weaning modes and protocol
Skip this Video
Download Presentation
Weaning Modes and Protocol

Loading in 2 Seconds...

play fullscreen
1 / 62

Weaning Modes and Protocol - PowerPoint PPT Presentation

  • Uploaded on

Weaning Modes and Protocol. Causes of Ventilator Dependence Assessment for Discontinuation Trial Spontaneous Breathing Trial (SBT) Extubation Criteria Failure of SBT Weaning Modes Weaning Protocols Role of Tracheostomy Long-term Facilities. Stages of Mechanical Ventilation. 2.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Weaning Modes and Protocol' - hayfa-brewer

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Causes of Ventilator Dependence
  • Assessment for Discontinuation Trial
  • Spontaneous Breathing Trial (SBT)
    • Extubation Criteria
  • Failure of SBT
  • Weaning Modes
  • Weaning Protocols
  • Role of Tracheostomy
  • Long-term Facilities
causes of ventilator dependence
Causes of Ventilator Dependence

Who is the “ventilator dependent’?

  • Mechanical ventilation > 24 h


  • Failure to respond during discontinuation attemps
assessment for discontinuation trial
Assessment for Discontinuation Trial

Criteria for discontinuation trial:

  • Evidence for some reversal of the underlying cause for respiratory failure
  • Adequate oxygenation and pH
  • Hemodynamic stability; and
  • The capability to initiate an inspiratory effort
Assessment for Discontinuation Trial

Extubation failure

  • 8-fold higher odds ratio for nosocomial pneumonia
  • 6-fold to 12-fold increased mortality risk
  • Reported reintubation rates range from 4 to 23% for different ICU populations
Assessment for Discontinuation Trial

Criteria Used in Weaning/Discontinuation in different studies

Assessment for Discontinuation Trial

Measurements used To Predict the Outcome of a Ventilator Discontinuation Effort in More Than One Study

Spontaneous Breathing Trial
  • Formal discontinuation assessments should be performed during spontaneous breathing
  • An initial brief period of spontaneous breathing can be used to assess the capability of continuing onto a formal SBT.
Spontaneous Breathing Trial
  • How to assess patient tolerance?
    • the respiratory pattern
    • the adequacy of gas exchange
    • hemodynamic stability, and
    • subjective comfort.
criteria used in several large trials to define tolerance of an sbt
Spontaneous Breathing TrialCriteria Used in Several Large Trials To Define Tolerance of an SBT*

*HR heart rate; Spo2 hemoglobin oxygen saturation.

Spontaneous Breathing Trial
  • The tolerance of SBTs lasting 30 to 120 min should prompt consideration for permanent ventilator discontinuation
Frequency of Tolerating an SBT in Selected Patients and Rate of Permanent Ventilator DiscontinuationFollowing a Successful SBT*

Spontaneous Breathing Trial

*Values given as No. (%). Pts patients.

†30-min SBT.

‡120-min SBT.

weaning to exhaustion
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
Rest 24 hrs

PaO2/FiO2 ≥ 200 mm Hg

PEEP ≤ 5 cm H2O

Intact airway reflexes

No need for continuous infusions of vasopressors or inotrops

> 100



Stable Support Strategy


Daily SBT

24 hours

30-120 min

RR > 35/min

Spo2 < 90%

HR > 140/min

Sustained 20% increase in HR

SBP > 180 mm Hg, DBP > 90 mm Hg






Mechanical Ventilation

Low level CPAP (5 cm H2O),

Low levels of pressure support (5 to 7 cm H2O)

“T-piece” breathing

Extubation Criteria
  • Ability to protect upper airway
    • Effective cough
    • Alertness
  • Improving clinical condition
  • Adequate lumen of trachea and larynx
    • “Leak test” to identify patients who are at risk for post-extubation stridor
post extubation stridor
Post Extubation Stridor

Extubation Criteria

  • The Cuff leak test during MV:
    • Set a tidal Volume 10-12 ml/kg
    • Measure the expired tidal volume
    • Deflated the cuff
    • Remeasure expired tidal volume (average of 4-6 breaths)
    • The difference in the tidal volumes with the cuff inflated and deflated is the leak
  • A value of 130ml  85% sensitivity

95% specificity

post extubation stridor1
Post Extubation Stridor

Extubation Criteria

  • Cough / Leak test in spontaneous breathing
    • Tracheal cuff is deflated and monitored for the first 30 seconds for cough.
    • Only cough associated with respiratory gurgling (heard without a stethoscope and related to secretions) is taken into account.
    • The tube is then obstructed with a finger while the patient continues to breath.
    • The ability to breathe around the tube is assessed by the auscultation of a respiratory flow.
Extubation Criteria
  • The risk of postextubation upper airway obstruction increases with
    • the duration of mechanical ventilation
    • female gender
    • trauma, and
    • Repeated or traumatic intubation
failure of sbt
Failure of SBT
  • Correct reversible causes for failure
    • adequacy of pain control
    • the appropriateness of sedation
    • fluid status
    • bronchodilator needs
    • the control of myocardial ischemia, and
    • the presence of other disease processes
  • Subsequent SBTs should be performed every 24 h
Failure of SBT
  • Left Heart Failure:
    • Increased metabolic demands
    • Increases in venous return and pulmonary edema
  • Appropriate management of cardiovascular status is necessary before weaning will be successful
Failure of SBT

