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

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 [305] 52.6 5.13%   C requested by SME for mild ARDS
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.54 [230] 0.516 4.60%   VD/VT for mild ARDS
ClinicalShuntFraction [0.200,0.400] [222] 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.

Learning Objectives:

  • Recognize worsening oxygenation
  • Respond to high pressure alarm

Recommended Actions:

  • Evaluate for pneumothorax
  • Decrease tidal volume to get acceptable delta P
  • Increase respiratory rate to get same minute ventilation
  • Increase rate and minute ventilation alarm thresholds
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) 405   -8.30% 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 [305] 40.7 1.74%   C requested by SME for moderate ARDS
PhysiologicDeadSpaceTidalVolumeRatio EqualTo 0.57 [230] 0.554 2.91%   VD/VT for moderate ARDS
OxygenSaturation LessThan Segment1 (0.977) [305] [309] 0.939   -3.96% SpO2
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) GreaterThan Segment1 (23.4) [305] 33.0   40.9% PIP
MechanicalVentilator-PlateauPressure(cmH2O) GreaterThan Segment1 (17.0) [305] 19.5   15.1% Pplat
ClinicalShuntFraction [0.300,0.500] [222] 0.292 2.53%   QS/QT for moderate ARDS (determined from blood gas values)
HorowitzIndex(mmHg) [100,200] [115] 136 0.00%   PaO2/FiO2 for moderate ARDS
HighPressureAlarmTriggered-FinalState EqualTo True [305] True Pass   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) 40.7
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.517
ClinicalShuntFraction 0.292
MechanicalVentilator-TidalVolume(L) 0.405
BloodPH 7.36
Aorta-Oxygen-PartialPressure(mmHg) 67.9
Aorta-CarbonDioxide-PartialPressure(mmHg) 45.6
Aorta-Bicarbonate-Molarity(mEq/L) 26.2
OxygenSaturation 0.939
HorowitzIndex(mmHg) 136
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 1.97
MechanicalVentilator-RespirationRate(1/min) 24.6
MechanicalVentilator-MeanAirwayPressure(cmH2O) 14.1
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 33.0
MechanicalVentilator-PlateauPressure(cmH2O) 19.5
HeartRate(1/min) 98.6
SystolicArterialPressure(mmHg) 128
DiastolicArterialPressure(mmHg) 71.7
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 9.95
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 40.7
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 16.2
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 31.8
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 345
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.407
MechanicalVentilator-InspiratoryExpiratoryRatio 0.435
MechanicalVentilator-InspiratoryTidalVolume(L) 0.405
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.458
MechanicalVentilator-LeakFraction 0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 1.60
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 9.60
PhysiologicDeadSpaceTidalVolumeRatio 0.554
PhysiologicShuntFraction 0.299
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelCompliance(mL/cmH2O) 47.0
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.01
TotalPositiveEndExpiratoryPressure(cmH2O) 9.98
EndTidalCarbonDioxidePressure(mmHg) 35.6
PhysiologicDeadSpace(mL) 239
AlveolarArterialGradient(mmHg) 266
AlveolarDeadSpace(mL) 116
AnatomicDeadSpace(mL) 123
ChestWallCompliance(L/cmH2O) 0.137
FractionOfInspiredOxygen 0.499
LungCompliance(L/cmH2O) 0.0592
VentilationPerfusionRatio 1.91
HeartStrokeVolume(mL) 54.6
HeartEjectionFraction 0.438
BloodVolume(L) 5.54
MeanArterialPressure(mmHg) 100
PulsePressure(mmHg) 56.7
CardiacOutput(L/min) 5.38
CarbonDioxideSaturation 0.191
RespiratoryExchangeRatio 0.818
SystemicVascularResistance(mmHg_s/mL) 1.07
OxygenConsumptionRate(mL/min) 223
CarbonDioxideProductionRate(mL/min) 182
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 status

Recommended Actions:

  • None

Ventilator settings are updated to:

  • TV = 450 mL -> 350 mL
  • Flow = 35 L/min -> 28 L/min
  • RR = 20 bpm -> 34 bpm

Ventilator alarm settings are updated to:

  • Low VT = 263 mL (~25% below the initial value)
  • High RR = 40 bpm (~10 bpm above the initial value or a max of 40 bpm)
Table 5. Data request validation results for Segment 3.
Property Name Validation Engine Value Percent Error Percent Change Notes
MechanicalVentilator-TidalVolume(mL) EqualTo 350 346 1.13%   VT (measured)
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) LessThan Segment2 (33.0) [305] 31.6   -4.22% PIP
HighPressureAlarmTriggered-FinalState EqualTo False [305] 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) 43.3
ClinicalPhysiologicDeadSpaceTidalVolumeRatio 0.581
ClinicalShuntFraction 0.256
MechanicalVentilator-TidalVolume(L) 0.346
BloodPH 7.36
Aorta-Oxygen-PartialPressure(mmHg) 74.3
Aorta-CarbonDioxide-PartialPressure(mmHg) 46.3
Aorta-Bicarbonate-Molarity(mEq/L) 26.2
OxygenSaturation 0.950
HorowitzIndex(mmHg) 149
IntrinsicPositiveEndExpiratoryPressure(cmH2O) 4.92
MechanicalVentilator-RespirationRate(1/min) 33.7
MechanicalVentilator-MeanAirwayPressure(cmH2O) 16.7
MechanicalVentilator-PeakInspiratoryPressure(cmH2O) 31.6
MechanicalVentilator-PlateauPressure(cmH2O) 19.0
HeartRate(1/min) 95.3
SystolicArterialPressure(mmHg) 130
DiastolicArterialPressure(mmHg) 70.8
MechanicalVentilator-TotalPulmonaryVentilation(L/min) 11.7
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L) 22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O) 43.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O) 14.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg) 29.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg) 348
MechanicalVentilator-ExpiratoryTidalVolume(L) 0.346
MechanicalVentilator-InspiratoryExpiratoryRatio 0.816
MechanicalVentilator-InspiratoryTidalVolume(L) 0.346
MechanicalVentilator-PeakExpiratoryFlow(L/s) 0.509
MechanicalVentilator-LeakFraction 0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O) 2.97
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O) 11.0
PhysiologicDeadSpaceTidalVolumeRatio 0.554
PhysiologicShuntFraction 0.262
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L) 22.8
TotalRespiratoryModelCompliance(mL/cmH2O) 48.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O) 8.02
TotalPositiveEndExpiratoryPressure(cmH2O) 12.9
EndTidalCarbonDioxidePressure(mmHg) 34.5
PhysiologicDeadSpace(mL) 239
AlveolarArterialGradient(mmHg) 264
AlveolarDeadSpace(mL) 116
AnatomicDeadSpace(mL) 123
ChestWallCompliance(L/cmH2O) 0.163
FractionOfInspiredOxygen 0.498
LungCompliance(L/cmH2O) 0.0594
VentilationPerfusionRatio 2.27
HeartStrokeVolume(mL) 56.9
HeartEjectionFraction 0.446
BloodVolume(L) 5.55
MeanArterialPressure(mmHg) 101
PulsePressure(mmHg) 59.7
CardiacOutput(L/min) 5.42
CarbonDioxideSaturation 0.220
RespiratoryExchangeRatio 0.819
SystemicVascularResistance(mmHg_s/mL) 1.07
OxygenConsumptionRate(mL/min) 225
CarbonDioxideProductionRate(mL/min) 184
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 5. Select outputs from the scenario.


Distributed under the Apache License, Version 2.0.

See accompanying NOTICE file for details.