Weaning from Mechanical ventilation .pdf

Ppt

1. Mechanical Ventilation
Weaning Strategies
Dr. Lenora Fernandez, FPCCP, MS
Professor, UP College of Medicine
Chief, Division of Pulmonary Medicine, UP-PGH

2. Objective:
•To enhance knowledge in weaning support from mechanical
ventilation.

3. WHAT IS YOUR WEANING TRIAL STYLE?
A.SBT, PS 5
B.SBT, PS 8
C.SBT, Tpiece
D.SIMV
E.Outright extubation
F.None of the above
Mentimeter code 47211139
https://www.menti.com/alkkprz6ymueMentimeter code 47211139

4. What is weaning?
Weaning covers the entire process of liberating the patient
from mechanical support and from the endotracheal tube,
including relevant aspects of terminal care.
Boles et al. Eur Respir J 2007; 29: 1033–1056
(ICC on ICM)
McConville & Kress. N EnglJ Med 2012;367:2233-9.
•As a rule, weaning should start as soon as possible.

5. 7 STAGES OF WEANING
no attempt at weaning
is desirable
the time when a physician
begins to think that the patient
might be ready come off the
ventilator; weaning readiness
the time of measuring and
interpreting weaning predictors
time of decreasing
ventilator support
(abruptly or gradually)
Failure to appreciate stage 2 (suspicion/weaning readiness)
probably leads to the greatest delays in weaning
Tobin M. Principles & Practice of Mech Vent, 3rd ed. 2012.
1
2
3
4
5
6
7

6. Delayed Weaning
INCREASE
Risk of
Complications
INCREASE
Cost of Care
MORTALITY
PROLONGED MECHANICAL
VENTILATION
INFECTIONS
$42,784 vs $13,0052
Definition:
> 21 days1
AIRWAY TRAUMA
TRACHEOSTOM
Y
Boles et al. Eur Respir J 2007; 29: 1033–1056
McConville & Kress. N EnglJ Med 2012;367:2233-9.

7. Pham et al. Lancet Respir Med 2023; 11: 465–76
n = 5869 (from 10,232 screened); 2017-2018; 50 countries, 481 ICU centers. Included
tracheostomized pts (19.6% throughout)
5869 intubated
•4% transferred before any attempt
•28% died wile on MV
77% underwent
> 1 extubation attempt (4523)
•2.6% transferred
after 1 attempt & not successfully weaned
65% (3817)
successfully weaned
Weaning success:
Extubated without
death or trach without
vent within next 7
days

8. Pham et al. Lancet Respir Med 2023; 11: 465–76
3654 extubated
13.7%
reintubated
29.5% died in ICU
Reintubation Implication

9. Stage 1:
Readiness Testing DAILY
Who are ready to wean?
Who are NOT ready to wean?
1

10. Stage 2
Review: Criteria for Readiness Testing
Evidence-based guidelines for weaning and discontinuing ventilatory
support, ACCP 2001
REQUIRED CRITERIA
1. The cause of the respiratory failure has improved
2. PaO2/FiO2 ≥150 or SpO2 ≥90% on FiO2 ≤40 % and PEEP ≤5 cmH2O
3. pH >7.25
4. Hemodynamic stability (no or low dose vasopressor medications)
5. Able to initiate an inspiratory effort
OPTIONAL CRITERIA
1. Hemoglobin ≥7 mg/dL
2. Core temperature ≤38 to 38.5°C
3. Mental status awake and alert or easily arousable
MacIntyre et al. Chest 2001; 120:375S.
2

11. ERS Task Force on Weaning from Mechanical
Ventilation, 2007: Assessing Readiness to Wean
Boles et al. Eur Respir J 2007; 29: 1033–1056

12. Stage 3
Weaning Predictors:
•Identify all patients ready to breathe independently
•Safe and easy to perform
•Highly reproducible
•Not subject to confounding influences
•Uses equipment and techniques that are routinely available
3

