01Five checks before you give any drug
Doses are weight-based and reported as ranges — start at the low end and escalate (you can always give more; you can't take it back). Before every drug:
- Allergies — easy to skip when rushed, costly to get wrong.
- Weight — especially in peds.
- Name — read the label, not the look of the vial; similar-looking vials cause most errors.
- Concentration — mg/mL vs mcg/mL; some drugs need dilution.
- Calculate the dose and draw up the right volume in the right-size syringe; for emergency drugs draw a single bolus.
- See the [Drawing Up & Labeling Drugs](/playbook/drawing-up-drugs) guide for syringe sizes and the color-code system.
02Induction agents
| Agent | Class | Adult dose | Why / when | Watch out |
|---|---|---|---|---|
| Propofol | Hindered phenol | 1.5–2.5 mg/kg (≈150–200 mg) | Workhorse; smooth; antiemetic; infusion for TIVA (100–300 mcg/kg/min) | ↓BP (↓SVR + contractility), worse if hypovolemic; injection pain |
| Etomidate | Imidazole | 0.2–0.3 mg/kg (≈14–20 mg) | Hemodynamically stable induction for the sick patient | Adrenal suppression (even 1 dose), myoclonus, PONV; no infusion |
| Ketamine | NMDA antagonist | 1–2 mg/kg IV (4 mg/kg IM) | Dissociative; analgesia, bronchodilation, can use when unstable / no IV | Emergence hallucinations, ↑secretions, ↑HR/BP |
Propofol injection pain: pre-treat with lidocaine and push slowly. Ketamine: pair with a benzo (hallucinations) and glycopyrrolate (secretions).
03Benzodiazepines & reversal
Midazolam (Versed) — short-acting benzo for anxiolysis (pre-op) and anterograde amnesia (e.g., before a stressful transport). - Adult 2 mg IV; peds 0.5 mg/kg PO or 0.1 mg/kg IV (up to ~2 mg).
Flumazenil — reverses benzodiazepine sedation/respiratory depression. - 0.2 mg over 15 s, repeat 0.1 mg q1 min to a max of ~1 mg. - Caution: can precipitate seizures in chronic benzo users (acute withdrawal).
04Opioids
Titrate to effect, and watch the respiratory rate as your gauge.
| Opioid | Rel. potency | Adult dose | Peak | Duration | Notes |
|---|---|---|---|---|---|
| Fentanyl | 100 | 0.5–1 mcg/kg (induction); 25–50 mcg boluses | ~5 min | ~45 min | Fast on/off; rigid chest with rapid bolus |
| Hydromorphone | 10 | ~0.2 mg, titrate | ~15–20 min | 4–5 h | Workhorse for post-op pain; no histamine |
| Morphine | 1 | ~2 mg, titrate | ~20 min | ~4 h | Histamine release → itch/↓BP |
| Meperidine | 0.1 | 12.5 mg (may repeat) | ~15 min | ~2 h | Mainly for post-op shivering/rigors |
Rule of thumb: "8 is great, 10 I'll take" — a spontaneous respiratory rate of 8–10 usually signals adequate analgesia without overdosing.
Naloxone reverses opioid sedation/respiratory depression: 0.04 mg IV, titrated. It can wear off before a long-acting opioid does (re-dose), and abrupt full reversal can cause flash pulmonary edema — go slow.
- Slamming a big fentanyl bolus → chest-wall rigidity that makes ventilation difficult.
- Fully reversing with a large naloxone dose — sudden pain, hypertension, and flash pulmonary edema.
05Non-opioid analgesics (multimodal)
Layering these reduces opioid need, PONV, and sedation:
- Acetaminophen — IV or PO; 15 mg/kg (max 1 g) IV q6h or 650 mg PO q6h; max 4 g/24 h. Check for other acetaminophen-containing meds.
- Ibuprofen (NSAID) — 600 mg PO. Don't combine with ketorolac.
- Ketorolac (NSAID) — 30 mg then 15–30 mg q6h IV/IM; ensure the patient is well hydrated (renal blood flow). Don't combine with ibuprofen.
- Ketamine (low-dose) and dexmedetomidine also provide opioid-sparing analgesia.