Various ventilator graphics

1. VENTILATOR GRAPHICS
Smrithi Rajeev
Department of Respiratory Therapy

2. PURPOSE OF VENTILATOR GRAPHICS
● Graphics are waveforms that reflect the patient-ventilator system and their
interactions.
● Purposes
○ Helps monitor the patient lung status (C and Raw)
○ Assesses patient response to therapy
○ Allows fine tuning the ventilator to reduce WOB and to optimize ventilation
○ Helps interpret, evaluate, and troubleshoot ventilator and patients’ responses
○ Monitors ventilator function and calculate respiratory mechanics

3. Ventilator
Graphs
Scalars Loops

4. SCALARS

6. BASIC CURVES SEEN WITH SCALARS

7. IDENTIFY

8. IDENTIFY

9. FLOW-TIME SCALAR
● A – Inspiratory Valve opens
● B – Peak inspiratory flow
● C – End of inspiratory flow
● D – Expiratory Valve opens
● E – Expiratory flow ends
● F – End of exhalation

10. FLOW-TIME SCALARS
● Useful to detect certain abnormalities.
● If expiratory flow doesn’t return to baseline before the next breath, there is auto-PEEP present.
● CPAP has a sinusoidal flow pattern unless PS has been added.

11. PRESSURE-TIME SCALAR
● Patient triggered breaths will have a negative deflection at the start of the
breath if pressure triggering is used.
● In volume modes, the shape of PT curve will be exponential rise for
mandatory breaths and sinusoidal for spontaneous breaths.
● In pressure modes, the shape of PT curve will be rectangular for mandatory
breaths and sinusoidal for spontaneous breaths.
● Addition of PEEP raises the baseline in the PT curve.
● The area under the entire curve equals the mean airway pressure.

12. VOLUME-TIME SCALAR
● Depends on the type of flow pattern used.
○ Ascending ramp pattern with square wave flow pattern
○ Exponential rise if the decelerating flow pattern is used
● Helpful to detect abnormalities (auto-PEEP or air leak) – Exhalation side of the curve
does not return to the baseline.

14. SPONTANEOUS BREATH

15. MECHANICAL BREATH

16. TYPICAL FLOW PATTERNS

17. INSP & EXP FLOW PATTERN

18. INADEQUATE INSPIRATORY FLOW

19. OBSTRUCTION & ACTIVE EXHALATION

20. AIR TRAPPING

21. RESPONSE TO BRONCHODILATORS

23. SPONTANEOUS BREATH

24. MECHANICAL BREATH

25. CONTROLLED BREATH Vs. ASSISTED BREATH

26. COMPONENTS OF INFLATION PRESSURE

28. PIP Vs. Pplat

29. INCREASED AIRWAY RESISTANCE

30. DECREASED COMPLIANCE

32. VOLUME-TIME SCALAR

33. AIR LEAKS

34. ACTIVE EXHALATION

35. LOOPS

37. PRESSURE VOLUME LOOP (BREATH TYPES)

38. PV LOOP COMPONENTS

39. PV LOOP WITH PEEP

40. WOB

41. INFLECTION POINTS

42. AIR LEAK

43. INADEQUATE INSPIRATORY FLOW

44. INCREASED AIRWAY RESISTANCE

47. OVERDISTENSION

48. FLOW-VOLUME LOOPS

50. AIR LEAK

51. AIR TRAPPING

52. INCREASED AIRWAY RESISTANCE

53. SECRETIONS/ WATER IN THE CIRCUIT

60. ● Breath Stacking
● Double triggering
● Flow hunger