In an ICU a self-inflating resuscitator compressed for an intubated adult fails to re-expand, the oxygen reservoir remains attached, the PEEP valve is in place, the air intake is covered by a blanket, and exhaled air leaks around the bag valves. Which troubleshooting action best restores resuscitator function during assembly?

The self-inflating resuscitator re-expands by elastic recoil that entrains room air through the air intake past the inlet one-way valve, so a blanket occluding that intake prevents refill even with normal oxygen flow, and a stuck inlet or patient valve both blocks refill and allows exhaled gas to leak around the valve assembly, which is why uncovering the intake and inspecting valves restores function while preserving the attached reservoir and PEEP valve required for an intubated adult. Verifying PEEP seating and exhalation-port seal addresses the observed leak but leaves the primary inlet obstruction uncorrected, so recoil still cannot draw volume and the bag remains collapsed. Uncovering the intake while removing the PEEP valve opens the inlet but disassembles a required component, sacrificing PEEP-dependent recruitment when the bag will refill with the valve left in place once inlet flow is restored. Uncovering the intake while raising oxygen flow to keep the reservoir inflated opens the inlet but misattributes re-expansion to fresh gas flow, whereas self-inflating bags refill from room air independent of flow and added flow does not free a stuck valve. A common exam caveat is confusing self-inflating resuscitators with flow-inflating Mapleson bags where flow does determine inflation. A practical bedside check is to complete assembly with reservoir and PEEP in place, uncover the intake, occlude the patient connector, compress and release to confirm brisk full re-expansion, visible valve movement, and reservoir refill without leak.