Ventilator Management Flashcards
Two classifications of bag mask:
- Self-inflating
2. Floppy bag (like one in the OR)
Manually controlled ventilation consists of two types:
- Bag-Mask
2. T-piece
What is an advantage of the Ambush bag over the floppy reservoir bag?
If we run out of gas while transporting the patient
Two types of ventilators:
- Manually controlled
2. Mechanically controlled
What makes Mapleson E and Jackson-Rees (Mapleson F) different?
Jackson-Rees has a manually inflating/flow-inflating bag at the distal end that allows us to mechanically ventilate the patient if we need to.
There are way to drive mechanical ventilation:
- Bellows driven ventilator
2. Piston driven ventilators
Bellow driven ventilators have ascending and descending bellows, what’s the difference?
- Ascending - goes up on expiration
- Descending - goes down on expiration
* we most commonly see ascending bellows because they are safer
For piston driven ventilators, where are the fresh gas flows stored?
In the outside chamber. (We could get a hypoxic mixture if the bellow gets a hole in it because the fresh gas may flow into the bellow and that would cause no fresh gas to flow to patient.)
What are the ventilation parameters?
- Cycle type
- Mode of ventilation
- FiO2
- Rate
- TV
- Flow Rate driving pressure
- I:E ratio
- PEEP
- Pressure support
- CPAP
True or False. For volume-cycled ventilation, alveolar ventilation is stable regardless of pulmonary compliance.
True
True or False. Volume-cycled ventilation is where we have a preset volume for lung inflation and unless we have a specific maximum pressure allowed, the machine will continue to deliver volume and the pressure could go up resulting in barotrauma.
True. Unless we reach a pressure limit set on the ventilator, the TV delivered will happen regardless of pressure.
True or False. Pressure-cycled ventilation could lead to under-ventilation.
True. Lung inflation occurs to a preset pressure and this can decrease our risk of barotrauma but can result in under-ventilation of our lungs if they aren’t very compliant.
What does plateau pressure measure?
How distensable the lungs are, what compliance and elastance of the lungs is, and where you are on the lung expansion curve.
Airflow resistance = ________ + ________
Peak pressure + pleateau pressure = airway resistance
What does controlled mandatory ventilation consist of?
- Initial TV or pressure set
- Volume or pressure delivered based on rate
- No patient initiation of breaths
What does assist-controlled ventilation consist of?
- Patient can initiate a breath
- Initiation. Ust stimulate pressure sensing valve
- When breath triggered, full TV is delivered
- When no trigger, full VT delivered
- Tachypnea can lead to alkalosis and auto-PEEP
What does SIMV stand for?
Synchronized intermittent mandatory ventilation
What does SIMV consist of?
- Pre-set volume or pressure rate
- Cycle waits for patient initiated breath
- Additional efforts do not initiate another breath (if we set them at 10 bpm and they are breathing 15 bpm, they will get 5 bpm at whatever volume they pull in)
What does pressure controlled ventilation consist of?
- Better control of peak airway pressure
- Inspiratory flow increases exponentially during inflation
- Volumes more prone to change with changes in pulmonary compliance
What does pressure support ventilation consist of?
- Augmentation of spontaneous breathing
2. Allows patient to determine respiratory parameters
How can we manipulate PaO2?
- FiO2
- Alveolar pressure
- Ventilation
- V/Q mismatching
Minute ventilation = _______ * ________
TV * Rate = MV
How do high flow rates in effect driving pressure in the bellows?
Increase the driving pressure
In I:E ratio, what are the two components of the I?
Inspiratory time + inspiratory pause
Longer inspiratory times can have what effects?
- Improve oxygenation
- Increase risk for auto PEEP (breath stacking)
- Decrease peak airway pressure
- Less well tolerated by patients
Extrinsic PEEP varies from intrinsic PEEP in what way?
Extrinsic - added to system
Intrinsic - ventilation issue
True of False. CPAP delivers positive pressure throughout the breathing cycle allowing a decrease in energy required to overcome negative airway pressure. This is mainly used for stenting the upper airway in non-intubated patients.
True.
What are the criteria for extubation?
- Vital capacity > 15 cc/kg
- NIF < -25 mmH2O
- Rate < 30 bpm
- TV > 5 cc/kg
- PaO2 > 300 mmHg on FiO2 1.0
- PaO2 > 70 mmHg on FiO2 0.21
- Sustained head lift > 5 sec
- Normothermic
- Hemodynamically stable
