07 Vent Basics Flashcards
When someone naturally inhales, do they use negative or positive pressure?
Negative pressure
What are the two types of vents that use negative pressure?
Iron lung and Chest Cuirass
Two types of sensitivity triggers
pressure trigger sensitivity and flow trigger sensitivity
Which ratio is smaller? i:e of 1:1 OR 1:2
1:2 **Think of it as a fraction
What is an inverse i:e ratio?
When the inspiration time is greater than the expiration time
What are the two things a vent can manipulate to deliver a breath?
Pressure OR volume
Four factors of every breath
Pressure, volume, flow, and time
What part of the machine is required to have someone on a ventilator with PEEP?
A functional exhalation valve
What is the function of the exhale valve? what position is the valve in during inspiration?
The exhale valve directs flow of the gas toward the patient. During inspiration, the valve is CLOSES.
Which trigger is more responsive for the patient and is the recommended setting to use whenever available?
Flow trigger sensitivity
What is the ideal i:e ratio?
1:2 or LESS
When would an inverse i:e ratio be used on a patient?
This is used in oxygenating in infants and adults who are critically ill
**Two ways that you can increase your pressure at the end of the expiratory phase
PEEP and CPAP
**PEEP helps what? hurts what?
Increases PaO2 (increases oxygenation), helps with alveolar recruitment (helps atelectasis), but will DECREASE venous return to the heart.
**Who should you not use PEEP for?
Someone who is hemodynamic. Remember increasing PEEP will decrease venous flow to the heart.
**What pt could use PEEP?
COPD- helps decrease the need for FiO2
Absorption Atelectasis- increases alveolar recruitment
O2 Toxicity- decreases the need for high FiO2
Increasing flow does what to i e
Decreases i time and increases e time
A larger volume does what to i and e
Larger will increase i and decrease e time
**Remember increasing the i time = LONGER inspiration time
An increased rate will do what to i and e?
Increasing the rate will decrease both
In PSV mode, what is the only factor that the pt does not have control over?
The pressure given with each breath (you set this)
