• Four Key Questions addressed the comparative benefits and harms across three airway management approaches by emergency medical services in the prehospital setting: Key Question 1 – bag valve mask [BVM] versus supraglottic airway [SGA]; Key Question 2 – BVM versus endotracheal intubation [ETI]); Key Question 3 – SGA versus ETI; and Key Question 4 – how the benefits and harms differ based on patient characteristics, techniques, and devices.
• The most common finding, across emergency types and age groups, was of no differences in primary outcomes when prehospital airway management approaches were directly compared.
• None of the conclusions were supported by high strength of evidence (SOE); thus, future, more rigorous studies could change the findings.
• The following conclusions for Key Questions 1-3 were supported by low or moderate SOE (see Table A):
  • Survival measured in-hospital or at 1-month post incident:
    • No difference in outcomes for all three comparisons in adult/mixed-age patients with cardiac arrest and pediatric patients with cardiac arrest.
    • No difference when BVM was compared with ETI in adult trauma patients.
  • Neurological function measured by the Cerebral Performance Category (CPC), Pediatric CPC, or modified Rankin Scale (mRS) in-hospital or at 1-month post incident:
    • When BVM was compared with SGA, outcomes favored BVM in adult patients with cardiac arrest.
    • When BVM was compared with ETI, there was no difference in outcomes in adult patients with cardiac arrest.
    • When SGA was compared with ETI, outcomes measured by the CPC favored ETI in adult patients with cardiac arrest; there was no difference in outcomes measured by the mRS in this group.
    • When ETI was compared with BVM or SGA, there was no difference in outcomes in pediatric patients with cardiac arrest.
  • Return of spontaneous circulation (ROSC) (prehospital, sustained, or overall):
    • When BVM was compared with SGA or ETI, there was no difference in outcomes in adult patients.
    • When SGA was compared with ETI, outcomes favored SGA in adult patients.
    • When ETI was compared with BVM or SGA, there was no difference in outcomes in pediatric patients.
  • First-pass successful advanced airway insertion (Key Question 3 only):
    • When SGA was compared with ETI, outcomes favored SGA in adult and pediatric patients with cardiac arrest and adult patients with mixed emergency types.
    • No difference when SGA was compared with ETI in adult patients with medical emergencies.
  • Overall successful advanced airway insertion (Key Question 3 only):
    • No difference when SGA was compared with ETI in adult patients with cardiac arrest, medical, or mixed emergency types.
• For other quantitatively analyzed comparisons and outcomes for Key Questions 1-3, there was insufficient evidence to support conclusions.
• Key findings for comparisons within ETI (Key Question 4):
  • Survival measured in hospital:
    • No difference when rapid sequence intubation (RSI) was compared to ETI with no medication in adult/mixed-age patients with trauma.
  • First-pass successful advanced airway insertion:
    • When RSI was compared to ETI with no medication, RSI was favored in adults/mixed-age patients with mixed emergency types; there was no difference in adults/mixed-age patients with trauma.
    • No difference when video laryngoscopy was compared with direct laryngoscopy in adult/mixed-age patients with cardiac arrest or mixed emergency types.
  • Overall successful advanced airway insertion:
    • When RSI was compared to ETI with no medication, RSI was favored in adults with trauma; there was no difference in adults/mixed-age patients with cardiac arrest or mixed emergency types.
    • No difference when video laryngoscopy was compared with direct laryngoscopy in adult/mixed-age patients with cardiac arrest or mixed emergency types.
• Implications based on the current body of evidence and finding that no one airway management approach was consistently superior:
  • It is possible all three airway management techniques have a role in prehospital care and the preferred airway approach depends on the setting, patient age and type, available provider expertise, and equipment.
  • Future research should:
    • Focus on rigorous studies, preferably randomized controlled trials (RCTs), given that important and frequent sources of bias in prehospital airway research are difficult to address in observational studies.
    • Construct comparisons that are more clearly defined by specific emergency types, patient groups, and emergency medical service (EMS) resources including training.

