Mild ARDS with Tension Pneumothorax

Description

A 25 year-old soldier was injured following an IED detonation while dismounted. He suffered a traumatic amputation of the right lower extremity below the knee, multiple puncture wounds from fragments in the left lower extremity and lost consciousness at the scene. A tourniquet was applied and the hemorrhage mitigated. Both eardrums were ruptured and his GCS was 12. He underwent a massive transfusion, received 10 units of whole blood, crystalloid infusions and platelets. In the operating room primary control of hemorrhage was achieved and the lower extremity amputation addressed using standard techniques. The patient arrived from the operating room on mechanical ventilation. He was sedated and is not currently triggering the ventilator. The patient is 5'9'' tall, weighs 170 lbs and has no known comorbidities or allergies.

Figure 1. Chest radiograph demonstrates subcutaneous air and small pneumomediastinum. There is no pneumothorax.

Segment Validation

Segment 1

Diagnosis: Mild ARDS.
Ventilator settings are (VT Target = 6.9 mL/kg (ideal)):

Mode	VT (L)	PIP (cmH2O)	Flow (L/min)	I:E	TI (s)	RR (bpm)	PEEP (cmH2O)	FiO2
VC-CMV	0.488	NA	52	NA	0.6	20	5	0.4

Table 1. Data request validation results for Segment 1.

Property Name	Validation	Engine Value	Percent Error	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 500 [17]	485.2	3.0%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	11.62	3.2%	Rinsp for mild ARDS
ExpiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	11.63	3.2%	Rexp for mild ARDS
RespiratoryCompliance(mL/cmH2O)	EqualTo 40 [229]	38.8	3.0%	C for mild ARDS
PhysiologicDeadSpaceTidalVolumeRatio	EqualTo 0.54 [229]	0.5154	4.7%	VD/VT for mild ARDS
ShuntFraction	EqualTo 0.2 [229]	0.2821	34.1%	QS/QT for mild ARDS
HorowitzIndex(mmHg)	[200,300] [115]	188.6	5.9%	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)	69
Patient-IdealBodyWeight(kg)	70.7
InspiratoryRespiratoryResistance(cmH2O_s/L)	11.6
ExpiratoryRespiratoryResistance(cmH2O_s/L)	11.6
RespiratoryCompliance(mL/cmH2O)	38.8
PhysiologicDeadSpaceTidalVolumeRatio	0.515
ShuntFraction	0.282
MechanicalVentilator-TidalVolume(L)	0.485
BloodPH	7.21
Aorta-Oxygen-PartialPressure(mmHg)	75.3
Aorta-CarbonDioxide-PartialPressure(mmHg)	66.5
Aorta-Bicarbonate-Molarity(mEq/L)	27
OxygenSaturation	0.929
HorowitzIndex(mmHg)	189
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.046
MechanicalVentilator-RespirationRate(1/min)	20
MechanicalVentilator-MeanAirwayPressure(cmH2O)	8.28
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	27.5
MechanicalVentilator-PlateauPressure(cmH2O)	18.4
HeartRate(1/min)	97.8
SystolicArterialPressure(mmHg)	112
DiastolicArterialPressure(mmHg)	78.8
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	9.7
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	11.6
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	11.6
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	36.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	21.6
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	43.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	255
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.485
MechanicalVentilator-InspiratoryExpiratoryRatio	0.25
MechanicalVentilator-InspiratoryTidalVolume(L)	0.485
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.882
MechanicalVentilator-LeakFraction	2.68E-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.0449
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.04
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
TotalPositiveEndExpiratoryPressure(cmH2O)	5.05
EndTidalCarbonDioxidePressure(mmHg)	47.3
PhysiologicDeadSpace(mL)	255
AlveolarArterialGradient(mmHg)	167
AlveolarDeadSpace(mL)	114
AnatomicDeadSpace(mL)	141
ChestWallCompliance(L/cmH2O)	0.107
FractionOfInspiredOxygen	0.399
LungCompliance(L/cmH2O)	0.0585
VentilationPerfusionRatio	2.08
HeartStrokeVolume(mL)	66.8
HeartEjectionFraction	0.513
BloodVolume(L)	5.63
MeanArterialPressure(mmHg)	96.2
PulsePressure(mmHg)	33.6
CardiacOutput(L/min)	6.54
CarbonDioxideSaturation	0.187
RespiratoryExchangeRatio	0.832
SystemicVascularResistance(mmHg_s/mL)	0.838
OxygenConsumptionRate(mL/min)	277
CarbonDioxideProductionRate(mL/min)	231
Patient-AlveoliSurfaceArea(m^2)	32.1
Patient-ExpiratoryReserveVolume(L)	0.809
Patient-FunctionalResidualCapacity(L)	1.51
Patient-InspiratoryCapacity(L)	2.89
Patient-InspiratoryReserveVolume(L)	2.35
Patient-ResidualVolume(L)	0.699
Patient-TidalVolumeBaseline(L)	0.54
Patient-TotalLungCapacity(L)	4.4
Patient-VitalCapacity(L)	3.7

