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	1.5%	VT (measured)
HorowitzIndex(mmHg)	[72,188] [6]	144.4	0.0%	PaO2/FiO2 (130 +/- 58)
ShuntFraction	[0.18,0.48] [6]	0.2845	0.0%	QS/QT (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
Patient-IdealBodyWeight(kg)	75.3
InspiratoryRespiratoryResistance(cmH2O_s/L)	11.9
ExpiratoryRespiratoryResistance(cmH2O_s/L)	11.9
RespiratoryCompliance(mL/cmH2O)	37.2
PhysiologicDeadSpaceTidalVolumeRatio	0.528
ShuntFraction	0.284
MechanicalVentilator-TidalVolume(L)	0.528
BloodPH	7.38
Aorta-Oxygen-PartialPressure(mmHg)	72.2
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.1
Aorta-Bicarbonate-Molarity(mEq/L)	26
OxygenSaturation	0.951
HorowitzIndex(mmHg)	144
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.254
MechanicalVentilator-RespirationRate(1/min)	22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	10.6
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	22
MechanicalVentilator-PlateauPressure(cmH2O)	20
HeartRate(1/min)	71.7
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)	35.9
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	31.1
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	30.4
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	0
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.248
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	5.25
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	5
TotalPositiveEndExpiratoryPressure(cmH2O)	5.26
EndTidalCarbonDioxidePressure(mmHg)	32.5
PhysiologicDeadSpace(mL)	278
AlveolarArterialGradient(mmHg)	267
AlveolarDeadSpace(mL)	128
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.119
FractionOfInspiredOxygen	0.5
LungCompliance(L/cmH2O)	0.0555
VentilationPerfusionRatio	2.86
HeartStrokeVolume(mL)	82.7
HeartEjectionFraction	0.571
BloodVolume(L)	5.51
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	41.5
CardiacOutput(L/min)	5.93
CarbonDioxideSaturation	0.0588
RespiratoryExchangeRatio	0.818
SystemicVascularResistance(mmHg_s/mL)	0.919
OxygenConsumptionRate(mL/min)	248
CarbonDioxideProductionRate(mL/min)	203
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]	538.2	3.4%		VT (measured)
Aorta-CarbonDioxide-PartialPressure(mmHg)	EqualTo Segment 1 (43.07) [9]	42.85	0.5%		PaCO2
Aorta-Oxygen-PartialPressure(mmHg)	GreaterThan Segment 1 (72.15) [6]	115.5		60.0%	PaO2
HorowitzIndex(mmHg)	[138,302] [6]	231	0.0%		PaO2/FiO2 (220 +/- 82)
HorowitzIndex(mmHg)	GreaterThan Segment 1 (144.4) [6]	231		60.0%	PaO2/FiO2
ShuntFraction	[0.08,0.36] [6]	0.1612	0.0%		QS/QT (0.22 +/- 0.14)
ShuntFraction	LessThan Segment 1 (0.2845) [6]	0.1612		-43.3%	QS/QT

Figure 2. Vitals and ventilator monitors for Segment 2.

Table 4. Data requests for Segment 2.

Property Name	Engine Value
Patient-Height(in)	71
Patient-IdealBodyWeight(kg)	75.3
InspiratoryRespiratoryResistance(cmH2O_s/L)	11.9
ExpiratoryRespiratoryResistance(cmH2O_s/L)	11.9
RespiratoryCompliance(mL/cmH2O)	43.8
PhysiologicDeadSpaceTidalVolumeRatio	0.528
ShuntFraction	0.161
MechanicalVentilator-TidalVolume(L)	0.538
BloodPH	7.39
Aorta-Oxygen-PartialPressure(mmHg)	115
Aorta-CarbonDioxide-PartialPressure(mmHg)	42.9
Aorta-Bicarbonate-Molarity(mEq/L)	26
OxygenSaturation	0.986
HorowitzIndex(mmHg)	231
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.458
MechanicalVentilator-RespirationRate(1/min)	22.9
MechanicalVentilator-MeanAirwayPressure(cmH2O)	23.3
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	34
MechanicalVentilator-PlateauPressure(cmH2O)	30.9
HeartRate(1/min)	69.2
SystolicArterialPressure(mmHg)	115
DiastolicArterialPressure(mmHg)	73.1
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	12.3
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	11.9
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	11.9
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	43.1
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	33.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	31.9
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	0
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.416
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	18.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	18
TotalPositiveEndExpiratoryPressure(cmH2O)	18.5
EndTidalCarbonDioxidePressure(mmHg)	34.1
PhysiologicDeadSpace(mL)	278
AlveolarArterialGradient(mmHg)	228
AlveolarDeadSpace(mL)	128
AnatomicDeadSpace(mL)	151
ChestWallCompliance(L/cmH2O)	0.211
FractionOfInspiredOxygen	0.5
LungCompliance(L/cmH2O)	0.0555
VentilationPerfusionRatio	2.54
HeartStrokeVolume(mL)	83.5
HeartEjectionFraction	0.573
BloodVolume(L)	5.54
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	42.1
CardiacOutput(L/min)	5.78
CarbonDioxideSaturation	0.0439
RespiratoryExchangeRatio	0.824
SystemicVascularResistance(mmHg_s/mL)	0.942
OxygenConsumptionRate(mL/min)	256
CarbonDioxideProductionRate(mL/min)	211
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.