Extubation Assessment in the ICU

OVERVIEW

The criteria used to assess a patient to determine whether they are ready for extubation is complex and multi-factorial.

  • Ventilator weaning and extubating are two distinct processes
  • Identifying patients for extubation based solely on clinical gestalt is inaccurate
  • Predicting patient readiness is based upon many different physiologic variables
  • No single parameter can accurately predict which patients are ready to resume spontaneous breathing

OPTIMAL RATE OF FAILED EXTUBATION

  • About 15% of patients overall fail extubation in ICU
  • the optimal rate is unknown, but is probably 5-10%
  • higher rates are likely to lead to unnecessary prolongation of intubation at the population level

APPROACH

  • determine disease resolution and consider other factors
  • identify candidates for spontaneous breathing trial
  • perform spontaneous breathing trial
  • identify candidates for extubation
  • extubation and post-extubation care

1. DETERMINE DISEASE RESOLUTION

Begins with the resolution of respiratory failure and/or the disease that prompted initiation of mechanical ventilation

  • Criteria to define disease resolution are not defined nor prospectively validated

A systemic approach emphasising objective surrogate markers of recovery:

A+B

  • Adequate oxygenation and gas exchange
  • PaO2 >60mmHg on FiO2 <40%
  • PEEP 5–8cmH2O
  • CXR stable or improving

C

  • absent or only low dose vasopressors/inotropes
  • with SBP>90mmHg or MAP>60mmHg
  • Stable cardiac rhythm
  • No tacycardia
  • No evidence of myocardial ischemia

D

  • Adequate mentation
  • Rousable (this is controversial: some advise GCS>8 equivalent, some able to follow commands, some neither!)
  • No continuous sedative infusion or neuromuscular blockade
  • no significant weakness (e.g. can lift head off pillow, raise arms in air for 15 seconds, clap hands)
  • pain controlled

E

  • No significant acidosis
  • No electrolytes disturbance (e.g. normal K, PO4 >0.4)
  • adequate fluid status (not overloaded)

F G

  • abdominal pain/ distention controlled
  • tolerating feeds
  • Adequate hemoglobin
  • Afebrile/ sepsis controlled

H I Consider other factors:

  • difficulty of intubation
  • need for further procedures
  • skill level of junior staff in unit overnight
  • time of day

2. IDENTIFY CANDIDATES IN THE ICU FOR A SPONTANEOUS BREATHING TRIAL (SBT)

3. PERFORM SPONTANEOUS BREATHING TRIAL

4. IDENTIFY PATIENTS READY FOR TRIAL OF EXTUBATION

  • Indices to reliably predict extubation do not exist!

Key questions

  • Awake or easily rousable?
  • Able to follow commands?
  • Minimal volume of respiratory secretions?
  • Intact gag and cough reflex to prevent aspiration? (absent gag is normal in many people)

Consider a cuff leak test to check for laryngeal oedema:

  • Laryngeal edema reported in as many as 40% of prolonged intubations
  • 5% patients experience severe upper airway obstruction following extubation
  • can be detected by ‘cuff leak’ test
  • see Cuff Leak Test

Remember to consider other factors:

  • difficulty of intubation
  • need for further procedures
  • skill level of junior staff in unit overnight
  • time of day

5. EXTUBATION AND POST-EXTUBATION CARE

  • Monitor closely for Laryngospasm and Post-extubation stridor — reintubation is not always need
  • Consider high flow nasal prongs or non-invasive ventilation to treat or prevent post-extubation respiratory failure

CCC Ventilation Series

Journal articles and textbooks

  • El-Khatib MF, Bou-Khalil P. Clinical review: liberation from mechanical ventilation. Crit Care. 2008;12(4):221. doi: 10.1186/cc6959. Epub 2008 Aug 6. Review. PubMed PMID: 18710593; PubMed Central PMCID: PMC2575571.
  • King CS, Moores LK, Epstein SK. Should patients be able to follow commands prior to extubation? Respir Care. 2010 Jan;55(1):56-65. Review. PubMed PMID: 20040124.
  • Krinsley JS, Reddy PK, Iqbal A. What is the optimal rate of failed extubation? Crit Care. 2012 Feb 20;16(1):111. doi: 10.1186/cc11185. Review. PubMed PMID: 22356725; PubMed Central PMCID: PMC3396264.
  • Macintyre NR. Evidence-based assessments in the ventilator discontinuation process. Respir Care. 2012 Oct;57(10):1611-8. Review. PubMed PMID: 23013898. [Free Fulltext]
  • Siner JM, Manthous CA. Liberation from mechanical ventilation: what monitoring matters? Crit Care Clin. 2007 Jul;23(3):613-38. Review. PubMed PMID: 17900486.

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the  Clinician Educator Incubator programme, and a CICM First Part Examiner.

He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.

His one great achievement is being the father of three amazing children.

On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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