机械通气波形分析(杜斌)

Flow (L/min)
Time (sec)
PEFR
Long TE
Higher PEFR
Shorter TE
Vol (mL)
Increased Raw
Higher PTA
Pressure (cm H2O)
Increased Airway Resistance
Flow (L/min)
Inspiration
COMPLIANCE
Increased Normal Decreased
VT levels
Pressure Targeted Ventilation
Volume (mL)
Paw (cm H2O)
Preset PIP
Volume (ml)
Air Leak
Air Leak
Time (sec)
Air Leak
Pa w (cm H2O)
Time (sec)
Inadequate Inspiratory Flow Active Inspiration or Asynchrony Patient’s effort
Flow
(L/min)
Normal Abnormal
Time (sec)
Inadequate Inspiratory Flow
Overdistension
With little or no change in VT
Normal Abnormal
Volume (ml)
Pressure (cm H2O)
Paw rises
Inadequate Inspiratory Flow
Adequate Flow
Inadequate Flow
Ventilator Waveforms
Scalars
Volume versus time Pressure versus time Flow versus time
Loops
Flow-Volume Pressure -Volume
Flow versus Time
SQUARE
DECELERATING
ACCELERATING
SINE
Volume vs Time
Volume (ml)
Inspiratory Tidal Volume
Inspiration
Expiration
TI
Time (sec)
Pressure versus Time
Peak Inspiratory Pressure PIP
Describe how loops are used to diagnose and manage problems in patients receiving mechanical ventilation
Monitoring Techniques Used During Mechanical Ventilation
Waveform Monitoring of the Mechanically Ventilated Patient
Tim Op’t Holt, Ed.D., R.R.T. Professor
Cardiorespiratory Care University of South Alabama
Objectives
Ventilator waveforms
pressure, volume and flow vs time scalars flow-volume and pressure volume loops
Allows analysis of
auto-PEEP, bronchodilator response, work of breathing, hyperexpansion, adequacy of flow, ventilator sensitivity, compliance, and leaks
Flow-Volume Loop
Inspiration PIFR
FRC
Volume (ml)
VT
PEFR Expiration
Air Trapping
Flow (L/min)
Inspiration
Normal Patient
}
Air Trapping Auto-PEEP
Expiration
Time (sec)
Describe the volume, pressure and flow versus time scalars.
Describe the use of scalars in the management of the mechanically ventilated patient.
Describe the flow-volume and pressure-volume loops as they are used in the mechanically ventilated patient.
PIP PPlat
Paw (cm H2O)
PIP
Normal
Increased PPlat (Decreased Compliance)
Normal PPlat (Normal Compliance)
Time (sec)
DECREASED COMPLIANCE
Lung Compliance Changes and the P-V Loop
Volume (ml)
Inappropriate Flow
Active Inspiration
Normal Abnormal
Paw (cm H2O)
Inadequate Sensitivity
Volume (mL)
Increased WOB
Paw (cm H2Oompliance
Paw (cm H2O)
Inspiration
Expiration
TI
TE
}
PEEP
Time (sec)
Pressure-Volume Loop
Vol (ml)
E I
Controlled
E
I
Assisted
I
E
Paw (cm H2O)
Spontaneous
I: Inspiration E: Expiration
Air Trapping
Inspiration
Flow (L/min)
Does not return to baseline
Volume (ml)
Normal Abnormal
Expiration
Increased Airway Resistance
Normal
PIP
PPlat
PIP High Raw
PPlat
Paw (cm H2O)
}
Normal
Increased PIP
Increased PTA (increased Airway Resistance)
Normal PPlat (Normal Compliance)
Response to Bronchodilator
Before
After
Volume (ml)
“Scooped out” pattern
Normal Abnormal
Decreased PEFR
Expiration
Work of Breathing
Volume (ml)
B
A
A: Resistive Work B: Elastic Work
Pressure (cm H2O)
Volume (ml)
Air Leak
Pressure (cm H2O)
Flow (L/min)
Air Leak
Inspiration
Air Leak in mL
Expiration
Volume (ml)
Normal Abnormal
Problems with Waveforms
Tend to be more qualitative than quantitative We tend to look at them, but not use them as
therapeutic or diagnostic tools It is not known if passive flow-volume loops
accurately correlate with findings from forced vital capacity flow volume loops Paucity of literature substantiating their value