13. Weaning Predictors
Measurement of O2
and gas ExchangePF ratioPOOR weaning
predictor
Measurements of
load on the
respiratory system
Minute Vent
5-6L/min
Compliance
N: 60-100WOB
POORINCONSISTENTNOT UNIVERSAL
Measurements of
respiratory muscle
capacity
NIF – 30 cm H20 or lessPOOR weaning
predictorif normal à no increase in success;
if reduced à probability of weaning failure
POOR weaning
predictor
Diaphragmatic Ultrasound
Combine with RSBI
CAN help
predict weaning
outcome
Modified from slide of Dr. Barbon

14. Composite/
Integrative
Indices
Weaning Predictors
•RSBI (f/Vt ratio)
•CROP Index
•P0.1/Pmax
•Simplified Weaning
Index
CROP Index:
•Compliance, Rate, Oxygenation, Pressure
•considers respiratory system's requirements
& respiratory muscles' ability to meet such
needs
•CROP >13mL/breath per min àeffective
weaning
•= Cdyn ×MIP ×(PaO2/PAO2)]/f
Cdyn = dynamic compliance
MIP = maximal negative pressure recorded during a
20-s occlusion of the airway
SWI= [f (PIP−PEEP)/MIP] ×[PaCO2/40] (> 9 à
effective weaningElewet al. The Egyptian Journal of
Hospital Medicine (April 2022)
Vol. 87, Page 1000-1005

15. Weaning
Indices
Elewet al. The Egyptian Journal of
Hospital Medicine (April 2022)
Vol. 87, Page 1000-1005
3.0-6.0 cm H2O

16. Weaning Predictors: Integrative Indices
•Most extensively studied and commonly used weaning predictor
•(f/VT)
•Measurement:
•Breathing room air x 1 minute without any ventilator assistance and measured using a hand held spirometer
•RSBI >105 breaths/min/L
•97% Sn, 64% Sp, PPV 78%, NPV 95%
•LR+ 1.66 to 2.1 and LR – 0.11
•Clinical Outcomes
•Not been shown to decrease duration of weaning or MV
RSBI
HIGH LOW
MODERA
TE
inc in
weaning
failure
Small
increase
in
probability
of
weaning
>105<105
Elewet al. The Egyptian Journal of
Hospital Medicine (April 2022)
Vol. 87, Page 1000-1005

17. Weaning Predictors: Integrative Indices
•Measuring while on MV (low PSV, CPAP or T piece):
•Values will be lower than during independent breathing
•MV settings: PS 0 PEEP 0
•Measuring respiratory frequency
•If on MV: may not be able to count untriggered breaths; “illogical if with PS” (Tobin)
•Ideally: handheld spirometer
•Other factors affecting RSBI:
•narrow endotracheal tube, female gender, sepsis, fever, supine position, anxiety, suctioning, and chronic restrictive lung disease
RSBI
HIGH LOW
STOPGO
>105<105
Elewet al. The Egyptian Journal of
Hospital Medicine (April 2022)
Vol. 87, Page 1000-1005

18. Do we need weaning predictors?
•N = 304
•The group that used clinical
criteria alone took ONE DAY
LESS to discontinue
mechanical ventilation.
•There was NO DIFFERENCE
in MV, LOS, or reintubation
rate.
•N = 336
•No weaning predictors were
measured
•Those who passed the screen
(adequate O2, hemodynamic
stability, spont inspiratory effort)
will undergo SBT
•>50% of patients tolerated SBT

19. Stage 4: Weaning Trials4
SBT with PS (5-8 cm H2O) vs without
Conditional Recommendation, Moderate-Quality Evidence
Remarks: This recommendation relates to how to
conduct initial SBT but does not inform how to
ventilate patients between unsuccessful SBTs.
Ouellette et al. ACCP/ATS CPG on
Liberation from MV. CHEST 2017;
151(1):166-180
Spontaneous Breathing Trial
•Daily use of SBT’s is safe and reduces time to extubationvs gradually
wean ventilator support.
•SBT with pressure augmentation vs without:
oMore successful (84.6% vs 76.7%; RR, 1.11)
oExtubationsuccess (75.4% vs 68.9%; RR, 1.09; 95%)
oTrendtoward lower ICU mortality (8.6% vs 11.6%; RR, 0.74)

