Building Medical Digital Twins with Pulse: Open Source Simulation Tools for Developers and Researchers
Webinar
×
En Route Care Scenario 3

Mild TBI with worsening ARDS

Description

A 25 year-old patient was involved in a training accident where a Humvee was wrecked. She has a mild traumatic brain injury, flail chest and pulmonary contusions. The patient is 5'7" tall, weighs 170 lbs and has no known allergies. She is sedated and not triggering the ventilator.

Figure 1. Chest radiograph demonstrates bilateral patchy opacities and ground glass appearance.

Segment Validation

Segment 1

Learning Objectives:

  • Evaluate ventilatory status

Recommended Actions:

  • None


Ventilator settings are:

Mode VT (L) PIP (cmH2O) Flow (L/min) I:E TI (s) RR (bpm) PEEP (cmH2O) FiO2
VC-AC 0.450 NA 35 NA 0.8 24 8 0.5

Ventilator alarm settings are:

  • High PIP = 33 cmH2O (~10 cmH2O above the initial value or a max of 40 cmH2O)
  • Low MVe = 6.8 L/min (~25% below the initial value)
  • Low VT = 330 mL (~25% below the initial value)
  • High RR = 34 bpm (~10 bpm above the initial value or a max of 40 bpm)
Table 1. Data request validation results for Segment 1.
Property Name Validation Engine Value Percent Error Percent Change Notes
MechanicalVentilator-TidalVolume(mL) EqualTo 450 441 1.92%   VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 11.5 4.53%   Rinsp for mild ARDS
ExpiratoryRespiratoryResistance(cmH2O_s/L) EqualTo 12 [17] 11.5 4.53%   Rexp for mild ARDS
RespiratoryCompliance(mL/cmH2O) EqualTo 50 [304] 52.6 5.13%   C requested by SME for mild ARDS
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.54 [229] 0.516 4.60%   VD/VT for mild ARDS
ClinicalShuntFraction [0.200,0.400] [221] 0.192 4.07%   QS/QT for mild ARDS (determined from blood gas values)
HorowitzIndex(mmHg) [200,300] [115] 196 1.91%   PaO2/FiO2 for mild ARDS



Figure 2. Vitals and ventilator monitors for Segment 1.


Table 2. Data requests for Segment 1.
Property Name Engine Value
Patient-Height(in) 67.0
Patient-IdealBodyWeight(kg) 61.6
InspiratoryRespiratoryResistance(cmH2O_s/L) 11.5
ExpiratoryRespiratoryResistance(cmH2O_s/L) 11.5
RespiratoryCompliance(mL/cmH2O) 52.6
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.456
ClinicalShuntFraction 0.192
MechanicalVentilator-TidalVolume(L) 0.441
BloodPH 7.38
Aorta-Oxygen-PartialPressure(mmHg) 98.0
Aorta-CarbonDioxide-PartialPressure(mmHg) 43.8
Aorta-Bicarbonate-Molarity(mEq/L) 26.1
OxygenSaturation 0.977
HorowitzIndex(mmHg) 196
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.536
MechanicalVentilator-RespirationRate(1/min) 24.0
MechanicalVentilator-MeanAirwayPressure(cmH2O) 11.6
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 23.4
MechanicalVentilator-PlateauPressure(cmH2O) 17.0
HeartRate(1/min) 90.5
SystolicArterialPressure(mmHg) 129
DiastolicArterialPressure(mmHg) 69.5
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 10.6
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 11.5
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 11.5
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 51.9
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 28.6
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 33.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 345
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.441
MechanicalVentilator-InspiratoryExpiratoryRatio 0.471
MechanicalVentilator-InspiratoryTidalVolume(L) 0.441
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.650
MechanicalVentilator-LeakFraction 0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.490
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 8.49
PhysiologicDeadSpaceTidalVolumeRatio 0.516
PhysiologicShuntFraction 0.194
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 11.5
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 11.5
TotalRespiratoryModelCompliance(mL/cmH2O) 58.5
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
TotalPositiveEndExpiratoryPressure(cmH2O) 8.54
EndTidalCarbonDioxidePressure(mmHg) 36.9
PhysiologicDeadSpace(mL) 222
AlveolarArterialGradient(mmHg) 238
AlveolarDeadSpace(mL) 99.2
AnatomicDeadSpace(mL) 123
ChestWallCompliance(L/cmH2O) 0.163
FractionOfInspiredOxygen 0.499
LungCompliance(L/cmH2O) 0.0790
VentilationPerfusionRatio 2.03
HeartStrokeVolume(mL) 59.1
HeartEjectionFraction 0.459
BloodVolume(L) 5.53
MeanArterialPressure(mmHg) 99.7
PulsePressure(mmHg) 59.6
CardiacOutput(L/min) 5.35
CarbonDioxideSaturation 0.0987
RespiratoryExchangeRatio 0.821
SystemicVascularResistance(mmHg_s/mL) 1.07
OxygenConsumptionRate(mL/min) 227
CarbonDioxideProductionRate(mL/min) 186
Patient-AlveoliSurfaceArea(m^2) 28.0
Patient-ExpiratoryReserveVolume(L) 0.738
Patient-FunctionalResidualCapacity(L) 1.38
Patient-InspiratoryCapacity(L) 2.63
Patient-InspiratoryReserveVolume(L) 2.16
Patient-ResidualVolume(L) 0.647
Patient-TidalVolumeBaseline(L) 0.479
Patient-TotalLungCapacity(L) 4.02
Patient-VitalCapacity(L) 3.37

