The document discusses several newer modes of mechanical ventilation including volume assured pressure support (VAPS), volume support (VS), pressure regulated volume control (PRVC), and adaptive support ventilation (ASV). VAPS switches between pressure control and volume control modes within a breath to ensure a minimum tidal volume. VS adjusts pressure support levels between breaths to maintain a target tidal volume. PRVC aims to deliver a set tidal volume with the lowest possible airway pressure by modifying flow and time. ASV automatically adapts support levels to provide a minimum minute ventilation with the least work of breathing.
An excellent tool to treat refractory hypoxia. Target audience are ICU junior physicians and Respiratory Therapists. It will take away the fear of "What is APRV?" from your hearts and you will feel ready to give it a try.
HERE IS A SEMINAR BASED ON ALL THE NEWER MODES OF MECHANICAL VENTILATION .
MY SINCERE APOLOGIES , BECAUSE I HAD TO TAKE INFORMATION FROM OTHERS SLIDES TOO , SINCE THERE IS VERY LESS INFORMATION AVAILABLE ABOUT THIS TOPIC
An excellent tool to treat refractory hypoxia. Target audience are ICU junior physicians and Respiratory Therapists. It will take away the fear of "What is APRV?" from your hearts and you will feel ready to give it a try.
HERE IS A SEMINAR BASED ON ALL THE NEWER MODES OF MECHANICAL VENTILATION .
MY SINCERE APOLOGIES , BECAUSE I HAD TO TAKE INFORMATION FROM OTHERS SLIDES TOO , SINCE THERE IS VERY LESS INFORMATION AVAILABLE ABOUT THIS TOPIC
Assessment of haemodynamics a critically ill patient and its management has always been a matter if debate. Over time a lot of studies and therapeutic interventions have been carried out. This presentation is a review of such interventions and their impact on the outcome.
Intro to Hypoxic pulmonary vasoconstriction Arun Shetty
Hypoxic pulmonary vasoconstriction, a seldom heard phenomenon but very effective physiologic property which helps lungs utilise ventilation to the maximum
Erector spinae plane block is a relatively novel approach to pain management for a variety of surgical procedures. ESP block is a challenging anesthesia and analgesia technique that needs more research.
Assessment of haemodynamics a critically ill patient and its management has always been a matter if debate. Over time a lot of studies and therapeutic interventions have been carried out. This presentation is a review of such interventions and their impact on the outcome.
Intro to Hypoxic pulmonary vasoconstriction Arun Shetty
Hypoxic pulmonary vasoconstriction, a seldom heard phenomenon but very effective physiologic property which helps lungs utilise ventilation to the maximum
Erector spinae plane block is a relatively novel approach to pain management for a variety of surgical procedures. ESP block is a challenging anesthesia and analgesia technique that needs more research.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
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Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
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TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
2. THE ORIGIN OF MECHANICAL
VENTILATION
• Andreas Vesalius is the first person to describe mechanical
ventilation in 1543
• “But the life may…be restored to the animal, an opening must be
attempted in the trunk of trachea, in which a tube of reed or cane
should be put; you will then blow into this, so that the lung may
rise again and the animal take in air.. And as I do this, and take
care that the lung is inflated in intervals, the motion of the heart
and arteries does not stop….”
3. • Mechanical ventilation is administered primarily in patients
unable to maintain adequate alveolar ventilation
• The role is supportive and is used to buy time while
addressing the condition that lead to respiratory failure.
• It should aim at “providing support , doing least harm”
4. • The ability of ventilator to initiate , maintain and terminate an
assisted breath derives its basis from “ equation of motion”
• Ventilator pressure to deliver a breath = pressure needed to
overcome the airway resistance + pressure needed to inflate
the chest wall and the lung
5. Equation of Motion
Ventilation
Pressure
(to deliver
tidal volume)
=
Elastic
Pressure
(to inflate lungs
and chest wall)
+
Resistive
Pressure
(to make air flow
through the
airways)
P = Resistance x Flow + Elastance x Volume
Pressure = Presistive + Pelastance
6. PROBLEMS WITH CONVENTIONAL MODES OF
VENTILATION
• IN critical care setting, all the parameters in equation of
motion change with time
• A ventilator setting appropriate for one point of time may not
be optimal with patient deterioration or improvement.
