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RSI medications and airway workflow

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RSI medications come down to two drugs pushed back to back: an induction agent to take consciousness away, and a paralytic to stop the patient from fighting the tube. RSI, rapid sequence intubation, used to run a third drug, a pretreatment agent, ahead of those two. Most crews have dropped it. Both doses run off a weight, and which weight is genuinely contested, more than most references admit.

This page covers the RSI medications Rapid Vent Calculator estimates doses for: six agents in two groups, the order they’re pushed, the honest split over actual versus ideal body weight, and the step page one keeps skipping, what happens to sedation once the paralytic takes hold. It closes with what happens next, the vent settings that start the moment the tube is secured.

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RSI medications at a glance: the adult dose table

Six agents, the same ones on Rapid Vent Calculator’s medications card, split into induction agents and neuromuscular blockers.

Agent Class Adult starting dose Onset Duration Why you’d reach for it Source
Ketamine Induction agent, dissociative 2 mg/kg About 30 seconds 5-10 minutes Preserves airway reflexes and respiratory drive; the default when blood pressure is already a problem FDA ketamine label; StatPearls NBK459276
Etomidate Induction agent, sedative-hypnotic 0.3 mg/kg About 1 minute 3-5 minutes Hemodynamically the quietest of the three; the most-used induction agent in US community EDs FDA AMIDATE label; Kei 2025
Propofol Induction agent, sedative-hypnotic 1.5 mg/kg About 40 seconds Minutes, titration-dependent Familiar and fast, but drops blood pressure more than the other two FDA propofol label
Succinylcholine Paralytic, depolarizing NMBA 1.5 mg/kg About 1 minute Shortest on this table, recovery in minutes Wears off fastest of anything here, useful if the airway plan changes mid-attempt StatPearls NBK459276; Bhat 2016
Rocuronium Paralytic, non-depolarizing NMBA 1 mg/kg About 1-2 minutes 31-67 minutes, by labeled dose No depolarizing-agent contraindications to screen for first StatPearls NBK459276; FDA rocuronium label
Vecuronium Paralytic, non-depolarizing NMBA 0.1 mg/kg First twitch depression about 1 minute; intubating conditions 2.5-3 minutes 25-40 minutes Continued paralysis once the tube is secured, not usually the first push FDA vecuronium label

Every dose here is an adult starting estimate, not an order, titrated and reassessed against the patient in front of you and the protocol you’re working under. Three rows carry a caveat worth knowing. Succinylcholine’s 1.5 mg/kg comes from StatPearls and from Bhat and colleagues’ review of emergency-department dosing, not from the manufacturer’s label, whose studied adult range tops out at 1.1 mg/kg; the emergency-airway figure sits above what the label describes. Rocuronium’s onset and duration have no published figure at exactly 1 mg/kg. The label reports 1.8 minutes to peak block and 31 minutes of clinical duration at 0.6 mg/kg, and 1.0 minute and 67 minutes at 1.2 mg/kg, so 1 mg/kg lands somewhere inside that bracket. And etomidate’s 40 mg ceiling is a limit some services apply and others do not. Rapid Vent Calculator applies it, and flags it on screen as a common maximum rather than a labelled one. No FDA label or guideline located here sets a milligram ceiling for etomidate, only a 0.2 to 0.6 mg/kg range, so the cap reads as app behavior the same way this site labels the acidosis multiplier in its vent-settings math a built-in heuristic rather than a published standard.

Rapid Vent Calculator’s medications card lays these out the same way, sitting below the vent settings on the results screen: mg/kg scalar next to the calculated milligram value for the weight you enter.

What are the 3 drugs used in rapid sequence intubation?

In practice it’s two: an induction agent and a paralytic. A third, a pretreatment agent such as fentanyl, lidocaine, or atropine, used to round out the sequence, but a 2023 review of emergency-department RSI pharmacotherapy notes that pretreatment agents have largely fallen out of favor outside select clinical scenarios. Most crews are really pushing two drugs, not three.

RSI dose weight basis: actual body weight or ideal body weight

The number behind every dose above is the patient’s actual weight, the one on the stretcher scale, not a weight adjusted for height or body type. That’s what Rapid Vent Calculator uses for all six agents. It’s worth naming the contrast directly. How tidal volume comes off ideal body weight on this site’s vent-settings math starts from height, because lungs scale with height, not with the number on a scale. RSI drugs follow different distribution logic, and actual weight is the more common starting point for dosing them, though the sources below split on it agent by agent.