Factors affecting ventilator demands

Failure of SBT

Therapeutic measures to enhance weaning progress

weaning modes
Weaning Modes
  • Patients receiving mechanical ventilation for respiratory failure who fail an SBT should receive a stable, nonfatiguing, comfortable form of ventilatory support
weaning modes1
Weaning Modes

Modes of Partial Ventilator Support

*SIMV synchronized intermittent mandatory ventilation; PSV pressure support ventilation; VS volume support; VAPS(PA) volume assured pressure support (pressure augmentation); MMV mandatory minute ventilation; APRV airway pressure release ventilation.

weaning modes2
Weaning Modes

PSV: Pressure Support

  • Gradual decrease in the level of PSV on regular basis (hours or days) to minimum level of 5-8 cm H2O
  • PSV that prevents activation of accessory muscles
  • Once the patient is capable of maintaining the target ventilatory pattern and gas exchange at this level, MV is discontinued
weaning modes3
Weaning Modes

SIMV: synchronized intermittent mandatory ventilation

  • Gradual decrease in mandatory breaths
  • It may be applied with PSV
  • Has the worst weaning outcomes in clinical trials
  • Its use is not recommended
weaning modes4
Weaning Modes

New Modes

  • VS, Volume support
  • Automode
  • MMV, mandatory minute ventilation
  • ATC, automatic tube compensation
  • ASV, adaptive support ventilation
weaning protocols
Weaning Protocols
  • With the assisted modes, to achieve patient comfort and minimize imposed loads, we should consider:
    • sensitive/responsive ventilator-triggering systems
    • applied PEEP in the presence of a triggering threshold load from auto-PEEP
    • flow patterns matched to patient demand, and
    • appropriate ventilator cycling to avoid air trapping are all important to
weaning protocols1
Weaning Protocols
  • Weaning protocols
    • Developed by multidisciplinary team
    • Implemented by respiratory therapists and nurses to make clinical decisions
    • Results in shorter weaning times and shorter length of mechanical ventilation than physician-directed weaning
  • Sedation protocols should be developed and implemented
role of tracheotomy
Role of Tracheotomy
  • Candidates for early tracheotomy:
    • High levels of sedation
    • Marginal respiratory mechanics
    • Psychological benefit
    • Mobility may assist physical therapy efforts.
role of tracheotomy1
Role of Tracheotomy
  • The benefits of tracheotomy include:
    • improved patient comfort
    • more effective airway suctioning
    • decreased airway resistance
    • enhanced patient mobility
    • increased opportunities for articulated speech
    • ability to eat orally, and
    • more secure airway
role of tracheotomy2
Role of Tracheotomy
  • Concerns:
    • Risk associated with the procedure
    • Long term airway injury
    • Costs
long term facilities
Long-term Facilities
  • Unless there is evidence for clearly irreversible disease (e.g., high spinal cord injury or advanced amyotrophic lateral sclerosis), a patient requiring prolonged mechanical ventilatory (PMV) support for respiratory failure should not be considered permanently ventilator-dependent until 3 months of weaning attempts have failed.
long term facilities1
Long-term Facilities
  • Critical-care practitioners should familiarize themselves with specialized facilities in managing patients who require prolonged mechanical ventilation
  • Patients who failed ventilator discontinuation attempts in the ICU should be transferred to those facilities
long term facilities2
Long-term Facilities
  • Weaning strategies in the PMV patient should be slow-paced and should include gradually lengthening SBTs
  • Psychological support and careful avoidance of unnecessary muscle overload is important for these types of patients
  • 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
readiness to wean
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)
oxygenation status
Oxygenation Status
  • PaO2≥ 60 mm Hg
  • FiO2 ≤ 0.40
  • PEEP ≤ 5 cm H2O
ventilation status
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
  • Functional respiratory muscles
intact airway protective mechanism
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
function of other organ systems
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
maximal inspiratory pressure
Maximal Inspiratory Pressure
  • Pmax: Excellent negative predictive value if less than –20 (in one study 100% failure to wean at this value)

An acceptable Pmax however has a poor positive predictive value (40% failure to wean in this study with a Pmax more than –20)

frequency volume ratio
Frequency/Volume Ratio
  • Index of rapid and shallow breathing RR/Vt
  • Single study results:
    • RR/Vt>105 95% wean attempts unsuccessful
    • RR/Vt<105 80% successful
  • One of the most predictive bedside parameters.
Measurements Performed Either While Patient Was Receiving Ventilatory Support or During a BriefPeriod of Spontaneous Breathing That Have Been Shown to Have Statistically Significant LRs To Predict theOutcome of a Ventilator Discontinuation Effort in More Than One Study*
weaning to exhaustion1
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
work of breathing
  • Pressure= Volume/compliance+ flow X resistance
  • High airway resistance
  • Low compliance
  • Aerosolized bronchodilators, bronchial hygiene and normalized fluid balance assist in normalizing compliance, resistance and work-of-breathing
auto peep
  • Increases the pressure gradient needed to inspire
  • Use of CPAP is needed to balance alveolar pressure with the ventilator circuit pressure
  • Start at 5 cm H2O, adjust to decrease patient stress
  • Inspiratory changes in esophageal pressure can be used to titrate CPAP


Auto PEEP +10






Auto PEEP +10



three methods for gradually withdrawing ventilator support
Three Methods for Gradually Withdrawing Ventilator Support

Although the majority of patients do not require gradual withdrawal of ventilation, those that do tend to do better with graded pressure supported weaning than with abrupt transitions from Assist/Control to CPAP or with SIMV used with only minimal pressure support.