Ventilator Management Flashcards
Vt
Tidal Volume
6-8 ml/kg
how much air the Pt breaths in a normal breath
the volume of air delivered per breath
IRV
Inspiratory reserve volume
The amount of air that can be forcefully inhaled after a normal tidal volume breath
ERV
Expiratory reserve volume
the amount of air that can be forcefully exhaled after a normal tidal volume breath
VC
Vital capacity
Vt+IRV+ERV=VC
RV
Residual Volume
the amount of air left in the respiratory tract following forceful exhalation
TLC
Total lung capacity
IRV+Vt+ERV+RV=TLC
Dead space
2ml/kg=dead space
the surfaces of airway that are not involved in gaseous exchange
F
Rate
Ve
Minute volume
FxVt
How much air is breathed in one minute
FiO2
Fraction of inspired oxygen
0.21-1 (21%-100%)
The ventilator feature that allows for very precise delivery of oxygen co cocentrations
I:E
Ratio of inspiration vs expiration
Pplat
Plateau Pressure
PEEP
Positive End Expiratory Pressure
PEEP is what keeeps the alveoli openso that oxygen can diffuse
PEFR
Peak Expiratory Flow Rate
500 to 700 L/min Males
380 to 500 L/min Females
A persons maximum speed of expiration, as measure with a peak flow meter
CMV
Controlled Mandatory Ventilation
Used in sedated, apneic,and paralyzed Pts
All Breaths are triggered,limited, and cycled by the ventilator
Pt has no ability to initiate their own breaths
SIMV
Synchronized Intermittent Mandatory Ventilation
Assisted mechanical ventilation synchronized with the Pt’s breathing
The ventilator senses the Pt taking a breath, then delivers a breath.
Spontaneous breathing by the pt occurs between the assisted mechanical breaths, which occur at preset intervals
if the Pt fails to take a breath the ventilator will provide a mechanical breath(backup rate can be set)
This mode is preferred for Pts with an intact respiratory drive
SIMV is similar to CPAP AND BIPAP because they are all spontaneously triggered by the Pt
AC
Assist- Controlled Ventilation
PSV
Pressure support ventilation
Pressure support makes it easier for the Pt to overcome the resistance of the ET tube and is often used during weaning because it reduces the work of breathing
Supports ventilation during inspiration
Pt determines tidal volumes, and rate
Requires consistent ventillatory effort by the Pt
CPAP/BPAP
Are similar to SIMV because they are all spontaneously triggered by the Pt
CPAP
Continuous Positive airway pressure
is the use of continuous positive pressure to maintain a continuous level of PEEP
CPAP uses mild air pressure to keep an airway open
BPAP
Bi-Level continous positive airway pressure
uses alternating levels of PEEP to maintain oxygenation, commonly used in pneumonia, COPD, asthma, etc…
BIPAP refers to a specific manufacturer, and technically is not a ventilator mode
Low pressure alarm
Pt disconnection from machine (most common cause) Chest tube leaks circuit leaks airway leaks hypovolemia
High Pressure alarms
Kinked line (most common cause) coughing secretions or mucus in the airway Pt biting the tube reduced lung compliance( Pneumothorax, ARDS) increased airway resistance
DOPE
Dislodged - Low pressure alarm
Obstructed- High pressure alarm
Pneumothorax- high pressure alarm
Equipment- (machine failure, dead batteries, etc…)
Controlled
The Pts F, and Vt is controlled completely
Intermittent
the Pt can take intermittent breaths (between controlled breaths)
Synchronized
the ventilator synchronizes the delivery of breath with the PTs inspiratory drive
Assist
The ventilator assists the Pts with their breathing(must have intact respiratory drive)
ALI
Acute lung injury
Pulmonary condition characterized by hypoxemic respiratory failure, diffuse pulmonary infiltrates on CXR, pulmonary wedge pressure
ARDS
Severe form of ALI differentiated by PaO2/FiO2 ratio
Asynchrony
Incongruity between Pt’s respiratory effort and ventilator delivery
Increases work of breathing
Auto- PEEP
Gas trapped in alveoli at the end of expiration caused by insufficient expiration time, bronchospasm, or mucous plugging. causes dyanmic alveolar hyperinflation, and increases work of breathing, also referred to as intrinsic PEEP
Barotrauma
Damage to lung tissue from high airway pressures.
alveolar reupture may lead to pneumothorax, pulmonary interstitial edema, and pnumomediastinum
Cyclic atelectasis
Repeated opening of alveoli on inspiration and collapsing on expiration
Derecruitment
collapse of open alveoli
dynamic alveolar hyperinflation
Increase in lung volume at end of expiration caused by incomplete exhalation
Extrensic PEEP
mechanical application of PEEP
Male IBW
50 kg + 2.3 for each inch over 5 ft (tauber says 3 for each inch)
Female IBW
45.5 kg + 2.3 kg for each inch over 5 ft (tauber says 3 for each inch)
Inspiratory flow
rate in which breath is delivered on ventilator. it is measured in LPM
higher the flow, faster the breath is delivered. flow is equal to tidal volume divided by inspiratory time(Ti)
Ti
Inspiratory time
Time over which tidal volume is delivered or pressure maintained(depending on mode)
Paw
average pressire to which lungs are exposed over one inspiratory/ expiratory cycle
PaO2/FiO2 ratio
Calculation used to quantify to degree of hypoxemia and oxygenation abnormality in Pts with acute repiratory failure. PaO2 derived from arterial blood gas divided by the FiO2
Normal is 500
Pts with ALI are
PIP
peak inspiratory Pressure
Measurement in lungs at peak of inspiration
Permissive hypercapnia
Lung-Protective ventilation strategy that uses low tidal volumes to reduce lung injury, associated with high volumes, and alveolar overdistention. CO2 allowed to rise as consequence
PEEP
Positive pressure maintained at end of expiration
therapy used in mechanical ventilation to increase volume of gas remaining in lungs at end of expiration (FRC)
Plateau Pressure
Pressure exerted on small airways and alveoli , measured by holding the inspiratory pause during ventilator delivered inspiration
Plateau Pressure abover 30 mmhg have been associated with alveolar distention lung injury
recruitment
refers to opening of collapsed alveoli
alveolar recruitment maneuvers refer to increasing PEEP, for short durations , to open collapsed alveoli and improve oxygenation
Level of PEEP. duration, and frequency of this manuver is determined by the clinician
trigger- sensitivity
measure of amount of negative pressure that must be generated by the Pt to trigger mechanical ventilator into inspiratory phase
Volutrauma
Volume related overdistention injury of alveoli inflicted by mechanical ventilation
