Hypoxemic Respiratory Failure - Pneumonia

Description

A 23 year old patient suffered developed shortness of breath, substernal chest pain and a productive cough following burn pit exposure. He was started on broad spectrum antibiotics and steroids for a suspected respiratory tract infection. Initial chest x-ray demonstrated some minor hilar infiltrates. On day 5 of his antibiotic course he developed worsening dyspnea, was febrile to 39.5 C, and his SpO2 was 91%. He was placed on high flow nasal cannula at 50% and 40 L/min. After 12 hours he was intubated.After intubation he is on mechanical ventilation and remains sedated with a RASS of -2.

The patient is 6'3'' and weighs 215 lbs. Suctioning reveals thick, tenacious, brownish-yellow secretions. Therapeutic bronchoscopy is performed and 15-20 mL secretions removed and sent for culture and sensitivity. Initial gram stain suggests acinetobacter baumanni. Antibiotics are changed to a carbapenem. He is scheduled for transport to definitive care in the morning.

Figure 1. Chest radiograph demonstrates bilateral infiltrates with right middle and lower lobe consolidation, but no signs of barotrauma.

Segment Validation

Segment 1

Learning Objectives:

Assess baseline status
Recognize moderate ARDS

Recommended Actions:

None

Ventilator settings are:

Mode	VT (L)	PIP (cmH2O)	Flow (L/min)	I:E	TI (s)	RR (bpm)	PEEP (cmH2O)	FiO2
PC-AC	NA	30	NA	NA	0.6	25	10	0.50

Ventilator alarm settings are:

High PIP = 40 cmH2O (~10 cmH2O above the initial value or a max of 40 cmH2O)
Low MVe = 10.1 L/min (~25% below the initial value)
Low VT = 404 mL (~25% below the initial value)
High RR = 35 bpm (~10 bpm above the initial value or a max of 40 bpm)

Table 1. Data request validation results for Segment 1.

Property Name	Validation	Engine Value	Percent Error	Notes
InspiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	12.4	3.08%	Rinsp for moderate ARDS
ExpiratoryRespiratoryResistance(cmH2O_s/L)	EqualTo 12 [17]	12.4	3.08%	Rexp for moderate ARDS
RespiratoryCompliance(mL/cmH2O)	EqualTo 40 [304]	42.8	6.72%	C requested by SME for moderate ARDS
PhysiologicDeadSpaceTidalVolumeRatio	EqualTo 0.57 [229]	0.553	3.03%	VD/VT for moderate ARDS
ClinicalShuntFraction	[0.300,0.500] [221]	0.292	2.54%	QS/QT for moderate ARDS (determined from blood gas values)
HorowitzIndex(mmHg)	[100,200] [115]	129	0.00%	PaO2/FiO2 for moderate ARDS

Figure 2. Vitals and ventilator monitors for Segment 1.

Table 2. Data requests for Segment 1.

Property Name	Engine Value
Patient-Height(in)	75.0
Patient-IdealBodyWeight(kg)	84.5
InspiratoryRespiratoryResistance(cmH2O_s/L)	12.4
ExpiratoryRespiratoryResistance(cmH2O_s/L)	12.4
RespiratoryCompliance(mL/cmH2O)	42.8
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.505
ClinicalShuntFraction	0.292
MechanicalVentilator-TidalVolume(L)	0.539
BloodPH	7.35
Aorta-Oxygen-PartialPressure(mmHg)	64.4
Aorta-CarbonDioxide-PartialPressure(mmHg)	47.1
Aorta-Bicarbonate-Molarity(mEq/L)	26.2
OxygenSaturation	0.926
HorowitzIndex(mmHg)	129
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.444
MechanicalVentilator-RespirationRate(1/min)	25.0
MechanicalVentilator-MeanAirwayPressure(cmH2O)	14.8
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	29.9
MechanicalVentilator-PlateauPressure(cmH2O)	23.2
HeartRate(1/min)	78.7
SystolicArterialPressure(mmHg)	114
DiastolicArterialPressure(mmHg)	75.5
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	13.5
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	42.3
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	27.1
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	32.5
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	347
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.539
MechanicalVentilator-InspiratoryExpiratoryRatio	0.333
MechanicalVentilator-InspiratoryTidalVolume(L)	0.539
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.865
MechanicalVentilator-LeakFraction	1.04e-13
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.409
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	10.4
PhysiologicDeadSpaceTidalVolumeRatio	0.553
PhysiologicShuntFraction	0.297
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelCompliance(mL/cmH2O)	46.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
TotalPositiveEndExpiratoryPressure(cmH2O)	10.4
EndTidalCarbonDioxidePressure(mmHg)	34.9
PhysiologicDeadSpace(mL)	327
AlveolarArterialGradient(mmHg)	271
AlveolarDeadSpace(mL)	158
AnatomicDeadSpace(mL)	169
ChestWallCompliance(L/cmH2O)	0.161
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0594
VentilationPerfusionRatio	2.28
HeartStrokeVolume(mL)	77.1
HeartEjectionFraction	0.539
BloodVolume(L)	7.07
MeanArterialPressure(mmHg)	95.6
PulsePressure(mmHg)	38.1
CardiacOutput(L/min)	6.07
CarbonDioxideSaturation	0.254
RespiratoryExchangeRatio	0.812
SystemicVascularResistance(mmHg_s/mL)	0.897
OxygenConsumptionRate(mL/min)	300
CarbonDioxideProductionRate(mL/min)	244
Patient-AlveoliSurfaceArea(m^2)	15.3
Patient-ExpiratoryReserveVolume(L)	0.969
Patient-FunctionalResidualCapacity(L)	1.43
Patient-InspiratoryCapacity(L)	3.46
Patient-InspiratoryReserveVolume(L)	2.84
Patient-ResidualVolume(L)	0.457
Patient-TidalVolumeBaseline(L)	0.622
Patient-TotalLungCapacity(L)	4.89
Patient-VitalCapacity(L)	4.43