20. McConville & Kress. N EnglJ Med 2012;367:2233-9.
Stage 4: Weaning Trials4
SBT:
•Switched to pressure support,
CPAP (5 cm PEEP) or T-piece
(zero PEEP) x at least 30 mins
•initiated while patient is awake &
not receiving sedative infusions
•PASS if NONE of the ff:
•RR > 35 breaths/minute for > 5
minutes
•SpO2 < 90%
•HR > 140, change in HR >
20%
•SBP > 180 or < 90 mmHg
•increased anxiety, or diaphoresis

21. VARIATIONS IN THE SBT

22. Do you shift first to SIMV before doing your
weaning trial?
A.Yes
B.No
C.Sometimes
Mentimeter code 47211139

23. Mode Method Advantages Disadvantages
SIMV • start 50- 80% of AC rate
• ¯mandatory breaths by
decrements of 2-4 bpm,
endpoint rate 4-6 bpm
• guaranteed
minimum no. of
mandatory breaths
• can still have
dysynchrony
• early patient
loading
PS • start at PS level to keep
RR<25-30/min
• ¯PS level by 2-4cmH2O,
endpoint 5-8 cmH2O
• patient synchrony
• gradual loading at
start of wean
• PS endpoint
variable (consider
ETT diameter and
length)
CPAP • 3-7cmH2O pressure
• single trial or multiple
trials of ­ duration,
endpoint 2 hrs.
• maintain higher
FRC
• can continue to
monitor inhaled
and exhaled vols.
• abrupt patient
loading (esp. if
pressure
triggered)
T-piece • single trial or multiple
trials of ­ duration,
endpoint 2 hrs.
• few false positive
(weaning success)
• simple set-up
• abrupt patient
loading
• high resistive load
with small ETT


Modes of Weaning from MV
Elewet al. The Egyptian Journal of Hospital Medicine (April 2022) Vol. 87, Page 1000-1005

24. PSV
•PSV vs SIMV vs intermittent T-piece trials
•shorter duration of weaning (5.7 days PSV versus 9.9 days SIMV)
[Brochard, et al].
•PSV was decreased from a mean of 19 cmH2O by 2 or 4 cmH2O per day.
•For those patients who have repeated difficulty tolerating weaning, PSV has also been observed to reduce the duration of mechanical ventilation
Multicenter RCT
N = 456
Interventions:
1.T piece
2.SIMV
3.PSV
•Significantly lower probability of remaining on
mechanical ventilation
•Shorter weaning duration with PSV
•Shorter total length of stay in the intensive care
unit
Use of PSV resulted in significant improvement
compared with using T piece or SIMV
Brochardet al. AJRCCM1994 Oct;150(4):896-903

25. Respiratory muscles never rest on this mode.
CONS OF SIMV (even with PS)
Prolonged
Weaning Period
•1990’s studies:
Brochard & Esteban
Increased WOB
•Marini, 1988
Increased metabolic
expenditure & Neuromuscular output
•El-Khatib, Respiration
2009
•Imsand, 1994
Dyssynchrony
•Robinson, 2013

26. NEWER MODES OF WEANING
•Automatic tube compensation
•better than SBT: Metaanalysis, Yi et al, Frontiers in Medicine 2021
•Adaptive support ventilation
•Proportional assist ventilation
•Network Meta (n=39 trials) Weaning with PAV high probability of being most effective ventilation mode (weaning success, reintubation, mortality rate) vs other ventilation modes.
Jhouet al, Frontiers in Medicine, Oct 2021
•NAVA (Neurallyadjusted ventilatory assist mode)
•Better than partial support modes(Metaanalysis, Yuan et al, Critical Care, June 2021)

27. Automatic Tube Compensation
•a ventilatory method aimed at compensating for the nonlinear pressure drop across the endotracheal tube during spontaneous breathing, is at least as successful as the use of simple T-tube or low-level PS for weaning from mechanical ventilation
•Useful if the ET is narrow
•Lack of controlled trials to make a meaningful recommendation
McConville & Kress. N EnglJ Med 2012;367:2233-9.

