Definition
- Intrinsic PEEP is also known as auto-PEEP or PEEPi
- Asthma / COPD patients have higher levels of PEEPi and are susceptible to dynamic hyper-inflation (DH) or “breath stacking”
Diagnosis
- Slow filling of manual ventilator bag
- Capnography trace that does not reaching plateau
- Expiratory flow not reaching zero in flow-time/volume graph
- Measure intrinsic PEEP (PEEPi)
DH increases intra-thoracic volume and results in:
- increased inspiratory work to trigger the vent
- increased risk of barotrauma
- decrease venous return, preload, cardiac output resulting in decreased cardiac output
Management – allow more time for exhalation with less breath stacking
- Treat reversible factors (bronchospasm, secretions)
- Reduce RR, decrease I:E ratio (typically to 1:3 – 1:5)
- Consider use of external PEEP (will decrease work to trigger vent)
- If patient has hypotension, disconnect circuit from ETT to observe prolonged exhalation and resolution of hypotension (don’t forget to involve RT and reconnect promptly!)
References