Mechanical Ventilation- Pressure/Volume/Flow curves
Patient triggers a breath (1) which means the machine will deliver a preset tidal volume (2), e.g. 500mls. This is the volume set by the user which we want to deliver with each breath.
As that volume enters the lung the pressure in the lung will go up (3). The pressure climb will stop at the same point as the maximum volume delivered.
As the breath is initiated flow will go up immediately to achieve the targets set until it reaches a constant flow and then plateaus off. (4).
When that preset volume is reached, flow will stop and then, as the patient breathes out, flow will actually come out of the patient, so the flow curve dips below our time axis. (5)
As that happens the pressure in the lung will start to fall (with PEEP it would not return to zero, but would stay at whatever pressure was set) (6).
And finally volume will come out of the lung and return to zero. (7)
- Peak and Plateau Pressure
- AC versus SIMV mode
- Positive End Expiratory Pressure (PEEP)
- Increase the rate or tidal volume?
- Phases of a breath- I:E ratio and cycle time
- Ventilation screen- what do those numbers mean?
- Pressure Support
- Modes of ventilation I
- Modes of ventilation II
- Physiologic effects
- Physiologic goals
- How do I describe how my patients ventilation?
- Trigger, Limit and Cycle
- Pressure support ventilation graphs
- ARDS and Proning
- 6 ways to be better with Bag-Valve-Mask
- Phase Variables
- Airway Pressure Release Ventilation (APRV)
- Pressure Volume Loop
- Lung compliance in volume controlled ventilation
- Pressure/Volume/Flow graphs
- A-a gradient
- Goals and Indications
- Anatomy of the Endotracheal Tube
- Lung Compliance
- Ventilation/Perfusion V/Q matching
- Ventilator Induced Lung Injury (VILI)
- Ventilator Associated Pneumonia (VAP)
- Phase variables...again...
Guidelines for the management of tracheal intubation in critically ill adults
Having read the guidelines I made these infographics. They are FREE. Just let me know your email address and they will be sent to you.