Medication guide
Airway pharmacology.
Sedatives, paralytics, and adjuncts used in RSI, DSI, and post-intubation care.
The 7 Ps of RSI
- Preparation — SOAP-ME: Suction, Oxygen, Airway gear, Positioning, Meds, ETCO₂ / EKG.
- Preoxygenation — 3 min NRB or NC 15 L + apneic oxygenation.
- Pretreatment — fentanyl (blunt sympathetic response), atropine (peds).
- Paralysis with induction — sedative + paralytic pushed together.
- Positioning — sniffing / ear-to-sternal-notch.
- Placement with proof — visualize cords, confirm waveform capnography.
- Post-intubation management — sedation, analgesia, lung-protective ventilation.
Drug reference
| Drug | Class | Dose | Onset | Duration | Notes |
|---|---|---|---|---|---|
| Ketamine | Dissociative sedative | 1–2 mg/kg IV (RSI); 4–5 mg/kg IM | 30–60 s IV | 10–20 min | Maintains BP and airway reflexes. First-line for shock. |
| Etomidate | Sedative-hypnotic | 0.3 mg/kg IV | 15–45 s | 5–10 min | Hemodynamically stable. Concern for adrenal suppression in sepsis. |
| Midazolam | Benzodiazepine | 0.1–0.3 mg/kg IV (induction) | 1–3 min | 15–30 min | Slower onset; can drop BP. Better for post-intubation sedation. |
| Propofol | GABA sedative | 1.5–2.5 mg/kg IV (induction) | 15–45 s | 5–10 min | Drops BP hard. Avoid in shock. |
| Succinylcholine | Depolarizing paralytic | 1.5 mg/kg IV; 3–4 mg/kg IM | 45–60 s | 6–10 min | Avoid: hyperkalemia, burns >24h, crush, myopathies, MH history. |
| Rocuronium | Non-depolarizing paralytic | 1–1.2 mg/kg IV | 45–90 s | 45–70 min | Safe when sux contraindicated. Reversible with sugammadex. |
| Vecuronium | Non-depolarizing paralytic | 0.1 mg/kg IV | 2–3 min | 30–60 min | Slower onset; used more for maintenance than RSI. |
| Fentanyl | Opioid analgesic | 1–3 mcg/kg IV (pretreat); 0.5–1 mcg/kg boluses post | 1–2 min | 30–60 min | Blunts sympathetic surge; avoid rapid push (chest wall rigidity). |
| Lidocaine | Sodium channel blocker | 1.5 mg/kg IV pretreat | 1–2 min | 10–20 min | Historically for ↑ICP; evidence is weak. Local practice varies. |
| Atropine | Anticholinergic | 0.02 mg/kg IV (peds < 1 y) | 1 min | 30–60 min | Pediatric pretreatment to prevent vagal bradycardia. |
Post-intubation golden rule
A paralyzed patient without sedation is awake, terrified, and unable to move. Start sedation immediately after tube confirmation — every time.
FAQ
What is the standard adult ketamine dose for RSI?
1–2 mg/kg IV push (typical 1.5 mg/kg). IM alternative is 4–5 mg/kg if no IV access.
Rocuronium vs succinylcholine for RSI?
Sux acts faster (~45 s) and wears off in 6–10 min; roc has similar onset at 1.2 mg/kg but lasts 45–70 min. Sux is avoided in hyperkalemia, crush injury, burns >24h old, and known myopathies.
What's the post-intubation sedation of choice?
Most systems use a ketamine drip (1–3 mg/kg/hr) or midazolam (0.05–0.1 mg/kg boluses). Add fentanyl for analgesia. Never leave a paralyzed patient without ongoing sedation.
What is DSI (Delayed Sequence Intubation)?
Give a dissociative dose of ketamine (1 mg/kg IV) to allow preoxygenation in the agitated hypoxic patient, wait 3 minutes, then paralyze and intubate.
When do you pretreat with atropine?
Consider atropine 0.02 mg/kg IV (min 0.1 mg) in pediatric patients under 1 year, or under 5 receiving a second dose of succinylcholine, to blunt vagal bradycardia.
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