This document discusses various aspects of mechanical ventilation including indications, types of breaths, modes, settings and principles. It begins by outlining the objectives and indications for mechanical ventilation. It then describes non-invasive positive pressure ventilation and invasive mechanical ventilation. The principles of mechanical ventilation are explained including types of breaths, triggering, cycling and basic mechanics. Finally, the document outlines various ventilator modes like assist-control, SIMV and pressure support as well as important settings like tidal volume, respiratory rate, PEEP, flow rate and FiO2.
A mechanical ventilator is a machine that helps a patient breathe (ventilate) when they are having surgery or cannot breathe on their own due to a critical illness. The patient is connected to the ventilator with a hollow tube (artificial airway) that goes in their mouth and down into their main airway or trachea
A mechanical ventilator is a machine that helps a patient breathe (ventilate) when they are having surgery or cannot breathe on their own due to a critical illness. The patient is connected to the ventilator with a hollow tube (artificial airway) that goes in their mouth and down into their main airway or trachea
Christian Powerpoint Backgrounds and TemplatesFPPT.com
When telling Bible stories to children at church, it is important to have a visual presentation to get the kids' attention. This Ten Commandments Powerpoint background is just one among FPPT's free Christian backgrounds and Powerpoint templates.
Christian Powerpoint Backgrounds and TemplatesFPPT.com
When telling Bible stories to children at church, it is important to have a visual presentation to get the kids' attention. This Ten Commandments Powerpoint background is just one among FPPT's free Christian backgrounds and Powerpoint templates.
Christian Backgrounds: Powerpoint (PPT) Template Noah's ArkFPPT.com
Noah Ark Powerpoint Template is perfect to help you teach children about the Bible. Or if you prefer you can check other free Christian backgrounds and Religious PowerPoint Templates at http://www.free-power-point-templates.com/tag/religious-and-christian-powerpoint-templates/.
Chinese Dragon Powerpoint Background and PPT Template FPPT.com
Chinese Dragon PowerPoint Template is a free PowerPoint template slide design that you can download for presentations on Chinese New Year or Chinese tour presentations. You can download this free dragon Powerpoint background and template at http://www.free-power-point-templates.com/chinese-dragon-powerpoint-template/
This slide include information regarding ventilators, modes of ventilators , its parts, weaning process, nursing care of patient in mechanical ventilation.
Mechanical ventilation ppt including airway, ventilator, tubings and connections, nursing management, trouble shooting common problems and issues, suctioning etc.
Weaning from mechanical ventilation , also called ventilator liberation, refers to the process of the patient assuming more and more of the work of breathing and finally demonstrating that ventilator support is no longer required.
Simply it means the process of withdrawing mechanical ventilatory support and transferring the work of breathing from the ventilator to the patient . Weaning can be accomplished with an endotrachel tube ( ETT) or a tracheostomy tube in place.
In the case of the ETT, the final step in the process is the removal of the tube( extubation). With a tracheostomy, the final step may be the ability to breath spontaneously for a designated period of time with the tube in place.
Weaning success is defined as absence of ventilatory support 48 hours following the extubation.
While the spontaneous breaths are unassisted by mechanical ventilation, supplemental oxygen, bronchodilators, low level pressure support ventilation or continuous positive airway pressure (CPAP) may be used to support and maintain adequate spontaneous ventilation and oxygenation.
Purpose
The purpose is to assess the probability that mechanical ventilation can be successfully discontinued.as
75% of mechanically ventilated patients are easy to be weaned off the ventilator with simple process.
10-15% of patients require a use of a weaning protocol over a 24-72 hours.
5-10% require a prolonged weaning plan.
1% of patients become dependent on chronic mechanical ventilation.
Indication
Improvement of the cause of respiratory failure.
Absence of major system dysfunction.
Appropriate level of oxygenation.
Adequate ventilatory status.
Intact airway protective mechanism.
Contraindication
Altered sensorium either drowsiness or restlessness.
