1. Ventilator Graphics: Not Just Pretty Lines
Ruben D Restrepo, MD, RRT, FAARC
Professor
The University of Texas Health Science Center at San Antonio

2. Objectives
Identify graphic display options provided by mechanical ventilators.
Describe how to use graphics to
more appropriately adjust the patient ventilator interface.

3. Introduction
Monitoring and analysis of graphic display of curves and loops during mechanical ventilation has become critical to determine
how patient is being ventilated
to assess problems occurring during ventilation

4. Uses of Flow, Volume, and Pressure Graphic Displays
Confirm mode functions
Detect auto-PEEP
Determine patient-ventilator synchrony
Assess and adjust trigger levels
Measure the work of breathing
Adjust tidal volume and minimize overdistension
Assess the effect of bronchodilator administration

5. Uses of Flow, Volume, and Pressure Graphic Displays
Detect equipment malfunctions
Determine appropriate PEEP level
Evaluate adequacy of inspiratory time in pressure control ventilation
Detect the presence and rate of continuous leaks
Assess inspiratory termination criteria during Pressure Support Ventilation
Determine appropriate Rise Time

6. Mechanical Ventilation
Graphics
SCALARS
LOOPS

7. SCALARS
Flow/Time
Pressure/Time
Volume/Time

8. LOOPS
Pressure-Volume
Flow-Volume

9. SCALARS
Flow/Time
Pressure/Time
Volume/Time

10. Spontaneous Breath
Inspiration
Time (sec)
Flow (L/min)
Expiration

11. Mechanical Breath
Inspiration
Time (sec)
Flow (L/min)
Expiration

12. Typical Flow Patterns
SQUARE
DECELERATING
ACCELERATING
SINE

13. Inspiratory Flow Pattern
Beginning of expiration
exhalation valve opens
Peak inspiratory flow rate
PIFR
Inspiration
Insp. time TI
Expiratory Time TE
Flow (L/min)
Total cycle time
TCT
Time (sec)
Beginning of inspiration
exhalation valve closes
Expiration

14. Expiratory Flow Pattern
Beginning of expiration
exhalation valve opens
Inspiration
Expiratory time TE
Time (sec)
Flow (L/min)
Duration of
expiratory flow
Expiration
Peak Expiratory Flow Rate
PEFR

15. Inspiratory Pause } Inspiration Flow (L/min) Time (sec) Expiration

16. Inadequate Inspiratory Flow
Patient’s effort
Active Inspiration
Normal
Abnormal
Time (sec)
Flow
(L/min)

17. Air Trapping Inspiration Normal Patient Time (sec) Flow (L/min) }
Auto-PEEP
Expiration

18. Response to Bronchodilator
Before
After
Time (sec)
Flow (L/min)
Long TE
PEFR
Shorter TE
Higher PEFR

19. SCALARS
Flow/Time
Pressure/Time
Volume/Time

20. Inspiratory Tidal Volume
Volume vs Time
Inspiratory Tidal Volume
Volume (ml)
Inspiration
Expiration TI
Time (sec)

21. Air Leak/Air Trapping
Volume (ml)
Volume lost
Time (sec)

22. SCALARS
Flow/Time
Pressure/Time
Volume/Time

23. Spontaneous Breath
Expiration
Paw (cm H20)
Time (sec)
Inspiration

24. Peak Inspiratory Pressure
Mechanical Breath
Peak Inspiratory Pressure
PIP
Paw (cm H2O)
Inspiration
Expiration TI TE }
PEEP
Time (sec)

25. CONTROLLED BREATH (Time Triggered) Mechanical Paw (cm H2O) Time (sec)
Time Triggered Breath

26. Assisted Breath (Patient Triggered)
Mechanical
Paw (cm H2O)
Time (sec)
Patient Triggered Breath

27. Assisted vs Controlled
Pressure (cmH20)
Time (sec)

28. Spontaneous vs. Mechanical
Inspiration
Paw (cm H2O)
Spontaneous
Expiration
Expiration
Inspiration
Time (sec)

29. Components of Inflation Pressure
PIP }
Transairway Pressure (PTA)
Paw (cm H2O)
Exhalation Valve Opens
Pplateau
(Palveolar)
Inspiratory Pause
Expiration
Begin Inspiration
Time (sec)
Begin Expiration

30. Inadequate Inspiratory Flow
Inadequate Flow
Adequate Flow
(cm H2O)
Paw
Time (sec)

31. LOOPS
Pressure-Volume
Flow-Volume

32. Pressure-Volume Loop (Type of Breath)
Vol (ml) I E I I
Paw
(cm H2O)
Controlled
Assisted
Spontaneous
I: Inspiration
E: Expiration

33. Components of Pressure-Volume LoopVT
Expiration
Volume (mL)
Inspiration
PIP
Paw (cm H2O)

34. PEEP and P-V Loop VT
PIP
Volume (mL)
PEEP
Paw (cm H2O)

35. Work of Breathing B A: Resistive Work B: Elastic Work A Volume (ml)
Pressure (cm H2O)

36. Inflection Points Upper Inflection Points Lower Inflection Point
Volume (mL)
Lower Inflection Point
Pressure (cm H2O)

