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]	172	0.00%	PaO2/FiO2 (130 +/- 58)
ApparentShuntFraction	[0.180,0.480] [6]	0.253	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
ApparentPhysiologicDeadSpaceTidalVolumeRatio	0.519
ApparentShuntFraction	0.253
MechanicalVentilator-TidalVolume(L)	0.528
BloodPH	7.39
Aorta-Oxygen-PartialPressure(mmHg)	86.1
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.0
Aorta-Bicarbonate-Molarity(mEq/L)	26.0
OxygenSaturation	0.969
HorowitzIndex(mmHg)	172
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)	69.9
SystolicArterialPressure(mmHg)	115
DiastolicArterialPressure(mmHg)	73.0
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)	30.9
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	347
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.528
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.528
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.977
MechanicalVentilator-LeakFraction	8.70e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.254
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5.00
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.25
PhysiologicDeadSpaceTidalVolumeRatio	0.528
ShuntFraction	0.224
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)	33.1
PhysiologicDeadSpace(mL)	278
AlveolarArterialGradient(mmHg)	252
AlveolarDeadSpace(mL)	128
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.117
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0555
VentilationPerfusionRatio	2.67
HeartStrokeVolume(mL)	83.5
HeartEjectionFraction	0.573
BloodVolume(L)	5.51
MeanArterialPressure(mmHg)	95.4
PulsePressure(mmHg)	42.1
CardiacOutput(L/min)	5.84
CarbonDioxideSaturation	0.0516
RespiratoryExchangeRatio	0.820
SystemicVascularResistance(mmHg_s/mL)	0.932
OxygenConsumptionRate(mL/min)	251
CarbonDioxideProductionRate(mL/min)	205
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)	0.535
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 Segment 1 (43.0) [9]	42.7	0.517%		PaCO2
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan (1.00) [6]	195		1.94e+04%	PaO2
HorowitzIndex(mmHg)	[138,302] [6]	389	25.3%		PaO2/FiO2 (220 +/- 82)
HorowitzIndex(mmHg)	GreaterThan (1.00) [6]	389		3.88e+04%	PaO2/FiO2
ApparentShuntFraction	[0.0800,0.360] [6]	0.106	0.00%		QS/QT (determined from blood gas values) (0.22 +/- 0.14)
ApparentShuntFraction	LessThan (1.00) [6]	0.106		-89.4%	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
ApparentPhysiologicDeadSpaceTidalVolumeRatio	0.504
ApparentShuntFraction	0.106
MechanicalVentilator-TidalVolume(L)	0.538
BloodPH	7.39
Aorta-Oxygen-PartialPressure(mmHg)	195
Aorta-CarbonDioxide-PartialPressure(mmHg)	42.7
Aorta-Bicarbonate-Molarity(mEq/L)	26.0
OxygenSaturation	0.996
HorowitzIndex(mmHg)	389
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)	64.1
SystolicArterialPressure(mmHg)	116
DiastolicArterialPressure(mmHg)	71.5
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)	32.5
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	350
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.538
MechanicalVentilator-InspiratoryExpiratoryRatio	0.506
MechanicalVentilator-InspiratoryTidalVolume(L)	0.538
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.885
MechanicalVentilator-LeakFraction	1.03e-15
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.421
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	18.4
PhysiologicDeadSpaceTidalVolumeRatio	0.528
ShuntFraction	0.0718
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)	34.8
PhysiologicDeadSpace(mL)	278
AlveolarArterialGradient(mmHg)	148
AlveolarDeadSpace(mL)	128
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.209
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0555
VentilationPerfusionRatio	2.35
HeartStrokeVolume(mL)	88.6
HeartEjectionFraction	0.589
BloodVolume(L)	5.54
MeanArterialPressure(mmHg)	95.3
PulsePressure(mmHg)	44.5
CardiacOutput(L/min)	5.68
CarbonDioxideSaturation	0.0367
RespiratoryExchangeRatio	0.825
SystemicVascularResistance(mmHg_s/mL)	0.957
OxygenConsumptionRate(mL/min)	259
CarbonDioxideProductionRate(mL/min)	214
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)	0.535
Patient-TotalLungCapacity(L)	4.54
Patient-VitalCapacity(L)	3.91

Scenario Output Plots

Figure 3. Select outputs from the scenario.