Mild TBI with worsening ARDS

Description

A 25 year-old active duty Marine 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:

Increase RR to 27 to get acceptable pH

Ventilator settings are:

Mode	VT (L)	PIP (cmH2O)	Flow (L/min)	I:E	TI (s)	RR (bpm)	PEEP (cmH2O)	FiO2
VC-CMV	0.42	NA	51	NA	0.51	20	8	0.50

Table 1. Data request validation results for Segment 1.

Property Name	Validation	Engine Value	Percent Error	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 420 [17]	407.9	2.9%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	11.49	4.3%	Rinsp for mild ARDS
ExpiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	11.49	4.3%	Rexp for mild ARDS
RespiratoryCompliance(mL/cmH2O)	EqualTo 40 [229]	40.2	0.5%	C for mild ARDS
PhysiologicDeadSpaceTidalVolumeRatio	EqualTo 0.54 [229]	0.4929	9.1%	VD/VT for mild ARDS
ShuntFraction	EqualTo 0.2 [229]	0.2127	6.2%	QS/QT for mild ARDS
HorowitzIndex(mmHg)	[200,300] [115]	211.2	0.0%	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
Patient-IdealBodyWeight(kg)	61.6
InspiratoryRespiratoryResistance(cmH2O_s/L)	11.5
ExpiratoryRespiratoryResistance(cmH2O_s/L)	11.5
RespiratoryCompliance(mL/cmH2O)	40.2
PhysiologicDeadSpaceTidalVolumeRatio	0.493
ShuntFraction	0.213
MechanicalVentilator-TidalVolume(L)	0.408
BloodPH	7.19
Aorta-Oxygen-PartialPressure(mmHg)	105
Aorta-CarbonDioxide-PartialPressure(mmHg)	69.9
Aorta-Bicarbonate-Molarity(mEq/L)	27.2
OxygenSaturation	0.969
HorowitzIndex(mmHg)	211
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.0429
MechanicalVentilator-RespirationRate(1/min)	19.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	10.5
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	27.5
MechanicalVentilator-PlateauPressure(cmH2O)	18.6
HeartRate(1/min)	129
SystolicArterialPressure(mmHg)	110
DiastolicArterialPressure(mmHg)	82.7
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	8.1
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	11.5
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	11.5
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	38.5
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	20.9
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	48.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	328
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.408
MechanicalVentilator-InspiratoryExpiratoryRatio	0.208
MechanicalVentilator-InspiratoryTidalVolume(L)	0.408
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.705
MechanicalVentilator-LeakFraction	3.48E-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.0371
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	8.04
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8
TotalPositiveEndExpiratoryPressure(cmH2O)	8.04
EndTidalCarbonDioxidePressure(mmHg)	53.6
PhysiologicDeadSpace(mL)	213
AlveolarArterialGradient(mmHg)	211
AlveolarDeadSpace(mL)	89.4
AnatomicDeadSpace(mL)	123
ChestWallCompliance(L/cmH2O)	0.123
FractionOfInspiredOxygen	0.498
LungCompliance(L/cmH2O)	0.0616
VentilationPerfusionRatio	1.69
HeartStrokeVolume(mL)	47.1
HeartEjectionFraction	0.416
BloodVolume(L)	5.65
MeanArterialPressure(mmHg)	96.3
PulsePressure(mmHg)	27.5
CardiacOutput(L/min)	6.05
CarbonDioxideSaturation	0.18
RespiratoryExchangeRatio	0.835
SystemicVascularResistance(mmHg_s/mL)	0.906
OxygenConsumptionRate(mL/min)	245
CarbonDioxideProductionRate(mL/min)	204
Patient-AlveoliSurfaceArea(m^2)	30.8
Patient-ExpiratoryReserveVolume(L)	0.71
Patient-FunctionalResidualCapacity(L)	1.35
Patient-InspiratoryCapacity(L)	2.54
Patient-InspiratoryReserveVolume(L)	2.06
Patient-ResidualVolume(L)	0.635
Patient-TidalVolumeBaseline(L)	0.476
Patient-TotalLungCapacity(L)	3.88
Patient-VitalCapacity(L)	3.25

Segment 2

The patient is loaded in the aircraft for transport to SAMMC. Halfway through the flight the ventilator starts alarming high inspiratory pressure. The SpO2 falls while PIP and Pplat increase. Heart rate decreases, and blood pressure remains constant. The patient is now triggering the ventilator at a much higher rate.
Learning Objectives:

Recognize worsening oxygenation

Recommended Actions:

Increase FiO2
Increase PEEP

Table 3. Data request validation results for Segment 2.

