PART trial

incomplete Journal Club Article

Wang Henry 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 Arrest". The Journal of the American Medical Association. 2018. 320(8):769-778.
PubMed Full text PDF

Clinical Question

• What is the effect of an initial airway management strategy using laryngeal tube insertion (LT), compared with endotracheal intubation (ETI), on survival among adults with out-of-hospital cardiac arrest (OHCA)?

Conclusion

• Initial LT, compared with ETI, was associated with greater likelihood of 72-hour survival
• Further research warranted given limitation in study and findings

Study Design

• Multicenter cluster-crossover randomized trial including 27 EMS agencies associated with US sites of the Resuscitation Outcomes Consortium
• The 27 EMS agencies were grouped into 13 randomization clusters
• Each cluster selected a crossover interval of 3-5 months
• Crossover dates and assigned interventions planned by lead statistician to achieve balance across sites

Population

Patient Demographics

• A total of 3,004 patients included
  • 1,505 assigned to initial LT
    • 1,285 received LT
    • 152 received BVM
    • 67 received ETI
    • 1 received an other unknown airway
    • All 1,505 patients included in primary analysis
  • 1,499 assigned to initial ETI
    • 1,160 received ETI
    • 200 received BVM
    • 138 received LT
    • 1 received an other unknown airway
    • 4 patients excluded as 72-hour survival was unknown, 1,495 patients included in primary analysis

Inclusion Criteria

• Adults 18 years or older
• Nontraumatic OHCA treated by participating EMS agencies and requiring anticipated ventilatory support or advanced airway management

Exclusion Criteria

• Patient less than 18 years old
• Traumatic arrests
• Patient who received initial clinical care by EMS agencies with ETI or SGA insertion capabilities that were not affiliated with the trial

Interventions

• EMS agencies randomized to either of 2 initial airway management strategies: LT or oral ETI
  • Protocol allowed use of neuromuscular block agents and video laryngoscopy, but no other techniques such as nasotracheal intubation
  • Protocol did not limit the number of attempts
  • If initial LT/ETI attempt failed, providers could perform rescue airway management using any available technique available to them
• Airway placement confirmed according to local EMS protocols
• Management of OCHA according to local protocols
  • This included termination of resuscitation

Outcomes

Primary and secondary outcomes analyzed on an intention-to-treat basis

Primary Outcome

• Survival to 72 hours after the OHCA
  • LT Group: 18.3%
  • ETI Group: 15.4%
  • Difference of 2.9% (95% CI, 0.2%-5.6%; P=0.05; relative risk, 1.19 [CI, 10.01-1.39]

Secondary Outcomes

• Return of spontaneous circulation (As determined by presence of palpable pulses on arrival to the emergency department)
  • LT Group: 27.9%
  • ETI Group: 24.3%
  • Adjusted difference, 3.6% [95% CI, 0.3%-6.8%]; P = .03
• Survival to hospital discharge
  • LT Group: 10.8%
  • ETI Group: 8.1%
  • Adjusted difference, 2.7% [95% CI, 0.6%-4.8%]; P = .01
• Favorable neurological status on hospital discharge
  • As defined by a Modified Rankin Scale 3 or less
  • LT Group: 7.1%
  • ETI Group: 5.0%
  • Adjusted difference, 2.1% [95% CI, 0.3%-3.8%] P = .02
• Other outcomes included EMS airway management course and hospital adverse events

Subgroup analysis

• A per-protocol analysis was performed
  • Analyzed cases in which patients received their designated airway intervention
  • BVM only patients were retained in their groups for this analysis
    • Authors believed BVM only was an expected course of airway management
  • Analysis determined that 72-hour survival was greater for LT than ETI
    • 18.3% vs 15.4%; risk difference, 2.9% [95% CI, 0.1%-5.7%]; P=0.45

• A post hoc GEE analysis of both the intention-to-treat and per-protocol populations was performed
  • Adjusted for age, sex, bystander- or EMS witnessed arrest, time to EMS arrival, bystander chest compressions, and initial cardiac rhythm
  • Intention-to-treat analysis:
    • Difference in 72-hour survival between LT and ETI was not statistically significant (adjusted difference, 2.1% [95% CI,−0.5%to 4.8%]; P = .11

Criticisms & Further Discussion

• EMS arrival to first airway attempt was 2.7 minutes shorter in the LT group compared to the ETI group
• ETI success rate of 51% in this trial lower than an expected 90% success rate as previously reported
• The LT group had a slightly higher number of OHCA patient with an initial shockable rhythm
• A greater number of patients in the LT group received therapeutic hypothermia or cardiac catheterizaions at the receiving hospitals
  • Both treatments could have independently lead to increased likelihood of 72-hour survival
• Trial does not assess quality of other factors that could influence 72-hour survival such as chest compression quality
• Trial does not evaluate other methods of supraglottic airway
• Result of the trial cannot be applied to an in-hospital setting

Funding

The trial was funded by a National Heart, Lung, and Blood Institute (NHLBI) program supporting large-scale, low-cost pragmatic clinical trials