Test 2 Flashcards
Lesson 1 and 3, modes
Cardiovascular Complication of mech vent
Reduced venous return, reduced cardiac output, hypotension
Airway Complication of mech vent
Contamination of lower resp tract
Gastrointestinal Complication of mech vent
nutritional deficiency
Renal complication of mech vent
decreased atrial natriuretic peptide, reduced urine output, increased antidiuretic hormone
Neuromuscular of mech vent
Sleep deprivation, Increased intracranial pressure, critical illness weekness
VILI
- Overdistention of alveoli causing damage and release of excessive inflammatory cytokines
- Barotrauma
VAP
- Often the result of aspiration of oral secretions and bacteria
- Increase head of bed, limit circuit changes to as needed
CMV Mode
- Acutely Ill patients
- Full Support
- All breaths mandatory
IMV
- Post Op Patients
- Partial support
- Combination of mandatory and spontaneous breaths
Ventilator monitors and adjusts airway pressure needed to deliver target volume
PRVC
PC modification of SIMV allows patient to breathe spontaneously throughout the set pressure
APRV
Uses artificial intelligence to titrate the level of respiratory support based on patient parameters
ASV
Control mode provides support in proportion to the neural output of the respiratory center of brain
PAV
Triggered, limited, and cycle by the electrical activity of the diaphragm
Neurally adjusted ventilatory assist
Dual Control
- Dual control is a more sophisticated version of setpoint control.
- Dual control allows the mechanical ventilator to switch between volume and pressure control during inspiration in accordance with clinician-established priorities.
- What may initially begin as a volume control breath may switch to pressure control.
Setpoint Control
Output is manipulated to match a constant preset input, allowing for VC or PC breaths
Intelligent Control
Uses automatic control and artificial intelligence to measure patient variables such as RR and PETCO
-These measurements are then used by the machine to adapt variables such as pressure to maintain patients in a designated “comfort zone.”
Servo Control
Dynamic and fluctuates on demand
-The machine output follows and amplifies the patient’s own flow pattern, allowing support to overcome abnormal respiratory workloads due to disease or artificial airways.
Adaptive Control
Allows automatic adjustment of one target variable over several breaths
PSV
- Pressure support used to help overcome work of breathing
- Little of no ventilatory support
CPAP
- Prevent alveolar collapse
- improve oxygenation
Respiratory Failure
is a general term used to describe any clinical situation in which inadequate gas exchange occurs in the lungs.
Respiratory failure is divided into two major categories, each of which includes many different diseases and conditions that can lead to respiratory failure.
- Type 1 Respiratory failure: Hypoxemic Resp Failure
- Type II Respiratory failure: Hypercapnic Resp Failure
Hypoxemic Resp Failure
involves inadequate blood oxygenation and low to normal levels of carbon dioxide. (oxygenation failure)
Hypercapnic Resp Failure
involves inadequate blood oxygenation with high levels of carbon dioxide. This condition is also referred to as ventilatory failure.
Patients with neuromuscular disease often present with an inability to
Achieve ideal tidal volumes
-Typically these patients breathe very shallowly and with higher respiratory rates than normal in order to try to maintain adequate ventilation.
Guarded Breathing
Less extensive trauma such as broken ribs may cause a patient to breathe shallowly to prevent exacerbation of pain
-can result in hypoventilation, which then progressives to resp failure
Patients with chronic lung disease may progress to respiratory failure as a result of a
comorbid infection, prolonged increased WOB that leads to fatigue, or damaged alveoli that impair normal gas exchange. Chronic lung disease does not usually result in pain during deep breathing.
What may contribute to respiratory failure in a patient who was in a very serious motor vehicle accident that resulted in critical injuries to the head and chest?
- Pain associated with deep breathing due to broken ribs and injured thoracic muscles
- Reduced ventilatory drive
refers to the various methods of therapeutic life support that involve the use of machines
Mechanical Ventilation: the machines help control a patient’s breathing with the goal of improving gas exchange and alleviating stress on the respiratory muscles.