37. Inadequate Sensitivity
Volume (mL)
Paw (cm H2O)
Increased WOB

38. Air Leak/Air Trapping
Volume (ml)
Air Leak
Pressure (cm H2O)

39. Inadequate Inspiratory Flow
Volume
(ml)
Active Inspiration
Inappropriate Flow
Normal
Abnormal
Paw (cm H2O)

40. Increased Raw
Higher PTA
Volume
(ml)
Higher PTA
Paw (cm H2O)

41. Hysteresis Normal Hysteresis Abnormal Hysteresis Volume (ml)
Pressure (cm H2O)

42. Lung Compliance Changes and the P-V Loop
Volume Targeted Ventilation
Preset VT
COMPLIANCE
Increased
Normal
Decreased
Volume (mL)
Paw (cm H2O)
PIP levels

43. Lung Compliance Changes and the P-V Loop
Increased
Normal
Decreased
VT levels
Pressure Targeted Ventilation
Volume (mL)
Paw (cm H2O)
Preset PIP

44. With little or no change in VT
Overdistension
With little or no change in VT
Normal
Abnormal
Volume (ml)
Pressure (cm H2O)
Paw rises

45. LOOPS
Pressure-Volume
Flow-Volume

46. Flow-Volume Loop Inspiration PIFR FRC VT PEFR Expiration Flow (L/min)
Volume (ml)
FRC VT
Flow (L/min)
PEFR
Expiration

47. Air Leak Normal Abnormal Inspiration Expiration Volume (ml)
Flow
(L/min)
Volume (ml)
Air Leak in mL
Normal
Abnormal
Expiration

48. Air Trapping Normal Abnormal Inspiration Expiration Flow (L/min)
Does not return
to baseline
Volume (ml)
Normal
Abnormal
Expiration

49. Increased Airway Resistance
Inspiration
Flow
(L/min)
Volume (ml)
Normal
Abnormal
“Scooped out”
pattern
Decreased PEFR
Expiration

50. Airway Secretions/ Condensate in the Circuit
Inspiration
Flow
(L/min)
Volume (ml)
Normal
Abnormal
Expiration

52. Modes of Ventilation Mechanical Spontaneous Volume Targeted Pressure

53. Spontaneous Breath
Flow
L/m
Pressure
cm H2O
Volume mL
Time (sec)

54. CPAP
Flow
L/m
Pressure
cm H2O
CPAP level
Volume mL
Time (sec)

55. PSV Patient Triggered, Flow Cycled, Pressure limited Mode Time (sec)
Flow Cycling
Flow
L/m
Set PS level
Pressure
cm H2O
Volume mL
Time (sec)

56. CPAP + PSV Flow Cycling Flow L/m Pressure cm H2O Volume mL Time (sec)
Set PS level
Pressure
cm H2O
CPAP level
Volume mL
Time (sec)

57. Modes of Ventilation Mechanical Spontaneous Volume Targeted Pressure

58. Controlled Mode (Volume- Targeted Ventilation)
Time triggered, Flow limited, Volume cycled Ventilation
Preset Peak Flow
Flow
L/m
Dependent on
CL & Raw
Pressure
cm H2O
Preset VT
Volume Cycling
Volume mL
Time (sec)

59. Assisted Mode (Volume-Targeted Ventilation)
Patient triggered, Flow limited, Volume cycled Ventilation
Flow
L/m
Pressure
cm H2O
Preset VT
Volume Cycling
Volume mL
Time (sec)

60. SIMV (Volume-Targeted Ventilation)
Pressure
Flow
Volume
(L/min)
(cm H2O)
(ml)
Spontaneous Breaths

61. Controlled Mode (Pressure-Targeted Ventilation)
Time Triggered, Pressure Limited, Time Cycled Ventilation
Time-Cycled
Pressure
Flow
Volume
(L/min)
(cm H2O)
(ml)
Set PC level
Time (sec)

62. Assisted Mode (Pressure-Targeted Ventilation)
Patient Triggered, Pressure Limited, Time Cycled Ventilation
Time-Cycled
Pressure
Flow
Volume
(L/min)
(cm H2O)
(ml)
Set PC level
Time (sec)

63. SIMV Mode (Pressure-Targeted Ventilation)
Flow
Volume
(L/min)
(cm H2O)
(ml)
Set PC level
Time (sec)
Spontaneous Breath

64. SIMV + PS (Pressure-Targeted Ventilation)
Time-Cycled
Flow-Cycled
Pressure
Flow
Volume
(L/min)
(cm H2O)
(ml)
Set PC level
Set PS level
Time (sec)
PS Breath

65. SIMV+PS (Volume-Targeted Ventilation)
Flow-cycled
Flow
Pressure
Volume
(L/min)
(cm H2O)
(ml)
Set PS level
PS Breath

66. SIMV + PS + CPAP (Pressure-Targeted Ventilation)
Flow
Volume
(L/min)
(cm H2O)
(ml)
Set PC level
Set PS level
CPAP level
Time (sec)

67. SIMV+PS + CPAP (Volume-Targeted Ventilation)
Flow
Pressure
Volume
(L/min)
(cm H2O)
(ml)
Set PS level
CPAP level
Time (sec)

69. THANK YOU NYC