![History
The roman physician Galen may have been the
first to describe mechanical ventilation: "If you take
a dead animal and blow air through its larynx
[through a reed], you will fill its bronchi and watch
its lungs attain the greatest distention.” Vesalius
too describes ventilation by inserting a reed or
cane into the trachea of animals. In 1908 George
Poe demonstrated his mechanical respirator by
asphyxiating dogs and seemingly bringing them
back to life.](https://image.slidesharecdn.com/simulationlecture11mechanicalventillation1-240330192829-1f83f7bc/85/Simulation_lecture_11_mechanical_ventillation-1-pptx-5-320.jpg)
Simulation_lecture_11_mechanical_ventillation[1].pptx
- 2. Contents Anatomy and Physiology Of Respiratory System Introduction About Mechanical Ventilation History Meaning of Mechanical Ventilation Indications for use Types or Forms Of Mechanical Ventilation Settings of Mechanical Ventilation Modes of Mechanical Ventilation Complications associated with Mechanical Ventilation Nursing Management of ventilator patients
- 3. Anatomy and Physiology Of Respiratory System
- 4. Introduction About Mechanical Ventilation Mechanical ventilation is typically used after an invasive intubation, a procedure wherein an endotracheal or tracheostomy tube is inserted into the airway. It is used in acute settings such as in the ICU for a short period of time during a serious illness. It may be used at home or in a nursing or rehabilitation institution if patients have chronic illnesses that require long-term ventilation assistance.
- 5. History The roman physician Galen may have been the first to describe mechanical ventilation: "If you take a dead animal and blow air through its larynx [through a reed], you will fill its bronchi and watch its lungs attain the greatest distention.” Vesalius too describes ventilation by inserting a reed or cane into the trachea of animals. In 1908 George Poe demonstrated his mechanical respirator by asphyxiating dogs and seemingly bringing them back to life.
- 6. Meaning of Mechanical Ventilation In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing.
- 7. Indications for use • • • • • • • • • Common medical indications for use include: Acute lung injury (including ARDS, trauma) Apnea with respiratory arrest, including cases from intoxication Chronic obstructive pulmonary disease (COPD) Acute respiratory acidosis with partial pressure of carbon dioxide (pCO2) > 50 mmHg and pH < 7.25, which may be due to paralysis of the diaphragm due to Guillain-Barré syndrome, Myasthenia Gravis, spinal cord injury, or the effect of anaesthetic and muscle relaxant drugs Increased work of breathing as evidenced by significant tachypnea, retractions, and other physical signs of respiratory distress Hypoxemia with arterial partial pressure of oxygen (PaO2) with supplemental fraction of inspired oxygen (FiO2) < 55 mm Hg Hypotension including sepsis, shock, congestive heart failure Neurological diseases such as Muscular Dystrophy Amyotrophic Lateral Sclerosis
- 8. Types or Forms Of Mechanical Ventilation The two major types of Mechanical Ventilation are Negative pressure and positive Pressure ventilation The main form of mechanical ventilation is positive pressure ventilation, which works by increasing the pressure in the patient's airway and thus forcing air into the lungs. Less common today are negative pressure ventilators (for example, the "iron lung") that create a negative pressure environment around the patient's chest, thus sucking air into the lungs.
