OBJECTIVE: Fio2 values of a new oxygen mask that exploits efficiencies afforded by sequential gas delivery (SGD) were compared to those of a nonrebreathing mask (NRM) and a Venturi oxygen mask. DESIGN: Prospective, single-blinded, randomized study. SETTING: Laboratory study. SUBJECTS:Eight healthy male volunteers. INTERVENTIONS: Volunteers breathed through each of the masks at various minute ventilations (VE). Oxygen flows were 2, 4, and 8 L/min to the SGD mask but only 8 L/min to the other masks. MEASUREMENTS AND MAIN RESULTS:Net FIO2 was calculated from end-tidal fractional concentrations of oxygen and CO2 with the alveolar gas equation. Only the SGD mask at an oxygen flow of 8 L/min consistently provided both FIO2>0.95 (at resting VE) and higher FIO2 than the other masks at all VE. The SGD mask delivered FIO2 comparable to other masks at only a fraction of the oxygen flow and was characterized by a consistent relation between FIO2 and oxygen flow for a given VE. CONCLUSION: We conclude that SGD can be exploited to provide FIO2>0.95 with oxygen flows as low as 8 L/min, as well as accurate and efficient dosing of oxygen even in the presence of hyperpnea.
RCT Entities:
OBJECTIVE:Fio2 values of a new oxygen mask that exploits efficiencies afforded by sequential gas delivery (SGD) were compared to those of a nonrebreathing mask (NRM) and a Venturi oxygen mask. DESIGN: Prospective, single-blinded, randomized study. SETTING: Laboratory study. SUBJECTS: Eight healthy male volunteers. INTERVENTIONS: Volunteers breathed through each of the masks at various minute ventilations (VE). Oxygen flows were 2, 4, and 8 L/min to the SGD mask but only 8 L/min to the other masks. MEASUREMENTS AND MAIN RESULTS: Net FIO2 was calculated from end-tidal fractional concentrations of oxygen and CO2 with the alveolar gas equation. Only the SGD mask at an oxygen flow of 8 L/min consistently provided both FIO2>0.95 (at resting VE) and higher FIO2 than the other masks at all VE. The SGD mask delivered FIO2 comparable to other masks at only a fraction of the oxygen flow and was characterized by a consistent relation between FIO2 and oxygen flow for a given VE. CONCLUSION: We conclude that SGD can be exploited to provide FIO2>0.95 with oxygen flows as low as 8 L/min, as well as accurate and efficient dosing of oxygen even in the presence of hyperpnea.
Authors: Alexandra Mardimae; Marat Slessarev; Jay Han; Hiroshi Sasano; Nobuko Sasano; Takafumi Azami; Ludwik Fedorko; Tim Savage; Rob Fowler; Joseph A Fisher Journal: Ann Emerg Med Date: 2006-10 Impact factor: 5.721
Authors: Tonny V Veenith; Eleanor L Carter; Julia Grossac; Virginia F Newcombe; Joanne G Outtrim; Sridhar Nallapareddy; Victoria Lupson; Marta M Correia; Marius M Mada; Guy B Williams; David K Menon; Jonathan P Coles Journal: J Cereb Blood Flow Metab Date: 2014-07-09 Impact factor: 6.200