These four broad conditions are considered the primary indicators for mechanical ventilation:
- Apnea
- Acute ventilatory failure
- Impending ventilatory failure
- Severe oxygenation defect
defined as rising Paco2 with a corresponding decrease in pH, causing an acidic condition in the blood known as respiratory acidosis.
Ventilatory Failure
A severe oxygenation defect is when blood oxygen levels are unresponsive or refractory to supplemental oxygen
Refractory Hypoxemia
The primary goal of mechanical ventilation
is to provide adequate oxygenation and alveolar ventilation to maintain normal blood oxygen and carbon dioxide levels.
Inspiratory limb
elivers medical gas to the patient through an artificial airway such as an endotracheal tube or tracheostomy tube.
expiratory limb
which delivers exhaled gases from the patient back to the ventilator to be measured.
VILI stands for
Ventilator-induced Lung Injury
Various VAP prevention strategies include:
- Elevating the head of the bed
- Frequent oral care
- Careful management of the airway cuff pressure
- Limiting circuit changes to an as-needed basis
- Use of specially designed antimicrobial endotracheal tubes
A mode of ventilation can be described by
specific combination of control variables, breathing sequence, and targeting scheme used to achieve these goals.
Control Variable
which is pressure or volume
- is the designated independent variable between pressure, volume, and flow as they relate to the equation of motion.
- If volume is the designated control variable, the shape of the pressure waveform is dependent on the volume setting and the resistance and compliance of the respiratory system. Volume is constant and pressure varies.
Breath Sequence
which is a pattern of mandatory or spontaneous breaths
Targeting Scheme
Which is the feedback control scheme used to shape the breath and determine the breathing sequence
___ is constant and ___ varies
Volume is constant and pressure varies.
Breath sequence can be subdivided into three categories:
- Continuous mandatory ventilation (CMV), where all breaths are mandatory
- Intermittent mandatory ventilation (IMV), where breaths can be mandatory or spontaneous
- Continuous spontaneous ventilation (CSV), where all breaths are spontaneous
CMV
Continuous Mandatory Ventilation; Where all breaths are mandatory
- is operated as volume control (VC-CMV) or pressure control (PC-CMV). Although every breath is mandatory, patients are capable of triggering a mandatory breath above the set rate.
- Because CMV is considered a full support method of mechanical ventilation, it is rare that the rate is set so low that a patient would hypoventilate in the event of apnea.
IMV
Intermittent Mandatory Ventilation; where all breaths can be mandatory or spontaneous
- Like CMV, IMV can be volume controlled (VC-IMV) or pressure controlled (PC-IMV)
- SIMV
CSV
Continuous Spontaneous Ventilation; where all breaths are spontaneous
- used for patients who require little to no ventilatory support and is often used to evaluate a patient’s ability to breathe spontaneously when considerating discontinuation of ventilatory support.
- pressure support (PS) can be applied to help overcome some of the work of breathing created by the artificial airway and the patient circuit.
- Continuous positive airway pressure (CPAP) or positive end-expiratory pressure (PEEP) can be set at minimal levels to prevent alveolar collapse and to improve oxygenation.
The control variable can be identified by looking at the ventilator’s
output waveforms (or by vents labels)
If volume is the control variable,
reductions in compliance or increases in resistance will result in maintenance of the set volume at the expense of higher airway pressures and potential lung injury.
If pressure is the control variable,
Reductions in compliance or increases in resistance will result in maintenance of the set pressure at the expense of potential hypoventilation.
Which of the following contribute to the classification of the mode of ventilation and the ability of the mode to meet the underlying goals of mechanical ventilation?
Breath sequence, Targeting scheme, Control variable
What is the control variable for a mode of ventilation if the volume waveform varies with changes in compliance and resistance?