Spo2 ˂90%
Rising PaCO2 with drop in PH
Tachypnoea ˃35/ min
Tachycardia ˃120 /min
Drop in systolic blood pressure
Sweating
Cold clammy skin
Signs of diaphragmatic weakness
Paradoxical abdominal wall movement
Assessment of readiness for weaning
Hemodynamic stability
Minimum inotropic support
Adequate cardiac output
Afebrile
Hematocrite greater than 25%
Respiratory stability
Improved chest x-ray
Arterial oxygen tension (PaO2) greater than 60mm Hg with fraction of inspired oxygen ( FiO2) less than 0.5
PaO2/FiO2 greater than 300 mm Hg
Positive end expiratory pressure (PEEP) less than 0-5 cm H2O
Vital capacity (VC) 10-15ml/kg
Spontaneous tidal volume (VT) 5ml/Kg
Respiratory rate less than 30 breaths/mim
Minute ventilation 5-10 L/min
Negative inspiratory pressure greater than -20cm H2O
Rapid shallow breathing index (RSBI) less than 105
metabolic factors stable
Electrolytes within normal range.
ABGs( Arterial blood gases) normalized
Other
Adequate management of pain and anxiety.
Patient is well rested
Weaning criteria
Weaning criteria are used to evaluate the readiness of a patient for a weaning trial and the likelihood of weaning success.
Clinical criteria
Ventilatory criteria
Oxygenation criteria
MECHANICAL VENTILATION IN NEUROLOGICAL AND NEUROLOGICAL CASES.pptxNeurologyKota
20% of all patients requiring mechanical ventilation suffer from neurological dysfunction.
Major contributor to prolongation of mechanical ventilation in over a third of patients admitted in ICU.
Artificial ventilation, also known as mechanical ventilation, is a medical intervention used to assist or replace spontaneous breathing in patients who are unable to breathe adequately on their own. This can be necessary in various clinical scenarios, such as during surgery, in critically ill patients, or those with respiratory failure. Here's an overview of artificial ventilation and related equipment:
Demonstration on Mechanical Ventilator.pptxShashi Prakash
Consist of
Definition of mechanical ventilator
Purpose of mechanical ventilator
Indications of mechanical ventilations
Normal cycle of Respiration
Lung volumes
Modes of ventilator Types of mechanical ventilators
Describe the alarms of mechanical ventilator
Contraindications of mechanical ventilation
Complication of mechanical ventilator
Role of nurses during weaning and care of patient with VAP
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!
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
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
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.
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
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
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.
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.
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
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
3. Objectives
• Discuss indications and techniques for non
invasive positive pressure ventilation.
• Describe characteristics of different types of
breath and modes of mechanical ventilation.
• Outline basic ventilator settings.
• Interactions between ventilatory parameters
and modifications needed to avoid harmful
effects of mechanical ventilation.
• Initial ventilator management that apply to
specific clinical situations.
5. Indications for Mechanical
Ventilation
• The work of breathing usually accounts for 5% of
oxygen consumption (V02).
•
In the critically ill patient this may rise to 30%.
•
Invasive mechanical ventilation eliminates the
metabolic cost of breathing.
6. Indications for Mechanical
Ventilation
•
Inadequate oxygenation (not corrected by
supplemental O2 by mask).
•
Inadequate ventilation (increased PaCO2).
•
Retention of pulmonary secretions (bronchial
toilet).
•
Airway protection (obtunded patient, depressed
gag reflex).
7. Indications
• Ventilation abnormalities:
•
•
•
•
•
Respiratory muscle fatigue
Chest wall abnormalities
Neuromuscular disease
Increased airway resistance and /or obstruction
Decreased ventilatory drive
• Oxygenation abnormalities:
• Refractory Hypoxaemia
• Excessive work of breathing
• Need for positive end expiratory pressure
8. Other indications
• Need for sedation and / or neuromuscular
blockade.
• Need to decrease systemic / myocardial
oxygen demand.
• Use of hyperventilation to reduce Raised
ICP.
