The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts

DOES ADEQUATE PRESSURE PROPAGATION OCCUR WITH NASAL CANNULA INTERMITTENT MANDATORY VENTILATION (NCIMV)?

Carter Tong, Mitchell Goldstein, T. A. Merritt, Michael Terry, Elba Fayard, Richard Peverini; Neonatology, Loma Linda University ChildrenÂ’s Hospital, Loma Linda, CA

Background: Nasal Cannula has long been used to deliver flow based ventilation. As nasal cannula flow traditionally has derived from a wall flow source,, pressure propagation at the nasal interface is highly variable. More recently, nasal cannula delivery of intermittent mandatory ventilation (IMV) has been advocated. We asked whether a novel high flow nasal cannula with a larger diameter than conventional nasal cannula would be useful to deliver adequate pressure propagated ventilation using traditional IMV settings. Methods: We studied three cannula: the Preemie Ram Cannula, the Newborn Ram Cannula, and the Infant Ram Cannula. An Avea Ventilator (Viasys) in TCPL-SIMV mode was used to deliver pressures of 10/5, 15/5, 20/5, 25/5, and 30/5 with an It of 0.35s and flow 8 LPM. Leak and tube compensation were disabled. Measures of PIP propagation, volume delivery at PIP propagation and PEEP of 5 cm H2O, as well as mean airway pressure generation at the wye were recorded. Results: As shown in the chart. Conclusions: Little deviation in the mean airway pressure at the wye was noted. This indicates flow/pressure propagation to the nasal cannula and thus low resistance to flow at typical PEEP levels Volume delivery was adequate at the different levels of PIP using a back pressure of 5 cm H2O, indicating a limiting factor of I-time and not flow or pressure propagation. PIP pressures were limited to delivery at ranges from 15-18 cm H2O. At this level, resistive forces inherent to the cannula would prevent excess pressure generation at the nose. NC-IMV is feasible and efficacious with the RAM cannula. At higher levels of PIP, the cannula may be protective. Sponsored Research - None