- 9. Types or Forms Of Mechanical Ventilation Negative Pressure Ventilator Positive Pressure Ventilator
- 10. Settings of Mechanical Ventilation • Mechanical Ventilator Settings regulates the rate, depth and other characteristics of ventilation. Settings are based on the patient’s status (ABGs, Body weight, level of consciousness and muscle strength)
- 11. PARAMETERS OF MECHANICAL VENTILATION ARE Respiratory Rate (f) :-Normally 10-20b/m Tidal Volume (VT) :-5-15ml/kg Oxygen Concentration(FIO2):-b/w 21-90% I:E Ratio:-1:2 Flow Rate:-40-100L/min Sensitivity/Trigger:- 0.5-1.5 cm H2O Pressure Limit:-10-25cm H2O PEEP :- Usually, 5-10 cmH2O
- 12. Connection to Ventilators • Face Mask • Airway • Laryngeal Mask • Tracheal Intubation • Tracheostomy
- 13. Modes of Mechanical Ventilation • Controlled Mandatory Ventilation (CMV) • Asst-Control Mandatory Ventilation (ACV) • Synchronized Intermittent Mandatory Ventilation(SIMV) • Positive Expiratory End Pressure(PEEP) • Continuous Positive Airway Pressure (CPAP) • Pressure Support Ventilation (PSV)
- 14. Modes of Mechanical Ventilation
- 15. Controlled Mandatory Ventilation (CMV) • Controlled Mechanical Ventilation (CMV). In this mode the ventilator provides a mechanical breath on a preset timing. Patient respiratory efforts are ignored. This is generally uncomfortable for children and adults who are conscious and is usually only used in an unconscious patient. It may also be used in infants who often quickly adapt their breathing pattern to the ventilator timing
- 16. Asst-Control Mandatory Ventilation (ACV) • Assist Control (AC). In this mode the ventilator provides a mechanical breath with either a pre-set tidal volume or peak pressure every time the patient initiates a breath. Traditional assist- control used only a pre-set tidal volume--when a preset peak pressure is used this is also sometimes termed Intermittent Positive Pressure Ventilation or IPPV. However, the initiation timing is the same--both provide a ventilator breath with every patient effort. In most ventilators a back-up minimum breath rate can be set in the event that the patient becomes apnoeic. Although a maximum rate is not usually set, an alarm can be set if the ventilator cycles too frequently. This can alert that the patient is tachypneic or that the ventilator may be auto-cycling (a problem that results when the ventilator interprets fluctuations in the circuit due to the last breath termination as a new breath initiation attempt)
- 17. Synchronized Intermittent Mandatory Ventilation(SIMV) • Synchronized Intermittent Mandatory Ventilation (SIMV). In this mode the ventilator provides a pre-set mechanical breath (pressure or volume limited) every specified number of seconds (determined by dividing the respiratory rate into 60 - thus a respiratory rate of 12 results in a 5 second cycle time). Within that cycle time the ventilator waits for the patient to initiate a breath using either a pressure or flow sensor. When the ventilator senses the first patient breathing attempt within the cycle, it delivers the preset ventilator breath. If the patient fails to initiate a breath, the ventilator delivers a mechanical breath at the end of the breath cycle. Additional spontaneous breaths after the first one within the breath cycle do not trigger another SIMV breath. However, SIMV may be combined with pressure support (see below). SIMV is frequently employed as a method of decreasing ventilatory support (weaning) by turning down the rate, which requires the patient to take additional breaths beyond the SIMV triggered breath.
- 18. Positive End Expiratory Pressure(PEEP) • PEEP) is functionally the same as CPAP, but refers to the use of an elevated pressure during the expiratory phase of the ventilatory cycle. After delivery of the set amount of breath by the ventilator, the patient then exhales passively. The volume of gas remaining in the lung after a normal expiration is termed the functional residual capacity (FRC). The FRC is primarily determined by the elastic qualities of the lung and the chest wall. In many lung diseases, the FRC is reduced due to collapse of the unstable alveoli, leading to a decreased surface area for gas exchange and intrapulmonary shunting (see above), with wasted oxygen inspired. Adding PEEP can reduce the work of breathing (at low levels) and help preserve FRC.
- 19. Continuous Positive Airway Pressure (CPAP) • (CPAP). A continuous level of elevated pressure is provided through the patient circuit to maintain adequate oxygenation, decrease the work of breathing, and decrease the work of the heart (such as in left-sided heart failure — CHF). Note that no cycling of ventilator pressures occurs and the patient must initiate all breaths. In addition, no additional pressure above the CPAP pressure is provided during those breaths. CPAP may be used invasively through an endotracheal tube or tracheostomy or non- invasively with a face mask or nasal prongs.
