Delayed Sequence Intubation Framing
Objective: Use delayed sequence intubation (DSI) for one job: calm the patient enough to give oxygen before you decide on a tube. It is not a reason to skip oxygen or a backup airway plan.
Why this matters
The patient will not keep a mask on. The oxygen saturation (SpO₂) is 70%. Crews skip straight to rapid sequence intubation (RSI). The sat then falls within seconds.
Delayed sequence intubation (DSI) means you dissociate the patient so you can give oxygen, and then you decide about a tube. Dissociate means you calm the fight against the mask. It is not paralysis.
DSI is not a national EMS pathway. Use it only if your protocol names it and you are trained. It is not “give ketamine and intubate now.”
- Use DSI only if your protocol names it. Otherwise use the airway pathway you do have. That may be RSI, a supraglottic airway (SGA), or a bag-valve-mask (BVM) until you reach the hospital.
- Before any drug, set out suction, a video laryngoscope or a direct laryngoscope, an SGA, and a spoken cannot-intubate-cannot-oxygenate (CICO) plan.
- This site does not publish milligrams. Ketamine for pain, for agitation, and for induction are not the same protocol line. See the ketamine lesson.
Clinical sequence
- Do not invent DSI because you read about it. If your protocol does not name it, use RSI or a two-person BVM until you reach the hospital, as you are authorized.
- Before any drug, set out suction, the laryngoscope you will use, an SGA, defibrillator pads, and a spoken CICO plan. Ketamine does not protect the airway just because someone said it does.
- The first drug is so the patient will accept oxygen. It is not a paralytic. Dissociate only enough that the patient will accept a mask, continuous positive airway pressure (CPAP), or a two-person BVM.
- When the sat is as good as you can get it, decide. Tube now, place an SGA, keep bagging, or move. Have a two-person BVM ready. The patient can still stop breathing. This is not RSI.
- If the sat is still falling, do not wait and watch. Do not add a paralytic from memory. Bag again with two people, change the plan, and follow the airway pathway you actually have.
Teaching points
- DSI tries to solve one problem. You cannot give oxygen to a hypoxic patient who is fighting the mask. Dissociation may let you use a non-rebreather mask, CPAP, or a BVM.
- RSI is induction plus paralysis, then the tube. DSI is calm the patient, give oxygen, then decide.
- The patient can still stop breathing. Have a two-person BVM ready. Give oxygen again between attempts.
- If the patient vomits, suction, position the head, and place an SGA or stop the attempt. Fighting the mask after ketamine is a warning. It is not a cue to give more drug from memory.
Common errors
- Calling every RSI “DSI” so you skip giving oxygen first.
- Having no CICO plan because someone said ketamine protects the airway.
- Using a pain-dose range of ketamine and calling it DSI.
Practice
One-minute check
Partner: this is hypoxic asthma, the patient is pulling the mask off, and your protocol includes DSI. Say the goal of the first drug. The goal is oxygen, not paralysis. Then name the next tool if the sat is still falling.
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.
- Difficult Airway Society guidelines hub — oxygenate, limit attempts, change the plan — DAS does not make DSI a field standard
- 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
Questions drawn only from this lesson. After you check, the key is highlighted. Education practice — not a certification exam.