The Never Ending Debate. Airway management in cardiac arrest.

Yes we are talking about airway management in cardiac arrest.

Yes this is another blog post on that topic, and if you are leaving the blog cause you had enough of that topic you have all my comprehension!

Still there?

I ask you just a few minutes of your time and attention to review two new studies that are making so much noise in the FOAMED world.

Here is the first trial:

Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome. The AIRWAYS-2 Randomized Clinical Trial.

Jonathan R. Benger, MD¹; Kim Kirby, MRes^1,2; Sarah Black, DClinRes²; et al

What kind of study is this:

This is a multicenter, cluster randomized clinical trial of paramedics from 4 ambulance services in England.

Inclusion criteria

• 18 years or older
• Non-traumatic OHCA

Exclusion criteria

• Detained by Her Majesty’s Prison Service
• Previously recruited to the trial (determined retrospectively);
• Resuscitation deemed inappropriate (using guidelines from the Joint Royal Colleges Ambulance Liaison Committee)
• Advanced airway already in place (inserted by another paramedic, physician, or nurse) when a paramedic participating in the trial arrived at the patient’s side;
• Known to be enrolled in another prehospital RCT
• The patient’s mouth opened less than 2 cm

Intervention

• Insertion of a second-generation supraglottic airway device with a soft non inflatable cuff (i-gel; Intersurgical) (759 paramedics)

Control

• Tracheal intubation using direct laryngoscopy (764 paramedics)

Main Outcome

• Modified Rankin Scale score at hospital discharge or 30 days after out-of-hospital cardiac arrest
• Secondary outcomes included ventilation success, regurgitation, and aspiration.

Results

Sample population

• 1523 paramedics involved
• 95 hospitals
• 13462 potentially eligible patients
• 4166 (31%)excluded
• 9296(69%) enrolled

Primary outcome

• The primary outcome was available for 9289 of 9296 patients (99.9%).
• In the supraglottic airway device group, 311 of 4882 patients (6.4%) had a good outcome (modified Rankin Scale score range, 0-3)
• In the TI group 300 of 4407 patients (6.8% adjusted OR, 0.92 [95%CI, 0.77 to 1.09];

Secondary outcomes

• The supraglottic airway device treatment strategy was significantly more successful in achieving ventilation after up to 2 attempts with tracheal intubation
• Two of the secondary outcomes, regurgitation and aspiration, were not significantly different between groups
• The median time to death was not significantly different between the groups
• The compression fraction was not significantly different between the group but in a very small sample of 66 patients

Image attribution https://twitter.com/AIRWAYS_2/status/1034456519369256960

Image attribution https://twitter.com/AIRWAYS_2/status/1034456519369256960

Conclusions

Among patients with out-of-hospital cardiac arrest, randomization to a strategy of advanced airway management with a supraglottic airway device compared with tracheal intubation did not result in a favorable functional outcome at 30days.

And here is the second trial:

Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest. A Randomized Clinical Trial

Henry E. Wang, MD, MS^1,2; Robert H. Schmicker, MS³; Mohamud R. Daya, MD, MS⁴; et al

What kind of study is this:

Multicenter pragmatic cluster-crossover clinical trial involving 37 EMS agencies from the Resuscitation Outcomes Consortium Paramedics where Randomized in 13 clusters. Crossover of clusters to the alternate strategy at 3- to 5-month intervals.

Inclusion criteria:

Adults with OHCA and anticipated need for advanced airway management

Intervention

• LT insertion (n = 1505 patients)

Control

• ETI (n = 1499 patients)

Main Outcome

• 72-hour survival

Secondary outcomes

• Return of spontaneous circulation
• Survival to hospital discharge
  Favorable neurological status at hospital discharge (Modified Rankin Scale score3)
• Key adverse events

Results

Population

• 3004 enrolled patients

Rates of initial airway success

• 90.3%with LT
• 51.6%with ET

Primary Outcome

• Seventy-two hour survival was 18.3%in the LT group vs 15.4%in the ETI group

Secondary Outcomes

• Return of spontaneous circulation in the LT group 27.9% vs 24.3% in ETI group
• Hospital survival LT group 10.8%vs 8.1% in ET group
• Favorable neurological status at discharge 7.1% in LT group vs 5.0% in ET group
• No significant differences in oropharyngeal or hypopharyngeal injury airway swelling or pneumonia or pneumonitis

Image attribution https://jamanetwork.com/data/Journals/JAMA/937477/joi180058va.png

Conclusions

Among adults with OHCA, a strategy of initial LT insertion was associated with significantly greater 72-hour survival compared with a strategy of initial ETI. These findings suggest that LT insertion may be considered as an initial airway management strategy in patients with OHCA,

Strength:

This is a well conducted study with a large population that investigated a relevant clinical  topic.

Limitations:

In the TI group the first passage success rate is particularly low (51%) and there is no mention on the percentage of reintubation. This makes the neurologic outcome of this group particularly subject to procedural bias.

In general there is no mention of the post resuscitation care protocol and we know how this period is important on neurological outcome and individual variation makes bias very likely on this particular end point.

References: 

• Henry E. Wang et al. Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac ArrestA Randomized Clinical Trial. 
• Jonathan R. Benger et al Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional OutcomeThe AIRWAYS-2 Randomized Clinical Trial
• Lars W. Andersen et al. Pragmatic Airway Management in Out-of-Hospital Cardiac Arrest