Updates in weaning from Mechanical Ventilation

2. Weaning form Mechanical
ventilation: Recent Updates
Gamal Rabie Agmy, MD, FCCP
Professor of Chest Diseases , Assiut University

4. Definition of Weaning
The transition process from
total ventilatory support
to spontaneous breathing.
This period may take many forms
ranging from abrupt withdrawal to
gradual withdrawal from ventilatory
support.
Gamal Agmy

5. • 75% of mechanically ventilated patients
are easy to be weaned off the ventilator
with simple process
• 10-15% of patients require a use of a
weaning protocol over a 24-72 hours
• 5-10% require a gradual weaning over
longer time
• 1% of patients become chronically
dependent on MV
Gamal Agmy

6. • Simple weaning (group 1) includes
patients who succeed the first weaning trial
and are extubated without difficulty
• Difficult weaning (group 2) includes
patients who fail the first weaning trial and
require up to 3 spontaneous breathing
trials or 7 days to achieve successful
weaning, and
• Prolonged weaning (group 3)
includes patients who require more than 7
days of weaning after the first weaning
trial. Gamal Agmy

7. Readiness To Wean
• Improvement of respiratory failure
• Absence of major organ system failure
• Appropriate level of oxygenation
• Adequate ventilatory status
• Intact airway protective mechanism
(needed for extubation)
Gamal Agmy

8. Oxygenation Status
• PaO2 ≥ 60 mm Hg
• FiO2 ≤ 0.40
• PEEP ≤ 5 cm H2O
Gamal Agmy

9. Ventilation Status
• Intact ventilatory drive: ability to control
their own level of ventilation
• Respiratory rate < 30
• Minute ventilation of < 12 L to maintain
PaCO2 in normal range
• VD/VT < 60%
• Functional respiratory muscles
Gamal Agmy

10. Intact Airway Protective Mechanism
• Appropriate level of consciousness
• Cooperation
• Intact cough reflex
• Intact gag reflex
• Functional respiratory muscles with ability
to support a strong and effective cough
Gamal Agmy

11. Function of Other Organ Systems
• Optimized cardiovascular function
– Arrhythmias
– Fluid overload
– Myocardial contractility
• Body temperature
– 1◦ degree increases CO2 production and O2
consumption by 5%
• Normal electrolytes
– Potassium, magnesium, phosphate and calcium
• Adequate nutritional status
– Under- or over-feeding
• Optimized renal, Acid-base, liver and GI functions
Gamal Agmy

12. • Several indexes have been employed to assess the
patient's ability to recover spontaneous breathing.
• Variables such as minute ventilation (Ve), maximum
inspiratory pressure (PImax), breathing frequency,
rapid shallow breathing index (RSBI, i.e., respiratory
frequency/tidal volume), tracheal airway occlusion
pressure 0.1 s (P 0.1), P0.1/ PImax >0.3,
P0.1Xf/VT<300 , a combined index named CROP
(compliance, rate, O2, pressure index) >13, IWI>25
and CORE >8 have been used in common clinical
practice
Predictors of Weaning Outcome
Gamal Agmy

13. • P0.1/PImax > 0.3
— P0.1 is pressure at the airway opening
0.1 s after start of inspiratory flow
— Correlates with central respiratory drive
• P0.1 x f/VT <300
• CROP index (dynamic compliance,
respiratory rate, oxygenation, maximum
inspiratory pressure index) >13
— Cdyn x PImax x (PaO2/PAO2)/f
— >13 good
— Cdyn = dynamic compliance
Gamal Agmy

14. • IWI (integrative weaning index) >25
— (CRS x SaO2)/(f/VT)
— CRS = static compliance of the
respiratory system
• CORE index (dynamic compliance,
oxygenation, rate, effort) >8
— Cdyn x (PImax/P0.1) x (PaO2/PAO2)/f
Gamal Agmy

15. • Among the numerous parameters used
in clinical practice, the rapid shallow
breathing index is one of the most
accurate.
Gamal Agmy

16. Spontaneous Breathing Trials
SBT to assess extubation readiness
– T-piece ,PS 5-8 cm H2O or CPAP 5 cm H2O
– 30-120 minutes trials
– If tolerated, patient can be extubated
SBT as a weaning method
– Increasing length of SBT trials
– Periods of rest between trials and at night
Gamal Agmy

17. Daily SBT
<100
Mechanical Ventilation
RR > 35/min
Spo2 < 90%
HR > 140/min
Sustained 20% increase in HR
SBP > 180 mm Hg, DBP > 90 mm Hg
Anxiety
Diaphoresis
30-120 min
PaO2/FiO2 ≥ 200 mm Hg
PEEP ≤ 5 cm H2O
Intact airway reflexes
No need for continuous infusions of vasopressors or inotrops
RSBI
Extubation
No
> 100
Rest 24 hrs
Yes
Stable Support Strategy
Assisted/PSV
24 hours
Low level CPAP (5 cm H2O),
Low levels of pressure support (5 to 7 cm H2O)
“T-piece” breathing
Gamal Agmy

