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MechanicalVentilator-ARDS

MechanicalVentilatorARDS

Description

A male patient with a predicted body weight of 60 kg is mechanically ventilated with varying severities of ARDS. These are the data sources:

  • Resistance: Rinsp is assumed equal to Rexp, taken from Arnal et al [17] (Table 3).
  • Compliance: All compliances were taken from Maj et al [230] (Table 1) derived as tidal volume (ie, mL/kg x PBW calcualted with ARDS equation for males) divided by driving pressure. Mild ARDS was mean minus 1 standard deviatio; moderate ARDS was the mean value; severe ARDS was mean plus 1 standard deviation.
  • Dead space: VD/VT values were taken from Maj et al [230] (Table 2).
  • Shunt: Values for QS/QT were a compromise between Maj et al [230] (Table 2, venous admixture) and Torres et al [365] (Table 3) to give realistic PO2 results for the simulated ventilator settings.
  • Ventilator Settings: All ventilator settings were takeng from Arnal et al [17] (Table 2) for a male patient aged 73 years and predicted body weight of 60 kg. Note that the mode for simulation is PC-CMV, which is equivalent to the mode used by Arnal et [17] for passive pateints. Equivalent settings for tidal volume, rate, and inspiratory time can be used for volume control simulations.
  • Blood Gas Values: Expected blood gas value for outputs of Pulse simulator were taken from the most complete source: Arnal et al [17] (Table 2). FiO2 values for moderate and severe ARDS were adjusted upward to give the expected P/F ratios for the given PaO2 ranges. Expected values for SpO2 were calculated from PaO2 using the equation from Gadrey et al [128].

Segment Validation

Segment 1

Diagnosis: Mild ARDS (severity = 0.3).
Ventilator settings are (VT Target = 6.9 mL/kg (ideal)):

Mode VT (mL) PIP (cmH2O) Flow (L/min) I:E TI (s) RR (bpm) PEEP (cmH2O) FiO2
PC-CMV 414 Adjust NA 0.83 1.3 21 10 0.31
Table 1. Data request validation results for Segment 1.
Property Name Validation Engine Value Percent Error Percent Change Notes
InspiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 11.6 3.17%   Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 11.6 3.17%   Rexp
RespiratoryCompliance(mL/cmH2O) EqualTo 40 [230] 41.3 3.23%   C
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.54 [230] 0.516 4.59%   VD/VT (determined from blood gas values)
ClinicalShuntFraction EqualTo 0.2 [230] [365] 0.183 9.12%   QS/QT (determined from blood gas values)
MechanicalVentilator-TidalVolume(mL) EqualTo 414 [17] 422 1.82%   VT (measured)
BloodPH [7.28,7.40] [17] 7.37 0.00%   pH
Aorta-Oxygen-PartialPressure(mmHg) [72.0,88.0] [17] 81.4 0.00%   PaO2
Aorta-CarbonDioxide-PartialPressure(mmHg) [37.0,46.0] [17] 44.8 0.00%   PaCO2
OxygenSaturation [0.940,0.970] [128] 0.963 0.00%   SpO2
HorowitzIndex(mmHg) [232,284] [17] 263 0.00%   PaO2/FiO2
HorowitzIndex(mmHg) [200,300] [115] 263 0.00%   PaO2/FiO2


Figure 1. Vitals and ventilator monitors for Segment 1.


