Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest: none applicable.
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: Nicholas Johnson and Ziad Nehme.
CoSTR Citation
Dewan M, Johnson NJ, Masterson S, Bray J. -on behalf of the International Liaison Committee on Resuscitation Basic Life Support Task Force. Bag Size for Manual Ventilation Consensus on Science with Treatment Recommendations [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Basic Life Support Task Forces, 2025 December 23. Available from: http://ilcor.org
Methodological Preamble and Link to Published Systematic Review
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with a systematic review of ventilation bag sizes PROSPERO citation CRD420117080475) conducted by members of the Basic Life Support Task Force.
Evidence for adult and pediatric literature was sought and considered by the Basic and Advanced Life Support Task Forces. These data were taken into account when formulating the Treatment Recommendations. This was the first systematic review that was completed on this topic.
Systematic Review
Webmaster to insert the Systematic Review citation and link to Pubmed using this format when it is available if published
Dewan M, Johnson N, Masterson S, Bray J. -on behalf of the International Liaison Committee on Resuscitation Basic Life Support Task Force. Bag Size for Manual Ventilation A systematic review [in draft].
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Adults with in-hospital or out-of-hospital cardiac arrest receiving manual ventilation during CPR
Intervention: Use of a smaller manual resuscitation bag than standard size (i.e. using pediatric bag for adult patients) for the patient to limit delivered tidal volume
Comparators: Use of a standard/larger bag (i.e. approximately 1500ml)
Outcomes: Clinical outcomes identified by the BLS Task Force a priori as: critical include survival to hospital discharge or 30 days with favorable neurological outcome, survival to hospital discharge/30 days; important include Survival to discharge or 30 days, Survival to hospital admission, Survival to any time interval after discharge or 30 days survival, Return of spontaneous circulation (ROSC); other delivered tidal volume, ventilation rate, barotrauma
Study Designs: Randomized controlled trials (RCTs) and non-randomized studies (non-randomized controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) are eligible for inclusion. Unpublished studies (e.g., conference abstracts, trial protocols) are excluded. All relevant publications in any language are included provided there is an English abstract. May include simulation studies if clinical studies found are not sufficient.
Timeframe: All years to database inception. search updated to October 13, 2025.
PROSPERO Registration CRD420251266387
Consensus on Science
No randomized controlled trials were identified. The available evidence consists of one before-and-after observational study 1 and two cross-over simulation studies 2,3 that compared two ventilation bag sizes during CPR. An additional small observational pilot study (n=50) compared bag sizes, but included too few patients receiving ventilations during CPR (n=17) to provide meaningful interpretation of the results between groups and was excluded.4
The included before-and-after observational clinical study examined 1,994 OHCA patients with advanced airways (supraglottic or endotracheal) and ventilations provided by emergency medical technicians and advanced life support intensive care paramedics.1 The study compared a period using standard adult volume (1000-1685ml) ventilation bags to a period using smaller-volume (450-700ml) ventilation bags, the smaller bag period included the COVID-19 pandemic. The ventilations in the simulation studies were performed in two minute scenarios by third year paramedic students via an advanced airway 3 or in ten minutes scenarios by registered nurses or basic emergency medical technicians in a moving ambulance via adult-sized facemasks.2
Across the included studies, definitions of “smaller-volume” bags varied and included pediatric or reduced-volume self-inflating bags (typically 500-1000ml) compared with standard adult bags (approximately 1500ml). Due to the small number of studies, and variations (ventilation techniques, airway type and co-interventions) between studies, no meta-analysis was possible.
