Mechanical Ventilation

  1. Mandatory Breath
    • Ventilator does all WOB
    • Triggered, Controlled (limited), cycled
  2. Assisted Breath 
    Started by patient & controlled (limited) & ended by ventilator. 
  3. Spontaneous Breath 
    • Started, controlled & ended by patient
    • Volume & pressure delivered based on patient demand & not by pre-selected amount set on vent. 
  4. Pressure cycled inspiration 
    Ends when preset pressure is reached. 
  5. Volume cycled inspiration
    Ends preset volume delivered
  6. Time cycled inspiration
    Ends when preset time met
  7. Flow cycled inspiration
    Ends flow decrease to preset level
  8. Manual cycled
    Patient or operator stops inspiration
  9. Negative pressure ventilation (extra thoracic) 
    • Vent controlled adjusting length inspiration (time cycled) & amount suction 
    • Home care, pts. neuromuscular 
    • Iron lung, chest cuirass 
  10. Volume Cycled 
    • Pressure applied to airways until preset volume delivered
    • Min volume constant, airway pressures increases or decrease changes pt compliance & airway resistance
  11. Pressure Cycled 
    • Positive pressure to airways until preset pressure reached. 
    • Tidal volume adjusted increasing or decreasing pressure limit 
    • Peak pressure constant, volume change lung compliance & airway resistance 
    • IPPB, continuous vent pts normal lungs
  12. Time Cycled
    • Positive pressure until preset time reached 
    • PIP limited by adjustable pop off valve 
    • Tidal volume increasing or decreasing PIP, insp time, flow 
    • Infant vent 
  13. Change Ventilator circuits 
    • Circuit grossly contaminated 
    • Malfuctioning
  14. High Pressure Limit Alarm 
    10 above peak airway pressure 
  15. Minimum Exhaled Volume Alarm 
    100 below exhaled tidal volume
  16. Low Pressure Limit Alarm 
    10 below peak airway pressure
  17. Oxygen Alarm
    5 above & below set FiO2
  18. Troubleshooting Low pressure Alarm 
    • Patient disconnect 
    • Leak ventilator circuit 
    • Insufficient flow
    • Endotracheal/Trach tube cuff leak 
  19. Troubleshooting High Pressure Alarm
    • Patient obstruction (ET tube, pnuemothorax) increase Raw secretions
    • Equipment (vent circuit)
  20. Troubleshooting Low Exhaled Volume Alarm
    • Patient disconnect (vent circuit) 
    • Low spontaneous tidal volume. 
  21. Initial Settings Infants 
    PIP 
    RR
    PEEP 
    • PIP       20-30 cmH2O
    • RR        20-30 bpm
    • PEEP     +2-+4 Max 8
  22. Indications for Mechanical Ventilation 
    • Apnea 
    • Acute Ventilatory Failure 
    • Impending vent failure-rising PaCO2
    • Oxygenation
  23. Initial Settings Mechanical Vent 
    Vent Mode ___,____,____,_____
    VT
    RR
    FiO2
    PEEP
    • Vent Mode: Control, A/C, IMV, SIMV
    • VT             8-12 (pick lowest)
    • RR             8-12
    • FiO2           40-60% 
    • PEEP          0-10
  24. Ideal Body Weight Equation 
    • Male:        106+6 over 5 ft
    • Female:     105+5 over 5 ft
  25. Exhaled Tidal Volume Equation 
    Vt= VE /f
  26. Minute Ventilation Equation 
    Vt X f
  27. Alveolar Minute Ventilation Equation 
    VA= (Vt-VD) X f
  28. Static Compliance Equation 
    • Exhaled Volume 
    • Pplat-PEEP
  29. Dynamic Compliance Equation 
    • Exhaled Volume 
    • PIP-PEEP
  30. Increasing Airway Resistance (Raw) on mechanical ventilator 
    • Peak inspiratory pressure (PIP) increases 
    • Plateau pressure (Ppl) remains same 
    • Raw can be estimated (PIP-Ppl)
  31. Common Causes for increasing Raw 
    • Secretions in airway 
    • Bronchospasm 
  32. Treatment for increasing airway resistance
    • Suction 
    • Bronchodilator 
  33. Decreasing lung Compliance (CL) on mechanical ventilator 
    • Peak inspiratory pressure (PIP) increases
    • Plateau pressure (Ppl) increases 
  34. Common causes for decreasing lung compliance 
    • Atelectasis 
    • Pulmonary Edema 
    • ARDS 
    • Pneumonia 
  35. Treatment for decreasing lung compliance 
    • Increase PEEP
    • Treat underlying cause 
  36. What is mean airway pressure (Paw)
    Average pressure transmitted to airway from start breath to beginning of next. 
