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	25	NA	NA	0.6	10	10	0.50

Ventilator alarm settings are:

High PIP = 35 cmH2O (~10 cmH2O above the initial value or a max of 40 cmH2O)
Low MVe = 11 L/min (~25% below the initial value)
Low VT = 310 mL (~25% below the initial value)
High RR = 40 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]	42.7	6.63%	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]	0.282	6.22%	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)	42.7
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.504
ClinicalShuntFraction	0.282
MechanicalVentilator-TidalVolume(L)	0.583
BloodPH	7.38
Aorta-Oxygen-PartialPressure(mmHg)	64.4
Aorta-CarbonDioxide-PartialPressure(mmHg)	43.9
Aorta-Bicarbonate-Molarity(mEq/L)	26.1
OxygenSaturation	0.933
HorowitzIndex(mmHg)	129
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.138
MechanicalVentilator-RespirationRate(1/min)	23.4
MechanicalVentilator-MeanAirwayPressure(cmH2O)	13.4
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	24.9
MechanicalVentilator-PlateauPressure(cmH2O)	24.1
HeartRate(1/min)	80.3
SystolicArterialPressure(mmHg)	113
DiastolicArterialPressure(mmHg)	76.0
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	13.7
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	42.2
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	39.0
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	31.6
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	348
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.583
MechanicalVentilator-InspiratoryExpiratoryRatio	0.306
MechanicalVentilator-InspiratoryTidalVolume(L)	0.583
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.680
MechanicalVentilator-LeakFraction	0.00
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.325
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	10.3
PhysiologicDeadSpaceTidalVolumeRatio	0.553
PhysiologicShuntFraction	0.284
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelCompliance(mL/cmH2O)	46.4
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
TotalPositiveEndExpiratoryPressure(cmH2O)	10.1
EndTidalCarbonDioxidePressure(mmHg)	34.0
PhysiologicDeadSpace(mL)	327
AlveolarArterialGradient(mmHg)	274
AlveolarDeadSpace(mL)	158
AnatomicDeadSpace(mL)	169
ChestWallCompliance(L/cmH2O)	0.162
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0592
VentilationPerfusionRatio	2.33
HeartStrokeVolume(mL)	74.8
HeartEjectionFraction	0.532
BloodVolume(L)	7.00
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	37.0
CardiacOutput(L/min)	6.01
CarbonDioxideSaturation	0.107
RespiratoryExchangeRatio	0.810
SystemicVascularResistance(mmHg_s/mL)	0.905
OxygenConsumptionRate(mL/min)	298
CarbonDioxideProductionRate(mL/min)	241
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 patient becomes agitated and respiratory rate increases and 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 (583)	394	-32.4%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	GreaterThan Segment1 (12.4) [304] [308]	20.5	65.8%	Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L)	GreaterThan Segment1 (12.4) [304] [308]	20.3	63.7%	Rexp
OxygenSaturation	LessThan Segment1 (0.933) [304] [308]	0.927	-0.590%	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)	20.3
RespiratoryCompliance(mL/cmH2O)	43.0
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.574
ClinicalShuntFraction	0.283
MechanicalVentilator-TidalVolume(L)	0.394
BloodPH	7.34
Aorta-Oxygen-PartialPressure(mmHg)	65.0
Aorta-CarbonDioxide-PartialPressure(mmHg)	48.5
Aorta-Bicarbonate-Molarity(mEq/L)	26.3
OxygenSaturation	0.927
HorowitzIndex(mmHg)	131
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.249
MechanicalVentilator-RespirationRate(1/min)	28.8
MechanicalVentilator-MeanAirwayPressure(cmH2O)	14.1
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	25.0
MechanicalVentilator-PlateauPressure(cmH2O)	21.0
HeartRate(1/min)	79.6
SystolicArterialPressure(mmHg)	113
DiastolicArterialPressure(mmHg)	75.5
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	11.5
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	20.5
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	20.1
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	42.5
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	26.6
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	29.8
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	342