• Facilitation of alveolar recruitment and
prevention of atelectasis.
9. NIPPV ( NON INVASIVE
POSITIVE PRESSURE
VENTILATION)
10. NIV vs. Invasive Mechanical
Ventilation
•NIV is defined as ventilatory support
provided via a tight fitting mask or similar
interface as opposed to invasive support,
which is provided via a laryngeal mask,
endotracheal tube or tracheostomy tube.
• Tight fitting masks deliver can CPAP,
BIPAP or NIV via the mechanical ventilator.
11. Advantages of NPPV
•
•
•
•
Reduced need for sedation
Preservation of airway protective reflexes
Avoidance of upper airway trauma
Decreased incidence of nosocomial sinusitis
and pneumonia
• Improved patient comfort
• Shorter length of ICU and hospital stay
• Improved survival
12.
13. Disadvantages of NPPV
•
•
•
•
•
Claustrophobia
Facial /nasal pressure lesions.
Unprotected airway
Inability to suction deep airway
Gastric distension with use of face mask or
helmet
• Possible upper extremity edema, axillary vein
thrombosis, tympanic dysfunction, and
intrahelmet noise with use of helmet
• Delay in intubation.
14. Contraindications of NPPV
•
•
•
•
•
•
•
•
Cardiac or respiratory arrest.
Haemodynamic instability
Uncooperative.
Inability to protect the airways.
High risk of aspiration.
Active upper GI bleed.
Severe encephalopathy.
Facial trauma, recent surgery &/or burn
15. Conditions likely to respond
to NPPV
• Hypoxaemic respiratory failure:
– Cardiogenic pulmonary edema without
haemodynamic instability
– Respiratory failure in IC patients.
(haematologic malignacies and
transplant patients)
– Patients not candidates for intubation
16. • Hypercapnic respiratory failure:
– AECOPD
– AE bronchial asthma
– Resp failure in patients with cystic
fibrosis
– Patients not candidates for
intubation
17. Initiation of NPPV
• Do not delay intubation if needed.
• Ensure appropriate mask or helmet size.
• Assess patients’ tolerance of the mask by
applying it by hands before securing the
harness.
• Explain the procedure to the patients
• Initial ventilation settings–
–
–
–
–
Mode: spontaneous
Trigger: maximum sensitivity
EPAP : 4-5 cm H2O
IPAP : 10-15 cm H2O
Rate: 6/min
18. Cont…
• Adjust difference between EPAP & IPAP to
achieve effective tidal vol. & CO2 clearance.
• EPAP increments of 2 cm H2O /step to
improve oxygenation by alveolar
recruitment.
• In assist control ventilation begin with VT 6-8
ml/kg.
• Titrate pressure, vol & FiO2 to achieve
appropriate PaO2 & PaCO2 levels.
• Ventilator changes can be made
every 15-30 mins.
21. Bare Essentials for Intubation
ALSOBLEED
Airway: oral Guedel airway to lift tongue off
posterior pharynx to facilitate mask ventilation
during pre-intubation phase.
2 Liquids: stop feed and aspirate ng tube.
3 Suction: extremely important to avoid pulmonary
aspiration.
4 Oxygen: preoxygenate patient and ensure a
source of O2 with a delivery mechanism
(ambu-bag and mask) is available
22. Bare Essentials for Intubation
ALSOBLEED
5 Bougie: to facilitate tube insertion in more difficult
airway.
6 Laryngoscope: have a long and short blade
available.
7 Endotracheal tube: for average adult, cuffed oral
endotracheal tube 7.0 for women and 8.0 for men.
8 End tidal CO2: to confirm correct position of tube.
9 Drugs: an induction agent, muscle relaxant,
sedative are usually required.
24. Principles of Mechanical
Ventilation
•
Positive pressure ventilation involves delivering
a mechanically generated ‘breath’ to get O2 in and
CO2 out.
•
Gas is pumped in during inspiration (Ti) and the
patient passively expires during expiration (Te).