Segment 2

The patient is loaded in the aircraft for transport to the medical center. Halfway through the flight the ventilator starts alarming high inspiratory pressure. The SpO2 falls while PIP and Pplat increase. The patient is now triggering the ventilator at a much higher rate.

Learning Objectives:

  • Recognize worsening oxygenation
  • Respond to high pressure alarm

Recommended Actions:

  • Decrease tidal volume
Table 3. Data request validation results for Segment 2.
Property Name Validation Engine Value Percent Error Percent Change Notes
MechanicalVentilator-TidalVolume(mL) LessThan Segment1 (441) 438   -0.754% VT reduced by PIP alarm cycling
InspiratoryRespiratoryResistance(cmH2O_s/L) GreaterThan Segment1 (11.5) [17] 22.8   99.1% Rinsp for increased PIP
ExpiratoryRespiratoryResistance(cmH2O_s/L) GreaterThan Segment1 (11.5) [17] 22.8   99.1% Rexp for increased PIP
RespiratoryCompliance(mL/cmH2O) EqualTo 40 [304] 42.6 6.37%   C requested by SME for moderate ARDS
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.57 [229] 0.554 2.91%   VD/VT for moderate ARDS
OxygenSaturation LessThan Segment1 (0.977) [304] [308] 0.948   -2.96% SpO2
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) GreaterThan Segment1 (23.4) [304] 27.2   15.8% PIP
MechanicalVentilator-PlateauPressure(cmH2O) GreaterThan Segment1 (17.0) [304] 20.2   18.7% Pplat
ClinicalShuntFraction [0.300,0.500] [221] 0.264 12.7%   QS/QT for moderate ARDS (determined from blood gas values)
HorowitzIndex(mmHg) [100,200] [115] 144 0.00%   PaO2/FiO2 for moderate ARDS
HighPressureAlarmTriggered-FinalState EqualTo True [304] False Fail   High PIP Alarm



Figure 3. Vitals and ventilator monitors for Segment 2.


Table 4. Data requests for Segment 2.
Property Name Engine Value
Patient-Height(in) 67.0
Patient-IdealBodyWeight(kg) 61.6
InspiratoryRespiratoryResistance(cmH2O_s/L) 22.8
ExpiratoryRespiratoryResistance(cmH2O_s/L) 22.8
RespiratoryCompliance(mL/cmH2O) 42.6
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.562
ClinicalShuntFraction 0.264
MechanicalVentilator-TidalVolume(L) 0.438
BloodPH 7.37
Aorta-Oxygen-PartialPressure(mmHg) 72.2
Aorta-CarbonDioxide-PartialPressure(mmHg) 44.9
Aorta-Bicarbonate-Molarity(mEq/L) 26.1
OxygenSaturation 0.948
HorowitzIndex(mmHg) 144
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 2.97
MechanicalVentilator-RespirationRate(1/min) 24.0
MechanicalVentilator-MeanAirwayPressure(cmH2O) 13.8
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 27.2
MechanicalVentilator-PlateauPressure(cmH2O) 20.2
HeartRate(1/min) 95.2
SystolicArterialPressure(mmHg) 129
DiastolicArterialPressure(mmHg) 70.2
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 10.5
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 42.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 22.8
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 32.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 345
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.442
MechanicalVentilator-InspiratoryExpiratoryRatio 0.471
MechanicalVentilator-InspiratoryTidalVolume(L) 0.438
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.416
MechanicalVentilator-LeakFraction 0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 1.78
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 9.78
PhysiologicDeadSpaceTidalVolumeRatio 0.554
PhysiologicShuntFraction 0.265
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelCompliance(mL/cmH2O) 47.5
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.01
TotalPositiveEndExpiratoryPressure(cmH2O) 11.0
EndTidalCarbonDioxidePressure(mmHg) 36.1
PhysiologicDeadSpace(mL) 239
AlveolarArterialGradient(mmHg) 267
AlveolarDeadSpace(mL) 116
AnatomicDeadSpace(mL) 123
ChestWallCompliance(L/cmH2O) 0.161
FractionOfInspiredOxygen 0.499
LungCompliance(L/cmH2O) 0.0594
VentilationPerfusionRatio 2.00
HeartStrokeVolume(mL) 57.4
HeartEjectionFraction 0.450
BloodVolume(L) 5.54
MeanArterialPressure(mmHg) 100
PulsePressure(mmHg) 59.2
CardiacOutput(L/min) 5.46
CarbonDioxideSaturation 0.158
RespiratoryExchangeRatio 0.818
SystemicVascularResistance(mmHg_s/mL) 1.05
OxygenConsumptionRate(mL/min) 223
CarbonDioxideProductionRate(mL/min) 183
Patient-AlveoliSurfaceArea(m^2) 11.2
Patient-ExpiratoryReserveVolume(L) 0.707
Patient-FunctionalResidualCapacity(L) 1.04
Patient-InspiratoryCapacity(L) 2.52
Patient-InspiratoryReserveVolume(L) 2.04
Patient-ResidualVolume(L) 0.333
Patient-TidalVolumeBaseline(L) 0.479
Patient-TotalLungCapacity(L) 3.56
Patient-VitalCapacity(L) 3.23