• Deliver the set parameters and take no feedback from the
patient
7. • Classical volume or pressure control modes are “OPEN
LOOPS” (feed back loop is absent )
• Newer modes target to make alterations with changing lung
and take feedback from patient parameters and are “closed
loop” type
8. Inspiration Expiration
0 1
20
0
0 1 2
3
-3
0
20
0
21
20
0
0 1 2
3
-3
0
20
0
2
Inspiration Expiration
Volume/Flow Control Pressure Control
Time (s) Time (s)
Paw
Paw
Pressure
Volume
Flow
9. Control Variables
Volume control
Tidal volumes are
guaranteed, even if
airway pressure
fluctuates
If lung mechanics are
poor, airway pressure
may rise to
unacceptable levels
Pressure control
Airway pressure level
is guaranteed
Tidal volumes are
not, and may change
if lung mechanics
vary
10. NEED OF NEWER MODES
• Conventional modes are uncomfortable
• More safely assist patient
• Less need for heavily sedation & paralysis
• More effectively ventilate/oxygenate
• Improve patient – ventilator synchrony
• Less haemodynamic compromise
• Lung protective ventilation : less likelihood of Ventilator Induced
Lung Injury
• More rapid weaning
12. Modern ventilators now incorporate complex computer based algorithms, and are
capable of simultaneously controlling two variables.
Intrabreath control (dual control WITHIN a single breath, DCWB):
During a part of an essentially pressure-targeted breath, flow is also controlled
Interbreath control (dual control from breath to breath, DCBB):
The configuration of a pressure-targeted breath is manipulated n SUBSEQUENT
breaths to deliver a targeted tidal volume
Dual-Controlled Modes
14. Dual Control within a Breath
volume-assured pressure support (VAPS)
• This is modification of pressure control mode
• This mode allows a feedback loop based on the volume
• It makes ventilator to switch from pressure control to volume
control if a minimum set TV is not achieved.
Bear 1000
Tbird
Bird 8400Sti
15. • operator adjustable parameters are same as in conventional PC mode
– pressure limit, peak flow rate, ventilator rate, and PEEP
• Additionally “minimum TV” is also defined
• This combination provides an optimal inspiratory flow during
assisted/controlled cycles, reducing the patient’s work of breathing
commonly seen during Ventilator Assisted Ventilation (VAV) and
causes lower intrinsic PEEP
• Unlike typical PSV, VAPS assures stable tidal volume along with
pressure support in patients with irregular breathing patterns
16. Benefits of VAPS
• Lower peak airway pressure
• Reduced patient work of breathing
• Improved gas distribution
• Less need for sedation
• Improved patient comfort
17. ADEQUATE PATIENT EFFORT
• If the delivered volume equals the preset volume, the
configuration of the breath is similar to that of a pressure
supported breath:
• the flow is decelerating
• the breath is flow-cycled
18. INADEQUATE PATIENT EFFORT
• If the flow fall below the set tidal volume within the assigned
inspiratory time, the machine delivers a volume controlled
breath :
•
• flow targeted
• volume cycled
19. Paw
cmH20
60
-20
60
Flow
L/min
Volume
Set flow limit
Set tidal volume cycle threshold
Set pressure limit
Tidal volume
met
Tidal volume
not met
Switch from Pressure control to
Volume/flow control
Inspiratory flow
greater than set flow
Flow cycle
Inspiratory flow
equals set flow
Pressure limit
overridden
L
0
0.6
40
20. • Set pressure limit should not be too high to cause
unwanted trauma to lung and generate higher volume
than minimal
• Set flow rates must not be very low as in situations
where minimal volume is not met it would cause a
delayed switch from pressure control to volume control
and would lead to unwanted prolongation of inspiratory
time
• Patients with airflow obstruction should be monitored
closely in order to prevent air trapping
DISADVANTAGES/ LIMITATIONS OF VAPS
21. Applications of VAPS
A patient who requires a substantial level of ventilatory support and has
a vigorous ventilatory drive to improve gas distribution and synchrony
A patient being weaned from the ventilator and having an unstable ventila
tory drive who may require backup tidal volume as a safety net
in case the patients effort or/and lung mechanics change
24. VS (Volume Support)
Entirely a spontaneous mode
Ventilator assesses initial breaths and steps up pressure support in
subsequent breaths if TV is low
25. Tidal volume is used as feedback control to adjust the
pressure support level
Intended to provide a control tidal volume and increased
patient comfort
Delivers a patient triggered (pressure or flow), pressure
targeted, flow cycled breath
o Can also be timed cycled (if TI is extended for some reason) or pressure cycled
(if pressure rises too high).
