Performance of ventilators at simulated altitude:

study of FiO2

Jean-Pierre Tourtier , Thomas Leclerc, Marc Borne

Military hospital Val-de-Grâce, Paris, France

Servicede Santédes Armées

Introduction (1):

Aero medical evacuation: ventilatory support

Ventilators: turbine technology

Hypobaric

FiO2 preset / assessed / delivered

Introduction (2):

2 ventilators:

T-bird VS02 LTV-1000

Methods (1):

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Cabin altitude simulation

Methods (2): �

Altitude simulated:

1500 m (4000 feet)

2500 m (6700 feet)

3000 m (3000 feet)

Methods (3): �

Lung simulation: VT1 Bioteck

Normal lung:(resistance : 5.6 cm H2O/L/min ; compliance : 50 ml/cm H2O)

Acute Respiratory Distress Syndrom:(resistance : 3.9 cm H2O/L/min ; compliance : 20 ml/cm H2O)

Methods (4): �

Ventilation parameters:

Lung model Normal lung ARDS

Vt set (ml) 700, 400 400, 250

Respiratory rate 12 20

I/E 1/2 1/1

Fi02 (%) 21,50,90 21, 50, 90

Methods (5): �

Measurements: Actual FiO2

paramagnetic analysis

Methods (6):paramagnetic analysis

focused magnetic field Oxygen is attracted electric potential

« gold standard »

Results (1): Normal lung, ARDS: T-bird VS02

Cabin Altitude

(m)

90 1500 2500 3000

FiO2set

50

50

50

50

Fi02assessed

48

43

55

50

FiO2delivered

49

53

57

61

Results (2): Normal lung, ARDS: T-bird VS02

Cabin Altitude

(m)

90 1500 2500 3000

FiO2set

90

90

90

90

Fi02assessed

87

76

94

84

FiO2delivered

88

96

99

99

Results (3): Normal lung, ARDS: LTV-1000

Cabin Altitude

(m)

90 1500 2500 3000 3000ARDS

Vt 450 ml

FiO2set

50 50

50

50

50

Fi02assessed

49

49

50

50

53

FiO2delivered

50

51

53

54

50

Results (4): Normal lung, ARDS: LTV-1000

Cabin Altitude

(m)

90 1500 2500 3000 3000ARDS

Vt 450 ml

FiO2set

90

90

90

90 90

Fi02assessed

87

76

88

92 92

FiO2delivered

88

96

94

95

90

Results (5): exampleNormal lung, FiO2 set=50%

Conclusion (1): T-bird VS02

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Variations between FiO2 set and delivered: high

Variations between FiO2 delivered and assessed: high

Inefficacity of ventilators Fi02 analysis

Conclusion (2): LTV-1000

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Variations between FiO2 set and delivered: moderate

Variations between FiO2 delivered and assessed: high

Inefficacity of ventilators Fi02 analysis

Conclusion (3): OXYMAN

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