Pressure
During volume-controlled ventilation, what variable will increase if lung compliance decreases?
Pressure
Which of the following are examples of targeting schemes used during different modes of mechanical ventilation?
- Control variable
- Adaptive control
- Servo control
- Setpoint control
- Dual control
- Adaptive control
- Servo control
- Setpoint control
- Dual control
With IMV, mandatory breaths are delivered
at a set rate.
SIMV
Synchronized intermittent Mandatory Ventilation; synchronization of the mandatory breaths to the patient effort
-prevents excessive work of breathing that can be attributed to set levels of pressure, volume, or flow that fail to meet the patient’s inspiratory demands.
The higher the levels of PS, the more
work of breathing is taken on by the ventilator.
patient has primary control over the respiratory rate, inspiratory flow, and the inspiratory time.
CSV
A patient on CMV is receiving a 450-mL tidal volume at a rate of 12 breaths per minute. If the patient triggers an additional breath it will be at a lower tidal volume compared to the set volume. T/F
FALSE. any patient-triggered breaths will be mandatory breaths delivered at the set level of tidal volume.
During CSV, the patient determines the tidal volume and respiratory rate, but pressure support can be lowered to decrease the work of breathing. T/F
FALSE. the patient determines the tidal volume and respiratory rate, but pressure support is used to augment the tidal volume. Increases in pressure support decrease the work of breathing.
Optimal Control
is an advanced form of adaptive control that utilizes an algorithm to optimize variables such as frequency and inspiratory pressure to achieve a ventilatory pattern that minimizes the work of breathing.
Also known as assist control
CMV:and is often used to initiate mechanical ventilation and allow a patient’s inspiratory muscles to rest while the ventilation strategy seeks to maintain oxygenation and ventilation.
CMV provides a set
volume or pressure and a minimum respiratory rate while also allowing the patient to trigger breaths as needed.
CMV Disadvantages
Disadvantages include a high mean airway pressure, which may result in lung injury. In addition, if the patient triggers excessive mandatory breaths, they may hyperventilate and experience respiratory alkalosis due to low arterial carbon dioxide levels. This rapid triggering may also result in auto-PEEP.
VC-CMV has the advantage of/ disadvantages
- being one of the most common and thus most familiar modes of ventilation to many clinicians.
- It allows for a constant tidal volume, even with changes in resistance and compliance. While a constant tidal volume is sometimes desirable, when resistance and compliance change, increased airway pressure can cause alveolar overdistension and barotrauma.
- A fixed inspiratory flow that is set incorrectly may result in asynchrony between the patient and ventilator, increasing the work of breathing.
PC-CMV has the advantage of / variable/disadvantages
- controlling pressure and reducing the risk of alveolar overdistension in the event of reduced compliance.
- The variable flow in PC-CMV may improve synchrony between the patient and the ventilator.
- the major disadvantages of PC-CMV are that it is often the most unfamiliar mode of ventilation for many clinicians and that the tidal volume is variable, depending on compliance and resistance.
SIMV is a form of
is a form of partial ventilatory support that provides either volume- or pressure-controlled breaths intermixed with spontaneous breaths. SIMV delivers mandatory breaths at a set rate with a given pressure or volume control.
Patients can breathe in between mandatory breaths, and these spontaneous breaths may be augmented with pressure support to help overcome some of the resistance of the patient circuit.
SIMV
SIMV is frequently used in/ advantages
weaning a patient from mechanical ventilation and postoperatively as a patient gradually comes out of anesthesia.
-Advantages: include the prevention of muscle atrophy and lower mean airway pressures than CMV.
PSV
Pressure support ventilation; is a spontaneous breathing mode where a patient’s breathing is supplemented with a set pressure level during inspiration.
- Because PSV is a spontaneous mode of ventilation, the patient determines the respiratory rate, inspiratory flow, and inspiratory time.
- entirely dependent on pt
CPAP
Continuous Positive Airway Pressure;ike PSV, is an entirely spontaneous mode of ventilation.