It adjusts pressure (up or down) to achieve the set volume (the
maximum pressure change is < 3 cm H2O and ranges from 0
cm H2O to 5 cm H2O below the high pressure alarm setting
26. INDICATIONS
Spontaneous breathing patient who require minimum
ventilatory effort
Patients who have inspiratory effort needing adaptive
support
Patients who are asynchronous with the ventilator
Used for patients ready to be “weaned” from the
ventilator
Used for patients who cannot do all the WOB but who
are breathing spontaneously
27. The ventilator delivers a single spontaneous pressure support
type of breath and uses variable pressure support levels to
provide the target tidal volume
During weaning or awakening from anesthesia, the patient
assumes a higher spontaneous tidal volume and the ventilator
decreases the pressure support level accordingly
28. When the spontaneous tidal volume decreases, the ventilator
increases the pressure support level automatically to maintain
the target tidal volume.
During VS, the ventilator frequency and minute ventilation are
determined by the triggering effort of the patient.
The inspiratory time is determined by the patient respiratory
demand.
29. VS (Volume Support)
(1), VS test breath (5 cm H2O);
(2), pressure is increased slowly until target volume is achieved;
(3), maximum available pressure is 5 cm H2O below upper pressure limit;
(4), VT higher than set VT delivered results in lower pressure;
(5), patient can trigger breath;
(6) if apnea alarm is detected, ventilator switches to control mode /PRVC
30. VS vs VAPS
• How does volume support differ from VAPS ?
In volume support, we are trying to adjust pressure so that,
within a few breaths, desired VT is reached.
In VAPS, we are aiming for desired VT tacked on to the
end of same breath if a pressure-limited breath is going to
fail to achieve VT
31. ADVANTAGES
• Guaranteed VT and VE
• Pressure supported breaths using the lowest required
pressure
• Decreases the patient’s spontaneous respiratory rate
• Decreases patient WOB
• Allows patient control of I:E time
• Breath by breath analysis
32. Disadvantages
• Spontaneous ventilation required
• VT selected may be too large or small for patient
• Varying mean airway pressure
• A sudden increase in respiratory rate and demand may
result in a decrease in ventilator support
35. PRESSURE REGULATED VOLUME CONTROL
• Ventilation that provides volume controlled breaths with
the lowest pressure possible by altering the flow and
inspiratory time
• Delivers patient or timed triggered, pressure-targeted
(controlled) and time-cycled breaths
36. • Ventilator measures VT delivered with VT set on the controls.
If delivered VT is less or more, ventilator increases or
decreases pressure delivered until set VT and delivered VT are
equal
• PRVC provides volume support while keeping the PIP at a
lowest level possible by altering the peak flow and inspiratory
time in response to changing airway or compliance
characteristics.
