Remifentanil
Ultiva
Ultra-short-acting μ-opioid agonist
μ-opioid agonist. Ester linkage hydrolyzed by nonspecific tissue + plasma esterases — no organ-dependent clearance.
Indications
- •TIVA component
- •Cardiac surgery analgesia
- •Awake fiberoptic intubation
- •OB GA cesarean (sometimes)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Bolus | 0.5–1 mcg/kg IV (slow over 30 sec) | — |
| Infusion | 0.05–0.5 mcg/kg/min | — |
| MAC sedation | 0.025–0.1 mcg/kg/min | — |
Pharmacokinetics
Onset 1 min. Context-sensitive half-time 3–4 min regardless of duration.
Hemodynamic effects
↓HR + ↓BP at high infusion rates.
Respiratory effects
Profound respiratory depression — must be paired with controlled ventilation or vigilant MAC.
Side effects
- !Acute opioid tolerance + post-infusion hyperalgesia (dose-dependent)
- !Bradycardia, hypotension
- !Chest wall rigidity (most reported of all opioids)
- !No residual postop analgesia → plan transition opioid before stopping
Contraindications
- ×No known absolute
Clinical pearls
- ★Bridge to long-acting analgesic (morphine 0.1–0.15 mg/kg or hydromorphone 10–20 mcg/kg) ~30 min before stop.
- ★Useful in hepatic + renal failure (organ-independent clearance).
- ★Co-infuse with propofol for TIVA — avoid oversedation by titrating each separately.
Education only — confirm against current package inserts and institutional protocols. Doses assume normal organ function unless otherwise noted.