18. Failure to Wean
Weaning to exhaustion
Auto-PEEP
Excessive work of breathing
Poor nutritional status
Overfeeding
Left heart failure
Decreased magnesium and phosphate leves
Infection/fever
Major organ failure
Technical limitation
Gamal Agmy

19. Weaning to Exhaustion
RR > 35/min
Spo2 < 90%
HR > 140/min
Sustained 20% increase in HR
SBP > 180 mm Hg, DBP > 90 mm Hg
Anxiety
Diaphoresis
Gamal Agmy

20. Gamal Agmy

21. First Recommendation
For acutely hospitalized patients
ventilated more than 24 h, we suggest
that the initial SBT be conducted with
inspiratory pressure augmentation (5-
8 cm H2O) rather than without (T-piece
or CPAP)
Gamal Agmy

22. Second Recommendation
For acutely hospitalized patients
ventilated for more than 24 h, we
suggest protocols attempting to
minimize sedation
Gamal Agmy

23. Third Recommendation
For patients at high risk for extubation
failure who have been receiving
mechanical ventilation for more than
24 h and who have passed an SBT, we
recommend extubation to preventive
NIV
Gamal Agmy

24. Third Recommendation
Patients at high risk for failure of
extubation may include those
patients with hypercapnia, COPD,
congestive heart failure, or other
serious comorbidities
Gamal Agmy

25. Noninvasive ventilation as a weaning strategy for
mechanical ventilation in adults with respiratory
failure: a Cochrane systematic review
Karen E.A. Burns et al CMAJ 2014. DOI:10.1503
Noninvasive weaning reduces rates of
death and pneumonia without increasing
the risk of weaning failure or reintubation.
In subgroup analyses, mortality benefits
were significantly greater in patients with
COPD
Gamal Agmy

26. Noninvasive ventilation as a weaning strategy for
mechanical ventilation in adults with respiratory
failure: a Cochrane systematic review
Karen E.A. Burns et al CMAJ 2014. DOI:10.1503
26. Rabie Agmy GM, Metwally MM. Noninvasive ventilation
in the weaning of patients with acute-on-chronic respiratory
failure due to COPD. Egyptian J Chest Dis
Tuberculosis2012;61:84–91
30. Rabie Agmy GM, Mohamed AZ, Mohamed
RN. Noninvasive ventilation in the weaning of patients with
acute-on-chronic respiratory failure due to
COPD. Chest 2004;126(Suppl 4):755.
Gamal Agmy

27. Official ERS/ATS clinical practice
guidelines: noninvasive ventilation
for acute respiratory failure
134-Gamal MR, Ashraf ZM, Rania NM
. Noninvasive ventilation in the weaning of
patients with acute-on-chronic respiratory failure
due to COPD. Chest 2004; 126: Suppl. 4,755S
136-Agmy GM, Metwally MM. Noninvasive
ventilation in the weaning of patients with acute-
on-chronic respiratory failure due to
COPD. Egyptian Chest Dis &TB 2012; 61: 84–91
Gamal Agmy

28. Fourth Recommendation
For acutely hospitalized adults who have
been mechanically ventilated for > 24 h,
we suggest protocolized rehabilitation
directed toward early mobilization
Gamal Agmy

29. Fifth Recommendation
We suggest managing acutely
hospitalized adults who have been
mechanically ventilated for > 24 h with a
ventilator liberation protocol
Gamal Agmy

30. Sixth Recommendation
We suggest performing a CLT in
mechanically ventilated adults who meet
extubation criteria and are deemed high
risk for PES
Gamal Agmy

31. Gamal Agmy

32. Seventh Recommendation
For adults who have failed a CLT but are
otherwise ready for extubation, we
suggest administering systemic steroids
at least 4 h before extubation; a repeated
CLT is not required
Gamal Agmy

33. Diaphragm Ultrasound as a
Novel Guide of Weaning from
Invasive Ventilation
Gamal Agmy , MD , FCCP
Professor of Chest Diseases and respiratory ICU,
Assiut University, Assiut , Egypt

34. Diaphragm Ultrasound as a
Novel Guide of Weaning from
Invasive Ventilation
Gamal Agmy , MD , FCCP
Professor of Chest Diseases and respiratory ICU,
Assiut University, Assiut , Egypt

35. Gamal Agmy

36. • DT was calculated as percentage
from the following formula:
T end-inspiration − T end-expiration
T end-expiration
• It was recorded at total lung
capacity (TLC) and residual volume
(RV).
Gamal Agmy

37. • DT was significantly different between
patients who failed and patients who
succeeded SBT.
• A cutoff value of a DT >40% was
associated with a successful SBT with a
sensitivity of 88%, a specificity of 92%, a
positive predictive value (PPV) of 95%,
and a negative predictive value (NPV) of
82%. Gamal Agmy