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 [193] 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 [193]	508	-2.37%	VT (measured)
HorowitzIndex(mmHg)	[72.0,188] [193]	124	0.00%	PaO2/FiO2 (130 +/- 58)
ClinicalShuntFraction	[0.180,0.480] [193]	0.355	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	0.482
ClinicalShuntFraction	0.355
MechanicalVentilator-TidalVolume(L)	0.508
BloodPH	7.35
Aorta-Oxygen-PartialPressure(mmHg)	61.8
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.3
Aorta-Bicarbonate-Molarity(mEq/L)	26.2
OxygenSaturation	0.923
HorowitzIndex(mmHg)	124
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)	98.2
SystolicArterialPressure(mmHg)	111
DiastolicArterialPressure(mmHg)	79.3
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)	31.5
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	346
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.508
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.508
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.962
MechanicalVentilator-LeakFraction	7.26e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.225
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.22
PhysiologicDeadSpaceTidalVolumeRatio	0.541
PhysiologicShuntFraction	0.361
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)	34.2
PhysiologicDeadSpace(mL)	285
AlveolarArterialGradient(mmHg)	278
AlveolarDeadSpace(mL)	134
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.112
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0525
VentilationPerfusionRatio	0.853
HeartStrokeVolume(mL)	62.6
HeartEjectionFraction	0.501
BloodVolume(L)	5.51
MeanArterialPressure(mmHg)	95.6
PulsePressure(mmHg)	31.7
CardiacOutput(L/min)	6.14
CarbonDioxideSaturation	0.0680
RespiratoryExchangeRatio	0.802
SystemicVascularResistance(mmHg_s/mL)	0.887
OxygenConsumptionRate(mL/min)	243
CarbonDioxideProductionRate(mL/min)	195
Patient-AlveoliSurfaceArea(m^2)	20.5
Patient-ExpiratoryReserveVolume(L)	0.849
Patient-FunctionalResidualCapacity(L)	1.35
Patient-InspiratoryCapacity(L)	3.03
Patient-InspiratoryReserveVolume(L)	2.51
Patient-ResidualVolume(L)	0.504
Patient-TidalVolumeBaseline(L)	0.524
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 [193]	518	-0.40%		VT (measured)
Aorta-CarbonDioxide-PartialPressure(mmHg)	EqualTo Segment1 (43.3) [264]	43.0	-0.84%		PaCO2
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan Segment1 (61.8) [193]	88.2		42.76%	PaO2
HorowitzIndex(mmHg)	[138,302] [193]	177	0.00%		PaO2/FiO2 (220 +/- 82)
HorowitzIndex(mmHg)	GreaterThan Segment1 (124) [193]	177		42.74%	PaO2/FiO2
ClinicalShuntFraction	[0.0800,0.360] [193]	0.214	0.00%		QS/QT (determined from blood gas values) (0.22 +/- 0.14)
ClinicalShuntFraction	LessThan Segment1 (0.355) [193]	0.214		-39.72%	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	0.464
ClinicalShuntFraction	0.214
MechanicalVentilator-TidalVolume(L)	0.518
BloodPH	7.36
Aorta-Oxygen-PartialPressure(mmHg)	88.2
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.0
Aorta-Bicarbonate-Molarity(mEq/L)	26.2
OxygenSaturation	0.969
HorowitzIndex(mmHg)	177
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)	71.2
SystolicArterialPressure(mmHg)	114
DiastolicArterialPressure(mmHg)	73.5
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)	33.0
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	0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.379
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	18.4
PhysiologicDeadSpaceTidalVolumeRatio	0.541
PhysiologicShuntFraction	0.219
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)	35.6
PhysiologicDeadSpace(mL)	285
AlveolarArterialGradient(mmHg)	256
AlveolarDeadSpace(mL)	134
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.197
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0525
VentilationPerfusionRatio	0.955
HeartStrokeVolume(mL)	80.7
HeartEjectionFraction	0.566
BloodVolume(L)	5.53
MeanArterialPressure(mmHg)	95.3
PulsePressure(mmHg)	40.9
CardiacOutput(L/min)	5.75
CarbonDioxideSaturation	0.0461
RespiratoryExchangeRatio	0.805
SystemicVascularResistance(mmHg_s/mL)	0.945
OxygenConsumptionRate(mL/min)	249
CarbonDioxideProductionRate(mL/min)	201
Patient-AlveoliSurfaceArea(m^2)	20.5
Patient-ExpiratoryReserveVolume(L)	0.849
Patient-FunctionalResidualCapacity(L)	1.35
Patient-InspiratoryCapacity(L)	3.03
Patient-InspiratoryReserveVolume(L)	2.51
Patient-ResidualVolume(L)	0.504
Patient-TidalVolumeBaseline(L)	0.524
Patient-TotalLungCapacity(L)	4.38
Patient-VitalCapacity(L)	3.88

Scenario Output Plots

Figure 3. Select outputs from the scenario.