Segment 2

Diagnosis: Pneumothorax.
The patient is loaded in the aircraft for transport to level III care. Twenty minutes into the transport SpO2 falls and PIP and Pplat are increased. (decreased compliance). The patient remains sedated and is not triggering the ventilator.

Table 3. Data request validation results for Segment 2.

Property Name	Validation	Engine Value	Percent Error	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 500 [17]	485.3	3.0%		VT (measured)
RespiratoryCompliance(mL/cmH2O)	LessThan Segment 1 (38.8) [304]	19.54		-49.6%	C
SystolicArterialPressure(mmHg)	LessThan Segment 1 (112.4) [304]	71.88		-36.1%	BP
DiastolicArterialPressure(mmHg)	LessThan Segment 1 (78.82) [304]	58.78		-25.4%	BP
Aorta-Oxygen-PartialPressure(mmHg)	LessThan Segment 1 (75.32) [186]	36.34		-51.7%	PaO2
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	GreaterThan Segment 1 (27.47) [304]	36.51		32.9%	PIP
MechanicalVentilator-PlateauPressure(cmH2O)	GreaterThan Segment 1 (18.44) [304]	30.28		64.2%	Pplat

Figure 3. Vitals and ventilator monitors for Segment 2.

Table 4. Data requests for Segment 2.

Property Name	Engine Value
Patient-Height(in)	69
Patient-IdealBodyWeight(kg)	70.7
InspiratoryRespiratoryResistance(cmH2O_s/L)	13.2
ExpiratoryRespiratoryResistance(cmH2O_s/L)	12.3
RespiratoryCompliance(mL/cmH2O)	19.5
PhysiologicDeadSpaceTidalVolumeRatio	0.515
ShuntFraction	0.438
MechanicalVentilator-TidalVolume(L)	0.485
BloodPH	7.23
Aorta-Oxygen-PartialPressure(mmHg)	36.3
Aorta-CarbonDioxide-PartialPressure(mmHg)	63.5
Aorta-Bicarbonate-Molarity(mEq/L)	26.9
OxygenSaturation	0.657
HorowitzIndex(mmHg)	91.3
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.00137
MechanicalVentilator-RespirationRate(1/min)	20
MechanicalVentilator-MeanAirwayPressure(cmH2O)	9.66
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	36.5
MechanicalVentilator-PlateauPressure(cmH2O)	30.3
HeartRate(1/min)	160
SystolicArterialPressure(mmHg)	71.9
DiastolicArterialPressure(mmHg)	58.8
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	9.71
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	13.2
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.3
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	19.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	15.4
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	30
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	277
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.485
MechanicalVentilator-InspiratoryExpiratoryRatio	0.25
MechanicalVentilator-InspiratoryTidalVolume(L)	0.485
MechanicalVentilator-PeakExpiratoryFlow(L/s)	1.43
MechanicalVentilator-LeakFraction	0
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.000957
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
TotalPositiveEndExpiratoryPressure(cmH2O)	5
EndTidalCarbonDioxidePressure(mmHg)	31.5
PhysiologicDeadSpace(mL)	255
AlveolarArterialGradient(mmHg)	138
AlveolarDeadSpace(mL)	114
AnatomicDeadSpace(mL)	141
ChestWallCompliance(L/cmH2O)	0.999
FractionOfInspiredOxygen	0.4
LungCompliance(L/cmH2O)	0.0193
VentilationPerfusionRatio	4.63
HeartStrokeVolume(mL)	24.2
HeartEjectionFraction	0.339
BloodVolume(L)	5.66
MeanArterialPressure(mmHg)	65.3
PulsePressure(mmHg)	13.1
CardiacOutput(L/min)	3.87
CarbonDioxideSaturation	0.209
RespiratoryExchangeRatio	0.788
SystemicVascularResistance(mmHg_s/mL)	0.874
OxygenConsumptionRate(mL/min)	266
CarbonDioxideProductionRate(mL/min)	210
Patient-AlveoliSurfaceArea(m^2)	32.1
Patient-ExpiratoryReserveVolume(L)	0.809
Patient-FunctionalResidualCapacity(L)	1.51
Patient-InspiratoryCapacity(L)	2.89
Patient-InspiratoryReserveVolume(L)	2.35
Patient-ResidualVolume(L)	0.699
Patient-TidalVolumeBaseline(L)	0.54
Patient-TotalLungCapacity(L)	4.4
Patient-VitalCapacity(L)	3.7

Segment 3

Resolution of pneumothorax with needle decompression.

