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. @subsection autotoc_md732 Segment Validation @subsubsection autotoc_md733 Segment 1 Learning Objectives: - Evaluate ventilatory status Recommended Actions: - None <br> Ventilator settings are: <table class="markdownTable"> <tr class="markdownTableHead"> <th class="markdownTableHeadNone"> 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	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 450	441	-1.90%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [18]	11.5	-4.43%	Rinsp for mild ARDS
ExpiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [18]	11.5	-4.43%	Rexp for mild ARDS
RespiratoryCompliance(mL/cmH2O)	EqualTo 50 [316]	52.3	4.50%	C requested by SME for mild ARDS
PhysiologicDeadSpaceTidalVolumeRatio	EqualTo 0.54 [238]	0.516	-4.50%	VD/VT for mild ARDS
ClinicalShuntFraction	[0.200,0.400] [229]	0.215	0.00%	QS/QT for mild ARDS (determined from blood gas values)
HorowitzIndex(mmHg)	[200,300] [119]	181	-9.75%	PaO2/FiO2 for mild ARDS

Figure 1. 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)	52.3
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.413
ClinicalShuntFraction	0.215
MechanicalVentilator-TidalVolume(L)	0.441
BloodPH	7.36
Aorta-Oxygen-PartialPressure(mmHg)	90.1
Aorta-CarbonDioxide-PartialPressure(mmHg)	42.9
Aorta-Bicarbonate-Molarity(mEq/L)	26.2
OxygenSaturation	0.971
HorowitzIndex(mmHg)	181
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)	91.0
SystolicArterialPressure(mmHg)	129
DiastolicArterialPressure(mmHg)	69.3
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)	34.0
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	0.220
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	11.5
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	11.5
TotalRespiratoryModelCompliance(mL/cmH2O)	57.9
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8.00
TotalPositiveEndExpiratoryPressure(cmH2O)	8.54
EndTidalCarbonDioxidePressure(mmHg)	36.7
PhysiologicDeadSpace(mL)	222
AlveolarArterialGradient(mmHg)	249
AlveolarDeadSpace(mL)	99.2
AnatomicDeadSpace(mL)	123
ChestWallCompliance(L/cmH2O)	0.159
FractionOfInspiredOxygen	0.499
LungCompliance(L/cmH2O)	0.0790
VentilationPerfusionRatio	1.01
HeartStrokeVolume(mL)	59.2
HeartEjectionFraction	0.459
BloodVolume(L)	5.53
MeanArterialPressure(mmHg)	99.7
PulsePressure(mmHg)	59.9
CardiacOutput(L/min)	5.39
CarbonDioxideSaturation	0.0431
RespiratoryExchangeRatio	0.809
SystemicVascularResistance(mmHg_s/mL)	1.06
OxygenConsumptionRate(mL/min)	228
CarbonDioxideProductionRate(mL/min)	184
Patient-AlveoliSurfaceArea(m^2)	28.0
Patient-ExpiratoryReserveVolume(L)	0.738
Patient-FunctionalResidualCapacity(L)	1.38
Patient-InspiratoryCapacity(L)	2.63
Patient-InspiratoryReserveVolume(L)	2.18
Patient-ResidualVolume(L)	0.647
Patient-TidalVolumeBaseline(L)	0.459
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:

Respond to increased PIP
Recognize dyssynchrony

Recommended Actions:

Evaluate for pneumothorax
Decrease RR to remove dyssynchrony

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)	305		-30.87%	VT reduced by PIP alarm cycling
InspiratoryRespiratoryResistance(cmH2O_s/L)	GreaterThan Segment1 (11.5) [18]	22.8		99.14%	Rinsp for increased PIP
ExpiratoryRespiratoryResistance(cmH2O_s/L)	GreaterThan Segment1 (11.5) [18]	22.8		99.14%	Rexp for increased PIP
RespiratoryCompliance(mL/cmH2O)	EqualTo 40 [316]	41.3	3.32%		C requested by SME for moderate ARDS
PhysiologicDeadSpaceTidalVolumeRatio	EqualTo 0.57 [238]	0.554	-2.87%		VD/VT for moderate ARDS
OxygenSaturation	LessThan Segment1 (0.971) [316] [320]	0.938		-3.45%	SpO2
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	GreaterThan Segment1 (23.4) [316]	33.2		41.69%	PIP
MechanicalVentilator-PlateauPressure(cmH2O)	GreaterThan Segment1 (17.0) [316]	17.4		2.33%	Pplat
ClinicalShuntFraction	[0.300,0.500] [229]	0.293	-2.42%		QS/QT for moderate ARDS (determined from blood gas values)
HorowitzIndex(mmHg)	[100,200] [119]	138	0.00%		PaO2/FiO2 for moderate ARDS

