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 [6] 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 [6]	528	1.54%	VT (measured)
HorowitzIndex(mmHg)	[72.0,188] [6]	145	0.00%	PaO2/FiO2 (130 +/- 58)
ClinicalShuntFraction	[0.180,0.480] [6]	0.285	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)	11.9
ExpiratoryRespiratoryResistance(cmH2O_s/L)	11.9
RespiratoryCompliance(mL/cmH2O)	36.9
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.530
ClinicalShuntFraction	0.285
MechanicalVentilator-TidalVolume(L)	0.528
BloodPH	7.38
Aorta-Oxygen-PartialPressure(mmHg)	72.4
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.1
Aorta-Bicarbonate-Molarity(mEq/L)	26.0
OxygenSaturation	0.951
HorowitzIndex(mmHg)	145
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.254
MechanicalVentilator-RespirationRate(1/min)	22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	10.6
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	22.0
MechanicalVentilator-PlateauPressure(cmH2O)	19.9
HeartRate(1/min)	71.6
SystolicArterialPressure(mmHg)	115
DiastolicArterialPressure(mmHg)	73.4
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	12.1
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	11.9
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	11.9
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	36.1
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	31.1
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	30.3
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	348
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.528
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.528
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.977
MechanicalVentilator-LeakFraction	5.87e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.254
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.25
PhysiologicDeadSpaceTidalVolumeRatio	0.528
ShuntFraction	0.285
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	11.9
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	11.9
TotalRespiratoryModelCompliance(mL/cmH2O)	42.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5.00
TotalPositiveEndExpiratoryPressure(cmH2O)	5.26
EndTidalCarbonDioxidePressure(mmHg)	32.4
PhysiologicDeadSpace(mL)	278
AlveolarArterialGradient(mmHg)	267
AlveolarDeadSpace(mL)	128
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.117
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0555
VentilationPerfusionRatio	2.86
HeartStrokeVolume(mL)	82.8
HeartEjectionFraction	0.571
BloodVolume(L)	5.51
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	41.5
CardiacOutput(L/min)	5.93
CarbonDioxideSaturation	0.0576
RespiratoryExchangeRatio	0.817
SystemicVascularResistance(mmHg_s/mL)	0.920
OxygenConsumptionRate(mL/min)	247
CarbonDioxideProductionRate(mL/min)	202
Patient-AlveoliSurfaceArea(m^2)	27.3
Patient-ExpiratoryReserveVolume(L)	0.855
Patient-FunctionalResidualCapacity(L)	1.48
Patient-InspiratoryCapacity(L)	3.06
Patient-InspiratoryReserveVolume(L)	2.52
Patient-ResidualVolume(L)	0.624
Patient-TidalVolumeBaseline(L)	0.537
Patient-TotalLungCapacity(L)	4.54
Patient-VitalCapacity(L)	3.91

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 [6]	538	3.44%		VT (measured)
Aorta-CarbonDioxide-PartialPressure(mmHg)	EqualTo Segment1 (43.1) [9]	42.8	0.559%		PaCO2
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan 1 [6]	116		1.15e+04%	PaO2
HorowitzIndex(mmHg)	[138,302] [6]	232	0.00%		PaO2/FiO2 (220 +/- 82)
HorowitzIndex(mmHg)	GreaterThan 1 [6]	232		2.31e+04%	PaO2/FiO2
ClinicalShuntFraction	[0.0800,0.360] [6]	0.159	0.00%		QS/QT (determined from blood gas values) (0.22 +/- 0.14)
ClinicalShuntFraction	LessThan 1 [6]	0.159		-84.1%	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)	11.9
ExpiratoryRespiratoryResistance(cmH2O_s/L)	11.9
RespiratoryCompliance(mL/cmH2O)	43.6
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.518
ClinicalShuntFraction	0.159
MechanicalVentilator-TidalVolume(L)	0.538
BloodPH	7.39
Aorta-Oxygen-PartialPressure(mmHg)	116
Aorta-CarbonDioxide-PartialPressure(mmHg)	42.8
Aorta-Bicarbonate-Molarity(mEq/L)	26.0
OxygenSaturation	0.986
HorowitzIndex(mmHg)	232
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.458
MechanicalVentilator-RespirationRate(1/min)	22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	23.3
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	34.0
MechanicalVentilator-PlateauPressure(cmH2O)	30.9
HeartRate(1/min)	69.2
SystolicArterialPressure(mmHg)	115
DiastolicArterialPressure(mmHg)	73.0
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	12.3
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	11.9
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	11.9
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	43.3
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	33.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	31.7
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	351
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.538
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.538
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.885
MechanicalVentilator-LeakFraction	1.37e-13
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.421
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	18.4
PhysiologicDeadSpaceTidalVolumeRatio	0.528
ShuntFraction	0.161
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	11.9
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	11.9
TotalRespiratoryModelCompliance(mL/cmH2O)	45.3
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18.0
TotalPositiveEndExpiratoryPressure(cmH2O)	18.5
EndTidalCarbonDioxidePressure(mmHg)	33.9
PhysiologicDeadSpace(mL)	278
AlveolarArterialGradient(mmHg)	228
AlveolarDeadSpace(mL)	128
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.209
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0555
VentilationPerfusionRatio	2.54
HeartStrokeVolume(mL)	83.6
HeartEjectionFraction	0.573
BloodVolume(L)	5.54
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	42.1
CardiacOutput(L/min)	5.78
CarbonDioxideSaturation	0.0415
RespiratoryExchangeRatio	0.823
SystemicVascularResistance(mmHg_s/mL)	0.942
OxygenConsumptionRate(mL/min)	254
CarbonDioxideProductionRate(mL/min)	209
Patient-AlveoliSurfaceArea(m^2)	27.3
Patient-ExpiratoryReserveVolume(L)	0.855
Patient-FunctionalResidualCapacity(L)	1.48
Patient-InspiratoryCapacity(L)	3.06
Patient-InspiratoryReserveVolume(L)	2.52
Patient-ResidualVolume(L)	0.624
Patient-TidalVolumeBaseline(L)	0.537
Patient-TotalLungCapacity(L)	4.54
Patient-VitalCapacity(L)	3.91

Scenario Output Plots

Figure 3. Select outputs from the scenario.