Detection of partial endotracheal tube obstruction by forced pressure oscillations
2007 (English)In: Respiratory Physiology & Neurobiology, ISSN 1569-9048, E-ISSN 1878-1519, Vol. 155, no 3, 227-233 p.Article in journal (Refereed) Published
Rapid airway occlusions during mechanical ventilation are followed immediately by high-frequency pressure oscillations. To answer the question if the frequency of forced pressure oscillations is an indicator for partial obstruction of the endotracheal tube (ETT) we performed mathematical simulations and studies in a ventilated physical lung model. Model-derived predictions were evaluated in seven healthy volunteers. Partial ETT obstruction was mimicked by decreasing the inner diameter (ID) of the ETT. In the physical model ETTs of different ID were used. In spontaneously breathing volunteers viscous fluid was applied into the ETT's lumen. According to the predictions derived from mathematical simulations, narrowing of the ETT's ID from 9.0 to 7.0 mm decreased the frequency of the pressure oscillations by 11% while changes of the respiratory system's compliance had no effect. In volunteers, a similar reduction (10.9%) was found when 5 ml fluid were applied. We conclude that analysis of pressure oscillations after flow interruption offers a tool for non-invasive detection of partial ETT obstruction.
Place, publisher, year, edition, pages
2007. Vol. 155, no 3, 227-233 p.
artificial ventilation, electrical analogue, endotracheal tube obstruction, non-invasive method, physical trachea-lung model, respiratory system
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-145768DOI: 10.1016/j.resp.2006.05.010ISI: 000244624900005PubMedID: 16861058OAI: oai:DiVA.org:uu-145768DiVA: diva2:396802