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
what can result if the sensitivity is set too high on a vent?
can cause increased effort to take a breath
Know that a sensitivity setting that is too low may cause what?
overtriggering of the ventilator and hyperventilation
Expect to set the positive inspiratory pressure alarm __ to __ cm of water higher than the patients baseline.
Be alert for an alarm that indicates
10
15
decreased lung compliance or a condition that does not allow full exhalation
what are 4 things you should monitor the patient for while on a vent?
continuously monitor the patients HR, EKG pattern, end-tidal CO2 level, and sPo2 reading
what is the normal end tidal CO2 level?
35 - 45 mmhg
what should you always have at the bedside of a mechanically ventilated patient? Two things
BVM
suction
if the patient moves or becomes agitated, if an alarm sounds for low or high positive air pressure, or the patient makes audible vocal sounds, what should you do?
check the ET tube depth
for the ventilated patient, be aware of and document what 6 things
baseline fraction of inspired O2, mode of ventilation, positive inspiratory pressure, positive expiratory pressure, pressure support, and tidal volume
what does the DOPE mnemonic stand for?
Dislodgement of the ET tube
Obstruction of the ET tube
Pneumothorax
Equipment failure
Alarms; Apnea - caused by insufficient breathing by a patient in the continuous positive airway pressure or pressure support mode
Fix -
switch ventilator mode to one that provides a set rate
what are some possible causes of a high airway pressure alarm?
(3)
(5)
(4)
Possible causes; ET tube obstruction from sputum, Kinks, or biting
Increased compliance or resistance from circumferential burns, bronchospasm, pneumothorax, endobronchial intubation, or a worsening lung process
Anxiety, fear, pain, or fighting the ventilator
what are four reasons you will get a low airway pressure alarm?
Ventilator disconnection
Leak in vent system
Leak in ET tube cuff
Inadvertent extubation
what are three reasons you will get a Oxygen pressure low alarm on a vent?
Empty O2 cylinder
Closed valve on the O2 cylinder
Unit not connected to the wall terminal
how does mechanical ventilation cause hypotension?
positive pressure increases intrathoracic pressure and decreases venous return and cardiac output
Ventilation hypotension; The greater the ____ pressure applied, the more profound the hypotensive response. This is most apparent when the positive end-_____ pressure exceeds __ cm of water
positive
expiratory
10
Volutrauma occurs when mechanical ventilation _____ and injures the alveoli. Volutrauma usually results from a ___ positive inspiratory pressure
overdistends
high
Also called intrinsic positive end-expiratory pressure, this complication occurs when a ventilator breath is not completely exhaled before the next inspiratory breath is delivered (stacking breaths)
what is it?
Auto-Positive End- Expiratory Pressure (Auto Peep)
what is auto peep?
This complication usually affects patients with asthma or COPD who require longer exhalation times
how do you fix; Auto-Positive End- Expiratory Pressure (Auto Peep)
Also called intrinsic positive end-expiratory pressure
If auto-positive end-expiratory pressure occurs, disconnect the ventilator and let the patient exhale completely.
what causes oxygen toxicity?
An FiO2 that exceeds 50% for a long time (or as little as 6 hours)
what are 5 adverse reactions to oxygen toxicity?
may cause the production of free radicals that damage the pulmonary epithelium, inactivate surfactant, and lead to intra-alveolar edema, interstitial thickening, and pulmonary fibrosis
what is the most common and fatal infection in critical care, affecting 9 - 27% of intubated patients.
VAP
what are the chances of VAP?
9 - 27% of intubated patients with an increase of 1 - 3% for every day of MV
what are some steps to prevent VAP? (4)
Steps to prevent include sterile suction, avoid saline lavage, regular oral care, elevate HOB 30 degrees.
If the apnea alarm sound on a vent, what is the correct intervention?
switch the ventilator to a mode that provides a set rate
what does central Venous Pressure Monitoring tell you
Represents right sided heart preload (blood volume in the right ventricle at the end of diastole)
The Central venous pressure has a normal range of what?
2 to 6 mmHg or 5 to 10 cm of water.