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.390
MechanicalVentilator-InspiratoryExpiratoryRatio	0.405
MechanicalVentilator-InspiratoryTidalVolume(L)	0.394
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.632
MechanicalVentilator-LeakFraction	0.0193
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	1.61
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	11.6
PhysiologicDeadSpaceTidalVolumeRatio	0.553
PhysiologicShuntFraction	0.286
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	20.5
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	20.7
TotalRespiratoryModelCompliance(mL/cmH2O)	46.9
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
TotalPositiveEndExpiratoryPressure(cmH2O)	10.3
EndTidalCarbonDioxidePressure(mmHg)	33.9
PhysiologicDeadSpace(mL)	327
AlveolarArterialGradient(mmHg)	256
AlveolarDeadSpace(mL)	158
AnatomicDeadSpace(mL)	169
ChestWallCompliance(L/cmH2O)	0.170
FractionOfInspiredOxygen	0.498
LungCompliance(L/cmH2O)	0.0591
VentilationPerfusionRatio	1.90
HeartStrokeVolume(mL)	76.4
HeartEjectionFraction	0.537
BloodVolume(L)	7.01
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	37.8
CardiacOutput(L/min)	6.08
CarbonDioxideSaturation	0.300
RespiratoryExchangeRatio	0.812
SystemicVascularResistance(mmHg_s/mL)	0.894
OxygenConsumptionRate(mL/min)	302
CarbonDioxideProductionRate(mL/min)	246
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 (394)	585	48.7%	VT (measured)
InspiratoryRespiratoryResistance(cmH2O_s/L)	LessThan Segment2 (20.5) [304] [308]	12.4	-39.7%	Rinsp
ExpiratoryRespiratoryResistance(cmH2O_s/L)	LessThan Segment2 (20.3) [304] [308]	12.4	-38.9%	Rexp
OxygenSaturation	GreaterThan Segment2 (0.927) [304] [308]	0.932	0.582%	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)	42.9
ClinicalPhysiologicDeadSpaceTidalVolumeRatio	0.513
ClinicalShuntFraction	0.279
MechanicalVentilator-TidalVolume(L)	0.585
BloodPH	7.37
Aorta-Oxygen-PartialPressure(mmHg)	65.4
Aorta-CarbonDioxide-PartialPressure(mmHg)	44.8
Aorta-Bicarbonate-Molarity(mEq/L)	26.1
OxygenSaturation	0.932
HorowitzIndex(mmHg)	131
IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.277
MechanicalVentilator-RespirationRate(1/min)	24.6
MechanicalVentilator-MeanAirwayPressure(cmH2O)	13.5
MechanicalVentilator-PeakInspiratoryPressure(cmH2O)	24.9
MechanicalVentilator-PlateauPressure(cmH2O)	24.2
HeartRate(1/min)	77.5
SystolicArterialPressure(mmHg)	114
DiastolicArterialPressure(mmHg)	75.0
MechanicalVentilator-TotalPulmonaryVentilation(L/min)	14.4
MechanicalVentilator-InspiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-ExpiratoryResistance(cmH2O_s/L)	12.4
MechanicalVentilator-StaticRespiratoryCompliance(mL/cmH2O)	42.5
MechanicalVentilator-DynamicRespiratoryCompliance(mL/cmH2O)	39.2
MechanicalVentilator-EndTidalCarbonDioxidePressure(mmHg)	32.1
MechanicalVentilator-EndTidalOxygenPressure(mmHg)	348
MechanicalVentilator-ExpiratoryTidalVolume(L)	0.585
MechanicalVentilator-InspiratoryExpiratoryRatio	0.326
MechanicalVentilator-InspiratoryTidalVolume(L)	0.585
MechanicalVentilator-PeakExpiratoryFlow(L/s)	0.712
MechanicalVentilator-LeakFraction	2.95e-05
MechanicalVentilator-IntrinsicPositiveEndExpiratoryPressure(cmH2O)	0.415
MechanicalVentilator-ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
MechanicalVentilator-TotalPositiveEndExpiratoryPressure(cmH2O)	10.4
PhysiologicDeadSpaceTidalVolumeRatio	0.553
PhysiologicShuntFraction	0.283
TotalRespiratoryModelInspiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelExpiratoryResistance(cmH2O_s/L)	12.4
TotalRespiratoryModelCompliance(mL/cmH2O)	46.3
ExtrinsicPositiveEndExpiratoryPressure(cmH2O)	10.0
TotalPositiveEndExpiratoryPressure(cmH2O)	10.3
EndTidalCarbonDioxidePressure(mmHg)	34.6
PhysiologicDeadSpace(mL)	327
AlveolarArterialGradient(mmHg)	274
AlveolarDeadSpace(mL)	158
AnatomicDeadSpace(mL)	169
ChestWallCompliance(L/cmH2O)	0.164
FractionOfInspiredOxygen	0.500
LungCompliance(L/cmH2O)	0.0587
VentilationPerfusionRatio	2.43
HeartStrokeVolume(mL)	78.5
HeartEjectionFraction	0.544
BloodVolume(L)	7.05
MeanArterialPressure(mmHg)	95.5
PulsePressure(mmHg)	38.7
CardiacOutput(L/min)	6.08
CarbonDioxideSaturation	0.155
RespiratoryExchangeRatio	0.811
SystemicVascularResistance(mmHg_s/mL)	0.894
OxygenConsumptionRate(mL/min)	300
CarbonDioxideProductionRate(mL/min)	243
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.