- 20. Pressure Support Ventilation • Pressure Support Ventilation (PSV). When a patient attempts to breath spontaneously through an endotracheal tube, the narrowed diameter of the airway results in higher resistance to airflow, and thus a higher work of breathing. PSV was developed as a method to decrease the work of breathing in-between ventilator mandated breaths by providing an elevated pressure triggered by spontaneous breathing that "supports" ventilation during inspiration
- 21. Complication • • • • • • • • • • Hypotension Pneumothorax Decreased Cardiac Output Nosocomial Pneumonia Positive Water Balance Increased Intracranial Pressure (ICP) Alarms turned off or nonfunctional Sinusitis and nasal injury Mucosal lesions Aspiration, GI bleeding, Inappropriate ventilation (respiratory acidosis or alkalosis, Thick secretions, Patient discomfort due to pulling or jarring of ETT or tracheostomy, High PaO2, Low PaO2, Anxiety and fear, Dysrhythmias or vagal reactions during or after suctioning, Incorrect PEEP setting, Inability to tolerate ventilator mode.
- 22. MECHANICAL VENTILATOR 22 • A mechanical ventilator is a machine that generates a controlled flow of gas into a patient’s airways. Oxygen and air are received from cylinders or wall outlets, the gas is pressure reduced and blended according to the prescribed inspired oxygen tension (FiO2), accumulated in a receptacle within the machine, and delivered to the patient using one of many available modes of ventilation.
- 23. Types of Mechanical ventilators 23 • Transport ventilators • Intensive-care ventilators • Neonatal ventilators • Positive airway pressure ventilators for NIV
- 24. Classification of positive-pressure ventilators • Ventilators are classified according to how the inspiratory phase ends. The factor which terminates the inspiratory cycle reflects the machine type. • They are classified as: Pressure cycled ventilator Volume cycled ventilator Time cycled ventilator 24
- 25. 1- Volume-cycled ventilator • Inspiration is terminated after a preset tidal volume has been delivered by the ventilator. • The ventilator delivers a preset tidal volume (VT), and inspiration stops when the preset tidal volume is achieved. 25
- 26. 2- Pressure-cycled ventilator • In which inspiration is terminated when a specific airway pressure has been reached. • The ventilator delivers a preset pressure; once this pressure is achieved, end inspiration occurs. 26
- 27. 3- Time-cycled ventilator • In which inspiration is terminated when a preset inspiratory time, has elapsed. • Time cycled machines are not used in adult critical care settings. They are used in pediatric intensive care areas. 27
- 28. Mechanical Ventilators Different Types of Ventilators Available: Will depend on your place of employment Ventilators in use in MCH Servo S by Maquet Savina by Drager
- 30. Ventilator mode • The way the machine ventilates the patient • How much the patient will participate in his own ventilatory pattern. • Each mode is different in determining how much work of breathing the patient has to do. 30
- 31. A- Volume Modes 31 • 1. CMV or CV • 2. AMV or AV • 3. IMV • 4. SIMV
- 32. B- Pressure Modes 1 Pressure-controlled ventilation (PCV) 2 Pressure-support ventilation (PSV) 3 Continuous positive airway pressure (CPAP) 4 Positive end expiratory pressure (PEEP) 5 Noninvasive bilevel positive airway pressure ventilation (BiPAP) 32
- 33. Control Mode Delivers pre-set volumes at a pre-set rate and a pre-set flow rate. The patient CANNOT generate spontaneous breaths, volumes, or flow rates in this mode.
- 34. Control Mode
- 35. Assist/Control Mode •Delivers pre-set volumes at a pre-set rate and a pre-set flow rate. •The patient CANNOT generate spontaneous volumes, or flow rates in this mode. •Each patient generated respiratory effort over and above the set rate are delivered at the set volume and flow rate.
