There were no significant differences in functional outcome or quality of life between the i-gel SGA and TI groups at three and six months after OHCA. This suggests that our initially reported findings are robust over time.”

The Debrief

OHCA research is fraught with limitations and developing an ideal methodology can be challenging. I believe the authors of the AIRWAY-2 trial did a fantastic job of doing their best to put together a data set that helps answer the question if SGAs vs endotracheal intubation made a difference in post OHCA survivors’ modified Rankin Score. I believe that every OHCA scenario is very different. In patients that have large amounts of emesis or other debris in the airway, a supraglottic airway may be challenging to manage and maintain patency. In other scenarios, a supraglottic airway device may be easily placed which may limit the time endotracheal intubation. At the end of the day, this paper does a nice job of allowing us to make a choice of what’s right for our patient/scenario and either airway adjunct is acceptable for long term outcomes.


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