Figure 2. 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)	41.3
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.419
ClinicalShuntFraction	0.293
MechanicalVentilator-TidalVolume(L)	0.305
BloodPH	7.34
Aorta-Oxygen-PartialPressure(mmHg)	68.4
Aorta-CarbonDioxide-PartialPressure(mmHg)	45.4
Aorta-Bicarbonate-Molarity(mEq/L)	26.3
OxygenSaturation	0.938
HorowitzIndex(mmHg)	138
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.0461
MechanicalVentilator-RespirationRate(1/min)	33.0
MechanicalVentilator-MeanAirwayPressure(cmH2O)	13.5
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	33.2
MechanicalVentilator-PlateauPressure(cmH2O)	17.4
HeartRate(1/min)	102
SystolicArterialPressure(mmHg)	129
DiastolicArterialPressure(mmHg)	72.8
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	10.1
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	41.0
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	12.1
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	31.4
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	343
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.306
MechanicalVentilator-InspiratoryExpiratoryRatio	0.444
MechanicalVentilator-InspiratoryTidalVolume(L)	0.305
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.466
MechanicalVentilator-LeakFraction	0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	1.94
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	9.94
PhysiologicDeadSpaceTidalVolumeRatio	0.554
PhysiologicShuntFraction	0.298
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	22.8
TotalRespiratoryModelCompliance(mL/cmH2O)	46.5
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8.00
TotalPositiveEndExpiratoryPressure(cmH2O)	8.05
EndTidalCarbonDioxidePressure(mmHg)	37.7
PhysiologicDeadSpace(mL)	239
AlveolarArterialGradient(mmHg)	261
AlveolarDeadSpace(mL)	116
AnatomicDeadSpace(mL)	123
ChestWallCompliance(L/cmH2O)	0.151
FractionOfInspiredOxygen	0.496
LungCompliance(L/cmH2O)	0.0583
VentilationPerfusionRatio	0.420
HeartStrokeVolume(mL)	53.2
HeartEjectionFraction	0.430
BloodVolume(L)	5.54
MeanArterialPressure(mmHg)	101
PulsePressure(mmHg)	55.8
CardiacOutput(L/min)	5.41
CarbonDioxideSaturation	0.168
RespiratoryExchangeRatio	0.806
SystemicVascularResistance(mmHg_s/mL)	1.07
OxygenConsumptionRate(mL/min)	224
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)	2.06
Patient-ResidualVolume(L)	0.333
Patient-TidalVolumeBaseline(L)	0.459
Patient-TotalLungCapacity(L)	3.56
Patient-VitalCapacity(L)	3.23

Segment 3

Ventilator settings are changed. Decrease RR to remove dyssynchrony.

Learning Objectives:

Evaluate status

Recommended Actions:

None

Ventilator settings are updated to:

RR = 24 bpm -> 12 bpm

Table 5. Data request validation results for Segment 3.

Property Name	Validation	Engine Value	Percent Error	Percent Change	Notes
HighPressureAlarmTriggered-FinalState	EqualTo False [316]	True	Fail		High PIP Alarm

Figure 3. 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)	40.8
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.350
ClinicalShuntFraction	0.298
MechanicalVentilator-TidalVolume(L)	0.446
BloodPH	7.34
Aorta-Oxygen-PartialPressure(mmHg)	67.5
Aorta-CarbonDioxide-PartialPressure(mmHg)	45.2
Aorta-Bicarbonate-Molarity(mEq/L)	26.3
OxygenSaturation	0.936
HorowitzIndex(mmHg)	135
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.318
MechanicalVentilator-RespirationRate(1/min)	16.8
MechanicalVentilator-MeanAirwayPressure(cmH2O)	12.3
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	36.0
MechanicalVentilator-PlateauPressure(cmH2O)	19.5
HeartRate(1/min)	105
SystolicArterialPressure(mmHg)	128
DiastolicArterialPressure(mmHg)	72.7
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	7.47
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	22.8
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	22.8
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	40.7
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	15.9
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	38.1
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	340
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.550
MechanicalVentilator-InspiratoryExpiratoryRatio	0.288
MechanicalVentilator-InspiratoryTidalVolume(L)	0.446
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.578
MechanicalVentilator-LeakFraction	0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.553
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	8.55
PhysiologicDeadSpaceTidalVolumeRatio	0.554
PhysiologicShuntFraction	0.307
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	22.8
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	22.8
TotalRespiratoryModelCompliance(mL/cmH2O)	47.6
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	8.00
TotalPositiveEndExpiratoryPressure(cmH2O)	8.32
EndTidalCarbonDioxidePressure(mmHg)	40.2
PhysiologicDeadSpace(mL)	239
AlveolarArterialGradient(mmHg)	269
AlveolarDeadSpace(mL)	116
AnatomicDeadSpace(mL)	123
ChestWallCompliance(L/cmH2O)	0.143
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0583
VentilationPerfusionRatio	0.960
HeartStrokeVolume(mL)	52.8
HeartEjectionFraction	0.429
BloodVolume(L)	5.54
MeanArterialPressure(mmHg)	101
PulsePressure(mmHg)	55.5
CardiacOutput(L/min)	5.54
CarbonDioxideSaturation	0.159
RespiratoryExchangeRatio	0.805
SystemicVascularResistance(mmHg_s/mL)	1.04
OxygenConsumptionRate(mL/min)	224
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)	2.06
Patient-ResidualVolume(L)	0.333
Patient-TidalVolumeBaseline(L)	0.459
Patient-TotalLungCapacity(L)	3.56
Patient-VitalCapacity(L)	3.23

Scenario Output Plots

Figure 4. Select outputs from the scenario.