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 [1] (Table 3).
  • Compliance: All compliances were taken from Maj et al [8] (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 [8] (Table 2).
  • Shunt: Values for QS/QT were a compromise between Maj et al [8] (Table 2, venous admixture) and Torres et al [13] (Table 3) to give realistic PO2 results for the simulated ventilator settings.
  • Ventilator Settings: All ventilator settings were takeng from Arnal et al [1] (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 [1] 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 [1] (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 [4].

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 [1] 11.6 3.17%   Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [1] 11.6 3.17%   Rexp
RespiratoryCompliance(mL/cmH2O) EqualTo 40 [8] 41.3 3.28%   C
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.54 [8] 0.516 4.59%   VD/VT (determined from blood gas values)
ClinicalShuntFraction EqualTo 0.2 [8] [13] 0.217 8.19%   QS/QT (determined from blood gas values)
MechanicalVentilator-TidalVolume(mL) EqualTo 414 [1] 422 1.82%   VT (measured)
BloodPH [7.28,7.40] [1] 7.37 0.00%   pH
Aorta-Oxygen-PartialPressure(mmHg) [72.0,88.0] [1] 77.7 0.00%   PaO2
Aorta-CarbonDioxide-PartialPressure(mmHg) [37.0,46.0] [1] 44.4 0.00%   PaCO2
OxygenSaturation [0.940,0.970] [4] 0.958 0.00%   SpO2
HorowitzIndex(mmHg) [232,284] [1] 251 0.00%   PaO2/FiO2
HorowitzIndex(mmHg) [200,300] [3] 251 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 0.217
MechanicalVentilator-TidalVolume(L) 0.422
BloodPH 7.37
Aorta-Oxygen-PartialPressure(mmHg) 77.7
Aorta-CarbonDioxide-PartialPressure(mmHg) 44.4
Aorta-Bicarbonate-Molarity(mEq/L) 26.1
OxygenSaturation 0.958
HorowitzIndex(mmHg) 251
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) 69.5
SystolicArterialPressure(mmHg) 115
DiastolicArterialPressure(mmHg) 72.7
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) 34.2
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 2.38e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.379
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 10.4
PhysiologicDeadSpaceTidalVolumeRatio 0.516
ShuntFraction 0.219
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 11.6
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 11.6
TotalRespiratoryModelCompliance(mL/cmH2O) 47.0
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 10.0
TotalPositiveEndExpiratoryPressure(cmH2O) 10.4
EndTidalCarbonDioxidePressure(mmHg) 37.4
PhysiologicDeadSpace(mL) 217
AlveolarArterialGradient(mmHg) 111
AlveolarDeadSpace(mL) 96.6
AnatomicDeadSpace(mL) 120
ChestWallCompliance(L/cmH2O) 0.148
FractionOfInspiredOxygen 0.309
LungCompliance(L/cmH2O) 0.0585
VentilationPerfusionRatio 2.00
HeartStrokeVolume(mL) 81.4
HeartEjectionFraction 0.580
BloodVolume(L) 4.16
MeanArterialPressure(mmHg) 95.4
PulsePressure(mmHg) 42.6
CardiacOutput(L/min) 5.66
CarbonDioxideSaturation 0.135
RespiratoryExchangeRatio 0.824
SystemicVascularResistance(mmHg_s/mL) 0.962
OxygenConsumptionRate(mL/min) 192
CarbonDioxideProductionRate(mL/min) 158
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 [1] 12.4 3.08%   Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [1] 12.4 3.08%   Rexp
RespiratoryCompliance(mL/cmH2O) EqualTo 35 [8] 35.5 1.42%   C
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.57 [8] 0.554 2.90%   VD/VT (determined from blood gas values)
ClinicalShuntFraction EqualTo 0.3 [8] [13] 0.304 1.28%   QS/QT (determined from blood gas values)
MechanicalVentilator-TidalVolume(mL) EqualTo 396 [1] 405 2.19%   VT (measured)
BloodPH [7.26,7.41] [1] 7.34 0.00%   pH
Aorta-Oxygen-PartialPressure(mmHg) [70.0,94.0] [1] 76.6 0.00%   PaO2
Aorta-CarbonDioxide-PartialPressure(mmHg) [39.0,50.0] [1] 47.6 0.00%   PaCO2
OxygenSaturation [0.940,0.970] [4] 0.953 0.00%   SpO2
HorowitzIndex(mmHg) [140,188] [1] 153 0.00%   PaO2/FiO2
HorowitzIndex(mmHg) [100,200] [3] 153 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 0.583
ClinicalShuntFraction 0.304
MechanicalVentilator-TidalVolume(L) 0.405
BloodPH 7.34
Aorta-Oxygen-PartialPressure(mmHg) 76.6