More common isn’t universal. The FDA’s rocuronium label backs actual weight directly, stating that obese patients should be dosed at 0.6 mg/kg based on actual body weight, with pharmacodynamics holding steady across obese and non-obese patients dosed that way. Succinylcholine’s actual-weight basis is even less contested: Erstad and Barletta’s 2021 review, a randomized trial by Lemmens and Brodsky, and Bhat and colleagues’ emergency-department chart review all land on the same answer for that one drug.

The other four split. That same Erstad and Barletta review recommends an ideal or adjusted weight for non-depolarizing paralytics generally, on the reasoning that these agents distribute mainly into lean tissue rather than fat, so lean mass may be the better basis in obesity. That puts rocuronium and vecuronium in real tension with the rocuronium label above. A 2024 study in the Western Journal of Emergency Medicine found that dosing rocuronium off ideal weight in obese ED patients didn’t reach statistical non-inferiority against actual weight, and shortened the drug’s paralytic window from 71 minutes to 43. A companion Erstad and Barletta review makes the same ideal-or-adjusted recommendation for ketamine and for propofol in obesity. No source located here recommends actual weight for vecuronium at all, and etomidate’s label just says “body weight” without picking a side.

None of that resolves for you, and it shouldn’t. The 2023 pharmacotherapy review covering this exact question states there’s insufficient evidence to change current dosing practice one way or the other, and Rapid Vent Calculator’s own medications card says close to the same thing in its footer note: displayed doses are calculated from entered actual body weight, and in obesity some references use ideal or adjusted body weight for selected agents, especially nondepolarizing paralytics. The formula multiplies whatever weight you enter. It has no way to know if that number is muscle or fluid overload, and no way to know what your protocol authorizes. That call is yours.

Do you dose RSI drugs on actual or ideal body weight?

It depends on the agent and the source. Actual weight is well supported for succinylcholine and defensible for rocuronium off its own label; ideal or adjusted weight has published support for ketamine, propofol, and non-depolarizing paralytics generally in obesity. Your protocol decides which one you’re authorized to use.

Induction agents: ketamine, etomidate, propofol

Choosing an induction agent is mostly a blood-pressure decision.

Ketamine keeps pressure up. It raises blood pressure, heart rate, and cardiac output by blocking catecholamine reuptake, and it preserves airway reflexes and respiratory drive better than the other two agents here, which is why it’s the default when a patient is already hypotensive or in shock.

Etomidate keeps pressure flat. SCCM’s 2023 guideline suggests there is no difference between etomidate and other induction agents on mortality or the rate of peri-intubation hypotension, and a recent look at intubation practice across fifteen community EDs found etomidate used in 91.6% of adult RSI inductions, against 4.3% for propofol and 4.1% for ketamine. It’s the field’s default for a reason.

Propofol drops pressure. Its own label describes hemodynamic depression “generally more pronounced than with other intravenous induction agents,” sometimes over 30%. The 1.5 mg/kg Rapid Vent Calculator uses sits at the top of the label’s reduced-dose band for elderly, debilitated, or higher-acuity patients rather than the fuller 2 to 2.5 mg/kg band for a healthy patient under general anesthesia, a defensible fit for who actually gets RSI’d, even though it’s still second-line here.

Ketamine’s dose gets adjusted in specific clinical scenarios, and that detail belongs on its own page, not this one. Which of the three you can reach for, and at what dose, is set by your agency’s formulary and standing orders before it is ever a preference.

Is ketamine or etomidate the better induction agent?

That comparison has real trial evidence behind it, adrenal suppression, mortality signal, ICU-specific data, and it’s its own page rather than two sentences here. What this page will say: SCCM’s guideline suggests no mortality difference between etomidate and induction agents broadly, a narrower statement than the head-to-head question that comparison actually answers.

Paralytics: succinylcholine, rocuronium, vecuronium

RSI drugs split into two paralytic families: depolarizing, succinylcholine alone on this table, and non-depolarizing, rocuronium and vecuronium. The practical difference is duration. Succinylcholine clears in minutes. Rocuronium and vecuronium don’t, by a wide margin, the subject of the next section.

Succinylcholine and rocuronium are the two paralytics actually built for this moment. SCCM’s 2023 guideline suggests either one for RSI in critically ill adults when there’s no contraindication to succinylcholine, and a 2023 pharmacotherapy review notes the literature shows minimal difference between succinylcholine and high-dose rocuronium in first-pass success. Pulled from the table above: succinylcholine clears in minutes, rocuronium runs from roughly half an hour to well past an hour depending on the dose.