Table 5. Data request validation results for Segment 3.

Property Name	Validation	Engine Value	Percent Error	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 500 [17]	485.5	2.9%		VT (measured)
RespiratoryCompliance(mL/cmH2O)	GreaterThan Segment 2 (19.54) [304]	32.43		66.0%	C
SystolicArterialPressure(mmHg)	GreaterThan Segment 2 (71.88) [304]	103.3		43.8%	BP
DiastolicArterialPressure(mmHg)	GreaterThan Segment 2 (58.78) [304]	70.33		19.7%	BP
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan Segment 2 (36.34) [186]	67.64		86.1%	PaO2
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	LessThan Segment 2 (36.51) [304]	26.91		-26.3%	PIP
MechanicalVentilator-PlateauPressure(cmH2O)	LessThan Segment 2 (30.28) [304]	21.93		-27.6%	Pplat

Figure 4. Vitals and ventilator monitors for Segment 3.

Table 6. Data requests for Segment 3.

Property Name	Engine Value
Patient-Height(in)	69
Patient-IdealBodyWeight(kg)	70.7
InspiratoryRespiratoryResistance(cmH2O_s/L)	11.7
ExpiratoryRespiratoryResistance(cmH2O_s/L)	12.4
RespiratoryCompliance(mL/cmH2O)	32.4
PhysiologicDeadSpaceTidalVolumeRatio	0.515
ShuntFraction	0.294
MechanicalVentilator-TidalVolume(L)	0.485
BloodPH	7.22
Aorta-Oxygen-PartialPressure(mmHg)	67.6
Aorta-CarbonDioxide-PartialPressure(mmHg)	65.7
Aorta-Bicarbonate-Molarity(mEq/L)	27
OxygenSaturation	0.908
HorowitzIndex(mmHg)	169
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	-0.0404
MechanicalVentilator-RespirationRate(1/min)	20
MechanicalVentilator-MeanAirwayPressure(cmH2O)	8.21
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	26.9
MechanicalVentilator-PlateauPressure(cmH2O)	21.9
HeartRate(1/min)	81.2
SystolicArterialPressure(mmHg)	103
DiastolicArterialPressure(mmHg)	70.3
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	9.71
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	11.7
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	28.7
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	22.2
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	39.4
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	260
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.453
MechanicalVentilator-InspiratoryExpiratoryRatio	0.25
MechanicalVentilator-InspiratoryTidalVolume(L)	0.485
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.839
MechanicalVentilator-LeakFraction	0.0667
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.0199
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.02
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
TotalPositiveEndExpiratoryPressure(cmH2O)	4.96
EndTidalCarbonDioxidePressure(mmHg)	44
PhysiologicDeadSpace(mL)	255
AlveolarArterialGradient(mmHg)	182
AlveolarDeadSpace(mL)	114
AnatomicDeadSpace(mL)	141
ChestWallCompliance(L/cmH2O)	0.0958
FractionOfInspiredOxygen	0.399
LungCompliance(L/cmH2O)	0.0578
VentilationPerfusionRatio	2.57
HeartStrokeVolume(mL)	65
HeartEjectionFraction	0.536
BloodVolume(L)	5.69
MeanArterialPressure(mmHg)	87.8
PulsePressure(mmHg)	33
CardiacOutput(L/min)	5.27
CarbonDioxideSaturation	0.189
RespiratoryExchangeRatio	0.827
SystemicVascularResistance(mmHg_s/mL)	0.928
OxygenConsumptionRate(mL/min)	275
CarbonDioxideProductionRate(mL/min)	228
Patient-AlveoliSurfaceArea(m^2)	32.1
Patient-ExpiratoryReserveVolume(L)	0.809
Patient-FunctionalResidualCapacity(L)	1.51
Patient-InspiratoryCapacity(L)	2.89
Patient-InspiratoryReserveVolume(L)	2.35
Patient-ResidualVolume(L)	0.699
Patient-TidalVolumeBaseline(L)	0.54
Patient-TotalLungCapacity(L)	4.4
Patient-VitalCapacity(L)	3.7

Scenario Output Plots

Figure 5. Select outputs from the scenario.