- CPAP utilizes a clinician-set level of positive pressure to maintain alveolar recruitment.
- Pt Dependent
Mr. Jones is a patient with no previous pulmonary history. He is going to be sedated and paralyzed for a surgical procedure. Which mode of mechanical ventilation is most appropriate in this scenario?
CMV
-Because Mr. Jones will be unable to handle his work of breathing due to paralysis, he will require the full ventilatory support provided by CMV.
Mrs. Smith’s doctor wants to balance the work of breathing between her and the ventilator in order to prevent breathing muscle atrophy. Which of the following modes of ventilation is most appropriate at this time?
SIMV
-The intent of SIMV is to provide respiratory muscle rest during mandatory breaths and to promote respiratory muscle usage during spontaneous breathing, preventing muscle atrophy.
Ms. Garcia’s illness has improved dramatically over the past few days and her doctor wants to determine how she may breathe if the ventilator is discontinued. Which mode of ventilation is most appropriate for the given situation?
PSV
-PSV is a purely spontaneous mode that will allow evaluation of the patient’s tidal volume and respiratory rate.
Mr. Washington’s illness is advancing into acute respiratory distress syndrome. He requires full ventilatory support, but the healthcare team is concerned about lung injury due to his poor lung compliance. Which mode of ventilation is most appropriate for the given scenario?
CMV-PC
-CMV-PC will provide full ventilatory support and control of the peak airway pressures, minimizing the risk of lung injury due to barotrauma.
APC
Adaptive Pressure Control; is a dynamic mode of ventilation that allows delivery of a set tidal volume at the lowest possible inspiratory pressure. APC is one of the modes of mechanical ventilation that goes by varying names depending on the manufacturer, but the underlying mechanics remain the same.
-A desired tidal volume is set; the ventilator monitors and adjusts the airway pressure needed to deliver the target volume.
APC is also known as:
Pressure-regulated volume control (PRVC) AutoFlow Adaptive pressure ventilation (APV) Volume control plus (VC+) Volume-targeted pressure control
APRV
(BiVent) Airway pressure release ventilation; is a time-cycled, pressure-controlled modification of SIMV that allows the patient to breathe spontaneously throughout the set ventilator pressures. APRV allows the clinician to set two levels of pressure and the time in which the ventilator provides the two pressures.
- PHigh/ low
- Thigh/low
The high pressure, Phigh, influences
the degree of lung inflation and the time spent at this pressure is Thigh.
The low pressure, P Low, influences
The level and duration of lung deflation is determined by the low-pressure setting, Plow, and the release time, termed Tlow.
In most instances, APRV is set up to achieve
nverse ratio ventilation, where the time spent in inspiration exceeds the time spent in expiration. This is done in an attempt to improve oxygenation and prevent derecruitment of alveoli.
APRV is known by many different names, depending on the ventilator, despite the fact that the underlying mechanics are the same. Other names include:
BiLevel BiVent BiPhasic Pressure control ventilation plus (PCV+) DuoPAP
ASV
Adaptive support ventilation; uses an artificial intelligence system to titrate the levels of respiratory support based on patient parameters. ASV automatically selects tidal volume and respiratory rate for mandatory breaths based on respiratory system mechanics and a target minute ventilation.
Target minute ventilation is based on the patient’s
ideal body weight (IBW) and estimated dead space volume. Using this calculated value, the clinician selects the percentage of minute ventilation the ventilator will support.
Tube compensation
(TC);much like pressure support, is designed to compensate for the resistance created by an artificial airway.
PAV
Proportional assist ventilation; is a control mode of ventilation that provides support in proportion to the neural output of the respiratory center in the brain.
NAVA
Neurally adjusted ventilatory assist; is a unique mode of ventilation in that it is triggered, limited, and cycled by the electrical activity of the diaphragm.
During APC ventilation, pressure is the target variable. T/F
FALSE.