Vecuronium sits on Rapid Vent Calculator’s medications card, but no guideline or reference in this research names it a first-line RSI paralytic the way it names rocuronium and succinylcholine. Its place here is continued paralysis after the tube is already secured, not the initial push. Weighing rocuronium against succinylcholine for that initial push, hyperkalemia risk, reversal, how long you’re willing to have someone paralyzed, is a real decision with real tradeoffs, made under whatever your agency’s protocol and medical direction actually specify, and it gets its own page rather than a paragraph here.

Which is given first, the induction agent or the paralytic?

Most crews push the induction agent first, then the paralytic, and either order is defensible. A 2023 review of emergency-department RSI pharmacotherapy states plainly that controversy exists over which drug should go first and that there’s insufficient evidence to meaningfully change current practice.

The case for paralytic first: shorter time to intubating conditions and a shorter apneic period, since the drug that stops spontaneous breathing starts working sooner. A 2025 Bayesian analysis of a prospective emergency-department cohort, over two thousand intubations across four years, found paralytic-first associated with fewer first-attempt failures, with a 95.7% probability the effect was real. The same study names its own limits: single center, a credible interval that brushes up against no effect, and no measurement of awareness during paralysis, which matters given the next section.

The case for induction first is older and simpler: nobody wants a patient paralyzed and aware, even briefly. This is a protocol and medical-direction question before it’s a research one. Follow what your agency trained you to run.

The 7 Ps: where the drugs sit in the sequence

StatPearls lays the sequence out in seven steps: preparation, pre-oxygenation, pretreatment, paralysis and induction, positioning, placement and confirmation, and post-intubation management.

  1. Preparation. Equipment checked, suction ready, a primary and backup airway plan.
  2. Pre-oxygenation. Building an oxygen reserve before the apneic period starts.
  3. Pretreatment. The mostly-optional step covered above.
  4. Paralysis and induction. The two pushes from the table at the top of this page happen here.
  5. Positioning. Sniffing position, cricoid pressure if your protocol still calls for it.
  6. Placement and confirmation. The tube goes in, and StatPearls puts confirmation here: end-tidal carbon dioxide detection, by quantitative or colorimetric method.
  7. Post-intubation management. The second drug decision, sedation, gets made here, and it’s the step the rest of this page is built around.

A cuff-pressure check also belongs on that last step’s list, and the 20-30 cm H2O window it gets checked against sits with the rest of the ranges in the normal ventilator values reference.

Post-intubation sedation is the step that gets dropped

Look at the duration column above and the problem is obvious. Etomidate wears off in three to five minutes; rocuronium runs anywhere from roughly half an hour to well over an hour, depending on the dose given. A patient who got etomidate for induction and rocuronium for paralysis can be lying there fully paralyzed and fully conscious long before the rocuronium wears off, if nobody pushes a second sedative.

That isn’t hypothetical. The ED-AWARENESS study followed adults intubated in the emergency department and found that 2.6% had possible or likely awareness while paralyzed, roughly three times the rate seen in the operating room. Rocuronium showed up in 70% of the awake-paralyzed patients against 31% of everyone else, an odds ratio over five. NAEMSP’s summary of that study is direct about the fix: a second post-intubation dose of sedative has to be protocolized, in the field and in the ED both, not left to whoever remembers.

Post-intubation sedation and analgesia is its own named step in the RSI medication sequence, not an afterthought, and StatPearls notes that most induction agents have short half-lives, which is exactly why sedation has to be restarted once the tube is in. What crews actually report at handoff is a RASS score, the same scale critical-care sedation guidelines point to when they suggest targeting light sedation over deep sedation in mechanically ventilated adults. On a transport vent, that sedation clock runs the entire ride, not just the first few minutes after the tube.

What is given after RSI to keep a patient sedated?

A sedative, often paired with an analgesic, though no prehospital-specific source in this research names one canonical agent or a fixed dose, and this page won’t invent one. What matters more than the specific drug is that a second dose gets protocolized and given on schedule, not left to whoever notices the patient moving first. Check your agency’s post-intubation sedation protocol. That’s the real answer here, and it’s supposed to vary by agency.

After the tube: the first ventilator settings

The drug math is done. The first ventilator settings after the tube start now, on a different weight than anything above.

Ideal body weight, not actual weight, drives tidal volume, because lung size tracks height rather than the number on a scale. From there the sequence is fixed: a tidal volume target, a minute ventilation target built off that same ideal weight, and a respiratory rate that falls out of dividing one by the other. NAEMSP’s prehospital ventilation position statement states plainly that settings should be disease-specific and mirror in-hospital best practice, not default to whatever the transport vent happens to be running.

