Weaning from mechanical ventilation and extubation by dr tareq

1. Weaning from Mechanical
Ventilation
and
Extubation
Dr. Tareq Rahman,
Resident, Year 4, Neonatology,
Bangabandhu sheikh mujib medical university,
dhaka, Bangladesh.

2. “To know the proper timing and rate of
weaning from the respirator requires
considerable judgment and experience. As a
rule, weaning should start as soon as
possible.”
Bendixin HH, Egbert LD, Hedley- Whyte J, Laver MB, Pontopippidan H. Respiratory care. St. Louis:
Mosby, 1965:149-50

3. Concerning matter
• No weaning protocol is 100% accurate in predicting successful
weaning and extubation
• Clinical judgment and experience play a large role
• In neonates, especially in the preterm population, the highest level
of evidence is lacking and weaning practices remain very physician-
dependent
• Early weaning will-
- Reduce the risk of nosocomial sepsis.
- Reduce ventilator associated complication.
- Reduce hospital stay, morbidity and mortality.
- Reduce patient discomfort.
- Facilitate parental bonding and developmentally appropriate
care.

4. Weaning Definition
• Weaning is the gradual reduction of ventilator
support and the transfer of respiratory control
and the work of breathing back to the patient,
eventually resulting in the discontinuation of
mechanical ventilation.
Wielenga et al 2016, Cochrane Database of Systematic Reviews, (3), [CD011106]. DOI:10.1002/14651858.CD011106.pub2

5. Concept of the weaning
• Weaning too slowly may be more dangerous than
weaning too fast, as it may result in excessive lung injury
and hypocarbia
• Weaning should be attempted throughout the day, not
just during rounds
• When gas exchange is satisfactory and the work of
breathing is not excessive, weaning should be attempted
Goldsmith JP, Karotkin EH, Assisted ventilation of the neonate. 6th edition : Elsevier, 2017

6. When to decide weaning
• Is the process responsible for the patient's respiratory failure
resolving or improving?
• Is the patient hemodynamically stable with no or minimal
vasopressor support?
• Is oxygenation adequate with a PaO2 of greater than 60 mm Hg with
an FiO2of less than 40% and a PEEP of less than 5 cm water?
• Are mental and neuromuscular statuses appropriate with the patient
on minimal or no sedation?
• Does the patient have adequate strength of the respiratory
muscles?
• Are the acid-base status and electrolyte status optimized?
Ryland P Byrd, Jr and Thomas M Roy, 2018, from
https://emedicine.medscape.com/article/304068-overview#a5

7. Weaning strategy
• Assess the weaning readiness
• Setting should be reduced in small increment in every 4-
6 hours:
- PIP: 2-3 cm H2O
- FiO2: 5-10% (Reduce FiO2 to 80% before
changing PIP, I:E or PEEP)
- PEEP: 1 cmH2O
- Rate: 5-10/min
- I time: 0.3-0.4 seconds
• After each change checking blood gases every 30-60
minutes.

8. Weaning mode
• SIMV- most widely used (van Kaam et al 2010; Alander et al
2013).
• SIMV + PS- extubated significantly earlier than infants treated
only with SIMV (Reyes et al 2006).
• PS- alone is less complex and likely to be equally effective,
provided sufficient PEEP to maintain lung volume recruitment
(Sant'Anna and Keszler, 2012).
• Volume targeted ventilation mode may accelerate weaning
from MV (Wheeler et al 2010; Klingenberg et al 2017).

10. Adjunctive therapy during weanig
• Permissive Hypercapnia:
Accepting higher levels of PaCO2 during
ventilation weaning to facilitate earlier extubation.
Randomized clinical trials in preterm infants suggest that
mild permissive hypercapnia is safe (Thome et al 2009).
• Permissive Hypoxemia:
Lower SpO2 targets lead to shorter requirements
for ventilatory support and supplemental oxygen.
Keeping SpO2 between 88% and 93% may be the best
approach (Sant'Anna and Keszler, 2012).