Segment 2

The patient is loaded onto the aircraft for transfer to trauma center care. During transport the SpO2 has fallen.

Learning Objectives:

Recognize hypoventilation due to increased secretions
Recognize oscillation of expiratory flow indicaint secretions

Recommended Actions:

Check for pneumothorax
Suction

Table 3. Data request validation results for Segment 2.

Property Name	Validation	Engine Value	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	LessThan Segment1 (539)	373	-30.9%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	GreaterThan Segment1 (12.4) [304] [308]	20.5	65.5%	Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L)	GreaterThan Segment1 (12.4) [304] [308]	21.4	72.9%	Rexp
OxygenSaturation	LessThan Segment1 (0.926) [304] [308]	0.915	-1.18%	SpO2

Figure 3. Vitals and ventilator monitors for Segment 2.

Table 4. Data requests for Segment 2.

Property Name	Engine Value
Patient-Height(in)	75.0
Patient-IdealBodyWeight(kg)	84.5
InspiratoryRespiratoryResistance(cmH2O_s/L)	20.5
ExpiratoryRespiratoryResistance(cmH2O_s/L)	21.4
RespiratoryCompliance(mL/cmH2O)	42.4
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.552
ClinicalShuntFraction	0.301
MechanicalVentilator-TidalVolume(L)	0.373
BloodPH	7.29
Aorta-Oxygen-PartialPressure(mmHg)	64.8
Aorta-CarbonDioxide-PartialPressure(mmHg)	54.8
Aorta-Bicarbonate-Molarity(mEq/L)	26.6
OxygenSaturation	0.915
HorowitzIndex(mmHg)	130
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	1.28
MechanicalVentilator-RespirationRate(1/min)	25.0
MechanicalVentilator-MeanAirwayPressure(cmH2O)	14.8
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	30.0
MechanicalVentilator-PlateauPressure(cmH2O)	19.9
HeartRate(1/min)	78.1
SystolicArterialPressure(mmHg)	114
DiastolicArterialPressure(mmHg)	75.9
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	9.32
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	20.5
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	20.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	42.1
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	18.7
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	33.2
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	334
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.373
MechanicalVentilator-InspiratoryExpiratoryRatio	0.333
MechanicalVentilator-InspiratoryTidalVolume(L)	0.373
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.600
MechanicalVentilator-LeakFraction	0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	1.08
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	11.1
PhysiologicDeadSpaceTidalVolumeRatio	0.553
PhysiologicShuntFraction	0.304
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	20.5
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	24.3
TotalRespiratoryModelCompliance(mL/cmH2O)	46.7
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
TotalPositiveEndExpiratoryPressure(cmH2O)	11.3
EndTidalCarbonDioxidePressure(mmHg)	37.7
PhysiologicDeadSpace(mL)	327
AlveolarArterialGradient(mmHg)	242
AlveolarDeadSpace(mL)	158
AnatomicDeadSpace(mL)	169
ChestWallCompliance(L/cmH2O)	0.156
FractionOfInspiredOxygen	0.497
LungCompliance(L/cmH2O)	0.0594
VentilationPerfusionRatio	1.59
HeartStrokeVolume(mL)	77.3
HeartEjectionFraction	0.539
BloodVolume(L)	7.08
MeanArterialPressure(mmHg)	96.0
PulsePressure(mmHg)	38.2
CardiacOutput(L/min)	6.04
CarbonDioxideSaturation	0.449
RespiratoryExchangeRatio	0.816
SystemicVascularResistance(mmHg_s/mL)	0.906
OxygenConsumptionRate(mL/min)	306
CarbonDioxideProductionRate(mL/min)	250
Patient-AlveoliSurfaceArea(m^2)	15.3
Patient-ExpiratoryReserveVolume(L)	0.969
Patient-FunctionalResidualCapacity(L)	1.43
Patient-InspiratoryCapacity(L)	3.46
Patient-InspiratoryReserveVolume(L)	2.84
Patient-ResidualVolume(L)	0.457
Patient-TidalVolumeBaseline(L)	0.622
Patient-TotalLungCapacity(L)	4.89
Patient-VitalCapacity(L)	4.43