•
The sum of Ti and Te is the respiratory cycle or
‘breath’.
25. Basic mechanics
Each mechanical ventilatory cycle can be
divided into 2 phases:
• Inspiration is the point at which exhalation
valve closes and fresh gas enters the chest.
• The amount of gas delivered during
inspiration is limited by 3 parameters that
can be set in the ventilator:
• Volume
• Pressure and/or
• Flow
26. • Cycling :
• Changeover from the end of inspiration to
the second phase , expiration.
• Cycling can occur in response to elapsed
time , delivered volume or a decrease in
flow rates.
• Expiration begins when the gas flow from
the ventilator is stopped and exhalation
circuit is opened to allow gas to escape from
the lungs.
27. • Triggering :
• Changeover from expiration to inspiration.
• All ventilators require some signal from the
patient to determine when inspiration should
begin.
• Triggering signal results when patients
inspiratory effort produces a drop in airway
pressure or diversion of a constant gas flow
in ventilator circuitry.
29. • In the absence of patients interaction with
the ventilator, breaths are delivered based
on elapsed time.
• This is called UNASSISTED OR
MANDATORY BREATH.
• Based on this definitions two ventilator
breath types are possible:
• Mandatory/ UnAssisted breath
• Assisted breath
30. Principles of Mechanical
Ventilation
•
In the fully ventilated patient, positive pressure
breaths are delivered either as preset volume or
pressure continuous mandatory breaths (CMV)
breaths.
•
The mechanical ventilator triggers the breath
and switches from inspiration to expiration when
the preset volume, pressure (or time) is
achieved/delivered.
•
During CMV the patient takes no spontaneous
breaths.
•
CMV is usually used in theatre and in very unwell
ICU patients.
31. Types of ventilator breaths
• A. volume cycled (control) breath
• Ensures delivery of a preset tidal
volume( unless the peak pressure limit is exceeded)
• On some ventilators setting of peak
inspiratory flow rate and choice of inspiratory
flow waveform( sine, square, decelerating)
determine length of inspiration.
• with volume cycled breaths, worsening
airway resistance or lung compliance results
in increase in peak inspiratory pressure.
32. B.Time cycled breath
• Often called pressure cycled( controlled)
breath, applies a constant pressure over
preset time.
• Produces a decelerating inspiratory flow
waveform as the pressure gradient between
the ventilator( constant pressure) patient(
pressure rises as lung fills) falls.
• In this setting , changes in the airway
resistance or lung compliance will alter the
tidal volume.
33. C. Flow cycled breath
• usually pressure support breath.
• Similar to a time cycled breath.
• However, pressure support is terminated
when the flow rate decreases to a
predetermined percentage of initial flow rate
e.g 25%.
34. Principles of Mechanical Ventilation
Volume cycled/ Control
Breath
Flow
Pressure
Pressure cycled/Control
Breath
Ti
Te
Ti
Te
35. Why is the peak airway pressure
(PAP) important?
• Ventilator Induced Lung Injury (VILI).
•
Mechanical ventilation is injurious to the lung.
•
Aim PAP< 35 cm H20.( platue pressure < 30 cm
water)
• HIGH PAP may cause barotruma(pneumothorax),
• Volutruma( lung parenchymal injury)
Don’t forget that the peak airway
pressure will also include the PEEP that
is added
36. Principles of Mechanical Ventilation
Volume Breath
Pressure Breath
Flow
Pressure
35 cm H20
Ti
Te
Ti
Te
39. Overview of topics
1. Settings
2. Modes
3. Advantages and disadvantages between
modes
4. Guidelines in the initiation of mechanical
ventilation
5. Common trouble shooting examples with
mechanical ventilation
41. Trigger
There are two ways to initiate a ventilator-delivered breath:
pressure triggering or flow-by triggering
When pressure triggering is used, a ventilatordelivered breath is initiated if the demand
valve senses a negative airway pressure
deflection (generated by the patient trying to
initiate a breath) greater than the trigger
sensitivity.
