MechanicalVentilatorRecruitment

Description

A standard patient is mechanically ventilated with moderate ARDS. The PEEP is increased to test the effects of improved lung recruitment. Ventilator setting and expected values were largely determined from Karbing et al [185] Table 2.

Segment Validation

Segment 1

Diagnosis: ARDS
Ventilator settings are set for TV = 6.9 mL/kg (ideal) and I:E = 0.5:

Mode	VT (mL)	PIP (cmH2O)	Flow (L/min)	I:E	TI (s)	RR (bpm)	PEEP (cmH2O)	FiO2
PC-CMV	520	Adjust	NA	NA	0.87	23	5	0.5

Table 1. Data request validation results for Segment 1.

Property Name	Validation	Engine Value	Percent Error	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 520 [185]	508	2.40%	VT (measured)
HorowitzIndex(mmHg)	[72.0,188] [185]	126	0.00%	PaO2/FiO2 (130 +/- 58)
ClinicalShuntFraction	[0.180,0.480] [185]	0.335	0.00%	QS/QT (determined from blood gas values) (0.33 +/- 0.15)

Figure 1. Vitals and ventilator monitors for Segment 1.

Table 2. Data requests for Segment 1.

Property Name	Engine Value
Patient-Height(in)	71.0
Patient-IdealBodyWeight(kg)	75.3
InspiratoryRespiratoryResistance(cmH2O_s/L)	12.1
ExpiratoryRespiratoryResistance(cmH2O_s/L)	12.1
RespiratoryCompliance(mL/cmH2O)	34.9
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.521
ClinicalShuntFraction	0.335
MechanicalVentilator-TidalVolume(L)	0.508
BloodPH	7.38
Aorta-Oxygen-PartialPressure(mmHg)	63.1
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.6
Aorta-Bicarbonate-Molarity(mEq/L)	26.1
OxygenSaturation	0.930
HorowitzIndex(mmHg)	126
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.225
MechanicalVentilator-RespirationRate(1/min)	22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	10.6
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	22.0
MechanicalVentilator-PlateauPressure(cmH2O)	20.0
HeartRate(1/min)	87.8
SystolicArterialPressure(mmHg)	112
DiastolicArterialPressure(mmHg)	77.7
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	11.6
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	12.1
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.1
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	34.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	29.9
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	30.9
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	347
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.508
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.508
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.962
MechanicalVentilator-LeakFraction	6.87e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.225
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.22
PhysiologicDeadSpaceTidalVolumeRatio	0.541
PhysiologicShuntFraction	0.342
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	12.1
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	12.1
TotalRespiratoryModelCompliance(mL/cmH2O)	40.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5.00
TotalPositiveEndExpiratoryPressure(cmH2O)	5.23
EndTidalCarbonDioxidePressure(mmHg)	33.3
PhysiologicDeadSpace(mL)	285
AlveolarArterialGradient(mmHg)	273
AlveolarDeadSpace(mL)	134
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.112
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0525
VentilationPerfusionRatio	2.00
HeartStrokeVolume(mL)	67.9
HeartEjectionFraction	0.520
BloodVolume(L)	5.51
MeanArterialPressure(mmHg)	95.6
PulsePressure(mmHg)	34.5
CardiacOutput(L/min)	5.96
CarbonDioxideSaturation	0.0913
RespiratoryExchangeRatio	0.815
SystemicVascularResistance(mmHg_s/mL)	0.915
OxygenConsumptionRate(mL/min)	243
CarbonDioxideProductionRate(mL/min)	198
Patient-AlveoliSurfaceArea(m^2)	20.5
Patient-ExpiratoryReserveVolume(L)	0.849
Patient-FunctionalResidualCapacity(L)	1.35
Patient-InspiratoryCapacity(L)	3.03
Patient-InspiratoryReserveVolume(L)	2.49
Patient-ResidualVolume(L)	0.504
Patient-TidalVolumeBaseline(L)	0.537
Patient-TotalLungCapacity(L)	4.38
Patient-VitalCapacity(L)	3.88

Segment 2

PEEP is increased for improved recruitment with PIP set to maintain target TV:

Mode	VT (mL)	PIP (cmH2O)	Flow (L/min)	I:E	TI (s)	RR (bpm)	PEEP (cmH2O)	FiO2
PC-CMV	520	Adjust	NA	NA	0.87	23	18	0.5

Table 3. Data request validation results for Segment 2.