Objective. To assess the comparative benefits and harms across three airway management approaches (bag valve mask [BVM], supraglottic airway [SGA], and endotracheal intubation [ETI]) by emergency medical services in the prehospital setting, and how the benefits and harms differ based on patient characteristics, techniques, and devices.

Data sources. We searched electronic citation databases (Ovid® MEDLINE®, CINAHL®, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus®) from 1990 to September 2020 and reference lists, and posted a Federal Register notice request for data.

Review methods. Review methods followed Agency for Healthcare Research and Quality Evidence-based Practice Center Program methods guidance. Using pre-established criteria, studies were selected and dual reviewed, data were abstracted, and studies were evaluated for risk of bias. Meta-analyses using profile-likelihood random effects models were conducted when data were available from studies reporting on similar outcomes, with analyses stratified by study design, emergency type, and age. We qualitatively synthesized results when meta-analysis was not indicated. Strength of evidence (SOE) was assessed for primary outcomes (survival, neurological function, return of spontaneous circulation [ROSC], and successful advanced airway insertion [for SGA and ETI only]).

Results. We included 99 studies (22 randomized controlled trials and 77 observational studies) involving 630,397 patients. Overall, we found few differences in primary outcomes when airway management approaches were compared.

• For survival, there was moderate SOE for findings of no difference for BVM versus ETI in adult and mixed-age cardiac arrest patients. There was low SOE for no difference in these patients for BVM versus SGA and SGA versus ETI. There was low SOE for all three comparisons in pediatric cardiac arrest patients, and low SOE in adult trauma patients when BVM was compared with ETI.
• For neurological function, there was moderate SOE for no difference for BVM compared with ETI in adults with cardiac arrest. There was low SOE for no difference in pediatric cardiac arrest for BVM versus ETI and SGA versus ETI. In adults with cardiac arrest, neurological function was better for BVM and ETI compared with SGA (both low SOE).
• ROSC was applicable only in cardiac arrest. For adults, there was low SOE that ROSC was more frequent with SGA compared with ETI, and no difference for BVM versus SGA or BVM versus ETI. In pediatric patients there was low SOE of no difference for BVM versus ETI and SGA versus ETI.
• For successful advanced airway insertion, low SOE supported better first-pass success with SGA in adult and pediatric cardiac arrest patients and adult patients in studies that mixed emergency types. Low SOE also supported no difference for first-pass success in adult medical patients. For overall success, there was moderate SOE of no difference for adults with cardiac arrest, medical, and mixed emergency types.
• While harms were not always measured or reported, moderate SOE supported all available findings. There were no differences in harms for BVM versus SGA or ETI. When SGA was compared with ETI, there were no differences for aspiration, oral/airway trauma, and regurgitation; SGA was better for multiple insertion attempts; and ETI was better for inadequate ventilation.

Conclusions. The most common findings, across emergency types and age groups, were of no differences in primary outcomes when prehospital airway management approaches were compared. As most of the included studies were observational, these findings may reflect study design and methodological limitations. Due to the dynamic nature of the prehospital environment, the results are susceptible to indication and survival biases as well as confounding; however, the current evidence does not favor more invasive airway approaches. No conclusion was supported by high SOE for any comparison and patient group. This supports the need for high-quality randomized controlled trials designed to account for the variability and dynamic nature of prehospital airway management to advance and inform clinical practice as well as emergency medical services education and policy, and to improve patient-centered outcomes.

Nancy Carney, Annette M. Totten, Tamara Cheney, et al. Prehospital airway management: A systematic review. Prehospital Emergency Care. 11 Jun 2021. DOI: 10.1080/10903127.2021.1940400

Carney N, Cheney T, Totten AM, Jungbauer R, Neth MR, Weeks C, Davis-O’Reilly C, Fu R, Yu Y, Chou R, Daya M. Prehospital Airway Management: A Systematic Review. Comparative Effectiveness Review No. 243. (Prepared by the Pacific Northwest Evidence-based Practice Center under Contract No. 290-2015-00009-I.) AHRQ Publication No. 21-EHC023. Rockville, MD: Agency for Healthcare Research and Quality; June 2021.DOI: 10.23970/AHRQEPCCER243. Posted final reports are located on the Effective Health Care Program search page.