37. INDICATIONS
• Patient who require the lowest possible pressure and a
guaranteed consistent VT
• ALI/ARDS
• Patients requiring high and/or variable ventilatory effort
• Patient with the possibility of changes in compliance of
lung/ Resistance of airway
38. A test breath at an
inspiratory pressure of
10cm H2O above a
PEEP (typically of
5cmH2O) is delivered
On the basis of the tidal
volume achieved with
this pressure, the
ventilator calculates the
system compliance
Each breath is delivered
after calculating the
compliance for the
preceding breath. The
flow and inspiratory
time is automatically
adjusted to deliver the
targeted tidal volume
with the lowest PIP
possible
ALGORITHM
39. PRVC (Pressure Regulated Volume
Control)
(1), Test breath (5 cm H2O);
(2) pressure is increased to deliver set volume;
(3), maximum available pressure;
(4), breath delivered at preset E, at preset f, and during preset TI;
(5), when VT corresponds to set value, pressure remains constant;
(6), if preset volume increases, pressure decreases; the ventilator continually monitors and adapts to the patient’s needs
40. • The increasing airflow resistance may be due to increasing
airway resistance (nonelastic resistance) or decreasing lung
compliance (elastic resistance)
• At constant flow, the PIP is increased due to increasing
airflow resistance.
• Increased Airflow Resistance (nonelastic or elastic) :
Increase PIP / Flow
• PRVC lowers the flow to reduce the driving pressure.
• Increased Airflow Resistance (nonelastic or elastic) : PIP /
Decrease Flow
41. To compensate for a lower inspiratory flow, PRVC prolongs the
inspiratory time to deliver the target volume
• (VT - Increased Constant Flow * decreased Inspiratory Time)
The ventilator will not allow delivered pressure to rise higher
than 5 cm H2O below set upper pressure limit
Example: If upper pressure limit is set to 35 cm H2O and
the ventilator requires more than 30 cm H2O to deliver a
targeted VT of 500 mL, an alarm will sound alerting the
clinician that too much pressure is being required to deliver
set volume
42. ADVANTAGES
• Maintains a minimum PIP
• Guaranteed VT and E
• Patient has very little WOB requirement
• Allows patient control of respiratory rate and E
• Variable E to meet patient demand
• Decelerating flow waveform for improved gas
distribution
• Breath by breath analysis
43. DISADVANTAGES
• Varying mean airway pressure
• May cause or worsen auto-PEEP
• When patient demand is increased, pressure level may
diminish when support is needed
• May be tolerated poorly in awake non-sedated patients
• A sudden increase in respiratory rate and demand may
result in a decrease in ventilator support
46. ASV (Adaptive Support Ventilation)
• A dual control mode that that PROVIDES A MANDATORY
MINUTE VENTILATION
• Unique: sets minimal work of breathing to deliver
desired minute ventilation
• Control variable is pressure
• Uses both pressure control and pressure support to
maintain a set minimum TV(volume target) using the least
required settings for minimal WOB depending on the
patient’s condition and effort
47. • Set parameters are patient ideal body weight, minimum
minute ventilation, PEEP and trigger ventilation
• It automatically adapts to patient demand by increasing or
decreasing support, depending on the patient’s elastic and
resistive loads
• Ventilator continuously optimizes I:E ratio to avoid any auto
PEEP
48. INDICATIONS
• Full or partial ventilatory support
• Patients requiring a lowest possible PIP and a
guaranteed VT
• ALI/ARDS
• Patients not breathing spontaneously and not triggering
the ventilator
• Patient with the possibility of work changes (CL and
Raw)
• Facilitates weaning
49. • Parameter input: patient’s body weight and desired percent
minute volume
• The body weight is used to estimate the dead space volume
and to calculate the alveolar volume
• For an estimated minute ventilation requirement for a patient,
the ventilator uses predetermined settings of 100 mL/min/kg
for adults and 200 mL/min/kg for children.
• The therapist may select the percent minute volume, ranging
from 20% to 200% of the predetermined adult or child setting
•
ASV WORKING PRINCIPLE
50. • For example, if 160% is selected for an adult, the minute
ventilation delivered by the ventilator will be about 160
mL/min/kg ( 100 X 160/100)
• Once the target minute ventilation is set, the ventilator uses test
breaths to measure the system compliance, airway resistance,
and any intrinsic PEEP.
