Critical care in the ED Flashcards
Typically, two types of Positive Pressure ventilators are used, what are they?
Volume controlled ventilators
Pressure controlled ventilators
what is volume controlled ventilation?
what are the advantages and disadvantages?
Volume controlled terminates inspiration when a specific volume of gas is delivered
The most common type
The advantage is that the patient receives guaranteed minute ventilation volume
The disadvantage is the potential for overinflation lung injury
what is Pressure controlled ventilation?
what are the advantages and disadvantages?
pressure controlled terminates inspiration when a specific pressure is achieved
The advantage is that limits the distending pressure of the lung
The disadvantage is that minute ventilation is not guaranteed and requires more attentive monitoring to prevent hypoventilation or hyperventilation
what is the inspiratory/expiratory ratio?
the duration of inspiration to expiration. Normally, the expiration is passive and twice as long as the active inspiration, making the ratio 1:2
What is Controlled Mandatory respiration?
what type of patient is it used for?
Delivers a set respiratory rate at a set tidal volume, overriding any respiratory effort by the patient
It is used for patients who are unconscious or have received a neuromuscular blocker
What is Assist control ventilation?
What type of patients is it used for?
Delivers a preset tidal volume for every breath, whether it is initiated by the patient or the ventilator
Is used for patients with apnea, patients receiving neuromuscular blockers or sedation, or patients who can initiate a breath but need more tidal volume than they can generate on their own.
What is Synchronized Intermittent Mandatory Ventilation?
What type of patient is it used for?
Delivers a preset rate and tidal volume and lets the patient breathe at his or her own pace and tidal volume
Is synchronized with the patients ventilatory efforts
Is used for patients being weaned from mechanical ventilation.
what is tidal volume
the volume of air inspired or expired in a single breath during regular respiration
what is the FiO2 of ambient air?
0.21
or 21%
Continuous Positive airway Pressure?
What type of patient is it used for?
Delivers constant positive pressure to the airway
Lets the patient breath at their own pace while providing positive pressure to the airway
Is used primarily to assess the patients ability to ventilate and oxygenate before extubation
What is Pressure- controlled ventilation?
Delivers a preset pressure, selected inspiratory time, and rate. Tidal volume depends on inspiratory time, pressure, and lung compliance.
Allows the patient to breath spontaneously, although the preset inspiratory time remains constant. The patient may need sedation.
Can cause an inverse inspiratory / expiratory ratio and requires close patient monitoring.
What is Pressure support ventilation?
Maintains a select amount of inspiratory pressure throughout the inspiratory cycle
Is used to overcome endotracheal resistance or assist with weaning
Lets the patient initiate each ventilator cycle at his or her own rate, timing, and tidal volume
Can be used with synchronized intermittent mandatory ventilation and continuous positive airway pressure
what is Airway pressure release ventilation (AVPR)?
Spontaneous breathing ventilatory mode in which two different levels of continuous positive airway pressure (a high and a low level) are set for time periods to have a maximized alveolar recruitment.
Used in the early stages of ARDS, multiple areas of lung collapse, that may be due to loss of functional surfactant, making the alveolar sacs unstable and prone to collapse due to unopposed surface tension. This situation can result in a reduced volume aerated lung, intrapulmonary shunting, and therefore poor oxygenation.
name 7 types of ventilation modes
Controlled mandatory Ventilation
Assist control ventilation
Synchronized Intermittent Mandatory Ventilation
Continuous Positive airway Pressure
Pressure- controlled ventilation
Pressure support ventilation
Airway pressure release ventilation (AVPR)
what is a plateau pressure?
a constant pressure value maintained during the inspiratory phase of ventilation. It is measured by pressing the pause or hold button during mechanical ventilation.
In a BMP, of a physician asks you for a Bicarb level and you can’t find it, what do you look for?
HCO-3 or total CO2
What is permissive hypercapnia?
A lung protection strategy that prevents lung injury from high pressures by decreasing alveolar ventilation. This strategy involves the use of low tidal volumes (4 to 6 ml/kg of ideal body weight) and pressure limited ventilation, allowing the arterial CO2 level to rise gradually and the pH to fall to 7.2 to 7.25.
When is hypercapnia not appropriate?
Most patients can tolerate this level of acidosis well, but is is not appropriate for patients with head injuries or severe metabolic acidosis
What is ideal body weight?
the expected weight of a person based on sex and height. For males, this equals 50 kg + 2.3 kg for each inch over 5ft. For females, this equals 45.5 kg + 2.3 kg for each inch over 5 ft.
The respiratory therapist usually assesses and documents the vent settings at least every
2 hours
expect to use a tidal volume of __ to __ ml/kg
8 - 9
For a patient with acute lung injury or ARDS, begin with a tidal volume of __ ml/kg of ideal body weight for ________ ________
6
permissive hypercapnia
vent settings; pressure
Start with a pressure support of __ cm of water and adjust to a tidal volume of __ to __ ml/kg as ordered. Expect the respiratory therapist to adjust the pressure as this changes.
20
6
8
lung compliance.
Expect the initial rate to range from __ to __ breaths per minute
8
18
Obtain an ABG __ minutes after initiating mechanical ventilation and __ minutes after changing ventilator settings.
20
20
Adjust the rate further based on the clinical goal and the patients response. The goal may be based on a range for partial pressure of CO2 as in a patient with ___ or pH as in ______ ______
traumatic brain injury
permissive hypercapnia
Know that positive end expiratory pressure exerts pressure above the atmospheric pressure level in the patients airways. This prevents alveolar collapse by increasing ______ _____ _____.
functional residual capacity.
what does PEEP stand for?
positive end expiratory pressure
in what ventilation mode settings can PEEP be used?
all of them
For most mechanically ventilated patients, expect to use PEEP of __ cm of _____ to prevent ______.
5
water
atelectasis
If PEEP exceeds __ cm of water, observe for signs of complications such as decreased _____ return, _____, and ______.
10
venous
hypotension
barotrauma
The normal inspiratory/expiratory ratio is : or :
1:2
1:3
For a patient with obstructive airway disease, such as asthma or chronic obstructive pulmonary disease, expect to set an expiratory ratio of : or longer to prevent air ______ and lung _______.
1:4
trapping
overdistention
If you are ordered to improve oxygenation, _____ the normal Inspiratory/ expiratory ratio so the inspiratory phase is longer than the expiratory phase, as in a ratio of : to $:_. Because this inverse-ratio ventilation is extremely uncomfortable for the patient, plan to administer what?
reverse
2:1
4:1
a sedative or assist with neuromuscular blockade.
with mechanical ventilation, set the sensitivity to recognize the patients spontaneous effort, which is usually what?
-1 to -2 cm of water