Pulmonary · Topic 7 of 28

Liberation from Mechanical Ventilation

Pulmonary · mechanical ventilation

Liberation from Mechanical Ventilation

Every day: lighten sedation, screen, and run a 30–120-minute breathing trial; decide extubation separately — straight to NIV if high risk.

Key numbers

SBT screen: oxygenation, hemodynamics, effortFiO₂ ≤ 0.5, PEEP ≤ 8

SBT for 30–120 minutes30–120 min

RSBI = respiratory rate ÷ tidal volume (L)RSBI < 105

Failed cuff leak: steroids ≥ 4 h pre-extubationsteroids ≥ 4 h before

01 · Defined bySBT screen: oxygenation, hemodynamics, effort

Screen for an SBT when the cause is reversing, there is no shock, SpO₂ ≥ 90% on FiO₂ ≤ 0.4–0.5 and PEEP ≤ 8 cmH₂O, respiratory rate < 35, and the patient triggers breaths.

02 · DoSBT for 30–120 minutes

Run the SBT for 30–120 minutes on minimal support; ATS/CHEST suggests pressure support of 5–8 cmH₂O for the first trial rather than T-piece or CPAP, which shortens time to extubation.

03 · DoHigh risk: extubate to NIV

Patients at high risk of extubation failure (over 65, COPD or hypercapnia, heart failure, other serious cardiorespiratory disease) who pass an SBT should be extubated directly to preventive noninvasive ventilation (strong recommendation).

Presentation

What you'll see

SBT failure: distress, desaturation or instabilityEnd the SBT for rapid shallow breathing or rising work of breathing, desaturation, significant heart-rate or blood-pressure change, arrhythmia, agitation or diaphoresis — judged on respiratory pattern, hemodynamics, gas exchange and comfort.

Diagnosis & monitoring

Work-up

RSBI = respiratory rate ÷ tidal volume (L)Rapid shallow breathing index = respiratory rate ÷ tidal volume (L); < 105 suggests spontaneous breathing will succeed, but it is imperfect and AARC 2024 says it is not needed before an SBT.

Do right now

In this order

First moves

Daily sedation interruption, then a breathing trial

→

SBT screen: oxygenation, hemodynamics, effortFiO₂ ≤ 0.5, PEEP ≤ 8

→

SBT for 30–120 minutes30–120 min

→

Passing the SBT is not extubation readiness

→

High risk: extubate to NIV

Why each step

Daily sedation interruption, then a breathing trialFor every patient ventilated more than 24 hours, use a protocol: interrupt or minimize sedation daily and, once the patient is awake and eligible, run a spontaneous breathing trial (SBT).

SBT screen: oxygenation, hemodynamics, effortScreen for an SBT when the cause is reversing, there is no shock, SpO₂ ≥ 90% on FiO₂ ≤ 0.4–0.5 and PEEP ≤ 8 cmH₂O, respiratory rate < 35, and the patient triggers breaths.

SBT for 30–120 minutesRun the SBT for 30–120 minutes on minimal support; ATS/CHEST suggests pressure support of 5–8 cmH₂O for the first trial rather than T-piece or CPAP, which shortens time to extubation.

Passing the SBT is not extubation readinessExtubation is a separate decision from stopping ventilatory support: also require adequate mentation, protective airway reflexes and cough, manageable secretions, and a patent upper airway.

High risk: extubate to NIVPatients at high risk of extubation failure (over 65, COPD or hypercapnia, heart failure, other serious cardiorespiratory disease) who pass an SBT should be extubated directly to preventive noninvasive ventilation (strong recommendation).

Management

Orders

Failed SBT: rest, find the cause, retry dailyAfter a failed SBT, return the patient to a comfortable, non-fatiguing mode of full support, look for and correct the reason for failure, and repeat the SBT every 24 hours.

Sedation off; if needed, restart at half doseFor daily interruption, stop the sedative infusion until the patient is awake and following commands; if re-sedation is needed for agitation or dyssynchrony, restart at half the previous dose and titrate.

Cuff leak test if high stridor riskDo a cuff leak test before extubation in patients at high risk for postextubation stridor: traumatic intubation, intubation longer than 6 days, a large tube, female sex, or reintubation after unplanned extubation.

Failed cuff leak: steroids ≥ 4 h pre-extubationIf the cuff leak test fails but the patient is otherwise ready, give systemic corticosteroids at least 4 hours before extubation; a repeat cuff leak test is not required.

Order early mobilization for ventilated patientsFor patients ventilated more than 24 hours, use protocolized rehabilitation directed toward early mobilization to shorten ventilation and improve function.

The rules

Know these

Liberate by removing the cause, not slow weaningVentilator discontinuation succeeds by identifying and eliminating the precipitants of respiratory failure, not by gradually turning support down; sedatives and opioids that accumulate are a common reason trials are delayed.

Ready to breathe or ready for extubation?

Commonly confused

Question	Can the patient breathe unassisted?
How it is judged	Spontaneous breathing trial, 30–120 min
Extra test	RSBI < 105 (optional)
If it fails	Rest on full support, fix the cause, retry in 24 h

More detail

Reference

Show 5 reference facts

Pressure-support SBTs lead to faster extubation and higher extubation success than T-piece trials, but have not clearly lowered reintubation rates.

AARC 2024 suggests a standardized daily assessment with the SBT completed before noon, and not raising FiO₂ during the SBT.

Consider tracheostomy once it is clear that prolonged ventilation will be needed (eg, beyond about 2 weeks) for comfort, communication and eating.

Unless the disease is clearly irreversible (high spinal cord injury, advanced ALS), do not label a patient permanently ventilator-dependent until 3 months of weaning attempts have failed.

After hypercapnic respiratory failure (eg, COPD), NIV is preferred over high-flow nasal oxygen for post-extubation support in high-risk patients unless NIV is contraindicated.

Pearl

Liberation asks two questions: can the patient breathe without the ventilator, and can the patient protect the airway without the tube?

Sources · Merck Manual Professional — Liberation from Mechanical Ventilation · Schmidt GA, Girard TD, et al. Official Executive Summary of an ATS/ACCP Clinical Practice Guideline: Liberation from Mechanical Ventilation in Critically Ill Adults. Am J Respir Crit Care Med 2017;195:115–119 · Roberts KJ et al. AARC Clinical Practice Guideline: Spontaneous Breathing Trials for Liberation From Adult Mechanical Ventilation. Respir Care 2024 · Merck Manual Professional — Treatment of Acute COPD Exacerbation · GOLD 2026 Report — Global Strategy for the Diagnosis, Management, and Prevention of COPD (Chapter 4) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).