For the critical outcome of survival to hospital discharge or 30 days with favorable neurological outcome, we identified very low-certainty evidence (downgraded for serious risk of bias and imprecision) from one observational study that compared a period using smaller-volume ventilation bags (~450-700ml) to a period using standard (~1000-1685ml) adult ventilation bags.1 In this before-and-after study (n=1,994), survival to hospital discharge with favorable neurological outcome (cerebral performance category 1-2) was higher in the larger bag period (n=49/663, 7%) compared to the smaller bag period (n=63/1331, 5%) (adjusted odds ratio [AOR]=0.65, 95%CI: 0.43 to 0.99).1
For the critical outcome of survival to hospital discharge or 30 days, we identified very low-certainty evidence (downgraded for serious risk of bias and imprecision) from one observational study that compared a period using smaller-volume ventilation bags (~450-700ml) to a period using standard (~1000-1685ml) adult ventilation bags.1.1 In this before-and-after study (n=1,994), there was no statistical difference in survival to discharge between the period using the larger bag size (n=80/663, 12%) and the smaller bag size (n=125/1331, 9%) (AOR=0.79, 95%CI: 0.57 to 1.09).1
For the important outcome of survival to hospital admission, we identified very low-certainty evidence (downgraded for serious risk of bias and imprecision) one observational study that compared a period using smaller-volume ventilation bags (~450-700ml) to a period using standard (~1000-1685ml) adult ventilation bags.1 In this before-and-after study (n=1,994), survival to hospital admission was higher in the larger bag period (n=276/633, 42%) compared to the smaller bag period (n=460/1331, 35%) (AOR= 0.73, 95%CI: 0.60 to 0.90).1
For the important outcome of ROSC, we identified very low-certainty evidence (downgraded for serious risk of bias and imprecision) from one observational study that compared a period using smaller-volume ventilation bags (~450-700ml) to a period using standard (~1000-1685ml) adult ventilation bags.1 In this before-and-after study (n=1,994), reported no statistical difference in ROSC between the period using the larger bag size (n=341/1663, 51%) and the smaller bag size (n=625/1331, 47%) (AOR=0.85, 95%CI: 0.70 to 1.03).1
For the outcome of tidal volume, we identified very-low certainty evidence from two cross-over simulation studies (downgraded for serious risk of bias, inconsistency, indirectness and imprecision).2,3 The simulation studies were inconsistent in their results of compliance with guideline recommended tidal volumes for adults (400-600mL/ 6-7ml/kg). Riyapan et al. reported higher guideline tidal volume compliance in the larger (1600ml) volume bag group (52% vs 0%, p<0.001), with 100% of tidal volumes <400ml with the smaller (500ml) volume bag (36.5% with the larger bag, p<0.001) and 11.4% exceeding 600mL with the larger (1600ml) bag (0% with smaller bag, p<0.001). Nehme and Boyle reported higher guideline tidal volume compliance with the smaller (1000ml) volume bag (3% vs 30%, p=0.02), with a larger percentage exceeding the upper normal limit with the larger (1600ml) bag (83% vs 37%) and a larger percentage <480ml with the smaller (1000ml) bag (13% vs 33%).
For the outcome of ventilation rate, we identified very-low certainty evidence (downgraded for serious risk of bias, inconsistency, and imprecision) from one observational clinical studies 1 and very-low certainty evidence (downgraded for serious risk of bias, inconsistency, indirectness and imprecision) from two cross-over simulation studies.2,3. The before-and-after study (n=1,994), reported no statistical difference in mean ventilation rates between the period using the larger bag size and the smaller bag size (11.9± 5.3 vs 12.0± 4.8, p=0.60).1 Adherence to guideline recommended ventilation rates (9 to 11 breaths/min) were marginally higher in the smaller bag period (28.4% vs 31.2%), but rates >18 breaths/min were similar between groups (10.6% and 9.7%). The Nehme and Boyle’s simulation study reported slightly higher but not statistically difference guideline compliance ventilation rates in the smaller (1000ml) bag group (23% vs 30%, p=0.77), with hyperventilation (>10 breaths/min) high in both groups (50% vs 47%). In the other simulation study, the average number of ventilations over 10 minutes was significantly lower in the smaller (500ml) volume bag group than in the larger (1600ml) volume bag group (29.2±12.4 versus 43.8±9.3, p<0.001).2
Adverse events
No clinical studies directly compared rates of emesis, aspiration, barotrauma, or other adverse events based on ventilation bag size.
Treatment Recommendations
We suggest the use of a standard size bag (1500 to 1600ml) for the ventilation of adults during cardiopulmonary resuscitation (weak recommendation, very low certainty of evidence).
Justification and Evidence to Decision Framework Highlights
This topic was prioritized by the Basic Life Support (BLS) Task Force based on emerging observational clinical studies evaluating the effect of manual resuscitation bag size on ventilation delivery during cardiac arrest.
Effective ventilation during CPR is essential to optimize oxygen delivery and carbon dioxide removal while minimizing the risk of harm from excessive ventilation. Hyperventilation during CPR has been associated with increased intrathoracic pressure, reduced venous return, decreased coronary and cerebral perfusion, and lower rates of ROSC and survival.5,6 These observations provide biologic plausibility for interventions aimed at avoiding excessive ventilation during resuscitation.