28. Adaptive Support Ventilation
•ASV is based on a computer-driven
closed-loop regulation system of the
ventilator settings which is responsive
to changes in both respiratory system
mechanics and spontaneous
breathing efforts
•Set the desired percentage of minute
ventilation
•Has benefit on post cardiac surgery
patients BUT was compared with
SIMV.
SBT in ASV:
•decrease PEEP to 5 cmH2O and lower target
minute volume (%MinVol) setting to reduce
pressure support as needed.
•If PS > 15 cmH2O, lower %MinVolfirst to 70%
and then to 25% to reduce PS gradually to 5-8
cmH2O.Koca. Open Access Text.

29. Neurally adjusted ventilatory assist (NAVA)
“a mode that uses diaphragm electrical activity to control the ventilator”

30. WEANING CATEGORIES:
ICC 2007 (SBT dependent)WIND (Weaning according to a New Definition)
No weaning: never experienced any separation
attempt *
Group 1Simple weaning
successful extubationafter first SBT
(5% mortality)
Shortweaning:
first attempt resulted in termination of weaning
process within 1 day (successful separation or early
death)
Group 2Difficult weaning
successful extubationafter 2-3 SBTs in
< 7 days
Difficultweaning: (intermediate)
weaning completed after > 1 day but in < 1 week
after 1stseparation attempt
Group 3Prolongedweaning
successful extubationafter > 3 SBTs
or by > 7 days (20% mortality)
Prolongedweaning:
Weaning still not terminated 7 days after 1st
separation attempt
* Separation attempt from MV: an SBT with or without extubation, or an extubationdirectly performed without
identified SBT (whatever the type: planned or unplanned extubation)
Beduneauet al. Am J Respir Crit Care Med Vol 195, Iss6, pp 772–783, Mar 15, 2017
Boles et al. Eur Respir J 2007; 29: 1033–1056

31. 1. Weaning definition: WIND criteria
Beduneau, AJRCCM 2017

32. Pham et al. Lancet Respir Med 2023; 11: 465–76
•91.5% met weaning eligibility criteria within first 3 days
•Median time from fulfilling weaning eligibility criteria to first attempt = 1 daybut
median of 5 days
•1013 (22·4%) patients had a delayin initiating first separation of 5 or more days
64.70%10.10%9.60%15.60%
0.00%20.00%40.00%60.00%80.00%100.00%120.00%
Short wean (≤1 day)Intermediate
(2-6 days)
Prolonged
(>7 days)
Weaning
Failure
•Of the 4523 (77·1%) patients with separation attempts:

33. Delayed Initiation of Weaning
Demographic Factors
•Frailty
•Admission for trauma
•Neurologic dx
Critical Illness Severity
•High SOFA score
Modifiable Factors
•Neuromm blocker use
•Moderate-
deep sedation
levels on
Day 1
•Sedation at
time of
weaning readiness
•Cardiac arrest was associated with decreased risk
of delayed initiation
Demographic Factors
•Frailty
•Older age
•Immunocompromised
•Neurologic dx
•Pre-existing limitations of
care
Critical Illness Severity
•High SOFA score
•Cardiac arrest
•Degree of
respiratory dysfunction
(RR, lower PF ratio, hi
driving P & PEEP) on
attempt
Modifiable Factors
•Deep sedation at time of
attempt
•Time interval
from weaning eligibility to
first separation attempt
Weaning Failure
•Chronic cardiac failure dx associated with weaning success
***sedation at time of weaning readiness remained strongly
associated with weaning failure in all sensitivity analyses
Pham et al. Lancet Respir Med 2023; 11: 465–76
FACTORS LEADING TO DELAYED WEANING &
WEANING FAILURE: WEANSAFE 2023