11. • Caffeine : infants assigned to caffeine were
ventilated for a shorter period, received less
continuous positive airway pressure (CPAP)
and oxygen supplementation, and had less
BPD (Schmidt et al 2006). Earlier
administration of caffeine was associated
with faster weaning (Davis et al 2010).

12. • Prophylactic administration of steroids may be helpful to
prevent reintubation rates in high risk neonates (Davis et
al 2001 ).
• Methylxanthine treatment stimulates breathing and
reduces the rate of apnea, increase the chances of
successful extubation of preterm infants (Henderson-
Smart et al 2003 )
• The evidence does not support the routine use of
doxapram to assist endotracheal extubation in preterm
infants eligible for the use of methylxanthine and / or
CPAP ( David et al 2000 )

13. Interventions to Improve Rates of Successful Extubation in Preterm InfantsA
Systematic Review and Meta-analysis
Kristin N. Ferguson, Calum T. Roberts, MBChB, Brett J. Manley, et alPeter G. Davis, MD
JAMA Pediatr. 2017;171(2):165-174. doi:10.1001/jamapediatrics.2016.3015
• Question What evidence-based interventions facilitate successful extubation in preterm infants?
• Findings In this systematic review with 50 studies eligible for inclusion, continuous positive airway pressure was superior to
head-box oxygen but inferior to nasal intermittent positive pressure ventilation and high-flow nasal cannula therapy’s
efficacy was similar to continuous positive airway pressure. Methylxanthines, corticosteroids, and chest physiotherapy
improved extubation success; however, doxapram did not.
• Meaning Preterm infants should be extubated to noninvasive respiratory support, and routinely be given caffeine;
corticosteroids should be used cautiously; and chest physiotherapy should be avoided owing to important adverse effects.
• Abstract
• Importance Clinicians aim to extubate preterm infants as early as possible, to minimize the risks of mechanical ventilation.
Extubation is often unsuccessful owing to lung disease or inadequate respiratory drive.
• Objective To conduct a systematic review and meta-analysis of interventions to improve rates of successful extubation in
preterm infants.
• Data Extraction and Synthesis One thousand three hundred seventy-nine titles were screened independently by 2
investigators to assess need for full-text review. Disagreements were resolved via consensus of all authors. Where no
Cochrane Review existed for an intervention, or not all identified studies were included, a new pooled analysis was
performed.
• Main Outcomes and Measures Primary outcomes were treatment failure or reintubation within 7 days of extubation.
• Results Fifty studies were eligible for inclusion. Continuous positive airway pressure reduced extubation failure in
comparison with head-box oxygen (risk ratio [RR], 0.59; 95% CI, 0.48-0.72; number needed to treat [NNT], 6; 95% CI, 3-9).
Nasal intermittent positive pressure ventilation was superior to continuous positive airway pressure in preventing extubation
failure (RR, 0.70; 95% CI, 0.60-0.81; NNT, 8; 95% CI, 5-13). High-flow nasal cannula therapy and continuous positive airway
pressure had similar efficacy (RR, 1.11; 95% CI, 0.84-1.47). Methylxanthines reduced extubation failure (RR, 0.48; 95% CI,
0.32-0.71; NNT, 4; 95% CI, 2-7) compared with placebo or no treatment. Corticosteroids (RR, 0.18; 95% CI, 0.04-0.97; NNT,
12; 95% CI, 6-100) and chest physiotherapy (RR, 0.32; 95% CI, 0.13-0.82; NNT, 15; 95% CI, 7-50) both reduced extubation
failure rates but were associated with significant adverse effects. Doxapram did not aid successful extubation (RR, 0.80; 95%
CI, 0.22-2.97).
• Conclusions and Relevance Preterm infants should be extubated to noninvasive respiratory support. Caffeine should be
used routinely, while corticosteroids should be used judiciously, weighing up the competing risks of bronchopulmonary
dysplasia and neurodevelopmental harm.