In current practice, standard adult manual resuscitation bags typically have a nominal volume of approximately 1500ml. Even with partial compression, such bags may deliver tidal volumes that exceed guideline recommendations, particularly in high-stress environments such as cardiac arrest. Studies conducted in simulation and limited clinical settings have demonstrated that providers frequently deliver excessive tidal volumes when using standard-sized bags.7,8
Across all outcomes, the certainty of evidence was ranked as very low. Evidence was derived from one observational clinical study and two simulation studies; no randomized clinical trials evaluating ventilation bag size during adult cardiac arrest were identified. In the observational cohort study, use of a smaller-volume bag was associated with significantly lower rates of favorable neurological outcome (5% vs 7%, adjusted odds ratio [AOR]=0.65, 95%CI: 0.43 to 0.99) and survival to hospital admission (35% vs 42%, AOR= 0.73, 95%CI: 0.60 to 0.90) and numerically lower survival to discharge (9% vs 12%, AOR=0.79, 95%CI: 0.57 to 1.09). These findings are impacted by substantial confounding, indirectness, and imprecision inherent to non-randomized designs, resulted in serious downgrading for risk of bias and inconsistency. Simulation studies demonstrated indirect and inconsistent results. Both simulation studies showed a higher proportion of ventilations with lower than guideline recommended delivered tidal volume with smaller bags and a higher proportion of ventilations with higher than guideline recommended delivered tidal volume with larger bags.
Given the very low certainty of evidence for critical outcomes and substantial uncertainty regarding the balance of benefits and harms, the Task Force judged that the balance of effects does not clearly favor a change in practice at this time. This uncertainty supports a weak recommendation for continued use of a standard adult manual resuscitation bag.
GRADE Table: BLS2404 Bag Size ventilation Grade Table
EtD: BLS2404 Bag Size Et D
Knowledge Gaps
There are no randomized controlled trials comparing smaller volume versus standard adult self-inflating ventilation bags during cardiopulmonary resuscitation for critical or important clinical outcomes.
Observational studies evaluating ventilation during resuscitation do not isolate ventilation bag size as the primary exposure and are subject to substantial confounding, including airway type, provider behavior, and resuscitation duration.
Evidence evaluating patient-centered outcomes, including return of spontaneous circulation, survival, and neurological outcome, stratified by ventilation bag size is lacking.
Adverse events potentially related to ventilation bag size, such as regurgitation or aspiration, are not consistently or systematically reported.
Data describing ventilation quality during cardiopulmonary resuscitation according to ventilation bag size in real-world clinical settings are limited.
References
1. Snyder BD, Van Dyke MR, Walker RG, Latimer AJ, Grabman BC, Maynard C, Rea TD, Johnson NJ, Sayre MR, Counts CR. Association of small adult ventilation bags with return of spontaneous circulation in out of hospital cardiac arrest. Resuscitation. 2023;193:109991. doi: 10.1016/j.resuscitation.2023.109991
2. Riyapan S, Hirunwidchayarat P, Ruangsomboon O, Chaisirin W, Limsuwat C, Surabenjawong U, Monsomboon A, Prapruetkit N, Chakorn T. Comparison between Pediatric-Sized and Adult-Sized Bag- Valve-Mask Ventilation for Achieving Appropriate Tidal Volume in Simulated Adult Out-of-Hospital Cardiac Arrest in a Moving Ambulance. Journal of the Medical Association of Thailand. 2021;104:1404 - 1410. doi: DOI: 10.35755/jmedassocthai.2021.09.10408
3. Nehme Z, Boyle MJ. Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation. BMC Emerg Med. 2009;9:4. doi: 10.1186/1471-227X-9-4
4. Yang BY, Blackwood JE, Shin J, Guan S, Gao M, Jorgenson DB, Boehl JE, Sayre MR, Kudenchuk PJ, Rea TD, et al. A pilot evaluation of respiratory mechanics during prehospital manual ventilation. Resuscitation. 2022;177:55-62. doi: 10.1016/j.resuscitation.2022.06.003
5. Aufderheide TP, Sigurdsson G, Pirrallo RG, Yannopoulos D, McKnite S, von Briesen C, Sparks CW, Conrad CJ, Provo TA, Lurie KG. Hyperventilation-induced hypotension during cardiopulmonary resuscitation. Circulation. 2004;109:1960-1965. doi: 10.1161/01.CIR.0000126594.79136.61
6. Aufderheide TP, Lurie KG. Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation. Crit Care Med. 2004;32:S345-351. doi: 10.1097/01.ccm.0000134335.46859.09
7. Merrell JG, Scott AC, Stambro R, Boukai A, Cooper DD. Improved simulated ventilation with a novel tidal volume and peak inspiratory pressure controlling bag valve mask: A pilot study. Resusc Plus. 2023;13:100350. doi: 10.1016/j.resplu.2022.100350
8. Dafilou B, Schwester D, Ruhl N, Marques-Baptista A. It's In The Bag: Tidal Volumes in Adult and Pediatric Bag Valve Masks. West J Emerg Med. 2020;21:722-726. doi: 10.5811/westjem.2020.3.45788