Mechanical Ventilation Flashcards
Inverse Ratio Ventilation
PCV plus prolong inspiratory time. Decreased insipratory flow rate is used to prolong the time for lung inflation (helps prevent aveolar collapse
Indications for inverse ratio
Refractory hypoxemia, or hypercapnia
Inverse ratio settings you can adjust
RR, Pressure support, I:E ratio, PEEP, FiO2
Adverse affects of Inverse ratio
Can cause Auto PEEP
Pressure Support (PSV)
Pt triggers each breath, but a set amount of pressure assists each breath
Indications for PSV
Weaning mode, patient only needs airway protection
PSV settings you can adjust
Pressure support, PEEP, FiO2
Adverse effects of PSV
may not receive adequate tidal volumes
High Frequency Ventilation (HFV)
Extremely small tidal volume ventilation with gas exchange occuring via diffusion. Lung is effectively kept open throughout ventilation. AKA open lung
High Frequency Ventilation (HFV) indications
Acute resp failure with need to provide lung protection. which prevents (volutrauma)
adverse effects of High Frequency Ventilation (HFV)
Very difficult mode of ventilation best used by those with alot of experience
Noninvasive Positive Pressure Ventilation (NPPV) AKA BiPAP
Mode used for a spontaneously breathing Pt in which you are trying not to intubate
Noninvasive Positive Pressure Ventilation (NPPV) AKA BiPAP indications
Acute resp failure, COPD, CHF, hypercapnic resp failure
Noninvasive Positive Pressure Ventilation (NPPV) AKA BiPAP adverse effects
May insuflate the stomach and the patient needs to be awake
Noninvasive Positive Pressure Ventilation (NPPV) AKA BiPAP Settings
Insp. pressure and exp. pressure, FiO2
Extrinsic PEEP
Prevents alveoli collapsing at the end of expiration and recruits already collapsed alveoli
Extrinsic PEEP indications
Improve gas exchange and increase lung compliance
Extrinsic PEEP adverse effects
Reduces cardiac filling and cardiac output, can over distend alveoli causing deadspace
Intrinsic PEEP. AKA Auto PEEP
caused by prolonged inspirtory times and the vent doesn’t give enough time for full expiration by the Pt
Ways to treat Auto PEEP
decrease the inspiratory time, increase the expiratory time and increase the PEEP to match the Pts
Plateau Pressure
The pressure needed at the end of inspiration to keep the alveoli open
What is the minimal flow resistance in a typical ETT
3-7 cm of H2O/liter/sec
Ways to overcome persistent hypoxia
- increase Pt sedation
- paralytics
- placing pt in a prone position
- nitric oxide
- inhaled prostacyclin
What is the greatest predictor of the pt being weaned off the vent
the RR/TV ratio
Criterior for coming off the vent
FiO2 < 0.5 and PEEP (< or =) 7.5 cm H2O
Assist Control (AC)
The Pt initiates the breath but a set tidal volume is delivered if the Pt doesn’t initiate the breath then a set rate of breathes is delivered
Assist Control (AC) Indications
Acute Resp failure, ARDS, Pneumonia
Assist Control (AC) Settings
RR, TV, PEEP, FiO2
Assist Control (AC) Adverse effects
Resp alkalosis due to hyperinflation or auto PEEP
Intermittent Mandatory Ventilation (IMV)
Vent delivers periodic breaths however spontaneous breaths are allowed between ventilator delivered breaths
Intermittent Mandatory Ventilation (IMV) Indications
reduce risk of alkalosis and hyper inflation, COPD, Asthma,
Intermittent Mandatory Ventilation (IMV) Settings
RR, TV, PEEP, FiO2
Intermittent Mandatory Ventilation (IMV) adverse effects
Large work of breathing and high pressures maybe needed to deliver the preset tidal volume
Syncronized vs Asyncronized
SIMV are syncronized breaths with spontaneous breathing. IMV can cause breath stacking and a breath being delivered while the Pt tries to exhale.
Pressure Control Ventilation (PCV)
Breathes are delivered at a certain pressure and rate with a variable TV.
Pressure Control Ventilation (PCV) Indications
Reduce risk of barotrauma, Pneumothorax, ARDS
Pressure Control Ventilation (PCV) Settings
RR, Pressure support
Pressure Control Ventilation (PCV) adverse effects
Variable inflation volumes R/T changes in lung mechanics