34. LESSONS FROM WEANSAFE 2023
Only 65% of patients on MV
for > 2 days were
successfully weaned.
Delayed initiation of weaning leads
to weaning
failure: longer interval from
meeting weaning
eligibility criteria to 1st separation
attempt.
Moderate to deep sedation
resulted to
delayed weaning initiation &
independently
associated with weaning failure.
Significant patient-level
variations in
weaning practices, esp
SBT use (> 30%
of successfully weaned did not
use SBT).
Pham et al. Lancet Respir Med 2023; 11: 465–76

35. For acutely hospitalized patients ventilated > 24 hours, we
suggest protocols attempting to minimize sedation.
Remarks: There is insufficient evidence to recommend any
protocol over another.
2016 ACCP/ATS Liberation from MV Guideline:
(Conditional recommendation, Low quality of evidence)
Ouellette, et al. (2016). Chest, S0012369216623243–.doi:10.1016/j.chest.2016.10.036

36. McConville & Kress. N EnglJ Med 2012;367:2233-9.
Stage 5: EXTUBATION5

37. If airway can be removed?
Peak cough flow > 160 L/min
Cough velocity 0.5-1.0 L/s

38. “Airway care score”ACS ≤7
Tanwar et al, J Anaesthesiol Clin Pharmacol.2019 Jan-Mar; 35(1): 85–91

40. Cuff Leak Test and Systemic Steroids
•We suggest performing a cuff leak test in mechanically ventilated
adults who meet extubationcriteria and are deemed high risk for
post-extubationstridor.
•For adults who have failed a cuff leak test but are otherwise ready
for extubation, we suggest administering systemic steroids for at
least 4 hours before extubation.
Fan et al. Ann Am ThoracSoc Vol 14, No 3, pp 441–443, Mar 2017
2016/17 ACCP/ATS Liberation from MV Guideline:
(Conditional recommendation, Very low certainty in the evidence)
(Conditional recommendation, Moderate certainty in the evidence)

41. Post Extubation Stridor
The Cuff Leak Test
•The expired tidal volume is measured with
the cuff inflated on Assist Control mode
with a tidal volume of 10-12ml/kg.
•The cuff is then deflated, 4 to 6
consecutive breaths are used to compute
the average value for the expiratory tidal
volume.
•The difference in the tidal volumes with
the cuff inflated and deflated is the leak.
•A value of 130ml (12% of inspiratory tidal
volume) gave a sensitivity of 85% and a
specificity of 95% to identify patients with
an increased risk of post extubation
stridor if leak is absent.
https://emcrit.org/pulmcrit/cuff-leak/

42. MANY CUT-OFFS FOR CUFF LEAK TEST
De Backer D. Critical Care 2005, 9:31-33 (DOI 10.1186/cc3031)
•Audible leak
•Volume loss around cuff >110 ml
(difference between inspired/exhaled volumes)
•Volume loss around cuff >24% tidal volume

43. Stage 6: POST-EXTUBATION
1 3 5 7
2 4 6

44. For patients at high risk for extubationfailure who have been
receiving mechanical ventilation > 24 hours, and who have passed
an SBT, we recommend extubationto preventative NIV.
•Patients at high risk for failure of extubation:
•Hypercapnia
•COPD
•CHF
•other serious co-morbidities
•NIV immediately after extubationto realize the outcome benefits
Ouellette, et al. (2016).. Chest, (), S0012369216623243–.doi:10.1016/j.chest.2016.10.036
(Strong recommendation, moderate quality of evidence)
2016/17 ACCP/ATS Liberation from MV Guideline:

45. NIV VS HFNC VS COT POST-EXTUBATION
•NIV OR HFNC as preventive or prophylactic use post-
extubation in high risk for reintubation and NOT as rescue
Shannon Fernando, Eddy Fan, et al. Intensive Care Medicine, 2022, 48 (2), pp.137-147.
ff10.1007/s00134-021-06581-1ff. ffhal04062606f

46. NIV VS HFNC VS COT POST-EXTUBATION
Shannon Fernando, Eddy Fan, et al. Intensive Care Medicine, 2022, 48 (2), pp.137-147.
ff10.1007/s00134-021-06581-1ff. ffhal04062606f