Segment 3

Patient is suctioned for large volume of thick secretions.

Learning Objectives:

Recognize that suctioning decreased airway resistance and restored tidal volume)

Recommended Actions:

None

Table 5. Data request validation results for Segment 3.

Property Name	Validation	Engine Value	Percent Change	Notes
MechanicalVentilator-TidalVolume(mL)	GreaterThan Segment2 (373)	539	44.6%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	LessThan Segment2 (20.5) [304] [308]	12.4	-39.6%	Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L)	LessThan Segment2 (21.4) [304] [308]	12.4	-42.2%	Rexp
OxygenSaturation	GreaterThan Segment2 (0.915) [304] [308]	0.923	0.880%	SpO2

Figure 4. Vitals and ventilator monitors for Segment 3.

Table 6. Data requests for Segment 3.

Property Name	Engine Value
Patient-Height(in)	75.0
Patient-IdealBodyWeight(kg)	84.5
InspiratoryRespiratoryResistance(cmH2O_s/L)	12.4
ExpiratoryRespiratoryResistance(cmH2O_s/L)	12.4
RespiratoryCompliance(mL/cmH2O)	42.8
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.511
ClinicalShuntFraction	0.293
MechanicalVentilator-TidalVolume(L)	0.539
BloodPH	7.32
Aorta-Oxygen-PartialPressure(mmHg)	65.8
Aorta-CarbonDioxide-PartialPressure(mmHg)	51.1
Aorta-Bicarbonate-Molarity(mEq/L)	26.4
OxygenSaturation	0.923
HorowitzIndex(mmHg)	132
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.444
MechanicalVentilator-RespirationRate(1/min)	25.0
MechanicalVentilator-MeanAirwayPressure(cmH2O)	14.8
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	29.9
MechanicalVentilator-PlateauPressure(cmH2O)	23.2
HeartRate(1/min)	76.0
SystolicArterialPressure(mmHg)	115
DiastolicArterialPressure(mmHg)	74.9
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	13.5
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	42.3
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	27.1
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	34.8
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	345
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.539
MechanicalVentilator-InspiratoryExpiratoryRatio	0.333
MechanicalVentilator-InspiratoryTidalVolume(L)	0.539
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.865
MechanicalVentilator-LeakFraction	7.06e-14
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.409
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	10.4
PhysiologicDeadSpaceTidalVolumeRatio	0.553
PhysiologicShuntFraction	0.297
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelCompliance(mL/cmH2O)	46.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
TotalPositiveEndExpiratoryPressure(cmH2O)	10.4
EndTidalCarbonDioxidePressure(mmHg)	37.5
PhysiologicDeadSpace(mL)	327
AlveolarArterialGradient(mmHg)	268
AlveolarDeadSpace(mL)	158
AnatomicDeadSpace(mL)	169
ChestWallCompliance(L/cmH2O)	0.161
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0594
VentilationPerfusionRatio	2.26
HeartStrokeVolume(mL)	80.1
HeartEjectionFraction	0.548
BloodVolume(L)	7.10
MeanArterialPressure(mmHg)	96.0
PulsePressure(mmHg)	39.7
CardiacOutput(L/min)	6.09
CarbonDioxideSaturation	0.372
RespiratoryExchangeRatio	0.813
SystemicVascularResistance(mmHg_s/mL)	0.899
OxygenConsumptionRate(mL/min)	301
CarbonDioxideProductionRate(mL/min)	245
Patient-AlveoliSurfaceArea(m^2)	15.3
Patient-ExpiratoryReserveVolume(L)	0.969
Patient-FunctionalResidualCapacity(L)	1.43
Patient-InspiratoryCapacity(L)	3.46
Patient-InspiratoryReserveVolume(L)	2.84
Patient-ResidualVolume(L)	0.457
Patient-TidalVolumeBaseline(L)	0.622
Patient-TotalLungCapacity(L)	4.89
Patient-VitalCapacity(L)	4.43

Scenario Output Plots

Figure 5. Select outputs from the scenario.