14.  Weaning Success: absence of ventilatory support 48
hours following the extubation (Boles et al 2007). While
the spontaneous breaths are unassisted by mechanical
ventilation but supplemental oxygen, bronchodilators,
pressure support ventilation, or continuous positive
airway pressure may be used to support and maintain
adequate spontaneous ventilation and oxygenation.
 weaning failure is defined as either the failure of
spontaneous breathing trial (SBT) or the need for
reintubation within 48 hours following extubation (Boles
et al 2007).

15.  ↑ Demand of energy:
↑Resistance
↓Compliance
Hypoxemia
Diaphragmatic splinting
 ↓ Supply of energy:
• Hypoxemia
• Anemia
• Electrolyte imbalance
 Accumulation of metabolic end products e.g. lactic acidosis.
Pathophysiology of weaning failure

16. Causes of weaning failure
Increased respiratory load
 Increased elastic load
- Unresolved lung disease
- Secondary pneumonia
- Left to right shunt (PDA)
- Abdominal distension
- Hyperinflated lungs
 Increased resistive load
- Thick/copious airway secretions
- Narrow/occluded endotracheal tube
- Upper airway obstruction
 Increased minute ventilation
- Pain and irritability
- Sepsis/hyperthermia
- Metabolic acidosis
Goldsmith JP, Karotkin EH, Assisted ventilation of
the neonate. 6th edition : Elsevier, 2017
Decreased respiratory capacity
 Decreased respiratory drive
- Sedation
- CNS infection
- PVH/PVL
- Hypocapnoea/alkalosis
 Muscular dysfunction
- Muscular catabolism and weakness
(malnutrition)
- Severe electrolyte disturbances
- Chronic pulmonary hyperinflation
(BPD)
 Neuromuscular disorders
- Diaphragmatic dysfunction
- Prolonged neuromuscular blockage
- Myotonic dystrophy
- Cervical spinal injury

17. Approaches to Assessment of
Extubation Readiness
 Respiratory Physiology
- Lung mechanics (compliance, resistance, tidal volume, etc.)
- Lung volume (chest radiograph, functional residual capacity, etc.)
- Pressure–time index
- Minute ventilation test
 Clinical Tests
- Spontaneous breathing trials
 Analysis of the Dynamics of Biological Signals
- Heart rate variability
- Respiratory variability
- Cardiorespiratory coupling and variability
Goldsmith JP, Karotkin EH, Assisted ventilation of the neonate. 6th edition.:Elsevier, 2017

18. Extubation Readiness Test
• Minute ventilation test led to a shorter
time on a ventilator (Gillespie et al 2003).
• Spontaneous breathing test
demonstrated fewer extubation failures
(Kamlin et al 2006)

19. Assessment During Spontaneous
Breathing Trial
Objective Parameters
• Adequate gas exchange
• Hemodynamic stability
• Stable ventilatory status
Subjective Clinical Evaluation
• Changes in mental state
• Progression or
deterioration of ventilatory
distress
• Signs of increased work of
breathing

20. Respiratory Mechanics for extubation readiness
Shalish W, et al. Arch Dis Child Fetal Neonatal Ed 2018;0:F1–F9.

24. • Total respiratory compliance (Crs, derived
from VT/PIP-PEEP) ≤ 0.9 mL/cm H2O was
associated with extubation failure, whereas a
value ≥ 1.3 mL/cm H2O was associated with
extubation success ( Balsan et al 1990 )

25. Ventilatory Settings for extubation
 Conventional Ventilation (AC, SIMV, PSV)
• SIMV: PIP ≤16 cm H2O, PEEP ≤6 cm H2O, rate ≤20, FiO2 ≤0.30
• AC/PSV, BW <1000 g: MAP ≤7 cm H2O and FiO2 ≤0.30
• AC/PSV, BW >1000 g: MAP ≤8 cm H2O and FiO2 ≤0.30
 Volume Ventilation
Tidal volume ≤4.0 mL/kg (5 mL/kg if <700 g or >2 weeks of age) and FiO2
≤0.30
 High-Frequency Oscillatory Ventilation
• BW <1000 g: MAP ≤8 cm H2O and FiO2 ≤0.30
• BW >1000 g: MAP ≤9 cm H2O and FiO2 ≤0.30
 High-Frequency Jet Ventilation
• BW <1000 g: PIP ≤14 cm H2O, MAP ≤7 cm H2O, and FiO2 ≤0.30
• BW >1000 g: PIP ≤16 cm H2O, MAP ≤8 cm H2O, and FiO2 ≤0.30
Goldsmith JP, Karotkin EH, Assisted ventilation of the neonate. 6th edition.:Elsevier, 2017