Aorta-CarbonDioxide-PartialPressure(mmHg) 47.6
Aorta-Bicarbonate-Molarity(mEq/L) 26.3
OxygenSaturation 0.953
HorowitzIndex(mmHg) 153
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) 66.9
SystolicArterialPressure(mmHg) 117
DiastolicArterialPressure(mmHg) 71.6
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) 33.5
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 347
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.405
MechanicalVentilator-InspiratoryExpiratoryRatio 0.845
MechanicalVentilator-InspiratoryTidalVolume(L) 0.405
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.768
MechanicalVentilator-LeakFraction 9.92e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.450
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 12.4
PhysiologicDeadSpaceTidalVolumeRatio 0.554
ShuntFraction 0.306
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 12.4
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 12.4
TotalRespiratoryModelCompliance(mL/cmH2O) 39.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
TotalPositiveEndExpiratoryPressure(cmH2O) 12.5
EndTidalCarbonDioxidePressure(mmHg) 37.1
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 2.31
HeartStrokeVolume(mL) 86.8
HeartEjectionFraction 0.594
BloodVolume(L) 4.23
MeanArterialPressure(mmHg) 95.6
PulsePressure(mmHg) 45.0
CardiacOutput(L/min) 5.81
CarbonDioxideSaturation 0.270
RespiratoryExchangeRatio 0.826
SystemicVascularResistance(mmHg_s/mL) 0.938
OxygenConsumptionRate(mL/min) 192
CarbonDioxideProductionRate(mL/min) 159
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 [1] 13.1 8.95%   Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [1] 13.1 8.98%   Rexp
RespiratoryCompliance(mL/cmH2O) EqualTo 33 [8] 32.7 0.970%   C
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.65 [8] 0.630 3.19%   VD/VT
ClinicalShuntFraction EqualTo 0.4 [8] [13] 0.399 0.213%   QS/QT (determined from blood gas values)
MechanicalVentilator-TidalVolume(mL) EqualTo 396 [1] 402 1.47%   VT (measured)
BloodPH [7.21,7.34] [1] 7.34 0.00%   pH
Aorta-Oxygen-PartialPressure(mmHg) [68.0,80.0] [1] 73.2 0.00%   PaO2
Aorta-CarbonDioxide-PartialPressure(mmHg) [44.0,56.0] [1] 48.7 0.00%   PaCO2
OxygenSaturation [0.920,0.950] [4] 0.946 0.00%   SpO2
HorowitzIndex(mmHg) [85.0,100] [1] 91.6 0.00%   PaO2/FiO2
HorowitzIndex(mmHg) LessThan 100 [3] 91.6   -8.40% 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 0.651
ClinicalShuntFraction 0.399
MechanicalVentilator-TidalVolume(L) 0.402
BloodPH 7.34
Aorta-Oxygen-PartialPressure(mmHg) 73.2
Aorta-CarbonDioxide-PartialPressure(mmHg) 48.7
Aorta-Bicarbonate-Molarity(mEq/L) 26.3
OxygenSaturation 0.946
HorowitzIndex(mmHg) 91.6
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) 66.9
SystolicArterialPressure(mmHg) 117
DiastolicArterialPressure(mmHg) 71.5
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) 30.5
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 583
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.402
MechanicalVentilator-InspiratoryExpiratoryRatio 1.00
MechanicalVentilator-InspiratoryTidalVolume(L) 0.402
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.803
MechanicalVentilator-LeakFraction 2.61e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.750
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 12.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 12.8
PhysiologicDeadSpaceTidalVolumeRatio 0.630
ShuntFraction 0.403
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) 34.1
PhysiologicDeadSpace(mL) 264
AlveolarArterialGradient(mmHg) 496
AlveolarDeadSpace(mL) 144
AnatomicDeadSpace(mL) 120
ChestWallCompliance(L/cmH2O) 0.126
FractionOfInspiredOxygen 0.799
LungCompliance(L/cmH2O) 0.0450
VentilationPerfusionRatio 2.86
HeartStrokeVolume(mL) 88.4
HeartEjectionFraction 0.598
BloodVolume(L) 4.25
MeanArterialPressure(mmHg) 95.7
PulsePressure(mmHg) 45.6
CardiacOutput(L/min) 5.91
CarbonDioxideSaturation 0.307
RespiratoryExchangeRatio 0.826
SystemicVascularResistance(mmHg_s/mL) 0.923
OxygenConsumptionRate(mL/min) 191
CarbonDioxideProductionRate(mL/min) 158
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.