When flow-by triggering is used, a continuous
flow of gas through the ventilator circuit is
monitored. A ventilator-delivered breath is
initiated when the return flow is less than the
delivered flow, a consequence of the patient's
effort to initiate a breath
42. Tidal Volume
• The tidal volume is the amount of air
delivered with each breath. The
appropriate initial tidal volume
depends on numerous factors, most
notably the disease for which the
patient requires mechanical
ventilation.
43. Respiratory Rate
• An optimal method for setting the
respiratory rate has not been
established. For most patients, an
initial respiratory rate between 12 and
16 breaths per minute is reasonable
44. Positive End-Expiratory
Pressure (PEEP)
• Mechanically ventilated patients usually
receive positive end-expiratory pressure
(PEEP), to overcome the loss of
physiological PEEP provided by the
larynx and vocal cords.
• Applied PEEP is generally added to mitigate
end-expiratory alveolar collapse.
45. PEEP
• PEEP is delivered throughout the respiratory
cycle and is synonymous to CPAP, but in the
intubated patient.
A typical initial applied PEEP is 5 cmH2O. However, up
to 20 cmH2O may be used in patients undergoing
low tidal volume ventilation for acute respiratory
distress syndrome (ARDS)
46. Flow Rate
• The peak flow rate is the maximum flow
delivered by the ventilator during inspiration.
Peak flow rates of 60 L per minute may be
sufficient, although higher rates are
frequently necessary.
• An insufficient peak flow rate is
characterized by dyspnea, spuriously low
peak inspiratory pressures, and scalloping
of the inspiratory pressure tracing
47. Inspiratory Time: Expiratory
Time Relationship (I:E Ratio)
• During spontaneous breathing, the
normal I:E ratio is 1:2, indicating that
for normal patients the exhalation time
is about twice as long as inhalation
time.
• If exhalation time is too short “breath
stacking” occurs resulting in an
increase in end-expiratory pressure
also called auto-PEEP.
• Depending on the disease
process, such as in ARDS, the I:E
ratio can be changed to improve
ventilation
48. Fraction of Inspired Oxygen
• The lowest possible fraction of inspired
oxygen (FiO2) necessary to meet
oxygenation goals should be used.
• This will decrease the likelihood that
adverse consequences of supplemental
oxygen will develop, such as absorption
atelectasis, accentuation of hypercapnia,
airway injury, and parenchymal injury
49. Modes of Ventilation: The
Basics
•
•
•
•
Assist-Control Ventilation :Volume Control
Assist-Control Ventilation: Pressure Control
Pressure Support Ventilation
Synchronized Intermittent Mandatory
Ventilation :Volume Control
• Synchronized Intermittent Mandatory
Ventilation :Pressure Control
50. Assist Control Ventilation
• A set tidal volume (if set to volume control)
or a set pressure and time (if set to pressure
control) is delivered at a minimum rate
• Additional ventilator breaths are given if
triggered by the patient.
51. • Once stabilised on CMV, the level of ventilatory
support may be reduced (weaning).
•
This can be done by providing a mixture of
synchronised intermittent mandatory breaths
(SIMV) and spontaneously triggered pressure
supported breaths (PSV).
52. Synchronized Intermittent
Mandatory Ventilation
Breaths are given are given at a set minimal rate,
however if the patient chooses to breath over the
set rate no additional support is given
One advantage of SIMV is that it allows patients to
assume a portion of their ventilatory drive
SIMV is usually associated with greater work of
breathing than AC ventilation and therefore is less
frequently used as the initial ventilator mode
Like AC, SIMV can deliver set tidal volumes
(volume control) or a set pressure and time
(pressure control)
Negative inspiratory pressure generated by
spontaneous breathing leads to increased venous
return, which theoretically may help cardiac output
and function
53. SIMV and Pressure Support
Ventilation
• In SIMV mode the ventilator allows two kinds of
breath.
