Ventilation Flashcards
What is VT?
Tidal Volume - volume of gas moved in and out of the lungs in a single inspiration and expiration
What is RV?
Residual Volume - the volume of gas remaining in the lungs after maximum expiration
What is IRV?
Inspiratory Reserve Volume- the maximum volume of additional air that can be inspired after normal inspiration
What is ERV?
Expiratory Reserve Volume - The maximum amount of gas that can be forcibly exhaled after a normal expiration
What is FRC?
Functional Residual Capacity - the volume of air present in the lungs at the end of passive expiration
What is IC?
Inspiratory capacity - the total volume of gas that can be inspired after a normal exhalation
What is Total Lung Capacity ?
The maximum volume of gas contained in the lungs after maximum inspiration
What is VC?
Vital Capacity - the greatest volume of gas that can be forcibly inhaled after maximal exhalation
What is FiO2?
Fraction of Inspired Oxygen - sets the oxygen percentage and controls the mixture of gases
What is the Fset?
Relates to the number of breaths that the ventilator is set to deliver in one minute
What is VT?
The amount of gas , in millilitres that is inhaled and exhaled in each breath
What is MV?
Minute Volume - the total volume of gas delivered to the pt in one minute
What is PEEP?
Positive End Expiratory Pressure - the Positive pressure in the lungs (above atmospheric pressure) that exists at the end of expiration and prevents the closure of alveoli
What is P.insp?
Peak Inspiratory Pressure - the highest level of pressure generated in the lungs during inspiration when the pt is ventilated
What is P.peak?
Peak Airway Pressure - the highest pressure during the previous breath
What is ETS?
Expiratory Trigger Sensitivity- a setting that defines the percentage (%) of peak inspiratory flow that will cycle the ventilator into exhalation
What is C.stat?
Static Compliance- it represents pulmonary compliance during periods without gas flow, such as during an inspiratory pause.
What is R.Insp?
Resistance- primarily derived from the resistance in the airways and ETT
What is RCexp?
Expiratory time constant- a dynamic measurement of respiratory function in both mandatory ventilated or spontaneously breathing patients. The rate at which the lung empties
How do you work out Tidal Volume (VT)?
5-8mL x pt weight
How do you work out (FRC) Functional Residual Capacity?
(ERV + RV) - Expiratory reserve volume + Reserve Volume
How do you work out Total lung capacity?
(IC + FRC) Inspiratory capacity + Functional Residual Capacity
How do you work out vital capacity (VC)?
(IRV +VT+ERV) Inspiratory reserve volume + Tidal volume + Expiratory reserve volume
what are the indications associated with mechanical ventilation?
- airway management
- management of respiratory distress
- to enable sedation or paralysis
- post op management
- increase lung volumes and reduce WOB
- prevention or reversal of alveolar trauma
what are the indications for the use of PEEp?
used when a patient requires assistance with ventilation in order to improve the ventilation and perfusion of the lungs and increase arterial oxygen tension
what causes high peak airway pressure and how would you troubleshoot this?
Ppeak is influenced by airway resistance and compliance
- check the ventilator and settings
- look listen and feel patient
- check endotracheal tube
- suction for patentcy
- CRX for positioning
- check for kinks or obstructions
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what is PS (pressure Support) and how does it work?
the patient has control over the respiratory frequency and the depth and length and flow of each breath.
-PS ventilation can also compensate for the increased work imposed by the resistance of the ETT and the ventilator.
what happens to the tidal volume when pressure support is manipulated?
Pressure support can have an effect on the tidal volume, as it can assist with the expansion of the lungs
what are some of the advantages Spontaneous Mode?
- ensures adequate lung expansion
- ensure adequate gas exchange
- will support a patients spontaneous inspiratory effort (making inspiration easier)
- pt controls inspiratory time, flow rate, frequency and expiratory time
what is the pre-requisite for a patient receiving Spontaneous Mode?
- pt RASS is -2 to 0
- pt 8 breaths a minute or is greater than ventilators set RR
- pt is able to initiate inspiration for every breath
what does SIMV stand for and briefly define this mode of ventilation
Synchonised Intermittent Mandatory Ventilation
-ensures a set number of breaths are delivered at a set volume every minute
what does DuoPAP mean and breifly define this mode of ventilation.
Duo Positive Airway Pressure
-the ventilator will deliver the number of breaths set, to the pressure set (Phigh), for the set amount of time (T-high), it will then release the breath to PEEP and offer the patient support for any breath taken in that time
what are the signs that a patient f not tolerating the ventilator?
- biting/coughing on the tube
- swallowing
- trying to remove the airway piece
describe your actions if you were having problems ventilating your patient
- review pt
- check your cuff
- check O2 + Co2 + RR
- check for kinks
- check equipment
- listen to chest
what is the function of the cuff on an ETT or Tracheostomy tube?
Provide a seal between the ETT and the tracheal wall to enable accurate delivery of tidal volumes during mechanical ventilation
what is a normal cuff pressure and how often should it be checked?
- cuff pressure should be maintained between 20-30cm H2O (as per the green section on the cuff manometer)
- it should be checked at the commencement of each shift or when cuff leak is suspected
Name a possible complication if the cuff pressure is too high
Too high- tissue ischemia, ulceration and necrosis of the tracheal wall
Name a possible complication if the cuff pressure is too low
Too low- leak of air, oropharygeal secretions around the ETT cuff, predisposing the pt to inadequate ventilation, de-recruitment, aspirational pneumonia and ETT migration
You are caring for a pt with an ETT. While performing a face shave, you accidentally sever the pilot line. What are your nursing actions?
- inform Drs immediately
- assist pt breathing
- get intubation trolley
your intubated patient suddenly starts making gurgling noises and their minute volume has decreased from 7L/min to 2L/min. What would you suspect has happened?
-pt may have built up secretions and require suctioning.
your agitated pt has self extubated, what are your immediate nursing actions?
- CODE BLUE
- place either a NRM or commence on manual rebreather bag with O2 runninig
- monitor airway and breathing
- sedation?
