Mechanical Ventilation

Hi, This is a new Nursing lecture about Mechanical Ventilation. What is Mechanical Ventilation? In this Nursing lecture, you will know what are the indications for mechanical ventilation.

1. Indications for Mechanical Ventilation
   • Impending Respiratory Failure
   • Acute Respiratory Failure/Arrest
   • Post-Operatively
2. Indications for Mechanical Ventilation
   • Impending Respiratory Failure
   • Progressively worsening clinical appearance.
   • Worsening CXR.
   • Hypoxemic Respiratory Failure.
   • Hypercapnic Respiratory Failure.
3. Indications for Mechanical Ventilation
   • Acute Respiratory Failure/Arrest
   • Acute change in ABG results
   • Respiratory Arrest/Status Post CPR
   • Acute epiglottitis/anaphylaxis
4. Indications for Mechanical Ventilation
   • Postoperatively
   • Oversedation/paralytics
   • Pain Control
   • Proper Immobilization
5. Key Terms in Mechanical Ventilation
   • Tidal Volume (Vt)
   • The volume of air inhaled and exhaled from the lungs.
   • Breaths per Minute (RR, f)
   • Also known as frequency.
   • Positive End Expiratory Pressure (PEEP)
   • Maintenance of above atmospheric pressure at the airway throughout exp. phase.
6. Key Terms in Mechanical Ventilation
   • Minute Ventilation (VE)
   • The total amount of volume moving in and out of the lung in one minute.
   • Fractional Inspired Oxygen (FiO2)
   • Correctly written with decimal place (21%-0.21; 100%-1.0)
   • Inspiratory:Expiratory Ratio (I:E ratio)
   • Normal I:E ratio 1:2-3
7. Negative Pressure Ventilation
   • Rarely Used; Currently used for patients with neuromuscular diseases.
   • Thoracic cage is encased where negative pressure is applied across the chest wall.
   • Generates subatmospheric pressures creating a difference in pressure gradients.
   • During exhalation, negative pressure is replace by atmospheric pressure allowing the lungs to deflate.
8. Negative Pressure Ventilation
   • Types of Negative Pressure Ventilators
9. Iron Lung circa 1950’s
10. Modern(ized) Iron Lung
11. Chest Cuirass
12. Complications with Negative Pressure Ventilation
    • Limited access for patient care.
    • Inability to properly monitor pulmonary mechanics.
    • Patient discomfort.
13. Positive Pressure Ventilation
    • Defined as the application of pressure to the lungs in order to improve gas exchange.
    • The Lungs are physically filled/ventilated with air using machinery.
    • Multiple modes, methods, and theory.
14. Positive Pressure Ventilation
    • Basically broken into two categories:
    • Control Modes.
    • Supportive Modes.
15. Control Modes of Ventilation
    • Assist/Control (usually abbreviated A/C also known as Volume Control VC).
    • Tidal Volume is set and remains constant.
    • Respiratory Rate is set.
    • Airway Pressure will vary according to lung compliance.
    • Ventilator will deliver set volume whether patient triggers a breath or mandatory breath is being delivered.
16. Control Modes of Ventilation
    • Pressure Control Ventilation (usually abbreviated PCV or sometimes PCIRV).
    • Upper Airway Pressure Level is set and remains constant.
    • Respiratory Rate is set.
    • Tidal volumes will vary according to lung compliance.
    • Ventilator will deliver set pressure level whether patient triggers a breath or mandatory breath is being delivered.
17. Control Modes of Ventilation
    • Pressure Regulated Volume Control (usually abbreviated PRVC).
    • Tidal Volume is set, however may or may not remain constant.
    • Respiratory Rate is set.
    • Ventilator will deliver volume however volume may decrease according to patient’s lung compliance.
    • A lung protective mode.
18. Supportive Modes of Ventilation
    • Synchronized Intermittent Mandatory Ventilation (usually abbreviated SIMV).
    • Tidal Volume is set and delivered on each mandatory breath.
    • Respiratory Rate is set.
    • When a patient triggers the ventilator spontaneously , the patient receives a Pressure Supported breath.
19. Supportive Modes of Ventilation
    • Pressure Support Ventilation (PSV)
    • Is a strictly patient dependant mode; patient must be breathing spontaneously.
    • An upper (inspiratory) pressure level is adjusted to provide adequate tidal volumes for each patient triggered breath.
    • PEEP is also adjusted as an independent pressure from the upper pressure level and is active during expiration.
    • PSV is a weaning mode.
20. Supportive Modes of Ventilation
    • Volume Support (VS)
    • Is a strictly patient dependant mode; patient must be breathing spontaneously.
    • Tidal Volume is set.
    • Each spontaneous breath is supported with dialed volume.
21. Supportive Modes of Ventilation
    • Continuous (Constant) Positive Airway Pressure (CPAP)
    • Is a strictly patient dependant mode; patient must be breathing spontaneously.
    • Closely resembles Pressure Support, however CPAP is a constant set pressure that does not change during inspiration or expiration.
    • CPAP is a weaning mode.
22. Drager Evita II
23. Puritan Bennett 840
24. Servo 900c
25. Servo 300a
26. Servo i
27. One of the Most Famous Ventilators
28. Complications to Mechanical Ventilation
    • Ventilator Induced Lung Injury (VILI)
    • Induced by excessive pressure (barotrauma)
    • Induced by excessive Volume (volutrauma)
    • Ventilator Associated Pneumonia (VAP)
    • Most commonly Pseudomonas, Gram Negative Bacilli, and staphylococci.
29. Ventilatory Discontinuance
    • Weaning
    • Process of discontinuing ventilatory support, regardless of the time frame involved.
    • Categories
    • Quick removal; routine
    • More gradual reduction in support (trach collar trials)
    • Ventilator dependent patients
30. Ventilatory Discontinuance
    • Success in discontinuing ventilatory support is related to the patients conditions in four main areas:
    • Ventilatory workload
    • Oxygenation status
    • Cardiovascular function
    • Psychological factors.
31. Ventilatory Discontinuance
    • Common indices in successful weaning:
    FiO2 <> 60 PaO2/FiO2 ratio > 200 PaCO2 <> 7.35 RSBI <>
32. Questions?