• Following determination of these variables, the ventilator selects
and provides the frequency, inspiratory time, I:E ratio, and high
pressure limit for mandatory and spontaneous breaths
51. • If there is no spontaneous triggering effort, the ventilator
determines and provides the mandatory frequency, tidal
volume, and high pressure limit needed to deliver the
preselected tidal volume, inspiratory time, and I:E ratio
• As the patient begins to trigger the ventilator, the number of
mandatory breaths decreases and the pressure support level
increases until a calculated tidal volume is able to provide
adequate alveolar volume
• (i.e., tidal volume = alveolar volume + 2.2 mL/kg of
deadspace volume)
52. Mandatory breaths in
ASV mode
• TRIGGER
• machine
• LIMIT
• Pressure limited
• Cycle
• Time cycled
Assisted breaths in ASV
mode
• Trigger
• Pressure or flow ( by
the patient )
• Limit
• Pressure limited
• Cycle
• Flow , pressure or
time by the patient
53. • Clinician enters patient data & % support
• Ventilator calculates needed minute volume & best rate/TV to
produce least work
• Targeted TV’s given as pressure control or pressure support
breaths
• If pt.’s f > “set” by ventilator , MODE : PS
• Ifpt’s f < “set” by ventilator , MODE : PC SIMV/PS
• If patient is apneic, all breaths are PC
• Rate where WOB is minimal
• Pressure adjusts in +/‐2 cm H2O to achieve Tidal Volume
54. ADVANTAGES
• Guaranteed VT and E
• Minimal patient Work Of Breathing
• Ventilator adapts to the patient
• Weaning is done automatically and continuously
• Variable to meet patient demand
• Decelerating flow waveform for improved gas
distribution
• Breath by breath analysis
55. Disadvantages
• Inability to recognize and adjust to changes in
alveolar VD
• Possible respiratory muscle atrophy
• Varying mean airway pressure
• In patients with COPD, a longer TE may be
required
• A sudden increase in respiratory rate and demand
may result in a decrease in ventilator support
57. AUTOMODE
The ventilator switch between mandatory and spontaneous breathing modes
Combines volume support (VS) and pressure-regulated volume control
(PRVC)
If patient is paralyzed; the ventilator will provide PRVC. All breaths are
mandatory that are ventilator triggered, pressure controlled and time cycled; the
pressure is adjusted to maintain the set tidal volume.
If the patient breathes spontaneously for two consecutive breaths, the ventilator
switches to VS. All breaths are patient triggered, pressure limited, and flow
cycled.
If the patient becomes apneic for 12 seconds; the ventilator switches back to
PRVC
Macquet Servo 300A
59. PROPOTIONAL ASSIST VENTILATION
• Advantage of improving ventilator patient synchrony
• Amplifies patient’s ventilatory effort giving patient freedom to
adopt his own breathing pattern
• Unloads respiratory muscles without imposing a fixed
breathing pattern thus allows synchrony
• Percentage of assistance to be delivered is set and other
parameters are adjusted automatically according to the patients
“air hunger”
• I:E ratio also decided by patient allowing more synchrony
60. • ADVANTAGES:
• Better synchrony
• More comfort in NIV with PAV compared to PSV
• Low airway pressures
• Optimal weaning
• Decreased work of breathing
• Early/late ALI/ARDS
• Hypercapnic ventilatory failure
61. DISADVANTAGE:
• If patient worsens or improves ,the proportion of assistance
needs to be readjusted according to patient’s clinical
condition
• This disadvantage has been adjusted in newer modification
“PAV + “ mode capable of sensing patient respiratory
mechanics and adjusting accordingly
63. MANADATORY MINUTE VENTILATION
• Modification of PSV
• Ventilator takes feedback to alter both respiratory rate and
level of pressure support to achieve set minimum minute
ventilation
• Operator sets: minimum minute ventilation (70-90% of
current minute volume) ,which is readjusted according to
patients clinical condition
64. • Patient fails to achieve set volume then ventilator provides the
deficit
• Reliable weaning mode
• Apneic patient or central drive pathology, MMV sets safety by
providing a set value ventilation as mandatory ventilation
• Caution : MMV lower than current MV increased WOB
MMV more than required MV unloading of
muscles atrophy
o D/A Rapid shallow breathing if RR is set too high
67. BiLevel Ventilation