  37. Assist Mode 
    • Patient initiates breath
    • During IPPB
    • NOT continuous ventialtion
  38. Control Mode 
    • Vent initiated breath at set rate 
    • NOT patient initiated 
  39. Assist/Control Mode 
    • Patient Set RR
    • Vent keeps certain rate 
    • Vent controls tidal volume for every breath 
  40. SIMV Mode 
    • Patient spont breath 
    • Vent gives minimum minute vent 
    • Weaning 
    • COPD to normalize ABG
    • Used instead of A/C reduce barotrauma 
    • Used w/ PEEP to reduce barotrauma 
  41. Pressure Control Ventilation (PCV)
    • Pressure Controlled Breaths
    • ARDS
    • Combined Inverse Ratio 
    • Used for 
    • Pts high FiO2 >60%, PEEP >15
    • High PIP >50
    • Low PaO2 & decrease compliance (ARDS)
    • Exhaled Vt varies, adjust IT or PIP 
  42. Inverse Ratio Ventilation (IRV)
    • Pressure or volume controlled breaths
    • Decreases PIP & PEEP
    • Used 
    • PIP >50
    • High FiO2 >60%, PEEP >15
    • Low PaO2 & decreased compliance 
    • Pts should be paralyzed (Pavulon) & sedated (versed) b/c inverse ratio is uncomfortable & difficult to tolerate
    • Start I:E Ratio 2:1 or greater 
    • Treat: ARDS
  43. Airway Pressure Release Ventilation (APRV)
    • Spont Breath at positive pressure level 
    • Uses lower PIP = lower mean airway pressure 
  44. Primary Controls for High Frequency Ventilation 
    • Rate control/frequency 
    • Amplitude/drive pressure regulator (volume)
    • % inspiratory time (I:E ratio) 
  45. Normalize High PaCO2
    • Deceases or remove deadspace
    • Increase tidal volume 
    • Increase respiratory rate 
  46. Normalize a low PaCO2
    • Increase deadspace 
    • Decrease respiratory rate 
    • Decrease tidal volume 
  47. Increase low PaO2
    • First: increase FiO2 by 5-10% (up to 60%)
    • Then: increases PEEP levels by 2-5 cmH2O
  48. Decrease High PaO2
    • First: decrease FiO2 to less than 0.60
    • Then: decrease PEEP
  49. Expiratory Retard 
    • Similar to purse lip breathing
    • Slows exhalation 
    • Decreases FRC 
    • Used for pts with COPD prevent airway collapse 
    • Does not change I:E Ratio or lengthen exp time. 
  50. Adjust Inspiratory Plateau (Inflation Hold) 
    • Inspiration held at end of breath for short time (0-2 sec)
    • Extends total inspiratory time, decreases time for exhalation, increases mean airway pressure. 
    • Increases diffusion gases & decreases microatelectasis 
  51. Best position for patient on mechanical ventilator 
    • Initially placed in supine position. 
    • Low or semi fowlers used for later, best positions
  52. What Happens when PEEP/CPAP is high?
    • PaO2 decreases 
    • Static compliance decreases 
    • Cardiac output/cardiac index decreases 
    • Hemodynamic pressure increase (PAP,PCWP) 
    • Decreased PVO2, SVO2
  53. How to calculate minimum flowrate 
    Flowrate: (tidal volume x Rate )X (I+E)
  54. Ventilator Protocols for ARDS 
    • Reduce Tidal volume to 6 ml/kg 
    • Keep plateau pressure <30
  55. Air trapping (auto PEEP) how to fix 
    • Increase inspiratory flow 
    • Increase expiratory time
    • Decrease inspiratory time
  56. Assessment for Weaning 
    VT
    VC
    f
    VE
    MIP/NIF
    MEP
    RSBI
    • VT          >5
    • VC          >10 
    • f            8-20
    • VE         <10
    • MIP/NIF  >20
    • MEP       >40
    • RSBI       <100 (RR/VT)
  57. Clinical Measurements for weaning 
    Qs/Qt 
    VD/VT
    • Qs/Qt         <20%
    • VD/VT           <60%
  58. Decreasing Ventilator Settings 
    • First: decrease vent settings 
    • Use IMV/SIMV & turn down man rate 
    • O2 decreased FIO2 set below 60%
    • Once 60% FiO2 reduce PEEP 2-5 at time 
  59. Methods for weaning 
    T-piece trail/ traditional method, trial and error. Patient taken completely off vent 
  60. Adverse conditions 
    • Increase HR >20
    • Change BP 10-20
    • Increases PaCO2 by >10
    • RR increases by >10 or >30
Author
Anonymous
ID
198320
Card Set
Mechanical Ventilation
Description
Respiratory Therapy
Updated