Use the following link to download the PDF of this file 2020-04-06 COVID19 intubation resources Note that this version talks about disconnecting the BVM+Filter from the BVM+PEEP assembly when taking this off for intubation BUT this is not recommended if you are at risk of connecting the BVM to an inserted SGA or ETT without a filter on.
Many places would either leave the unit together (MaskFilterBVM/PEEP) and/or turn down their oxygen flow but that has a risk of forgetting to turn it back up again. If there is little to no oxygen forward flow thru the filter of your setup then these steps are likely unecessary as you are not blowing virus particles back out thru the filter potentially.
Some use a low flow O2 addition to the BVM setup that is between the BVM valve and the patient to improve CPAP and PEEP. See EMcrit and AIME for their descriptions of this.