-a desired tidal volume is set and the ventilator monitors and adjusts the airway pressure needed to deliver the target volume.
Which of the following modes is used to provide inverse ratio ventilation?
APRV
-APRV is set up to achieve inverse ratio ventilation, where the time spent in inspiration exceeds the time spent in expiration. This is done in an attempt to improve oxygenation and prevent derecruitment of alveoli.
Which of the following modes of ventilation selects tidal volume and respiratory rate for mandatory breaths based on respiratory system mechanics and target minute ventilation?
ASV
-ASV automatically selects tidal volume and respiratory rate for mandatory breaths based on respiratory system mechanics and a target minute ventilation.
Which of the following modes is inappropriate for a patient with an inadequate respiratory drive or motor neuron disease?
NAVA, PAV
If ABG shows fully comp. CO2 retention is still
Hypoventilation- dont change vent (pH is primary)
Ventilatory Failure highs/low
High PaCO2, Low pH
Oxygenation failure highs/ lows
Low PaO2, norm or low PaCO2, Not exchanging enough gas
Oxygenation failure consider/ txs
positive and expiratory pressure. Apply with mask CPAP or while intubated txs: PEEP or FiO2 (fix gas exchange) -CPAP -EPAP (all treat oxygenation not CO2)
Ventilatory Failure consider/ txs
Mech. VENTILATION. Apply with mask ventilation or intubate
txs: BiPAP/ Bi-Level
- intubate and ventilate
Deadspace vs. Shunt
Both V/Q mismatch
shunt= perfusion without ventilation
Deadspace= Ventilation without perfusion
What happens to Alveolar Air Equation when patient is hypoventialting
It will come out normal
First sign of hypoxia
increase HR
NIF cut off
-20mmH2O
VC cut off
10ml/kg
Vt cut off
5ml/kg
Ve cut off
<5 or >10
RSBI cut off
105
RR cut off
35bpm
Chronic resp failure
combination of hypoxic and ventilatory failure
-Increase PaCO2 leads to kidneys retaining bicarbonate to normalize the pH
When to switch to CPAP
Lower FiO2 or 0.6 or less
- raise CPAP until PaO2/SpO2 adequate
- goal is less O2 and compensate with PEEP
When to switch to BiPAP
Initial settings 10/5 and current FiO2
When to swtich to invasive mech vent
Failing BiPAP -On higher IPAP (mid-high teens) -pH is low and PaCO2 still high, signs of fatigue -poor oxygenation, apnea (pH low as 7.25, PaCO2 above 55)
Volume
Assured tidal volume
Pressure Variable
if compliance decreases or resistance increases, pressure increases
Pressure
Limited peak pressure
Volume variable
If compliance decreases or resistance increases, the tidal volume will go down
Flow Variable
Pt can take in at a flowrate determined by the pt and lung conditions. Generally creates a descending ramp type waveform (Ti)
Modes (options for breath deliver)
CMV (A/C), SIMV, CPAP, PCV (breath type), PSV (most common)
Breath Sequence (divided into 3 categories)
Continuous Mandatory Ventilation (CMV)- all mandatory,
Intermittent Mandatory Vent. (IMV)- Both,
Continuous Spontaneous Vent (CSV)- all spontaneous
PSV can be used for all of the following
Overcome ETT resistance, with CPAP, with SIMV
PSV for overcoming endo-tracheal tubing resistance is usually set at
4-8
When setting either A/C or SIMV to assure full ventilatory support you need
adequate rate and Vt in case the patient stops breathing
The value that can change with each breath during volume controlled ventilation is
Pressure
With pressure ventilation which one of the following values is variable?
Tidal Volume
If a patient with restrictive lung disease needs a smaller tidal volume, what other parameter needs to be adjusted to maintain the same PaCO2?
Rate
The advantage of choosing volume ventilation over pressure ventilation is
Assured Minute Ventilation