What these numbers are, and what they are not

Rapid Vent Calculator’s medications card runs six multiplications the moment you hit calculate, laid out in the same two groups this page uses, each row showing the mg/kg scalar next to the calculated milligram value. That’s the moment doing six multiplications in your head is the worst possible use of your attention, which is the reason this exists.

What it doesn’t do is decide anything. It has never seen your patient, so it has no way to know if this is the stable patient who can take etomidate on autopilot or the one in shock where that choice actually matters. It doesn’t know what your protocol authorizes, whether paralytic goes first or induction does, or which weight your protocol specifies for a given drug. Those calls are yours, made from the patient in front of you and the training behind you. What the free RSI dose and vent calculator removes is the arithmetic underneath those calls, not the calls themselves.

Sources

  1. Acquisto NM, Mosier JM, Bittner EA, et al. Society of Critical Care Medicine clinical practice guidelines for rapid sequence intubation in the critically ill adult patient. Critical Care Medicine. 2023;51(10):1411-1430. https://pubmed.ncbi.nlm.nih.gov/37707378/
  2. Engstrom K, Brown CS, Mattson AE, Lyons N, Rech MA. Pharmacotherapy optimization for rapid sequence intubation in the emergency department. American Journal of Emergency Medicine. 2023;70:19-29. https://pubmed.ncbi.nlm.nih.gov/37196592/
  3. StatPearls. Intubation Endotracheal Tube Medications (NBK459276). Updated January 19, 2025. https://www.ncbi.nlm.nih.gov/books/NBK459276/
  4. FDA prescribing information, ketamine hydrochloride injection. DailyMed. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=58c86d9b-8694-4bd8-8254-f19ee3ad60b0&type=display
  5. FDA prescribing information, AMIDATE (etomidate) injection. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=b7ed5bf8-ba75-44dc-8f81-96b4ad5766be
  6. FDA prescribing information, propofol injectable emulsion. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=800646b8-83a8-01d9-3dc8-bb2ddcb8570c
  7. FDA prescribing information, succinylcholine chloride injection. DailyMed. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=3deac02b-392c-4ee4-9abf-7fe5b8975147
  8. FDA prescribing information, rocuronium bromide injection. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=309aeb1b-8022-4df7-8194-ae6529e3395c
  9. FDA prescribing information, vecuronium bromide injection. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=dceeec01-2910-4489-8d70-9c0c711d17ab
  10. Erstad BL, Barletta JF. Dosing of neuromuscular blocking agents in patients with obesity: a narrative review. Anaesthesia and Intensive Care. 2021;49(2):98-104. https://pubmed.ncbi.nlm.nih.gov/33906465/
  11. Erstad BL, Barletta JF. Drug dosing in the critically ill obese patient: a focus on sedation, analgesia, and delirium. Critical Care. 2020;24:315. https://pmc.ncbi.nlm.nih.gov/articles/PMC7282067/
  12. Lemmens HJ, Brodsky JB. The dose of succinylcholine in morbid obesity. Anesthesia and Analgesia. 2006;102(2):438-442. https://pubmed.ncbi.nlm.nih.gov/16428539/
  13. Bhat R, Mazer-Amirshahi M, Sun C, et al. Accuracy of rapid sequence intubation medication dosing in obese patients intubated in the emergency department. American Journal of Emergency Medicine. 2016. https://pubmed.ncbi.nlm.nih.gov/27727068/
  14. McDowell M, Lewandowski A, Desai D, et al. Rocuronium dosing by ideal vs total body weight in obesity: a prospective, observational non-inferiority study. Western Journal of Emergency Medicine. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC10777192/
  15. Catoire P, Driver B, Prekker ME, Freund Y. Effect of administration sequence of induction agents on first-attempt failure during emergency intubation: a Bayesian analysis of a prospective cohort. Academic Emergency Medicine. 2025;32:123-129. https://pmc.ncbi.nlm.nih.gov/articles/PMC11816003/
  16. Pappal RD, Roberts BW, Mohr NM, et al. The ED-AWARENESS study, summarized by NAEMSP Article Bites #30. Annals of Emergency Medicine. 2021. https://naemsp.org/2021-3-7-what-is-the-incidence-of-awareness-during-paralysis-following-emergent-intubation-the-ed-awareness-study/
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  19. Kei J, Eurick T, Hauck TA. Intubation practices in community emergency departments. Annals of Emergency Medicine. 2025;86(2). https://pubmed.ncbi.nlm.nih.gov/39797884/