Property Name	Validation	Engine Value	Percent Error	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 420 [17]	411.7	2.0%		VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	13.2	9.5%		Rinsp for severe ARDS
ExpiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	13.22	9.6%		Rexp for severe ARDS
RespiratoryCompliance(mL/cmH2O)	EqualTo 33 [229]	30.6	7.6%		C for severe ARDS
PhysiologicDeadSpaceTidalVolumeRatio	EqualTo 0.65 [229]	0.6333	2.6%		VD/VT for severe ARDS
ShuntFraction	EqualTo 0.4 [229]	0.4216	5.3%		QS/QT for severe ARDS
HorowitzIndex(mmHg)	LessThan 100 [115]	114.9		14.9%	PaO2/FiO2 for severe ARDS

Figure 3. Vitals and ventilator monitors for Segment 2.

Table 4. Data requests for Segment 2.

Property Name	Engine Value
Patient-Height(in)	67
Patient-IdealBodyWeight(kg)	61.6
InspiratoryRespiratoryResistance(cmH2O_s/L)	13.2
ExpiratoryRespiratoryResistance(cmH2O_s/L)	13.2
RespiratoryCompliance(mL/cmH2O)	30.6
PhysiologicDeadSpaceTidalVolumeRatio	0.633
ShuntFraction	0.422
MechanicalVentilator-TidalVolume(L)	0.412
BloodPH	7.23
Aorta-Oxygen-PartialPressure(mmHg)	57.4
Aorta-CarbonDioxide-PartialPressure(mmHg)	64
Aorta-Bicarbonate-Molarity(mEq/L)	27
OxygenSaturation	0.869
HorowitzIndex(mmHg)	115
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.278
MechanicalVentilator-RespirationRate(1/min)	24.6
MechanicalVentilator-MeanAirwayPressure(cmH2O)	11.6
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	33.8
MechanicalVentilator-PlateauPressure(cmH2O)	21.6
HeartRate(1/min)	119
SystolicArterialPressure(mmHg)	112
DiastolicArterialPressure(mmHg)	81.3
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	10.1
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	13.1
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	13.2
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	30.6
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	16
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	32.3
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	348
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.466
MechanicalVentilator-InspiratoryExpiratoryRatio	0.271
MechanicalVentilator-InspiratoryTidalVolume(L)	0.412
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.974
MechanicalVentilator-LeakFraction	0
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.121
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	8.12
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8
TotalPositiveEndExpiratoryPressure(cmH2O)	8.28
EndTidalCarbonDioxidePressure(mmHg)	35.5
PhysiologicDeadSpace(mL)	273
AlveolarArterialGradient(mmHg)	279
AlveolarDeadSpace(mL)	150
AnatomicDeadSpace(mL)	123
ChestWallCompliance(L/cmH2O)	0.0998
FractionOfInspiredOxygen	0.499
LungCompliance(L/cmH2O)	0.0445
VentilationPerfusionRatio	3.12
HeartStrokeVolume(mL)	52.6
HeartEjectionFraction	0.442
BloodVolume(L)	5.69
MeanArterialPressure(mmHg)	96.4
PulsePressure(mmHg)	30.3
CardiacOutput(L/min)	6.26
CarbonDioxideSaturation	0.194
RespiratoryExchangeRatio	0.827
SystemicVascularResistance(mmHg_s/mL)	0.876
OxygenConsumptionRate(mL/min)	234
CarbonDioxideProductionRate(mL/min)	194
Patient-AlveoliSurfaceArea(m^2)	5.31
Patient-ExpiratoryReserveVolume(L)	0.679
Patient-FunctionalResidualCapacity(L)	0.71
Patient-InspiratoryCapacity(L)	2.42
Patient-InspiratoryReserveVolume(L)	1.95
Patient-ResidualVolume(L)	0.0313
Patient-TidalVolumeBaseline(L)	0.476
Patient-TotalLungCapacity(L)	3.13
Patient-VitalCapacity(L)	3.1

Segment 3

Ventialtor settings are changed. PEEP and FiO2 increased, tidal volume decreased.

