The Science Journal of the American Association for Respiratory Care

2001 OPEN FORUM Abstracts


Robert Estetter RRT, DeanHolland RRT, Jennifer DeLaGarza RRT, KennethHawkins RRT, Grant O?Keefe MD MPH, Departments of Respiratory Careand Surgery Parkland Health and Hospital System, Dallas, TX

BACKGROUND: Qualitativechanges in the shape of pressure/time scalars (P/T scalars) have been shownto correlate with changes in resistance and compliance during HFOV. The significanceof these findings is dependent upon a clinician?s ability to interpret changes.However, no standard for interpretation of these P/T scalars has been determined.The purpose of this work is to illustrate a potential standard approach forinterpretation of P/T scalars in HFOV.

Methods: A database of P/T scalars was collected over a three year period consisting of HFOVwaveforms captured from multiple models (bench, animal and patient). The dataconsists of analog P/T scalars obtained at the thermometer port of the circuitry.These measurements were converted to digital form 50,000 times per second (utilizinga Tektronix TDS 3032). P/T tracings were then analyzed to create an ideal construct.



DISCUSSION:We propose that an idealized P/T scalar provides an essential component of futureinvestigation into factors affecting sub-tidal volume delivery. Our work contributesa tool not previously available in the management of HFOV. We find P/T scalarsto be an adjunct that is both sensitive and specific to real-time clinical changesallowing an immediate response to potentially harmful alterations in the patientcourse. Further research is needed to establish the utility of P/T scalars outsideof a research environment.


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