• The first is delivered according to the preset
waveform and is the “mandatory breath”. The timing
of the start of this breath may be triggered by the
patient’s respiratory effort but, if the patient is not
making sufficient respiratory effort, is determined by
the ventilator. The second is a spontaneous breath. If
SIMV is combined with pressure support then the
ventilator facilitates this second breath by providing
pressure support. This second type of breath is
entirely dependent on patient effort.
• The graphs illustrate the changes in pressure and
flow that occur with first a mandatory breath and then
a pressure-supported breath
55. SIMV and Pressure Support
Ventilation
• Ventilator assisted breaths are synchronized with
the patient’s breathing to prevent the possibility
of a mechanical breath on top of a spontaneous
breath.
•
However, the patient’s attempt at a breath would
not be enough to generate an adequate tidal
volume on its own, hence the term ‘pressure
support’.
56. Pressure Support
Ventilation
• The patient controls the respiratory rate
and exerts a major influence on the
duration of inspiration, inspiratory flow rate
and tidal volume
• The model provides pressure support to
overcome the increased work of breathing
imposed by the disease process, the
endotracheal tube, the inspiratory valves
and other mechanical aspects of
ventilatory support.
57. PSV
•
As patients improve, mandatory breaths are
withdrawn and receive pressure-supported breaths
alone.
•
Finally, as tidal volumes improve, the level of
pressure support is reduced and then withdrawn
so patients breathe spontaneously with PEEP
alone.
•
Extubation can now be contemplated.
•
Spontaneous modes of breathing should always
be encouraged as respiratory muscle function is
maintained
59. • PSV augments the patients own
respiratory effort and best adjusted by
observing changes in patients resp
rate, vt and comfort.
• Pressure support is only delivered during
inspiration and the patient’s attempt at breathing
triggers the breath rather than the ventilator.
•
A standard level of pressure support delivered in
inspiration is 20 cm H20
60. Airway pressure & flow tracings for commonly used modes of mechanical
ventilation
61. Advantages of Each Mode
Mode
Advantages
Assist Control Ventilation (AC)
Reduced work of breathing compared
to spontaneous breathing
AC Volume Ventilation
Guarantees delivery of set tidal
volume
AC Pressure Control Ventilation
Allows limitation of peak inspiratory
pressures
Pressure Support Ventilation (PSV)
Patient comfort, improved patient
ventilator interaction
Synchronized Intermittent Mandatory
Ventilation (SIMV)
Less interference with normal
cardiovascular function
62. Disadvantages of Each
Mode
Mode
Disadvantages
Assist Control Ventilation (AC)
Potential adverse hemodynamic
effects, may lead to inappropriate
hyperventilation
AC Volume Ventilation
May lead to excessive inspiratory
pressures
AC Pressure Control Ventilation
Potential hyper- or hypoventilation with
lung resistance/compliance changes
Pressure Support Ventilation (PSV)
Apnea alarm is only back-up, variable
patient tolerance
Synchronized Intermittent Mandatory
Ventilation (SIMV)
Increased work of breathing compared
to AC
63. Successful Weaning and Extubation
• To succeed, the initiating cause of respiratory failure,
sepsis, fluid and electrolyte imbalance and nutritional
status should all be treated or optimised.
• Failure to wean is associated with:
• Ongoing high V02.
• Muscle fatigue.
• Inadequate drive.
• Inadequate cardiac reserve.
64. Successful Weaning and
Extubation
•
Weaning screens exist to help select patients for
extubation.
•
In the unsupported patient, if f/Vt is >100,
extubation is likely to be unsuccessful.
•
There is some evidence to support extubation to
NIV, particularly in patients with COPD.
