Mechanical Vent Review Flashcards
(47 cards)
What are the differences between normal and mechanical ventilation?
Normal: negative pressure, intrapleural, pulmonic and thoracic pressure becomes negative.
Mechanical vent: positive pressure, intrapleural remains negative but intrapulmonic becomes positive as well as intrathoracic
Whatare two physiological effects of mechanical ventilation?
1:decreased venous return due to increased intrathoracic pressure (decreased preload
2:mechanical ventilation will falsely increase cvp values.
Types of respiratory failure
Type 1: hypoxic( gas exchange)
Type 2: hypercapnia (ventilation)
4 physiological reasons for mechanical ventilation
Support alveolar ventilation,support gas exchange, increase lung volume, reduce WOB
Endotracheal intubation indications
Failure to oxygenate, ventilate, maintain/protect, clinical progression.
ET tubes are for short-med timeframe, Trach is for long term.
Define flow
Volume moving across time
Mechanical ventilation is made Up of 3 components, what are they?
Flow, volume, pressure
What is the relationship between volume and pressure?
Volume and pressure are inseparable, an increase in volume results in increased pressure
How does flow relate to volume and pressure?
- Flow is volume moving across time, flow creates volume, and volume creates pressure.within a space.
What are 3 major goals of mechanical ventilation?
Decrease WOB, support/optimize oxygenation and ventilation, balance pH
What are 4 things a vent cannot do for a pt.
A vent cannot… Assist w/cellular gas exchange, aid transport of gases, influence cellular uptake, force pt to exhale (asthma)
What are the 4 modes of classic ventilation.
Assist /control mode, synchronized intermittent mandatory ventilation (simv), pressure control, pressure support
What is a controlled breath?
A breath that is completely controlled by the ventilator. The patient does nothing.
What is an assisted breath?
The vent senses a change inpressure or flow, this is a triggered breath. When sensed a breath is delivered.
When volume is a set perimeter, what will vary ?
Pressure will vary
When pressure is a set parameter, what will vary?
Volume will vary
Define assist control parameters.
RR + vt are set, pressure will vary, peep is an adjunct. Pt can initiate additional breaths
Define SIMV + parameters
Combination of A/C and spontaneous breathing.
The vent will delivery mandatory set breathes with set vt in coordination with the patients own breaths.
.set parameters include: RR sync with pt., tidal volume, pressure support to help pt initiated breaths.
Define pressure controlled ventilation + set perameters
The vent will deliver a set number of breaths per min until a set pressure is reached. This is a time cycled, pressure limited mode of ventilation. Volume will vary.
Set parameters include pressure control, rr, inspiratory time.
What components make up the i:e ratio?
RR+ i-time
Define pressure Support + perameters
Adjunct not a mode of ventilation. PSV provides an inspiratory boost to spontaneously breathing patients.
Set parameters are pressure (5-20 cmh2o)peep
How is Vtcalculated?
Based on ideal body weight (6 -8ml/kg)
ARDS 4-8ml/kg
Define peak-flow
The speed of gas flowing from the machine and into the lungs. Measured in litres / min. Not monitored.
What is the preferred airway for patients requiring long term ventilatory support
Tracheostomy
