2012 OPEN FORUM Abstracts
PEAK PRESSURES MEASURED AT THE DISTAL TIP OF PEDIATRIC ENDOTRACHEAL TUBES DURING AN INTRAPULMONARY PERCUSSIVE VENTIALTION CYCLE: A BENCH TEST.
Zachary J. Quinby; Childrens Hospital Colorado, Aurora, CO
Background: Airway clearance is often impaired in intubated pediatric patients. The use of sedation, bypass of the glottis, and decreased airway diameter due to the presence of an artificial airway all significantly affect expiratory flows and the ability to clear secretions. The use of Intrapulmonary Percussive Ventilator therapy (IPV) inline with the circuit of a conventional ventilator has been shown to be an effective means of clearing secretions as evidenced by comparison of chest xrays, however concerns have been raised surrounding the lack of knowledge of PIPs delivered at the distal end of the ETT and thus, the safety of the treatment. This bench test is designed to give a point of reference for PIPs at the distal tip of an ETT during such a treatment and identify the effects of ETT size and IPV settings. Method: An IPV was teed into a pediatric/adult vent circuit with a one way valve to allow the system to maintain PEEP. PIP data was gathered with the IPV set at an Operational Pressure of 25, 35, and 45psig. Percussion was set to 10, 8, and 6.5 at Operational Pressure setting. Test was performed on 4.0, 5.0, and 6.0 ETTs on a PEEPs of 5 and 10 in PC SIMV, f10, Ti 0.8, and deltaP 10. A BioTek VT Plus analyzer was used to monitor PIPs at the distal end of the ETT followed by a test lung. The highest value seen during a one minute cycle on each setting was recorded. Results: PIPs increased as ETT size increased when compared to like settings on the IPV and ventilator. As frequency (percussion) decreased on the IPV, there was a modest variation in PIPs, though not necessarily an increase. ETT size and Operational pressure seemed to have the greatest affect on PIPs. The highest PIPs observed were on the 6.0 ETT on a PEEP of 10, and IPV set at 45psig and percussion at 6.5; PIPs as high as 35 were achieved. Conclusion: IPV can be safely delivered when teed into a circuit on a conventional ventilator, but the practitioner should be cognizant of the effect of the inverse relationship the percussion has on PIPs, the direct relationship ETT size has on PIPs, and carefully consider risk/benefit when using an operational pressure of 45psig on larger ETT sizes. A higher operational pressure may be necessary to be effective patients with smaller ETTs due to the high degree of attenuation. Sponsored Research - None PIPS OBSERVED DURING IPV ON 4.0, 5.0, AND 6.0 ETTS Note: Recoreded PIPs represent the highest pressure seen during the one minute cycle.