65. Guidelines in the Initiation of
Mechanical Ventilation
• Primary goals of mechanical ventilation are
adequate oxygenation/ventilation, reduced
work of breathing, synchrony of vent and
patient, and avoidance of high peak
pressures
• Set initial FIO2 on the high side, you can
always titrate down
• Initial tidal volumes should be 8-10ml/kg,
depending on patient’s body habitus. If
patient is in ARDS consider tidal volumes
between 5-8ml/kg with increase in PEEP
66. Guidelines in the Initiation of
Mechanical Ventilation
• Use PEEP in diffuse lung injury and ARDS
to support oxygenation and reduce FIO2
• Avoid choosing ventilator settings that limit
expiratory time and cause or worsen auto
PEEP(espl in obstructive airway disease)
• When facing poor oxygenation, inadequate
ventilation, or high peak pressures due to
intolerance of ventilator settings consider
sedation, analgesia or neuromuscular
blockage
68. Trouble Shooting the Vent
• If we have a patient with history of COPD/asthma
with worsening oxygen saturation and increasing
hypercapnia differential includes:
– Given the nature of the disease process, patients
have difficultly with expiration (blowing off all the
tidal volume)
– Must be concern with breath stacking or autoPEEP
– Management options include:
Decrease respiratory rate
Decrease tidal volume
Adjust flow rate for quicker
inspiratory rate
Increase sedation
Adjust I:E ratio
69. Trouble Shooting the Vent
• Increase in patient agitation and dis-synchrony on the
ventilator:
– Could be secondary to overall
discomfort
• Increase sedation
– Could be secondary to feelings of
air hunger
– Options include increasing tidal volume,
increasing flow rate, adjusting I:E ratio,
increasing sedation
70. Trouble shooting the vent
• If you are concern for acute respiratory distress
syndrome (ARDS)
– Correlate clinically and radiologic
findings of diffuse patchy infiltrate on
CXR
– Obtain a PaO2/FiO2 ratio (if < 200 likely
ARDS)
– Begin ARDS net protocol:
• Low tidal volumes
• Increase PEEP rather than FiO2
• Consider increasing sedation to promote
synchrony with ventilator
71. ARDS Protocol
• Start with a PEEP of 5 and uptitrate..optimal PEEP is
usually 8-15 cm H2O.
• Start with a Vt of 8 ml/kg then gradually decrease till
Vt of 6 ml/kg is reached.
• P plat should be < 30.
• Ph> 7.15 is acceptable.
72. CM V
PSV
PEE P
S IM V
PSV
M a n d a to ry
O v erla p
S p o n ta n eo u s
73. Standard Ventilator Settings
MORITE
Mode
O2
CMV, Volume Control
0.5 (50% 02)
Respiratory Rate
12/minute
Inspiratory Action
Set Vt at 500 mls
Inspiratory Time
Set I:E ratio 1:2
Expiratory Action
Set PEEP at 5 cm H20
Be Aware
PAP ≤35 cm H2O
74. HYPOTENSION ASSOC WITH
MECHANICAL VENTILATION
• 1)TENSION PNEUMOTHORAX
• 2)CONVERSION FROM NEGATIVE TO POSITIVE
INTRATHORASIC PRESSURES.
• 3)Auto PEEP.
• 4)AMI./ MYOCARDIAL ISCHAEMIA.
75. TAKE HOME MESSAGE
• 1) Goals of NIV and IPPV are to suppport
ventilation and oxygenation, reduce work of
breathing and patient comfort.
• 2)NPPV is best utilized in C/A/C patients
whose resp condition is expected to improve
in 48-72 hrs.
• 3)Guidelines for initiating mechanical
ventilation should be carefully followed.
• 4)Inspiratory plateue pressures should be
maintained <30 cm H2o.
76. TAKE HOME MESSAGE
• 5) During mech ventilation, patient must be carefully
monitored using vent alarm systems, rintermittant
ABG analysis, pulse oximetry , physical assessment,
and chest radiograph as needed.
• 6) Hypotension in ventilated pt should be prompt
evaluated for pneumothorax, auto PEEP, AMI.
• 7)The primary determinants of oxygenation are Fi02
and Mean airway pressure whereas alveolar
ventilation affects CO2 exchange.
• 8) THE Complex interaction of inspiratory pressures,
I:E Ratio, Fio2, and PEEP must be evaluated.