Segment 3

Ventilator settings are changed. Decrease VT to prevent premature cycling by high-pressure alarm with increased RR to maintain alveolar ventilation.

Learning Objectives:

  • Evaluate effects of changes

Recommended Actions:

  • Increase PEEP and FiO2 to improve oxygenation

Ventilator settings are updated to:

  • TV = 450 mL -> 350 mL
  • Flow = 35 -> 28
Table 5. Data request validation results for Segment 3.
Property Name Validation Engine Value Percent Error Percent Change Notes
MechanicalVentilator-TidalVolume(mL) EqualTo 350 357 1.99%   VT (measured)
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) LessThan Segment2 (27.2) [304] 31.5   15.8% PIP
HighPressureAlarmTriggered-FinalState EqualTo False [304] False Pass   High PIP Alarm



Figure 4. Vitals and ventilator monitors for Segment 3.


Table 6. Data requests for Segment 3.
Property Name Engine Value
Patient-Height(in) 67.0
Patient-IdealBodyWeight(kg) 61.6
InspiratoryRespiratoryResistance(cmH2O_s/L) 22.8
ExpiratoryRespiratoryResistance(cmH2O_s/L) 22.8
RespiratoryCompliance(mL/cmH2O) 42.1
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.568
ClinicalShuntFraction 0.271
MechanicalVentilator-TidalVolume(L) 0.357
BloodPH 7.34
Aorta-Oxygen-PartialPressure(mmHg) 71.8
Aorta-CarbonDioxide-PartialPressure(mmHg) 48.2
Aorta-Bicarbonate-Molarity(mEq/L) 26.3
OxygenSaturation 0.944
HorowitzIndex(mmHg) 144
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 0.0876
MechanicalVentilator-RespirationRate(1/min) 30.0
MechanicalVentilator-MeanAirwayPressure(cmH2O) 13.4
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 31.5
MechanicalVentilator-PlateauPressure(cmH2O) 19.1
HeartRate(1/min) 96.6
SystolicArterialPressure(mmHg) 129
DiastolicArterialPressure(mmHg) 71.5
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 10.7
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 41.4
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 16.0
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 28.8
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 345
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.309
MechanicalVentilator-InspiratoryExpiratoryRatio 0.667
MechanicalVentilator-InspiratoryTidalVolume(L) 0.357
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.460
MechanicalVentilator-LeakFraction 0.135
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 2.43
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 10.4
PhysiologicDeadSpaceTidalVolumeRatio 0.554
PhysiologicShuntFraction 0.275
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelCompliance(mL/cmH2O) 47.0
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
TotalPositiveEndExpiratoryPressure(cmH2O) 8.09
EndTidalCarbonDioxidePressure(mmHg) 34.3
PhysiologicDeadSpace(mL) 239
AlveolarArterialGradient(mmHg) 255
AlveolarDeadSpace(mL) 116
AnatomicDeadSpace(mL) 123
ChestWallCompliance(L/cmH2O) 0.156
FractionOfInspiredOxygen 0.498
LungCompliance(L/cmH2O) 0.0591
VentilationPerfusionRatio 1.77
HeartStrokeVolume(mL) 55.8
HeartEjectionFraction 0.443
BloodVolume(L) 5.55
MeanArterialPressure(mmHg) 101
PulsePressure(mmHg) 57.8
CardiacOutput(L/min) 5.40
CarbonDioxideSaturation 0.291
RespiratoryExchangeRatio 0.817
SystemicVascularResistance(mmHg_s/mL) 1.07
OxygenConsumptionRate(mL/min) 222
CarbonDioxideProductionRate(mL/min) 181
Patient-AlveoliSurfaceArea(m^2) 11.2
Patient-ExpiratoryReserveVolume(L) 0.707
Patient-FunctionalResidualCapacity(L) 1.04
Patient-InspiratoryCapacity(L) 2.52
Patient-InspiratoryReserveVolume(L) 2.04
Patient-ResidualVolume(L) 0.333
Patient-TidalVolumeBaseline(L) 0.479
Patient-TotalLungCapacity(L) 3.56
Patient-VitalCapacity(L) 3.23

Segment 4

Ventilator settings are changed. PEEP and FiO2 increased.

