Page 51 - Journal of Special Operations Medicine - Fall 2016

Figure 2 Delivered fraction of inspired oxygen (Fio ) Table 5 Factors Influencing Delivered Fraction of Inspired
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according to oxygen concentrator (OC) oxygen flow chart. Oxygen
Factor p Value
OC flow <.0001
MV <.0001
I/E .022
PEEP .046
I/E = inspiratory-to-expiratory ratio; OC = oxygen concentrator;
PEEP = positive end-expiratory pressure; MV = minute ventilation.
limited surgical unit setting. However, modifications of
the ventilator settings may significantly affect the de-
livered Fio . This study provides useful clinical perfor-
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mance data for the Elisée ventilator when paired with
the SeQual Integra 10-OM OC for use in mechanical
ventilation in austere locations.
Effects of I/E Ratio on Delivered Fio 2
There was a statistically significant difference in Fio The French Army is deployed in the African desert with
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when the expiratory time was modified to I/E = 1/2 (Ta- light, mobile units providing intensive care and surgery
ble 4) when all the other parameters remained constant.
close to the point of battlefield injury. Logistic support
for the FSU is a difficult challenge. Compressed oxy-
Effects of PEEP on Delivered Fio 2 gen is routinely one of the first needs in intensive care
There was statistically significant difference between the or anesthesia. Oxygen resources in our current location
delivered Fio at 0, 10, and 15cmH O of PEEP when all are severely limited, and oxygen delivery for ventilated
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the other parameters remained constant (Table 4).
patients can be challenging in any austere environment.
The use of cumbersome oxygen production modules
Factors Affecting the Delivered Fio 2 is not possible in these settings. FSUs have a few high-
The factors that independently affected the delivered Fio pressure oxygen cylinders, and OC for production of
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were OC flow, minute ventilation, I/E, and PEEP (Table 5).
low-pressure oxygen. The predictable difficulty in re-
supplying oxygen cylinders and use of OC are factors
Discussion influencing the choice of ventilators in such contexts.
Some ventilators functioning with a piston, turbine,
In this study, we showed the Elisée 350 ventilator is able or compressor do not need compressed gas to gener-
to deliver high Fio with an OC tested in a resource- ate flow and may be used with a low-pressure oxygen
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Table 4 Effects of I/E Ratio and PEEP on Delivered Fio source. The Elisée 350 ventilator is one such modern
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OC Flow (L/min) ventilator chosen by FMHS for its ventilation capabili-
ties to equip FSUs and for the possibility to be supplied
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Parameter 2 4 8 by a low-pressure oxygen source. Boussen et al. tested
PEEP several transport ventilators and showed the Elisée 350
0 34.75 — 69.5 was appropriate to deliver mechanical ventilation to
critically ill patients, with a level of performance compa-
5 35 — 69.5
rable to an intensive care unit ventilator. Additionally,
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10 35.25* — 70.25* they showed this ventilator has a short, useful duration
15 35.5* — 71* of 2 hours and 45 minutes when it is used with a 1,000L
I/E ratio compressed oxygen cylinder (ventilator settings: Fio , 1;
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1/1 36** 50** 75.5** PEEP, 5; tidal volume, 500mL; rate, 12). That is more
1/2 34.8 46.6 69.5 than the LTV 1000 ventilator, which is known to be a
high consumer of compressed oxygen (duration is less
1/4 34.5 47.5** 70.5** than 40 minutes with 700L of oxygen in a cylinder),
1/9 35.5** 48.5** 72.5** due to a constant flow of 10L/min during exhalation
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I/E = inspiratory-to-expiratory ratio; OC = oxygen concentrator; to allow stabile PEEP. The lower oxygen consumption
PEEP = positive end-expiratory pressure. of the Elisée 350 may be explained by a smaller turbine
*p < .01 compared with PEEP of 0 cmH O with I/E ratio of 1/2; respi- that requires less oxygen flow; however, it still would
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ratory rate (RR), 12/min; and tidal volume (Vt), 500 mL.
**p < .01 compared with I/E ratio of 1/2 with PEEP of 0 cmH O; RR, require too much flow in the primary inflow port to
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12/min; and Vt, 500 mL. drive mechanic ventilation in a low-resources context.
Fio Delivered by Ventilator With Oxygen Concentrator 33
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