Is a spontaneous breathing mode in which two levels of pressure
i.e. high /low are set
Substantial improvements for SPONTANEOUS BREATHING
Better synchronization,
More options for supporting spontaneous breathing
Potential for improved monitoring
68. BiLevel Ventilation
Synchronized TransitionsSpontaneous Breaths
Spontaneous Breaths
Paw
cmH20
60
-20
1 2 3 4 5 6 7
Also called
Biphasic
Bivent
DuoPAP
These modes deliver
pressure-controlled breaths
time-triggered
time-cycled breaths
using a set-point targeting scheme
69. This mode maintains a constant pressure
(set point) even in the face of spontaneous
breaths
There are two pressures to be set
Phigh
Plow
There are two time intervals to be set
Time spent on P high – Thigh
Time spent on P low - T low
Patient can breath spontaneously at both
these pressures
T high T low T high
BiPAP
70. CPAP
TIME
T high T low T high
PCV
BIPAP
Unrestricted spontaneous breathing
Allows reduced sedation and promote
weaning
Phigh
improves oxygenation
promotes alveolar recruitment
Plow
Allows exhalation
Maintains recruitment
71. P high & P low
The volume difference between the two
Two levels of functional FRC
Creates a driving pressure
Determines the VT
Permit gas to enter the lung units
Represents the difference between
airway pressure (Paw) and alveolar
pressure (Palv)
T high T low T high
PCV
72. Airway Pressure Release Ventilation
• Is a Bi-level form of ventilation with sudden short releases in
pressure to rapidly reduce FRC and allow for ventilation
• Can work in spontaneous or apneic patients
• APRV is similar but utilizes a very short expiratory time for
PRESSURE RELEASE
• this short time at low pressure allows for ventilation
73. APRV always implies an inverse I:E ratio
All spontaneous breathing is done at upper pressure level
74. INDICATIONS
• Partial to full ventilatory support
• Patients with ALI/ARDS
• Patients with refractory hypoxemia due to
collapsed alveoli
• Patients with massive atelectasis
• May use with mild or no lung disease
75. • Provides two levels of CPAP and allows spontaneous
breathing at both levels when spontaneous effort is present
• Both pressure levels are time triggered and time cycled
76. • The release phase ( expiratory phase) brings down mean airway
pressure and plays significant role in maintaining normocarbia.
• It has dual functionality:
• In spontaneously breathing pt patients breathes with supported
breaths thus reducing need for sedation
• In absence of spontaneous breathing bi-level pressure acts as
time cycled inverse ratio ventilation.
77. • Vt depends of upon respiratory compliance and difference between
two CPAP levels
79. ADVANTAGES
• Allows inverse ratio ventilation (IRV) with or without
spontaneous breathing (less need for sedation or paralysis)
• Improves patient-ventilator synchrony if spontaneous
breathing is present
• Improves mean airway pressure
80. • Improves oxygenation by stabilizing collapsed alveoli
• Allows patients to breath spontaneously while continuing
lung recruitment
• Lowers PIP
• May decrease physiologic deadspace
81. DISADVANTAGES AND RISKS
• Variable VT
• Could be harmful to patients with high expiratory resistance
(i.e., COPD or asthma)
• Auto-PEEP is usually present
• Caution should be used with hemodynamically unstable
patients
• Asynchrony can occur is spontaneous breaths are out of sync
with release time
• Requires the presence of an “active exhalation valve”
83. Automatic Tube Compensation
• Available in the Evita 4 ventilator (Dräger Medical)
• The PB840 ventilator has a similar feature which is
called tubing compensation (TC).
• Can be applied in all ventilation modes
• A mode of ventilation that offsets and compensates
for the airflow resistance imposed by the artificial
airway
84. • Overcome Work Of Breathing added by artificial airways
• It allows the patient to have a breathing pattern as if
breathing spontaneously without an artificial airway
• Improve patient/ventilator synchrony by providing variable
fast inspiratory flow
85. INDICATIONS
• patient who has compromised respiratory function
( COPD, malnutrition, respiratory muscle failure)
• Those who have failed previous extubation attempt
• The “difficult to wean” patient
87. • Due to varying inspiratory flow rates, no single level of pressure
support can actually fully compensate for WOB caused by the
ETT.
