Delayed Sequence Intubation

Author: Michelle Lin, MD
Updated: 8/31/2012

Delayed Sequence Intubation (DSI)

General Concepts

  • DSI is procedural sedation/dissociation where the procedure is preoxygenation
  • Breaks up the sequence of RSI to preoxygenate prior to paralysis—prolongs safe apnea duration and decreases risk of gastric insufflation or aspiration
  • Maintains patient’s spontaneous respirations and reflexes

Candidates for DSI

  • Agitated due to EtOH, head injury, or psychosis, but with normal lungs
  • Agitated, but with lungs capable of being oxygenated on non-rebreather (NRB) mask: hypoxic due to COPD, pneumonia, ARDS
  • Agitated, but require non-invasive positive pressure ventilation (NIPPV) to preoxygenate
  • Unobtainable or unacceptable vital signs due to any of the above
  • Need to perform a procedure that the patient is not tolerating prior to intubation (e.g. NGT placement prior to intubation of GI bleeder)


  • Dose: 1 mg/kg IV push (may need to re-dose 0.5 mg/kg to maintain dissociation)
  • Pros: 30 sec onset, achieves dissociative state, maintains spontaneous respirations and airway reflexes, maintains hemodynamic stability
  • Cons: May increase intracranial pressure in patients with high MAP, may cause laryngospasm, use with caution in patients with CAD, HTN, or tachycardia

Equipment and Troubleshooting

  • Respiratory therapist
  • Nasal cannula (NC)
  • Non-rebreather (NRB) mask
  • Bag valve mask (BVM) with PEEP valve
  • 2 O2 flow meters (NRB or BVM, NC)
  • Ventilator with NIPPV settings
  • Non-vented mask with straps for CPAP
  • End tidal CO2 monitor

Pearls: DSI ≠ NIV

  • Preoxygenation may be achieved with NC, NRB mask, OR NIPPV, depending on the patient’s needs
  • If your patient is not agitated, NIV may be sufficient without the need for sedation/dissociation
  • Intubation may be avoided if adequate dissociation and oxygenation is attained

Delayed Sequence Intubation (DSI) algorithm

Delayed Sequence Intubation (DSI) algorithm

Note: During CPAP or BMV, it may take several minutes (may be as long as 10 minutes) to bring the oxygen saturation > 95%, while increasing PEEP up to 15 cm H2O.


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