- 36. Assist Control 36 • Volume or Pressure control mode • Parameters to set: – Volume or pressure – Rate – I – time – FiO2
- 37. Assist Control 37 • Machine breaths: – Delivers the set volume or pressure • Patient’s spontaneous breath: – Ventilator delivers full set volume or pressure & I-time • Mode of ventilation provides the most support
- 39. Delivers a pre-set number of breaths at a set volume and flow rate. Allows the patient to generate spontaneous breaths, volumes, and flow rates between the set breaths. Detects a patient’s spontaneous breath attempt and doesn’t initiate a ventilatory breath – prevents breath stacking SYCHRONIZED INTERMITTENT MANDATORY VENTILATION (SIMV):
- 40. SIMV 40 Synchronized intermittent mandatory ventilation • Machine breaths: – Delivers the set volume or pressure • Patient’s spontaneous breath: – Set pressure support delivered • Mode of ventilation provides moderate amount of support • Works well as weaning mode
- 41. SIMV cont. Machine Breaths Spontaneous Breaths 41
- 42. IMV 57 Ingento EP & Drazen J: Mechanical Ventilators, in Hall JB, Scmidt GA, & Wood LDH(eds.): Principles of Critical Care
- 43. Volume Modes 43
- 44. PRESSURE REGULATED VOLUME CONTROL (PRVC): 44 • This is a volume targeted, pressure limited mode. (available in SIMV or AC) • Each breath is delivered at a set volume with a variable flow rate and an absolute pressure limit. • The vent delivers this pre-set volume at the LOWEST required peak pressure and adjust with each breath.
- 45. PRVC (Pressure regulated volume control) 45 A control mode, which delivers a set tidal volume with each breath at the lowest possible peak pressure. Delivers the breath with a decelerating flow pattern that is thought to be less injurious to the lung…… “the guided hand”.
- 46. PRCV: Advantages 46 Decelerating inspiratory flow pattern Pressure automatically adjusted for changes in compliance and resistance within a set range Tidal volume guaranteed Limits volutrauma Prevents hypoventilation
- 47. PRVC: Disadvantages Pressure delivered is dependent on tidal volume achieved on last breath Intermittent patient effort variable tidal volumes Pressur e Flo w Volum e Set tidal volume 47 © Charles Gomersall 2003
- 48. Pressur e Flo w Volum e Set tidal volume PRVC: Disadvantages 48 © Charles Gomersall 2003 Pressure delivered is dependent on tidal volume achieved on last breath Intermittent patient effort variable tidal volumes
- 49. PRVC 49
- 50. POSITIVE END EXPIRATORY PRESSURE (PEEP): 50 • This is NOT a specific mode, but is rather an adjunct to any of the vent modes. • PEEP is the amount of pressure remaining in the lung at the END of the expiratory phase. • Utilized to keep otherwise collapsing lung units open while hopefully also improving oxygenation. • Usually, 5-10 cmH2O
- 51. 51
- 52. Pplat • Measured by occluding the ventilator 3-5 sec at the end of inspiration • Should not exceed 30 cmH2O 52
- 53. Peak Pressure (Ppeak) 53 • Ppeak = Pplat + Pres Where Pres reflects the resistive element of the respiratory system (ET tube and airway)
- 54. Ppeak • Pressure measured at the end of inspiration • Should not exceed 50cmH2O? 54
- 55. Auto-PEEP or Intrinsic PEEP 55 – Normally, at end expiration, the lung volume is equal to the FRC – When PEEPi occurs, the lung volume at end expiration is greater than the FRC
- 56. Auto-PEEP or Intrinsic PEEP 56 • Why does hyperinflation occur? – Airflow limitation because of dynamic collapse – No time to expire all the lung volume (high RR or Vt) – Decreased Expiratory muscle activity – Lesions that increase expiratory resistance
- 57. Auto-PEEP or Intrinsic PEEP 57 • Adverse effects: – Predisposes to barotrauma – Predisposes hemodynamic compromises – Diminishes the efficiency of the force generated by respiratory muscles – Augments the work of breathing – Augments the effort to trigger the ventilator
- 58. • This is a mode and simply means that a pre- set pressure is present in the circuit and lungs throughout both the inspiratory and expiratory phases of the breath. • CPAP serves to keep alveoli from collapsing, resulting in better oxygenation and less WOB. • The CPAP mode is very commonly used as a mode to evaluate the patients readiness for extubation. 58 Continuous Positive Airway Pressure (CPAP):
- 59. Combination “Dual Control” Modes 59 Combination or “dual control” modes combine features of pressure and volume targeting to accomplish ventilatory objectives which might remain unmet by either used independently. Combination modes are pressure targeted Partial support is generally provided by pressure support Full support is provided by Pressure Control
- 60. Thank You (Save the life Safely)