Give seven criteria upon which the choice of a particular ventilator is based.
Indication, Pathology, goals, interface, location, length of time, staff familiarity
PAP is commonly usedC in the hospital setting for ----------- and in the home setting for-------
Improving oxygenation, OSA
The most commonly used ventilator technique in the treatment of acute-on-chronic respiratory failure is?
BiLevel positive airway pressure
What type of ventilation reduces the requirement for heavy patient sedation?
NPPV
Define Full Ventilatory Support and Partial Ventilatory Support.
Full ventilatory support has the ventilator providing all the energy necessary to maintain the patient's effective alveolar ventilation. Partial ventilatory support has the patient participating in the WOB to help maintain effective alveolar ventilation.
The minimum rate setting that would be considered full ventilator y support is 8 breaths/min, and the tidal volume range should be
6 to 12 ml/kg.
What type of ventilatory support should be used when the patient has acute ventilatory failure caused by ventilatory muscle fatigue or a high WOB? Why?
Full ventilatory support while allowing the ventilatory muscles to rest while supplying all the necessary ventilation.
Flow triggered, pressure targeted, time cycled.
Assisted
Time triggered, volume targeted, volume cycled
Mandatory
Pressure triggered, pressure targeted, time cycled
Assisted
Flow triggered, pressure triggered, flow cycled
Spontaneous
What is the main advantage of volume ventilation?
The main advantage of volume ventilation is that it guarantees a specific volume delivery and minute ventilation regardless of changes in lung compliance and resistance or patient effort.
A patient develops bronchospasm during volume ventilation. What will happened to the peak inspiratory pressure? Why?
The PIP will rise any time there is an increase in airway resistance, such as the bronchospasm
A patient develops bronchospasm during volume ventilation. What will happened to:
The peak inspiratory pressure? Why?
The amount of volume will remain constant because it is the set variable.
What are the advantages of using NPPV in acute respiratory failure?
Advantages:
� Avoidance of complications associated with artificial airways
� Flexibility in initiating and removing mechanical ventilation
� Reduced requirements for heavy sedation
� Preservation of airway defense
� Speech
� Swallowing mechanism
� Reduce
What are the disadvantages of using NPPV in acute respiratory failure?
Disadvantages:
� Gastric distention
� Skin pressure lesions
� Facial pain
� Dry nose
� Eye irritation
� Discomfort
� Claustrophobia
� Poor sleep
� Mask leaks
When the patient's lung condition worsens during volume ventilation, the peak inspiratory pressure _______ (increases; decreases), which may lead to alveolar ____________ (hyperinflation; hypoventilation). When the patient's lung condition improves, _____
Increase, hyperinflation, less
What may result when sensitivity is set too low?
Inappropriate sensitivity settings will increase the work to trigger inspiration and may cause patient-ventilator dyssynchrony
When pressure is targeted as the control variable, what varies with changing lung characteristics?
Volume will change with change in lung characteristics
When a patient's lung condition worsens during pressure-targeted ventilation, volume delivery ______ (increases; decreases), which may lead to alveolar _________ (hyperventilation; hypoventilation). When a patient's lung condition improves, ________ (more
decrease, hypoventilation, less
Volume Ventilation
Advantages
� Delivers specific volume regardless of lung characteristics
� Improved lung conditions generate less pressure in the lungs
� Most RCPs comfortable with this type of ventilation
Disadvantages
� Deteriorating lung conditions cause increased PA
Pressure Ventilation
Advantages
� Decreased risk of overdistention of the lungs
� Descending flow pattern better matches patient's needs, decreasing the patient's WOB
� May be more comfortable for spontaneously breathing patients
Disadvantages
� RCPs are less familiar with th
Name the three breath delivery techniques
CMV, SIMV, Spontaneous modes
CMV is also known as?
Controlled mechanical ventilation, continuous mechanical ventilation, assist/control ventilation
What trigger is used when a ventilator is in the control mode?
Time triggered
When is controlled ventilation appropriate?
Control mode is appropriate for patients who are obtunded because of drugs; are sedated and paralyzed; have cerebral malfunction, spinal cord or phrenic nerve injury or have motor nerve paralysis with no voluntary efforts
In what two patient situations might deliberate hyperventilation be beneficial? Why?
Iatrogenic hyperventilation may benefit patients with closed head injury or who are recovering from neurosurgery because respiratory alkalosis reduces ICPs
What three triggers may begin inspiration in the A/C mode?
Time, pressure and flow
What can happen to a patient's acid-base status if the patient's ventilatory drive increases while the person is ventilated in the A/C mode?
An increased ventilatory drive will increase patient triggering. This will cause hyperventilation and respiratory alkalosis
What are the control variables in PC-CMV?
The control variables are time/patient trigger, pressure limit, time cycled
What ventilator mode should be used when guarding against increasing pressures is more important than guaranteeing a tidal volume?
PC-CMV
How does IMV differ from CMV?
IMV differs from CMV in that IMV allows the patient to breathe spontaneously between mandatory breaths in CMV all breaths are machine breaths
How does SIMV differ from IMV?
With SIMV the mandatory breaths may be patient triggered. When the operator selected time interval is reached the ventilator waits for the next patient inspiratory effort When this effort is sensed the ventilator synchronously delivers a mandatory breath
Spontaneous breathing through a ventilator circuit may be obtained in what two ways?
Spontaneous breathing through a ventilator circuit may be obtained from a continuous gas flow or a demand valve.
What may be used to reduce the WOB for spontaneous breaths during ventilation in the SIMV mode?
Add Pressure support
What are the Advantages/Disadvantages of the A/C mode?
Assist/Control advantages:
� guaranteed minimum VE
� can provide synchronous patient breaths
� patient can set rate
� guaranteed volume or pressure breath with each breath
Disadvantages:
� respiratory alkalosis
� high airway pressures and associated compl
What are the Advantages/Disadvantages of the IMV mode?
Advantages
� Can be used for weaning
� May reduce respiratory alkalosis associated with assist/control
� Prevents respiratory muscle atrophy
� Lower airway pressure
Disadvantages
� Excessive WOB if flow and sensitivity are not set correctly
� Hypercapnia
What are the advantages and disadvantages of having an intubated patient breathe spontaneously through a ventilator circuit?
Advantages of using a ventilator as a T-piece include the monitoring capabilities of the ventilator plus the monitoring capabilities of the ventilator plus the ability of the ventilator to alarm is something undesirable occurs. The disadvantage is that so
In PSV the operator sets what?
Inspiratory pressure, expiratory pressure (PEEP), sensitivity and FiO2
What determines tidal volume in PSV?
Pressure gradient (?P), lung compliance, airway resistance and patient effort
A very high flow setting in PSV may cause inspiration to?
End inspiration prematurely
Describe PRVC.
PCRV is patient or time triggered, pressure limited and time cycled. The ventilator will not allow the pressure to rise higher than 5 cmH2O below the upper pressure limit setting
Describe VS.
Patient triggered, pressure limited and flow cycled.
What is the difference between PRVC and VS?
With PRVC inspiration can be either be time triggered or patient triggered. In VS, inspiration is only patient triggered. A PRVC breath is time cycled and a VS breath is usually flow cycled.
The mode of ventilation that requires two levels of CPAP and allows the patient to breathe spontaneously at both levels is known as:
APRV
APRV was originally intended to ventilate patients with
Stiff lungs