1. Dallas 2015 TFQO: David Stanton COI 328 EVREVs: Volker Wenzel COI 253& Emmanuelle Bourdon COI 333 Taskforce: BLS Passive ventilation techniques

2. Dallas 2015 COI Disclosure (specific to this systematic review) Commercial/industry None Potential intellectual conflicts None

3. Dallas 2015 2010 Treatment Recommendation For lay rescuers performing chest compression–only CPR, there is insufficient evidence to recommend the use of any specific passive airway manoeuvre or adjunct ventilation device.

4. Dallas 2015 C2015 PICO Population:Among adults and children who are in cardiac arrest in any setting Intervention:does addition of any passive ventilation technique (eg positioning the body, opening the airway, passive oxygen administration) to chest compression-only CPR Comparison:compared with just chest compression- only CPR Outcomes:change Survival with Favorable neurological/functional outcome at discharge, 30 days, 60 days, 180 days AND/OR 1 year, Survival only at discharge, 30 days, 60 days, 180 days AND/OR 1 year, ROSC, bystander initiated CPR, oxygenation

5. Dallas 2015 Inclusion/Exclusion & Articles Found Inclusion Published comparative studies Exclusion Animal and manikin studies Unpublished data, letters 23 Articles reviewed, and 3 included for review

6. Dallas 2015 2015 Proposed Treatment Recommendations We suggest that in cardiac arrest in the prehospital setting, EMS providers may consider passive ventilation using an orophyrangeal tube and oxygen delivery mask while performing continuous chest compressions (weak evidence, low quality of evidence, subject to serious bias).

7. Dallas 2015 Risk of Bias in studies

8. Dallas 2015

9. Evidence profile table

10. Dallas 2015 Evidence profile table

11. Dallas 2015 Evidence profile table

12. Dallas 2015 Proposed Consensus on Science statements ​ For the critical outcome of „favorable neurological/functional outcome at discharge, 30 days, 60 days, 180 days AND/OR 1 year,“, we identified two studies; one randomized controlled trial (Saissy JM 2000;1523) and one retrospective study (Bobrow BJ 2009;656). Both studies were downgraded due to risk of serious bias. Saissy et al studied continuous insufflation of air or oxygen (CIO) through microcannulas inserted into the inner wall of a modified intubation tube and generating a permanent positive intrathoracic pressure; endpoints were respiratory effects of the intervention compared with intermittent positive pressure ventilation; however, none of the patients in either group survived to hospital discharge. In the Bobrow et al. study, paramedics selected either oropharyngeal airway and high flow oxygen by nonrebreather facemask [46/459 (10%) survivors with adjusted neurologically intact survival to hospital discharge)] without assisted ventilation, or bag-valve-mask ventilation at 8/min [53/560 (9.5%)] survivors with adjusted neurologically intact survival to hospital discharge]. There was an advantage with selected either oropharyngeal airway and high flow oxygen by nonrebreather facemask over bag-valve-mask ventilation in neurologically intact survival at hospital discharge in patients with witnessed VF/VT [39/102 (38.2%) vs. 31/120 (25.8%); OR 2.5 (95% CI 1.3-4.6)]; this positive effect vanished when assessing non-witnessed VF/VT [3/41 (7.3%) vs. 8/58 (13.8%); OR 0.5 (95% CI 0.2-1.6)], or non-shockable rhythms [4/316 (1.3%) vs. 14/381 (3.7%); OR 0.3 (95% CI 0.1-1.0)]..

13. Dallas 2015 For the critical outcome of survival only at discharge, 30 days, 60 days, 180 days AND/OR 1 year, there was only data from the retrospective Bobrow et al. study, with identical numbers to the aforementioned analysis of neurologically intact (oropharyngeal airway and high flow oxygen by nonrebreather facemask [46/459 (10%) survivors with adjusted neurologically intact survival to hospital discharge)] without assisted ventilation vs. bag-valve-mask ventilation at 8/min [53/560 (9.5%)]. For the critical outcome of return of spontaneous circulation, there were two RCTs [the aforementioned Saissy study and Bertrand C 2006;843 (constant flow insufflation of oxygen (CFIO) through Boussignac multichannel endotracheal compared to standard endotracheal intubation and mechanical ventilation)] and the aforementioned study by Bobrow et al. In the Saissy study, outcome of experimental treatment vs. standard treatment was comparable [13/48 (27.1%) vs. 10/47 (21.3%) P=NS, calculated OR 0.71 (95 % CI 0.27 to 1.82)]; in the Bertrand study it was comparable as well [67/355 (19%) vs. 71/341 (21%) P=0.99, calculated OR 1.13 (95 % CI 0.7786 to 1.6411) and also comparable in the retrospective Bobrow et al study [123/459 (26.8%) vs. 169/560 (30.2%), reported OR 0.8 (0.7-1.0)]. For the important outcome of “oxygenation”, there were two RCTs [the aforementioned Saissy and Bertrand study, while the aforementioned study by Bobrow et al. did not report respiratory parameters. In the Saissy study, outcome of experimental treatment vs. standard treatment was PaO2 375 ± 147 vs. 195 ± 101 mm Hg (ICU admission) and PaCO2 34 ± 3 vs. 65 ± 18 mm Hg (ICU admission); both P 70% (P=0.009). However, quality was low in both studies. For the important outcome of “bystander CPR”, data was available in the Bertrand and Bobrow studies; outcome of experimental treatment vs. standard treatment in the Bertrand study was 31/355 (9%) vs. 33/341 (10%); P=0.65; while it was in the Bobrow study 177/459 (38.6%) vs. 242/560 (43.2%); P=n/a, reported OR 0.8 (0.6-1.1).

14. Dallas 2015 Draft Treatment Recommendations We suggest that in cardiac arrest in the prehospital setting, EMS providers may consider passive ventilation using an orophyrangeal tube and oxygen delivery mask while performing continuous chest compressions (weak evidence, low quality of evidence, subject to serious bias).

15. Dallas 2015 Knowledge Gaps This topic may relate to the EMS compression only worksheet True patency of airway never verified in studies selected, movement of air induced by chest compressions highly variable, changes over time, and never measured Specific research required More studies required to improve quality No data in paeds