IV hypnotic
Propofol
Diprivan Induction agent — yellow 10 mg/mL (1% lipid emulsion)
The default induction agent: fast on, fast off, drops blood pressure and stops breathing.
Typical adult doses
| Indication | Dose | Onset | Duration |
|---|---|---|---|
| Induction (healthy adult < 55 y) | 1.5–2.5 mg/kg IV (label 2–2.5) | 30–45 s | 5–10 min |
| Induction (elderly, debilitated, ASA III–IV) | 1–1.5 mg/kg IV, slowly | 30–60 s | 5–10 min |
| Maintenance infusion | 100–200 mcg/kg/min | — | — |
| Sedation (MAC) | 25–75 mcg/kg/min | — | — |
Mechanism
Positive allosteric modulator of GABA-A receptors → increased chloride conductance → hypnosis.
Key effects
- ↓ SVR and ↓ contractility → hypotension
- Apnea; blunts airway reflexes (good for LMA placement)
- Antiemetic
- Pain on injection
Watch out for
- Hypotension in elderly, hypovolemic, severe AS/CAD
- Strict asepsis — the emulsion supports microbial growth; follow label time limits for drawn syringes
- Propofol infusion syndrome with prolonged high-dose infusions
- Label contraindication: egg/soy allergy history — allergy societies note most egg/soy-allergic patients tolerate it; the team and pharmacy decide
Pimp questions
Pimp question 1
Why does propofol drop blood pressure?
Answer
Vasodilation (↓SVR), myocardial depression and a blunted baroreflex.
Pimp question 2
Why is propofol white?
Answer
It is a lipid emulsion (soybean oil, egg lecithin, glycerol).
Pimp question 3
Which induction agent best suppresses airway reflexes?
Answer
Propofol — one reason it is preferred for LMA placement.