1. CLINICAL UTILITY OF VENTILATOR GRAPHICS
Vijay Deshpande, MS, RRT, FAARC
Assistant Professor,
Georgia State University Atlanta, Georgia.
Essential of ventilator graphics.

3. TYPES OF WAVEFORMS
There are two types of ventilator waveforms: scalars and loops
Scalars are tracings of three parameters:
pressure, volume and flow against time.
- Flow vs Time ( type of flow pattern)
- Pressure vs. Time: clinically very important waveform
- Volume vs. Time: volume delivered to the patient
Loops
pressure vs. volume and, flow vs. volume.

12. Auto-PEEP or air trapping
Inadequate expiratory time
Too high a respiratory rate
Long Inspiratory Time
Prolonged exhalation due to bronchoconstriction
A higher inspiratory flow rate (in volume-cycled ventilators)
or short TI (in time-cycled ventilators) allows
for a longer TE and may eliminate auto-PEEP

18. Components of Pressure-Time Curve
Plateau Pressure ( Pplat ) or Alveolar Pressure
Inflation Hold or Inspiratory Pause control.
the plateau pressure is the same as the alveolar pressure.
Transairway Pressure (PTA = PIP – Pplat )
the pressure required to overcome airway resistance.
Bronchospasm, airway secretions,
and other types of airway obstructions (PIP-Pplat).
Cs = VT
P plat - PEEP

19. PIP, Pplat , PTA, and TI.

21. Inspiratory Tidal Volume
Inspiratory Phase
Expiratory Phase
Inspiratory Time

25. abnormalities in flows associated with obstruction.

30. ARDS on a volume-targeted mode
switch to pressure targeted ventilation, or a reduction in VT .
ARDS on a volume-targeted mode

32. PIFR, PEFR
Tidal Volume
End of Expiration and Beginning of Inspiration

37. Flow limited, time triggered, volume cycled ventilation

38. Flow limited, patient triggered, volume cycled ventilation