Table 2. Data requests for Segment 1.
Property Name Engine Value
Patient-Height(in) 64.3
Patient-IdealBodyWeight(kg) 60.0
InspiratoryRespiratoryResistance(cmH2O_s/L) 11.6
ExpiratoryRespiratoryResistance(cmH2O_s/L) 11.6
RespiratoryCompliance(mL/cmH2O) 41.3
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.549
ClinicalShuntFraction 0.183
MechanicalVentilator-TidalVolume(L) 0.422
BloodPH 7.37
Aorta-Oxygen-PartialPressure(mmHg) 81.4
Aorta-CarbonDioxide-PartialPressure(mmHg) 44.8
Aorta-Bicarbonate-Molarity(mEq/L) 26.1
OxygenSaturation 0.963
HorowitzIndex(mmHg) 263
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.385
MechanicalVentilator-RespirationRate(1/min) 21.0
MechanicalVentilator-MeanAirwayPressure(cmH2O) 15.1
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 21.5
MechanicalVentilator-PlateauPressure(cmH2O) 20.8
HeartRate(1/min) 70.4
SystolicArterialPressure(mmHg) 115
DiastolicArterialPressure(mmHg) 73.0
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 8.84
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 11.6
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 11.6
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 40.5
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 36.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 34.5
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 197
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.422
MechanicalVentilator-InspiratoryExpiratoryRatio 0.833
MechanicalVentilator-InspiratoryTidalVolume(L) 0.422
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.750
MechanicalVentilator-LeakFraction 7.43e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.379
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 10.4
PhysiologicDeadSpaceTidalVolumeRatio 0.516
PhysiologicShuntFraction 0.197
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 11.6
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 11.6
TotalRespiratoryModelCompliance(mL/cmH2O) 47.2
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 10.0
TotalPositiveEndExpiratoryPressure(cmH2O) 10.4
EndTidalCarbonDioxidePressure(mmHg) 37.8
PhysiologicDeadSpace(mL) 217
AlveolarArterialGradient(mmHg) 107
AlveolarDeadSpace(mL) 96.6
AnatomicDeadSpace(mL) 120
ChestWallCompliance(L/cmH2O) 0.148
FractionOfInspiredOxygen 0.309
LungCompliance(L/cmH2O) 0.0585
VentilationPerfusionRatio 1.61
HeartStrokeVolume(mL) 79.9
HeartEjectionFraction 0.577
BloodVolume(L) 4.17
MeanArterialPressure(mmHg) 95.3
PulsePressure(mmHg) 41.9
CardiacOutput(L/min) 5.62
CarbonDioxideSaturation 0.156
RespiratoryExchangeRatio 0.825
SystemicVascularResistance(mmHg_s/mL) 0.967
OxygenConsumptionRate(mL/min) 193
CarbonDioxideProductionRate(mL/min) 159
Patient-AlveoliSurfaceArea(m^2) 27.2
Patient-ExpiratoryReserveVolume(L) 0.687
Patient-FunctionalResidualCapacity(L) 1.28
Patient-InspiratoryCapacity(L) 2.45
Patient-InspiratoryReserveVolume(L) 2.02
Patient-ResidualVolume(L) 0.594
Patient-TidalVolumeBaseline(L) 0.434
Patient-TotalLungCapacity(L) 3.73
Patient-VitalCapacity(L) 3.14

Segment 2

Diagnosis: Moderate ARDS (severity = 0.6).
Ventilator settings are (VT Target = 6.6 mL/kg (ideal)):

Mode VT (mL) PIP (cmH2O) Flow (L/min) I:E TI (s) RR (bpm) PEEP (cmH2O) FiO2
PC-CMV 396 Adjust NA 0.91 1.2 23 12 0.50
Table 3. Data request validation results for Segment 2.
Property Name Validation Engine Value Percent Error Percent Change Notes
InspiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 12.4 3.08%   Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 12.4 3.08%   Rexp
RespiratoryCompliance(mL/cmH2O) EqualTo 35 [230] 35.5 1.32%   C
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.57 [230] 0.554 2.90%   VD/VT (determined from blood gas values)
ClinicalShuntFraction EqualTo 0.3 [230] [365] 0.277 8.08%   QS/QT (determined from blood gas values)
MechanicalVentilator-TidalVolume(mL) EqualTo 396 [17] 405 2.19%   VT (measured)
BloodPH [7.26,7.41] [17] 7.34 0.00%   pH
Aorta-Oxygen-PartialPressure(mmHg) [70.0,94.0] [17] 78.1 0.00%   PaO2
Aorta-CarbonDioxide-PartialPressure(mmHg) [39.0,50.0] [17] 48.0 0.00%   PaCO2
OxygenSaturation [0.940,0.970] [128] 0.955 0.00%   SpO2
HorowitzIndex(mmHg) [140,188] [17] 156 0.00%   PaO2/FiO2
HorowitzIndex(mmHg) [100,200] [115] 156 0.00%   PaO2/FiO2


Figure 2. Vitals and ventilator monitors for Segment 2.


