Professor Loma Linda University Children's Hospital Loma Linda University Children's Hospital Loma Linda, California, United States
Background: High-frequency Jet Ventilation has been used for pediatric applications for some time. Initially utilized for small preterm infants with pulmonary interstitial emphysema in rescue based applications, HFJV has found increased applications in larger patients with an air-leak syndrome or other disease processes where CO2 clearance cannot be achieved with conventional ventilation alone. Still, in specific applications, more efficient HFJV with enhanced ventilatory profiles might produce better outcomes. Bubble Continuous Positive Airway Pressure (bCPAP) has been used in non-invasive applications. Its superiority to conventional CPAP systems is related to an oscillatory component manifest through the ventilation cycle.
Objective: We asked if a combined ventilation mode using bCPAP as a PEEP source for HFJV could provide ventilation that may offer advantages over HFJV paired with a ventilator derived conventional PEEP source.
Design/Methods: For this study, we used an HFJV (Bunnell, Inc) set to 240 breaths per minute (4 Hz), Jet PIP of 20 cm H2O, and IT of 0.02 seconds. A Babi.Plus™ (Babi-Plus.com) was set to provide +4 cm H2O in tandem with HFJV. Data were sampled at 1000 Hz using flow and pressure manometry (Validyne Engineering, Northridge) and Easy Sense 2100 acquisition software (Validyne Engineering, Northridge). Conformed acquired ventilation flow signatures were analyzed using DADiSP (DSP Development Corporation, Newton, MA). Using a Butterfield Wave filter, flow data were abstracted for prominent spectral changes with and without the presence of the bCPAP signature using fast Fourier transform analysis to transform the data into the frequency domain.
Results: Application of the bCPAP appears to result in a more uniform propagation of primary and daughter frequencies, as noted in the graphic. Consistent amplitude magnitudes were present through the second daughter generation. Conclusion(s): Tandem use of the HFJV and bCPAP produce a defined effect on HFJV. While the clinical applicability of these changes in the propagation of useful jet ventilation beyond the primary intended frequency may require further trials, it appears that the augmentation of certain aspects of the ventilatory cycle is worthy of further consideration.
Flow spectrum with (left) and without (right) bCPAP effect.
Authors/Institutions: Mitchell Goldstein, Loma Linda University Children's Hospital, Loma Linda, California, United States; Munaf Kadri, Loma Linda Univ Children's Hospital, Loma Linda, California, United States; Carter K. Tong, Loma Linda University, Department of Cardiopulmonary Sciences, Loma Linda, California, United States; Thurman A. Merritt, Loma Linda University Children's Hospital, Lebanon, Oregon, United States; Elba Fayard, Loma Linda University Children Hospital, Grand Terrace, California, United States; Ricardo Peverini, Loma Linda University Children's Hospital, Loma Linda, California, United States