MV DISCONTINUATION

1. MV DISCONTINUATION RC 171: UNIT 7

2. Objectives Overview Reasons For Vent Dependance Patient Evaluax Weaning Methods Selecting A Method Pt Monitoring During Weaning Failure To Wean & Terminal Extubation

3. Overview MV should only be applied for as long as it takes to resolve the contributing factors to the respiratory failure Acute - <72 hrs Vent dependant - > 1-2weeks Permanently vent dependant - >3 months failed weaning

4. Overview Sometimes Vent support can be D/C’d while maintaining an artifixl airway MV Discontinuax Weaning Extubax

5. Reasons for Dependance Determinants of Ventilatory workload Level of ventilax needed Metabolic rate, CNS drive Dead space Lung mechanics Compliance Resistance Imposed WOB Artifixl airway & other mechanical factors

6. Reasons for Dependance Demand v. Capability Respiratory Insufficiency = Ventilatory demand > capability Will lead to respiratory failure Inability to reverse causes leading to initiation of MV Ventilax Oxygenax CV function Psychological Other Multi system causes

7. Patient Evaluation T47-1 p1159 Oxygenax Ventilax Ventilax Mechanics Resp muscle strength Ventilatory Demand Other Body Systems Evaluax of Airway

8. Patient Evaluation T47-1 p1159 Oxygenax FiO2 <0.5 PEEP <8 (5) cmH2O PaO2 >60 mmHg SaO2 >90% P(A-a)O2 <350 mmHg PaO2 / FiO2 >150

9. Patient Evaluation T47-1 p1159 Ventilax PaCO2 <50 mmHg pH >7.35

10. Patient Evaluation T47-1 p1159 Ventilatory Mechanics Rate <30 bpm* Vt >5 ml/kg VC >10 ml/kg Clstatic >25 ml/cmH2O RSBI or f/Vt <105 Appearance Weak shallow breathing Respiratory paradox Alternating abdomen & chest wall breathing Grunting, retracting, nasal flaring, accessory muscle use & thoracic cage support

11. Patient Evaluation T47-1 p1159 Respiratory Muscle Strength NIF < -25 mmHg* Ventilatory Drive or Demand Ve <10 l/m

12. Patient Evaluation T47-1 p1159 Other systems Metabolic Adequate Nutrix provided to maintain muscle strength & mass High in proteins Too many carb’s can increase CO2 produx Renal & electrolytes BUN & Cr Urine output, at least 1 l/day Cardiovascular T47-2 p1161 CO & CI Rate & rhythm Blood pressure Syst, Diast, & MAP CVP’s, PA, & Wedge when available Psychological & Neural Stable Ventilatory drive Adequate secrex clearance Airway protex Level of consciousness

13. Patient Evaluation T47-1 p1159 Airway Evaluax Even though ready to d/c MV, may not be ready to extubate Ability to protect airway & remove secrexs Edema or inflammax (swelling) Leak test Deflate cuff, if no swelling is present you should have a significant cuff leak. If severe swelling is present you will observe little or no leak

14. Patient Evaluation T47-1 p1159 Airway Eval Cont’d Stridor Squeaky high pitched wheeze indicating dangerous narrowing of the glottis Treated with Racemic epinephrine 0.5 ml of 2.25% epinephrine in 3ml NS nebulized Cool Aerosol w/ supplemental O2 Dexamethasone (decadron) 1mg in 4 ml NS nebulized Or IV injex

15. I & E Stridor

16. Weaning Methods Spontaneous breating trial SIMV PSV

17. Weaning Methods Spontaneous Breathing Trial (SBT) B47-8 p1165 Placed on T-Tube, Trach collar, Tube comp, or ps 5/peep5 Multiple trials per day of SBT followed by vent support for muscle recovery Initial trial is evaluated after only a few minutes, if pt is ok the trial is extended Subsequent trials are extended until pt is able to stay off vent all day, and rest on vent at noc Eventually vent goes on standby and pt only uses it prn Failed SBT’s require 24 hr vent rest before attempting again Important not to push your pt to the failure point Multiple Short trials are more benefixl than one long trial to failure point Patient types <72 hrs of MV Quickly reversed condition once unsedated (Trauma)

18. Weaning Methods SIMV weaning Involves gradual redux of mechanical rate based on pt assessment 2 methods of SIMV weaning Gradual Begin with full support, reduce Ventilatory support in a stepwise fashion until complete spontaneous breathing is achieved Rebuilds muscle strength and coordinax gradually Abrupt As soon as pt can breathe spontaneously you limit mechanical ventilax to that which is only necessary to make up for the difference b/w the pt capability & their demand In any case SIMV weaning has proven to be inefficient weaning when compared to SBT or PSV

19. Weaning Methods PSV PSV max PS adjusted to provide 8-10 ml/kg (i.e. full support) Once the pt can breathe spontaneously, PS is reduced to minimal levels only to make up for loss of anatomical peep & resistance caused by the artifixl airway (ATC or 5/5)

20. Selecting a Method Method is Patient Dependant Every pt situation is different & may require various variaxs to the three methods of weaning. Each case should be considered & initiated based on the best fit for the scenario Continuous adjustment or switching of methods may be needed as the trials succeed or fail

21. Monitoring During WeaningT47-1 p1159 Same parameters as are used to judge readiness to wean or to initiate MV Oxygenax Ventilax Ventilatory mechanics resp muscle strength Ventilatory drive

22. Failure to Wean / Chronically Dependant when a pt is unable to wean, either because of failure or physical inability, the will be deemed permanently vent dependant failure to wean for >3 months These pt’s will find homes in LTAC Long term acute care Or at home with help of family & home health organizations

23. Terminal Weaning (ETD) Terminal Weaning When a pt is extubated due to catastrophic or irreversible illness Based on medical & family decisions/choice When extubax will surely lead to death w/draw of life support measures