机械通气波形分析(杜斌)

Ventilator Waveforms
Scalars
Volume
versus time Pressure versus time Flow versus time
Loops
Flow-Volume
Pressure
-Volume
Flow versus Time
SQUARE
With little or no change in VT
Normal Abnormal
Volume (ml) Pressure (cm H2O)
Paw rises
Inadequate Inspiratory Flow
Adequate Flow
Paw (cm H2O)
Inadequate Flow
Volume (ml)
Air Leak
Pressure (cm H2O)
Air Leak
Inspiration
Flow (L/min)
Volume (ml) Air Leak in mL
Normal Abnormal
Expiration
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
DECELERATING
ACCELERATING
SINE
Volume vs Time
Inspiratory Tidal Volume
Volume (ml)
Inspiration Expiration
TI
Time (sec)
Pressure versus Time
Paw (cm H2O) Peak Inspiratory Pressure PIP
Allows
analysis of
auto-PEEP,
bronchodilator response, work of breathing, hyperexpansion, adequacy of flow, ventilator sensitivity, compliance, and leaks
Waveform Monitoring of the Mechanically Ventilated Patient
Tim Op’t Holt, Ed.D., R.R.T. Professor Cardiorespiratory Care University of South Alabama
Objectives
Time (sec)
PEFR
Long TE
Shorter TE
Higher PEFR
Increased Raw
Higher PTA
Vol (mL)
Pressure (cm H2O)
Increased Airway Resistance
Inspiration
Flow (L/min)
Volume (ml)
Time (sec)
Inadequate Inspiratory Flow
Active Inspiration or Asynchrony
Patient’s effort
Normal Abnormal
Flow
(L/min)
Time (sec)
Inadequate Inspiratory Flow
“Scooped out” pattern
Normal Abnormal
Decreased PEFR
Expiration
Work of Breathing
Volume (ml)
B A: Resistive Work B: Elastic Work
A
Pressure (cm H2O)
Overdistension
Volume (ml)
Active Inspiration Inappropriate Flow Normal Abnormal
Paw (cm H2O)
Inadequate Sensitivity
Volume (mL)
Increased WOB
Paw (cm H2O)
Normal
PIP
PIP
Low Compliance
PPlat
Paw (cm H2O)
PPlat
PIP
Increased PPlat (Decreased Compliance) Normal PPlat (Normal Compliance)
Normal
Time (sec)
DECREASED COMPLIANCE
Lung Compliance Changes and the P-V Loop
Inspiration
Flow (L/min)
Does not return to baseline
Volume (ml)
Normal Abnormal
Expiration
Increased Airway Resistance
Normal
PIP PIP
High Raw
PPlat
Paw (cm H2O)
Inspiration Expiration } TI
PEEP
TE
Time (sec)
Pressure-Volume Loop
E
Vol (ml)
E
I
Controlled Assisted
I
I
E
Paw (cm H2O)
Spontaneous
I: Inspiration E: Expiration
Flow-Volume Loop
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. Describe how loops are used to diagnose and manage problems in patients receiving mechanical ventilation
Inspiration PIFR FRC VT
Volume (ml)
PEFR Expiration
Air Trapping
Inspiration
Flow (L/min)
Normal Patient
Time (sec)
}
Air Trapping Auto-PEEP
Expiration
Air Trapping
PPlat
}
Normal
Increased PIP Increased PTA (increased Airway Resistance) Normal PPlat (Normal Compliance)
Response to Bronchodilator
Before After
Flow (L/min)

Monitoring Techniques Used During Mechanical Ventilation
Ventilator
pressure,
waveforms
volume and flow vs time scalars flow-volume and pressure volume loops
Increased Normal Decreased
Volume (mL)
VT levels
COMPLIANCE
Paw (cm H2O)
Preset PIP
Pressure Targeted Ventilation
பைடு நூலகம்
Air Leak
Volume (ml)
Air Leak
Time (sec)
Air Leak