Table 4. Data requests for Segment 2.
Property Name Engine Value
Patient-Height(in) 64.3
Patient-IdealBodyWeight(kg) 60.0
InspiratoryRespiratoryResistance(cmH2O_s/L) 12.4
ExpiratoryRespiratoryResistance(cmH2O_s/L) 12.4
RespiratoryCompliance(mL/cmH2O) 35.5
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.584
ClinicalShuntFraction 0.277
MechanicalVentilator-TidalVolume(L) 0.405
BloodPH 7.34
Aorta-Oxygen-PartialPressure(mmHg) 78.1
Aorta-CarbonDioxide-PartialPressure(mmHg) 48.0
Aorta-Bicarbonate-Molarity(mEq/L) 26.3
OxygenSaturation 0.955
HorowitzIndex(mmHg) 156
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.465
MechanicalVentilator-RespirationRate(1/min) 22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O) 17.7
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 24.7
MechanicalVentilator-PlateauPressure(cmH2O) 23.9
HeartRate(1/min) 68.5
SystolicArterialPressure(mmHg) 116
DiastolicArterialPressure(mmHg) 72.3
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 9.27
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 12.4
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 12.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 35.5
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 31.9
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 33.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 346
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.405
MechanicalVentilator-InspiratoryExpiratoryRatio 0.845
MechanicalVentilator-InspiratoryTidalVolume(L) 0.405
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.768
MechanicalVentilator-LeakFraction 9.63e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.450
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 12.4
PhysiologicDeadSpaceTidalVolumeRatio 0.554
PhysiologicShuntFraction 0.299
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 12.4
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 12.4
TotalRespiratoryModelCompliance(mL/cmH2O) 40.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
TotalPositiveEndExpiratoryPressure(cmH2O) 12.5
EndTidalCarbonDioxidePressure(mmHg) 37.4
PhysiologicDeadSpace(mL) 233
AlveolarArterialGradient(mmHg) 257
AlveolarDeadSpace(mL) 113
AnatomicDeadSpace(mL) 120
ChestWallCompliance(L/cmH2O) 0.132
FractionOfInspiredOxygen 0.499
LungCompliance(L/cmH2O) 0.0495
VentilationPerfusionRatio 1.67
HeartStrokeVolume(mL) 83.1
HeartEjectionFraction 0.586
BloodVolume(L) 4.24
MeanArterialPressure(mmHg) 95.5
PulsePressure(mmHg) 43.2
CardiacOutput(L/min) 5.69
CarbonDioxideSaturation 0.284
RespiratoryExchangeRatio 0.827
SystemicVascularResistance(mmHg_s/mL) 0.956
OxygenConsumptionRate(mL/min) 194
CarbonDioxideProductionRate(mL/min) 161
Patient-AlveoliSurfaceArea(m^2) 10.9
Patient-ExpiratoryReserveVolume(L) 0.671
Patient-FunctionalResidualCapacity(L) 0.976
Patient-InspiratoryCapacity(L) 2.40
Patient-InspiratoryReserveVolume(L) 1.96
Patient-ResidualVolume(L) 0.305
Patient-TidalVolumeBaseline(L) 0.434
Patient-TotalLungCapacity(L) 3.37
Patient-VitalCapacity(L) 3.07

Segment 3

Diagnosis: Severe ARDS (severity = 0.9).
Ventilator settings are (VT Target = 6.6 mL/kg (ideal)):

Mode VT (mL) PIP (cmH2O) Flow (L/min) I:E TI (s) RR (bpm) PEEP (cmH2O) FiO2
PC-CMV 396 Adjust NA 1.0 1.2 25 12 0.80
Table 5. Data request validation results for Segment 3.
Property Name Validation Engine Value Percent Error Percent Change Notes
InspiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 13.1 8.96%   Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 13.1 8.96%   Rexp
RespiratoryCompliance(mL/cmH2O) EqualTo 33 [230] 32.7 0.970%   C
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.65 [230] 0.630 3.19%   VD/VT
ClinicalShuntFraction EqualTo 0.4 [230] [365] 0.376 6.19%   QS/QT (determined from blood gas values)
MechanicalVentilator-TidalVolume(mL) EqualTo 396 [17] 402 1.47%   VT (measured)
BloodPH [7.21,7.34] [17] 7.33 0.00%   pH
Aorta-Oxygen-PartialPressure(mmHg) [68.0,80.0] [17] 74.4 0.00%   PaO2
Aorta-CarbonDioxide-PartialPressure(mmHg) [44.0,56.0] [17] 49.1 0.00%   PaCO2
OxygenSaturation [0.920,0.950] [128] 0.948 0.00%   SpO2
HorowitzIndex(mmHg) [85.0,100] [17] 93.1 0.00%   PaO2/FiO2
HorowitzIndex(mmHg) LessThan 100 [115] 93.1   -6.93% PaO2/FiO2