Readings for central venous pressure are to be taken how?
with the patient lying supine and at the end of expiration and at the established zero reference point, which is the phlebostatic axis.
Complications of central venous pressure monitoring include what? (4)
pneumothorax, hemothorax, inadvertent arterial puncture, and bleeding.
Intracranial pressure consists of
10% ___
10% ___
80% _____
CSF
blood
brain tissue
Normally, intracranial compliance maintains an intracranial pressure of __ to __ mmHg
0
10
what is the SOFA score?
The Diagnosis of an organ dysfunction should be based on an increase in the Sequential (sepsis related) Organ Failure Assessment (SOFA) score of 2 points or more.
Sepsis begins when a bacterial infection advances from its original local site and enters the systemic circulation. When this occurs, it is called _______.
bacteremia
what is the clinical criteria for septic shock?
clinical criteria for septic shock include refractory hypotension requiring the use of a vasopressor to maintain a MAP of 65 mmHg and a serum lactate of greater than 2, despite adequate fluid resuscitation.
Clinical criteria for septic shock include refractory hypotension requiring the use of a vasopressor to maintain a MAP of __ mmHg and a serum lactate of greater than __, despite adequate fluid resuscitation.
65
2
Lactate levels rising in a septic patient are a sign that the body is using this type of metabolism.
anaerobic.
This is said to be the hallmark of septic shock
refractory hypotension
MODS stands for what?
Multiple Organ Dysfunction Syndrome, such as ARDS or acute kidney injury
what are 10 lab values associated with the diagnosis of sepsis?
Hyperglycemia
WBC
protein C
Arterial hypoxemia
Oliguria
Elevated creatinine level
coagulation abnormalities
Hyperbilirubinemia
Hyperlactatemia
what is Hyperlactatemia?
a serum lactate of 2 or more
what is Hyperbilirubinemia?
a total bilirubin level that exceeds 4 mg/dl
in sepsis, what is the parameter you should look for in Thrombocytopenia?
a platelet count of less than 100
in sepsis, what should you look for in WBC count?
greater than __, less than __, or normal with more than __% bands
greater than 12, less than 4, or normal with more than 10% bands
Sepsis is usually diagnosed how?
through a combination of detailed history and assessment.
Three interventions are part of the initial priorities for treating sepsis, what are they?
Fluid resuscitation
Blood pressure control
Antimicrobial therapy
what are three things to keep in mind for fluid resuscitation in the treatment of sepsis?
Fluid resuscitation -
Begin as soon as sepsis is recognized
The goal is to achieve a MAP of 65 mmHg
Rapidly administer up to 30ml/kg as ordered in the first 3 hours
Name three pressors (both names) that may be used in the treatment of sepsis
norepinephrine (Levophed), dopamine (Intropin), and Vasopressin (epinephrine, or Adrenaline
another name for norepinephrine is what?
Levophed
another name for dopamine is what?
Intropin
in sepsis, how can adrenal insufficiency contribute to the effects of vasopressors?
Refractory Hypotension - may be the result of adrenal insufficiency, which reduces the level of cortisol, which can decrease the vasopressor response to catecholamines. As a result, peripheral vascular resistance drops and hypotension ensues.
what may be ordered to treat adrenal insufficiency in the treatment of sepsis?
Solu-Cortef may be ordered as corticosteroid therapy IV hydrocodone if fluid resuscitation and vasopressor therapy do not restore hemodynamic stability.
Which mode of mechanical ventilation lets the patient breathe at his or her own tidal volume?
A. Pressure control ventilation
B. Synchronized intermittent mandatory ventilation
C. Assist control
D. Continuous positive airway pressure
Synchronized intermittent mandatory ventilation
Which measurement indicates hypoperfusion in a patient with sepsis?
A. An abnormal blood pressure reading
B. A central venous pressure of 10 mm Hg
C. An elevated temperature measurement
D. An elevated serum lactate level
D
An elevated serum lactate level is a useful indicator of hypoperfusion and can occur with normal blood pressure. The nurse should not wait for hypotension before initiating fluid resuscitation if the patient has signs of hypoperfusion