Learning Objectives:

Evaluate effects of changes

Recommended Actions:

Increase tidal volume to previous setting
Patient unable to trigger fast enough to improve pH

Ventilator settings are updated to:

FIO2 = 0.50-1.00
PEEP = 8-12 cmH2O
VT = 0.42-0.34 L

Mode	VT (L)	PIP (cmH2O)	Flow (L/min)	I:E	TI (s)	RR (bpm)	PEEP (cmH2O)	FiO2
VC-CMV	0.34	NA	51	NA	0.41	20	12	1.00

Table 5. Data request validation results for Segment 3.

Property Name	Validation	Engine Value	Percent Error	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 340 [17]	327	3.9%		VT (measured)
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan Segment 2 (57.35) [186]	79.86		39.2%	PaO2

Figure 4. Vitals and ventilator monitors for Segment 3.

Table 6. Data requests for Segment 3.

Property Name	Engine Value
Patient-Height(in)	67
Patient-IdealBodyWeight(kg)	61.6
InspiratoryRespiratoryResistance(cmH2O_s/L)	13.2
ExpiratoryRespiratoryResistance(cmH2O_s/L)	13.2
RespiratoryCompliance(mL/cmH2O)	31.7
PhysiologicDeadSpaceTidalVolumeRatio	0.633
ShuntFraction	0.411
MechanicalVentilator-TidalVolume(L)	0.327
BloodPH	7.18
Aorta-Oxygen-PartialPressure(mmHg)	79.9
Aorta-CarbonDioxide-PartialPressure(mmHg)	72.2
Aorta-Bicarbonate-Molarity(mEq/L)	27.2
OxygenSaturation	0.934
HorowitzIndex(mmHg)	80.1
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.168
MechanicalVentilator-RespirationRate(1/min)	37.5
MechanicalVentilator-MeanAirwayPressure(cmH2O)	15.5
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	30.4
MechanicalVentilator-PlateauPressure(cmH2O)	23
HeartRate(1/min)	132
SystolicArterialPressure(mmHg)	111
DiastolicArterialPressure(mmHg)	82.1
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	12.3
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	13.1
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	13.2
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	31.5
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	17.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	33.2
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	735
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.327
MechanicalVentilator-InspiratoryExpiratoryRatio	0.356
MechanicalVentilator-InspiratoryTidalVolume(L)	0.327
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.512
MechanicalVentilator-LeakFraction	0
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.611
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	12
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	12.6
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	12
TotalPositiveEndExpiratoryPressure(cmH2O)	12.2
EndTidalCarbonDioxidePressure(mmHg)	38.5
PhysiologicDeadSpace(mL)	273
AlveolarArterialGradient(mmHg)	641
AlveolarDeadSpace(mL)	150
AnatomicDeadSpace(mL)	123
ChestWallCompliance(L/cmH2O)	0.115
FractionOfInspiredOxygen	0.997
LungCompliance(L/cmH2O)	0.0442
VentilationPerfusionRatio	3.18
HeartStrokeVolume(mL)	50.1
HeartEjectionFraction	0.428
BloodVolume(L)	5.74
MeanArterialPressure(mmHg)	96.6
PulsePressure(mmHg)	29.1
CardiacOutput(L/min)	6.63
CarbonDioxideSaturation	0.18
RespiratoryExchangeRatio	0.834
SystemicVascularResistance(mmHg_s/mL)	0.829
OxygenConsumptionRate(mL/min)	243
CarbonDioxideProductionRate(mL/min)	203
Patient-AlveoliSurfaceArea(m^2)	5.31
Patient-ExpiratoryReserveVolume(L)	0.679
Patient-FunctionalResidualCapacity(L)	0.71
Patient-InspiratoryCapacity(L)	2.42
Patient-InspiratoryReserveVolume(L)	1.95
Patient-ResidualVolume(L)	0.0313
Patient-TidalVolumeBaseline(L)	0.476
Patient-TotalLungCapacity(L)	3.13
Patient-VitalCapacity(L)	3.1

Scenario Output Plots

Figure 5. Select outputs from the scenario.