A patient is brought in by ambulance in cardiac arrest.  As is your practice, you start CPR and focus on bag valve mask ventilation (BVM) while the code gets started.  The patient is resuscitated and eventually intubated as they were not conscious after return of spontaneous circulation.  You wonder, if use of BVM is associated with an increased risk of pneumonia given that the airway isn’t defended as well compared to a cuffed endotracheal tube.

There is an ongoing conversation in the literature about the best approach to airway management in cardiac arrest.  One potential reason to favor early endotracheal intubation (ETI) is to defend the airway from gastric contents and secretions which may be aspirated during resuscitation.  A retrospective analysis1 of the Cardiac Arrest Airway Management (CAAM) trial2 (a randomized trial comparing ETI versus BVM in out of hospital cardiac arrest) evaluated the 409 patients (202 who received BVM, 207 who received ETI) who survived to admission for early onset pneumonia (EOP).  EOP was defined as a radiographic infiltrate or change in auscultation plus any one of the following: 1) WBC > 10K or < 3K, 2) temperature > 38.5 or < 35, 3) purulent tracheal aspirates, 4) PaO2:FiO2 ratio < 300. EOP was found in 53% of the overall cohort.  The BVM and ETI groups were equal in the incidence of EOP at 53% in each group.

So, based on this trial, it would not appear that the incidence of EOP is different if the patient undergoes BVM or ETI during their cardiac resuscitation. 

Reference: 

1. Baekgaard JS, Triba MN, Brandeis M, et al. Early-onset pneumonia following bag-mask ventilation versus endotracheal intubation during cardiopulmonary resuscitation: A substudy of the CAAM trial. Resuscitation. Published online 2020. doi:10.1016/j.resuscitation.2020.06.011

2. Jabre P, Penaloza A, Pinero D, et al. Effect of Bag-Mask Ventilation vs Endotracheal Intubation During Cardiopulmonary Resuscitation on Neurological Outcome After Out-of-Hospital Cardiorespiratory Arrest: A Randomized Clinical Trial. JAMA. 2018;319(8):779-787. doi:10.1001/jama.2018.0156