Property Name	Validation	Engine Value	Percent Error	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	EqualTo 520 [185]	518	0.402%		VT (measured)
Aorta-CarbonDioxide-PartialPressure(mmHg)	EqualTo Segment1 (43.6) [254]	43.7	0.183%		PaCO2
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan Segment1 (63.1) [185]	95.5		51.2%	PaO2
HorowitzIndex(mmHg)	[138,302] [185]	191	0.00%		PaO2/FiO2 (220 +/- 82)
HorowitzIndex(mmHg)	GreaterThan Segment1 (126) [185]	191		51.2%	PaO2/FiO2
ClinicalShuntFraction	[0.0800,0.360] [185]	0.190	0.00%		QS/QT (determined from blood gas values) (0.22 +/- 0.14)
ClinicalShuntFraction	LessThan Segment1 (0.335) [185]	0.190		-43.3%	QS/QT (determined from blood gas values)

Figure 2. Vitals and ventilator monitors for Segment 2.

Table 4. Data requests for Segment 2.

Property Name	Engine Value
Patient-Height(in)	71.0
Patient-IdealBodyWeight(kg)	75.3
InspiratoryRespiratoryResistance(cmH2O_s/L)	12.1
ExpiratoryRespiratoryResistance(cmH2O_s/L)	12.1
RespiratoryCompliance(mL/cmH2O)	41.2
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.510
ClinicalShuntFraction	0.190
MechanicalVentilator-TidalVolume(L)	0.518
BloodPH	7.38
Aorta-Oxygen-PartialPressure(mmHg)	95.5
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.7
Aorta-Bicarbonate-Molarity(mEq/L)	26.1
OxygenSaturation	0.976
HorowitzIndex(mmHg)	191
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.411
MechanicalVentilator-RespirationRate(1/min)	22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	23.3
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	34.0
MechanicalVentilator-PlateauPressure(cmH2O)	31.0
HeartRate(1/min)	70.7
SystolicArterialPressure(mmHg)	115
DiastolicArterialPressure(mmHg)	74.5
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	11.9
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	12.1
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.1
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	40.9
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	32.4
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	32.4
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	350
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.518
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.518
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.875
MechanicalVentilator-LeakFraction	3.00e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.379
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	18.4
PhysiologicDeadSpaceTidalVolumeRatio	0.541
PhysiologicShuntFraction	0.197
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	12.1
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	12.1
TotalRespiratoryModelCompliance(mL/cmH2O)	43.0
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18.0
TotalPositiveEndExpiratoryPressure(cmH2O)	18.4
EndTidalCarbonDioxidePressure(mmHg)	34.9
PhysiologicDeadSpace(mL)	285
AlveolarArterialGradient(mmHg)	245
AlveolarDeadSpace(mL)	134
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.197
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0525
VentilationPerfusionRatio	2.13
HeartStrokeVolume(mL)	81.1
HeartEjectionFraction	0.566
BloodVolume(L)	5.54
MeanArterialPressure(mmHg)	96.3
PulsePressure(mmHg)	41.0
CardiacOutput(L/min)	5.73
CarbonDioxideSaturation	0.0942
RespiratoryExchangeRatio	0.818
SystemicVascularResistance(mmHg_s/mL)	0.958
OxygenConsumptionRate(mL/min)	249
CarbonDioxideProductionRate(mL/min)	204
Patient-AlveoliSurfaceArea(m^2)	20.5
Patient-ExpiratoryReserveVolume(L)	0.849
Patient-FunctionalResidualCapacity(L)	1.35
Patient-InspiratoryCapacity(L)	3.03
Patient-InspiratoryReserveVolume(L)	2.49
Patient-ResidualVolume(L)	0.504
Patient-TidalVolumeBaseline(L)	0.537
Patient-TotalLungCapacity(L)	4.38
Patient-VitalCapacity(L)	3.88

Scenario Output Plots

Figure 3. Select outputs from the scenario.