Delayed sequence intubation
Patients requiring intubation who are agitated, have alterations in mental status, or are otherwise unable to tolerate prexoygenation (whether via nasal cannula, nonrebreather mask, bag-valve mask, or non-invasive positive pressure ventilation (NIPPV)) pose a unique challenge to emergency clinicians. Weingart, et al, propose a "delayed-sequence intubation" approach to maximize preoxygenation in an effort to minimize hypoxemia and adverse events related to the apneic period during intubation. Similar to procedural sedation, except the procedure is preoxygenation itself.
- Patients requiring intubation but are unable to tolerate preoxygenation due to altered mental status, severe hypoxemia, agitation, or other reason
- Likely safe for use in pediatrics
- Patients who require an additional procedure prior to intubation (i.e., NGT placement for GI bleeding)
- No absolute contraindications when performed urgently
- Induction agent
- Paralytic agent
- Laryngoscope (type based on clinical indication and provider preference/experience)
- Direct laryngoscope with blade of provider's choice or
- Video laryngoscope (Glidescope, C-Mac, KingVision, etc.) or
- Fiberoptic device
- Endotracheal tube
- End-tidal CO2 device (colorimetric or quantitative)
- Intubation adjuncts (bougie, lighted stylet, etc)
- Method of preoxygenation (NC, NRB, C-PAP, etc)
- Nonrebreather mask and nasal cannula for apneic oxygenation
- Assemble required equipment and staff
- Be prepared for failed airway/deterioration
- Patient on cardiac monitor with pulse oximetry (preferably waveform capnography)
- Apply non-rebreather mask and nasal cannula, set flow to 15 L/min each
- Administer induction agent,
- Ideally ketamine 1-2mg/kg given mp blunting of patient respirations or airway reflexes
- In hypertensive and tachycardic patients, dexmedetomidine can be administered at 1 mcg/kg. It is a α-2 agonist, which provides sedation with no blunting of respiratory drive or airway reflexes
- If SpO2 is <95% then use NIPPV or bag-valve mask with PEEP valve at 5-15 cmH20
- If no improvement within 10 minutes, consider proceeding to intubation with suboptimal pulse oximetry reading
- Administer neuromuscular blocker and wait 45-60 seconds
- Perform apneic oxygenation using 15 L/min O2 via nasal prongs +/- continue CPAP
- Intubate patient
- Same as NIPPV
- Medication reaction/side-effects
- Other medications (remifentanil) may be considered but lack evidence and do not have the same characteristics of ketamine (preserved airway protective reflexes, preserved respiratory drive, rapid onset)
- Weingart found that a small subset of patients (severe asthma) improved sufficiently as to no longer require intubation. In these cases, avoid neuromuscular blockade, allow the induction agent to wear off (or administer further boluses to preserve oxygenation)
- Surgical airways
- Weingart SD, Trueger NS, Wong N, Scofi J, Singh N, Rudolph SS. Delayed Sequence Intubation: A Prospective Observational Study. Ann Emerg Med. DOI: http://dx.doi.org/10.1016/j.annemergmed.2014.09.025
- Löllgen RM, Webster P, Lei E, Weatherall A. Delayed sequence intubation for management of respiratory failure in a 6-year-old child in a paediatric emergency department. Emerg Med Australas. 2014 Jun;26(3):308-9. doi: 10.1111/1742-6723.12196. Epub 2014 Apr 8. PubMed PMID: 24712856.
- Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165-75.e1. Epub 2011 Nov 3. Review. PubMed PMID: 22050948.
- Weingart SD. Preoxygenation, reoxygenation, and delayed sequence intubation in the emergency department. J Emerg Med. 2011 Jun;40(6):661-7. Epub 2010 Apr 8. Review. PubMed PMID: 20378297.
- Abdelmalak B, Makary L, Hoban J, Doyle DJ. Dexmedetomidine as sole sedative for awake intubation in management of the critical airway. J Clin Anesth 2007;19:370–3.
- Weingart SD, Trueger NS, Wong N, Scofi J, Singh N, Rudolph SS. Delayed Sequence Intubation: A Prospective Observational Study. Ann Emerg Med. DOI: http://dx.doi.org/10.1016/j.annemergmed.2014.09.025.