47. McConville & Kress. N EnglJ Med 2012;367:2233-9.

48. Do you have a standard weaning protocol in
your institution?
A.Yes
B.Yes, but I usually don’t use it J
C.No
Mentimeter code 47211139

49. Ventilator Liberation Protocols
•We suggest acutely hospitalized adults who have been
mechanically ventilated > 24 hours be managed with a ventilator
liberation protocol, rather than no protocol.
Fan et al. Ann Am ThoracSoc Vol 14, No 3, pp 441–443, Mar 2017
(Conditional recommendation, Low certainty in the evidence)
2016/17 ACCP/ATS Liberation from MV Guideline:
Desirable consequences:
•25-hour reduction in MV duration
•1-day reduction in ICU length of stay
•No significant effect on overall mortality or reintubation rates
Remarks.
protocol may be either personnel driven or computer driven.
There is insufficient evidence to recommend any ventilator liberation
protocol over another.

51. Sample: Asian Hospital PROPOSED Assessment

52. AI system predict the optimal timing for mechanical ventilation
weaning for intensive care unit patients: A 2-stage prediction
approach
•N = 5873 cases included for
machine learning modeling
•AUC = 0.843 to 0.953.
•Impact analysis: effectively and
precisely predict the optimal timing
to wean intubated patients
•AI models could shorten patients’
intubation time by 21 hours.
Liu et al. (2022) Front. Med. 9:935366. doi: 10.3389/fmed.2022.935366
Liao et al.Diagnostics2022, 12, 975. https:// doi.org/10.3390/diagnostics12040975

53. EARLY VS LATE TRACHEOSTOMY?
•Teragniet al, JAMA 2010: Early 6-8 days vs late (13-15 days):
early trach not associated with significant decrease in VAP,
ventilator days, ICU days, or mortality.
•Young et al, JAMA 2013: early (within 4 days) vs late (>10 days):
no difference in mortality, ICU length of stay, or adverse events.

54. Weaning styles for tracheostomized pts in
WEANSAFE:
SBT:
•T-tube
•CPAP ≤5 cm H2O or
•PSV: PS ≤7 cm H2O, PEEP ≤5 cm H2O
•Tracheostomy mask oxygenation
Pham et al. Lancet Respir Med 2023; 11: 465–76

55. How will you now do your weaning trial?
Type your answer
Mentimeter code 47211139

56. WEANING BEST PRACTICE:
Issue Best-Practice Description
Daily assessment for liberation potentialConduct at least daily
Criteria might include: evidence of reversal of the underlying
cause of respiratory failure, adequate oxygenation on PEEP
<8 and FiO2 <0.50, hemodynamic stability, and ability to
initiate an inspiratory effort.
SBT (30-120 mins)Once meeting the liberation criteria, SBT should be
conducted before determining whether extubationcan occur.
Generally, the SBT should last 30-120 minutes.
Linking SAT and SBTFollow a sedation protocol.
Conduct the SBT while the patient is undergoing a sedation
awakening trial (SAT).
SBT FailurePlace back on previous settings or a comfortable level of
pressure support and reassess the following day for liberation
potential.https://www.aarc.org/nn19-ventilator-weaning-protocols/

57. Issue Best-Practice Description
Cuff leak test pre-extubationPrior to extubation, in adults who have met extubationcriteria
AND are deemed high risk for post-extubationstridor (PES)
(e.g., traumatic intubation, intubation >6 days, large
endotracheal tube, female, reintubation after an unplanned
extubation), perform a cuff leak test.
If there is insufficient leak (failed test), recommended that
systemic steroids be administered at least 4 hours before
extubation.
A repeat cuff leak test prior to extubationis not required.
Prophylactic NIV post-extubationFor patients ventilated for >24 hours who pass an SBT AND are
at high risk for extubationfailure (e.g., patient with hypercarbia,
COPD, CHF, or other co-morbidities), apply preventive NIV
following extubation.
Recommended to apply NIV immediately after extubationto
realize outcome benefits.
https://www.aarc.org/nn19-ventilator-weaning-protocols/
WEANING BEST PRACTICE:

58. See you in 2024 !