26. ABG criteria for extubation
• PO2: 50-70mmHg (arterial only)
• PCO2: 45- 55 mmHg
• pH: > 7.25
• HCO3 : > than 17.5 mmol/l
• BD: no lower than -6
• BE: no higher than + 6
• Lactate: < 2 mmol/l
Neonatal practice guideline 2015, Winnipeg Regional Health, Manitoba, Canada.

27. • International survey on periextubation practices in extremely preterm
infants
• H Al-Mandari, W Shalish, E Dempsey, M Keszler, P G Davis, G Sant'Anna
• Objective To determine periextubation practices in extremely preterm infants (<28 weeks gestation).
• Design A survey consisting of 13 questions related to weaning from mechanical ventilation, assessment of
extubation readiness and postextubation respiratory support was developed and sent to clinical directors
of level III NICUs in Australia, Canada, Ireland, New Zealand and USA. A descriptive analysis of the results
was performed.
• Results 112/162 (69%) units responded; 36% reported having a guideline (31%) or written protocol (5%)
for ventilator weaning. Extubation readiness was assessed based on ventilatory settings (98%), blood
gases (92%) and the presence of clinical stability (86%). Only 54% ensured that infants received caffeine
≤24 h prior to extubation. 16% of units systematically extubated infants on the premise that they passed a
Spontaneous Breathing Test with a duration ranging from 3 min (25%) to more than 10 min (35%). Nasal
continuous positive airway pressure was the most common type of respiratory support used (84%)
followed by nasal intermittent positive pressure ventilation (55%) and high-flow nasal cannula (33%).
Reintubation was mainly based on clinical judgement of the responsible physician (88%). There was a lack
of consensus on the time frame for definition of extubation failure (EF), the majority proposing a period
between 24 and 72 h; 43% believed that EF is an independent risk factor for increased mortality and
morbidity.
• Conclusions Periextubation practices vary considerably; decisions are frequently physician dependent and
not evidence based. The definition of EF is variable and well-defined criteria for reintubation are rarely
used. High-quality trials are required to inform guidelines and standardise periextubation practices.

28. Extubation Procedure
 Two person procedure
1. Apply transcutaneous monitoring and allow to stabilise before extubation.
2. Ensure that an individual skilled in intubation is readily available before proceeding.
3. Not given the feed scheduled immediately before extubation or is NPO for 1 hour.
Ensure the stomach is empty by passing a gastric catheter. Suction any milk.
4. Check if the neonate has had or requires adjunctive therapy.
5. Ensure nCPAP or nasal cannula is set-up if required.
6. Place infant in supine position. Head midline.
7. Suction ETT, oropharynx, and nares.
8. Using adhesive remover, remove tape.
9. Using manual ventilation give the infant a inspiration.
10. Withdraw the endotracheal tube smoothly.
11. If nCPAP required, apply promptly and secure.
12. Suction the oro-nasopharynx as needed.
13. If plan is not to extubate to nCPAP and oxygen required, apply nasal cannula with low
flow O2.
14. Observe the infant for increased signs of respiratory distress.
15.Measure and record a blood gas one hour post extubation or as ordered.
Ref: Neonatal Policy & Procedures Manual 2016, Convenant Health, Albetra, Canada

29. Key Elements of Postextubation
Management
Respiratory Support
• Continuous positive airway
pressure
• Nasal intermittent positive-
pressure ventilation
• Heated humidified high-
flow nasal cannula
Adjunctive Therapies
• Caffeine
• Racemic epinephrine
• Chronic diuretics
• Chest physiotherapy
• Inhaled and/or systemic
steroids

