Delayed Sequence Intubation Framing
Objective: Place DSI in the right box: ketamine-level calm so you can preoxygenate, not a shortcut around an airway exam.
Why This Is Hard
They will not tolerate a mask and SpO₂ is 70%. Crews skip straight to RSI and desaturate in 20 seconds. DSI teaching (Weingart and later EMS adoptions): a dissociative dose so you can preoxygenate, then a separate intubation sequence. It is not “ketamine and go.”
- Only if your protocol names DSI. Otherwise it is RSI or BVM until destination.
- Suction, VL/DL, SGA, and a spoken CICO plan still come out before the drug.
- This site does not publish milligrams. Ketamine ranges for pain, agitation, and induction are not interchangeable — see the ketamine lesson.
Field Rules (Education)
- Problem DSI tries to solve: you cannot preoxygenate a fighting, hypoxic patient. Dissociation may let you apply NRB/CPAP/BVM.
- It is not RSI: RSI is induction plus paralysis, then the tube. DSI is calm, oxygenate, then decide.
- Apnea still happens. Have a two-person BVM. DAS: re-oxygenate between attempts.
- If they vomit: suction, position, SGA or abort. Fighting the mask after ketamine is a warning, not a cue to add more from memory.
Field Pitfalls
- Calling every RSI “DSI” so you skip preoxygenation.
- No CICO plan because “ketamine preserves the airway.”
- Using an analgesic ketamine range and calling it DSI.
Practice
60-second drill
Partner: hypoxic asthma, tearing the mask off, protocol includes DSI. Say the goal of the first drug (preoxygenation vs paralysis) and the next tool if the sat still falls.
Related: Preoxygenation, Ketamine.
Sources & Further Study
Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.
- NASEMSO National Model EMS Clinical Guidelines (2022) — U.S. EMS model language; protocol still wins
- Difficult Airway Society guidelines hub — oxygenate, limit attempts, change the plan
- Weingart & Levitan, Ann Emerg Med 2015 — delayed sequence intubation — dissociation to allow preoxygenation — not a substitute for a CICO plan; protocol owns whether DSI exists
- DSI exists only where trained and authorized. Protocol owns the sequence.
Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.
Check Your Understanding
Street decisions from this lesson only. After you check, the key is highlighted. Education practice — not a certification exam.