Figure 3. Vitals and ventilator monitors for Segment 3.


Table 6. Data requests for Segment 3.
Property Name Engine Value
Patient-Height(in) 64.3
Patient-IdealBodyWeight(kg) 60.0
InspiratoryRespiratoryResistance(cmH2O_s/L) 13.1
ExpiratoryRespiratoryResistance(cmH2O_s/L) 13.1
RespiratoryCompliance(mL/cmH2O) 32.7
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.652
ClinicalShuntFraction 0.376
MechanicalVentilator-TidalVolume(L) 0.402
BloodPH 7.33
Aorta-Oxygen-PartialPressure(mmHg) 74.4
Aorta-CarbonDioxide-PartialPressure(mmHg) 49.1
Aorta-Bicarbonate-Molarity(mEq/L) 26.3
OxygenSaturation 0.948
HorowitzIndex(mmHg) 93.1
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.792
MechanicalVentilator-RespirationRate(1/min) 25.0
MechanicalVentilator-MeanAirwayPressure(cmH2O) 18.9
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 26.0
MechanicalVentilator-PlateauPressure(cmH2O) 25.0
HeartRate(1/min) 68.9
SystolicArterialPressure(mmHg) 115
DiastolicArterialPressure(mmHg) 72.5
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 10.0
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 13.1
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 13.1
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 32.7
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 28.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 30.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 582
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.402
MechanicalVentilator-InspiratoryExpiratoryRatio 1.00
MechanicalVentilator-InspiratoryTidalVolume(L) 0.402
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.803
MechanicalVentilator-LeakFraction 0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.750
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 12.7
PhysiologicDeadSpaceTidalVolumeRatio 0.630
PhysiologicShuntFraction 0.395
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 13.1
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 13.1
TotalRespiratoryModelCompliance(mL/cmH2O) 36.2
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
TotalPositiveEndExpiratoryPressure(cmH2O) 12.8
EndTidalCarbonDioxidePressure(mmHg) 34.3
PhysiologicDeadSpace(mL) 264
AlveolarArterialGradient(mmHg) 494
AlveolarDeadSpace(mL) 144
AnatomicDeadSpace(mL) 120
ChestWallCompliance(L/cmH2O) 0.126
FractionOfInspiredOxygen 0.799
LungCompliance(L/cmH2O) 0.0450
VentilationPerfusionRatio 1.82
HeartStrokeVolume(mL) 82.8
HeartEjectionFraction 0.585
BloodVolume(L) 4.26
MeanArterialPressure(mmHg) 95.1
PulsePressure(mmHg) 42.6
CardiacOutput(L/min) 5.70
CarbonDioxideSaturation 0.318
RespiratoryExchangeRatio 0.827
SystemicVascularResistance(mmHg_s/mL) 0.950
OxygenConsumptionRate(mL/min) 193
CarbonDioxideProductionRate(mL/min) 159
Patient-AlveoliSurfaceArea(m^2) 5.45
Patient-ExpiratoryReserveVolume(L) 0.663
Patient-FunctionalResidualCapacity(L) 0.703
Patient-InspiratoryCapacity(L) 2.37
Patient-InspiratoryReserveVolume(L) 1.93
Patient-ResidualVolume(L) 0.0404
Patient-TidalVolumeBaseline(L) 0.434
Patient-TotalLungCapacity(L) 3.07
Patient-VitalCapacity(L) 3.03

Scenario Output Plots


Figure 4. Select outputs from the scenario.


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