30. Post extubation Noninvasive Respiratory
Support
• Infants extubated to nasal intermittent
positive pressure ventilation (NIPPV) were
less likely to fail extubation than those
infants extubated to nasal continuous
positive airway pressure ventilation
Davis et al,Cochrane Database Syst Rev 2001;(3):CD003212

31. EXTUBATION FAILURE
• In clinical trials, extubation failure has
been defined either by using specific
clinical criteria or by the perceived need
for reintubation. The time frame in various
RCTs has commonly ranged from 24 to 72
hours but occasionally is up to 1 week
after extubation.
Giaccone A, Jensen E, Davis P, et al: Definitions of extubation success in very premature infants:
a systematic review. Arch Dis Child Fetal Neonatal Ed 99(2):F124-F127, 2014.

32. Criteria for reintubation
• Severe apnea requiring positive pressure ventilation.
• Multiple episodes of apnea: >6 within 6 hours.
• Hypoxemia: FiO2 >50% to maintain SpO2 >88%.
• Hypercapnia: PCO2 (partial pressure of carbon
dioxide ) >60 with pH <7.25.
• Excessive work of breathing with severe retractions.
Sant'Anna GM and Keszler M, Weaning infants from mechanical ventilation, Clin Perinatol 39 (2012) 543–562

33. Risk Factors for Extubation
Failure in Neonates
General
• Sedation (narcotics or benzodiazepines)
• Multiple endotracheal intubations
• Difficult or traumatic intubation
• Neurologic or neuromuscular disorder
• Genetic disorders
• Airway abnormalities
• Positive fluid balance
• Acidosis prior to extubation (pH <7.20)
• Hemodynamic instability
• Sepsis and necrotizing enterocolitis

34. Risk Factors for Extubation
Failure in Neonates
Preterm Infants
• Low gestational age (<26 weeks)
• Extremely low birth weight (<1000 g)
• Low current weight
• Male gender
• Intraventricular hemorrhage (grade III and/or IV)
• Hemodynamically unstable patent ductus arteriosus
• Lack of caffeine administration preextubation
• Extubation from high ventilatory settings (FiO2 and rates)
• Inadequate provision of noninvasive respiratory support after extubation
Goldsmith JP, Karotkin EH, Assisted ventilation of the neonate. 6th edition.:Elsevier, 2017

35. Unplanned Extubation
• Definition : Extubation of a patient that was not
immediately planned, i.e. an accidental extubation.
• Prevention :
1. Early recognition that securing method compromised.
2. Hourly inspection of endotracheal tube taping to
ensure it remains securely attached to baby’s face and
endotracheal tube.
3. Prioritise endotracheal tube re-strap if the securing
method is noted to be compromised/loose.
4. When handling an intubated infant at least 2 members
of staff are required, with one staff member supporting
the ventilator tubing and ETT.

36. Clinical Presentation :
• Sudden clinical deterioration with decrease in
heart rate and oxygen saturation.
• Loss of chest wall movement with ventilation.
• Increase in leak noted by ventilator.
• Loss of end tidal CO2 detection.
• Loss of air entry sounds on auscultation.
• Audible cry.

37.  Management of unplanned extubation :
1. Emergenc condition and commence airway support.
2. Stop continuous milk feeds if these are running. Aspirate gastric contents
3. Medical staff to promptly attend to manage.
4. Confirm unplanned extubation (consider use of CO2 detector or visual inspection with
laryngoscope).
5. Remove endotracheal tube and gastric tube. Be careful of removing existing tape; use
adhesive remover as required.
6. Assess ventilation status and provide CPAP, or mask IPPV if required.
7. Ensure continuous ECG and Saturation monitoring.
8. Re-intubate if required, secure endotracheal tube, replace gastric tube and
decompress stomach.
9. Chest X-ray to confirm endotracheal tube location/position.
Brian K. Walsh, Neonatal and Pediatric Respiratory Care, 5th edition: Saunders Elsevier; 2018
Neonatal Directorate Management Committee 2017, Government of western australia north metropolitan health service,