Learning Objectives:

  • Evaluate effects of changes

Recommended Actions:

  • None

Ventilator settings are updated to:

  • FIO2 = 0.50 -> 0.65
  • PEEP = 8 -> 10 cmH2O
Table 7. Data request validation results for Segment 4.
Property Name Validation Engine Value Percent Error Percent Change Notes
MechanicalVentilator-TidalVolume(mL) EqualTo 350 346 1.23%   VT (measured)
OxygenSaturation GreaterThan Segment2 (0.948) [304] [308] 0.971   2.39% SpO2
Aorta-Oxygen-PartialPressure(mmHg) GreaterThan Segment3 (71.8) [185] 104   44.7% PaO2



Figure 5. Vitals and ventilator monitors for Segment 4.


Table 8. Data requests for Segment 4.
Property Name Engine Value
Patient-Height(in) 67.0
Patient-IdealBodyWeight(kg) 61.6
InspiratoryRespiratoryResistance(cmH2O_s/L) 22.8
ExpiratoryRespiratoryResistance(cmH2O_s/L) 22.8
RespiratoryCompliance(mL/cmH2O) 44.3
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.519
ClinicalShuntFraction 0.208
MechanicalVentilator-TidalVolume(L) 0.346
BloodPH 7.24
Aorta-Oxygen-PartialPressure(mmHg) 104
Aorta-CarbonDioxide-PartialPressure(mmHg) 62.6
Aorta-Bicarbonate-Molarity(mEq/L) 26.9
OxygenSaturation 0.971
HorowitzIndex(mmHg) 173
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 5.10
MechanicalVentilator-RespirationRate(1/min) 24.0
MechanicalVentilator-MeanAirwayPressure(cmH2O) 15.5
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 25.6
MechanicalVentilator-PlateauPressure(cmH2O) 19.6
HeartRate(1/min) 107
SystolicArterialPressure(mmHg) 129
DiastolicArterialPressure(mmHg) 74.4
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 8.56
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 44.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 14.3
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 43.6
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 412
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.412
MechanicalVentilator-InspiratoryExpiratoryRatio 0.471
MechanicalVentilator-InspiratoryTidalVolume(L) 0.346
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.563
MechanicalVentilator-LeakFraction 0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 1.49
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 11.5
PhysiologicDeadSpaceTidalVolumeRatio 0.554
PhysiologicShuntFraction 0.211
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelCompliance(mL/cmH2O) 48.8
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 10.0
TotalPositiveEndExpiratoryPressure(cmH2O) 15.1
EndTidalCarbonDioxidePressure(mmHg) 48.9
PhysiologicDeadSpace(mL) 239
AlveolarArterialGradient(mmHg) 296
AlveolarDeadSpace(mL) 116
AnatomicDeadSpace(mL) 123
ChestWallCompliance(L/cmH2O) 0.183
FractionOfInspiredOxygen 0.598
LungCompliance(L/cmH2O) 0.0592
VentilationPerfusionRatio 1.76
HeartStrokeVolume(mL) 51.9
HeartEjectionFraction 0.423
BloodVolume(L) 5.65
MeanArterialPressure(mmHg) 102
PulsePressure(mmHg) 54.5
CardiacOutput(L/min) 5.55
CarbonDioxideSaturation 0.544
RespiratoryExchangeRatio 0.830
SystemicVascularResistance(mmHg_s/mL) 1.05
OxygenConsumptionRate(mL/min) 238
CarbonDioxideProductionRate(mL/min) 198
Patient-AlveoliSurfaceArea(m^2) 11.2
Patient-ExpiratoryReserveVolume(L) 0.707
Patient-FunctionalResidualCapacity(L) 1.04
Patient-InspiratoryCapacity(L) 2.52
Patient-InspiratoryReserveVolume(L) 2.04
Patient-ResidualVolume(L) 0.333
Patient-TidalVolumeBaseline(L) 0.479
Patient-TotalLungCapacity(L) 3.56
Patient-VitalCapacity(L) 3.23

Scenario Output Plots


Figure 6. Select outputs from the scenario.


Distributed under the Apache License, Version 2.0.

See accompanying NOTICE file for details.