• ATC uses known static resistance for each size and type of
ETT/tracheal tube, and measures flow rates.
• Pressure is applied and continuously adjusted proportional to
resistance.
88. • With ATC, the pressure delivered by the ventilator to
compensate for the airflow resistance is active during
inspiration and expiration.
• It is dependent on the airflow characteristics and the flow
demand of the patient.
• For example, when the airway diameter decreases or flow
demand increases, the pressure is raised to overcome a higher
airflow resistance or increased flow demand.
89. ADVANTAGES
• Designed to Maintain Tracheal Pressure at Baseline
• Does not require ongoing assessment of resistance!
• Pressure Applied Based Upon Resistive Properties of the
Airway and Patients Inspiratory Flow
• Positive Pressure During Inspiration
• Negative Pressure During Exhalation
• Effectively unloads resistive effort imposed by ETT
• Improves patient – ventilator synchrony
• Reduces risk of lung injury
91. Neurally adjusted ventilatory assist (NAVA)
• A mode of mechanical ventilation in which the patient’s electrical
activity of the diaphragm (EAdi or Edi) is used to guide the optimal
functions of the ventilator .
• The neural controls of respiration originated in the patient’s
respiratory center are sent to the diaphragm via the phrenic nerves.
• In turn, bipolar electrodes are used to pick up the electrical activity
• The electrodes are mounted on a disposable EAdi catheter and
positioned in the esophagus at the level of the diaphragm.
92. Neural adjusted ventilator assist
NAVA
Neuro-VentilatoryCoupling
Central Nervous System
Phrenic Nerve
Diaphragm Excitation
Diaphragm Contraction
Chest Wall and Lung Expansion
Airway Pressure, Flow and
Volume
New
Technology
Ideal
Technology
Current
Technology
Ventilator
Unit
93. INDICATIONS
• NAVA is available for adults, children, and neonates,
and it has been used successfully in the management
and weaning of mechanically ventilated patients with
spinal cord injury.
• Other uses and potential applications of NAVA include
patients with head injury, COPD, and history of
ventilator dependency.
•
• The ability to wean these patients rapidly reduces or
eliminates the incidence of disuse atrophy of the
diaphragm
96. SIGNAL CAPTURE
All muscles (including the diaphragm
and other respiratory muscles) generate
electrical activity to excite muscle
contraction.
The electrical activity of the diaphragm
is captured by an esophageal catheter
with an attached electrode array. The
signal is filtered in several steps and
provide the input for control of the
respiratory assist delivered by the
ventilator.
97. In a healthy subject only 5% of
maximum capacity of neuro
ventilatory coupling is used to
generate an adequate Vt
98. Benefits of NAVA
• Synchrony with least possible delay
• Safer and improved ventilation
• Leaks do not cause false initiation of breaths (unaffected by circuit)
• Eliminates man sleep disturbances
• Adapts to altered metabolic demand with consistent unloading
• Prevents disuse atrophy
• Improves NIV
99. • In other modes auto-PEEP increases work of ventilator
initiation in COPD and asthma , this does not effect ventilatory
cycle in NAVA thus overall WOB decreases in these patients
101. NEOGANESH(SMARTCARE)
• Closed loop type modification of PSV WITH INREGRATED
ARTIFICIAL INTELLIGENCE
• Adjusts ventilator assistance depending on patient,s
respiratory pattern and literature based weaning protocols
• Based on 3 fundamental principles:
– Adapt PS to patient’s present clinical situation
– In case of stability wean off PS
– Initiate spontaneous breathing trials as per prerecorded clinical
guidelines
102. • Ventilator takes feedback from monitored RR, VT, etCO2
• Trials have shown that it reduces weaning failure and also
hastens weaning duration.