Abstract
Background: The VOCSN (Ventec Life Systems, Bothell, WA) device integrates up to five therapies (ventilation, oxygen concentrator, cough assist, suction, and nebulization) and can operate using two low flow oxygen sources: internal concentrator or bleed-in from an external gas source. We evaluated the oxygen flow requirements using the VOCSN pulse dose internal concentrator (PDIC) vs the VOCSN and Trilogy 100 ventilator (Philips Respironics, Murrysville, PA) using an external oxygen concentrator (EC). We hypothesized the flow necessary to achieve a specified FIO2 would be lower when using the pulse dose internal concentrator. Methods: The VOCSN and Trilogy 100 were compared using passive and active circuits connected to a TTL test lung (Michigan Instruments, Grand Rapids, MI). Three simulated lung models using different TTL test lung parameters included: normal – Cst 60 mL/cm H2O and Raw 5 cm H2O/L/s, restrictive – Cst 30 mL/cm H2O and Raw 5 cm H2O/L/s, and obstructive – Cst 60 mL/cm H2O, Raw 20 cm H2O/L/s. Using pressure ventilation, the peak pressure and rise time were titrated to achieve VT of 500mL as measured by a Certifier FA Plus (TSI Inc, Shoreview MN). Additional settings include: 12 breaths/min, PEEP 5 cm H2O, and IT 1.0 second. VOCSN PDIC and a Millennium M10 (Respironics, Murrysville, PA) EC flow were adjusted to achieve a measured FIO2 of approximately 0.40. Flow from the EC was measured by the Certifier FA Plus and FIO2 was measured by the Handi + oxygen analyzer (Maxtec, Salt Lake City, UT) at the inlet of the test lung. At least three measurements were done for each ventilator, circuit type, lung model, and oxygen concentrator combination. Data for the three lung models were averaged for each test configuration and reported as the mean ± SD for each circuit type. Results: The oxygen flow in L/min required to maintain a FIO2 of 0.40 (mean ± SD) with passive and active circuits respectively was: VOCSN-PDIC 2.61 ± 0.02 and 2.68 ± 0.12, VOCSN-EC 3.05 ± 0.16 and 5.59 ± 0.36, Trilogy-EC 4.78 ± 0.70 and 8.28 ± 1.31. Measured VT and FIO2 for all lung models, test configurations, and circuit types averaged 502 ± 8 mL and 0.397 ± 0.006 respectively. Conclusions: Oxygen flow requirement was lowest with the VOCSN ventilator using pulse dose internal oxygen concentrator with both the passive and active circuits, and with VOCSN using an external oxygen concentrator with the passive circuit compared to the Trilogy 100 ventilator.
Footnotes
Commercial Relationships: Mark Siobal: Aerogen, Aerogen Pharma
Support: We received disposable and non-disposable equipment (circuits, ventilators and a concentrator) as well as oxygen from Ventec Life Systems for the purposes of this study.
- Copyright © 2019 by Daedalus Enterprises
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