ROCURONIUM
1. Introduction
Rocuronium is a non-depolarizing neuromuscular blocking agent (NDNMBA) of the aminosteroid group.
2. Classification
|
Class |
Drug |
|
Aminosteroid |
Rocuronium, Vecuronium, Pancuronium |
|
Benzylisoquinolinium |
Atracurium, Cisatracurium |
3. Mechanism of Action
- Competitive antagonist at nicotinic acetylcholine receptors (Nm) at neuromuscular junction
- Prevents depolarization → flaccid paralysis
Sequence of paralysis:
- Small muscles (eyes, face)
- Limbs
- Intercostals
- Diaphragm (last)
Recovery → reverse order
4. Pharmacokinetics
|
Parameter |
Rocuronium |
|
Onset |
60–90 sec (fast) |
|
Duration |
30–60 min |
|
Metabolism |
Minimal hepatic |
|
Elimination |
Hepatobiliary (major) |
|
Half-life |
60–120 min |
Compared to vecuronium → faster onset
5. Dosing (ICU & RSI)
RSI Dose
- 1–1.2 mg/kg IV
→ Comparable onset to succinylcholine
Maintenance / ICU infusion
- Bolus: 0.1–0.2 mg/kg
- Infusion: 5–12 µg/kg/min
6. Indications in ICU
Airway & Ventilation
- Rapid sequence intubation
- Hyperkalemia risk
- Burns
- Neuromuscular disease
- Severe ARDS → ventilator synchrony
- Status asthmaticus (refractory)
- Raised ICP (prevents coughing/straining)
Procedural
- Central line insertion (rarely)
- Imaging (MRI/CT if needed)
7. Rocuronium vs Succinylcholine
|
Feature |
Rocuronium |
Succinylcholine |
|
Type |
Non-depolarizing |
Depolarizing |
|
Onset |
Fast (60–90 sec) |
Very fast (30–60 sec) |
|
Duration |
Longer (30–60 min) |
Short (5–10 min) |
|
Hyperkalemia |
No |
Yes |
|
Malignant hyperthermia |
No |
Yes |
|
Fasciculations |
No |
Yes |
Guideline shift:
Rocuronium increasingly preferred for RSI when sugammadex available
8. Advantages in Critical Care
- Hemodynamically stable
- No histamine release
- No increase in ICP/IOP
- Safe in:
- Burns
- Neuromuscular disorders
- Hyperkalemia
9. Adverse Effects
Common
- Prolonged paralysis (especially in ICU)
- ICU-acquired weakness (when prolonged use)
Rare
- Anaphylaxis (higher risk among NMBAs )
- Tachycardia (mild)
10. Contraindications / Caution
- Severe hepatic dysfunction → prolonged action
- Obesity → dose based on ideal body weight (IBW)
- Myasthenia gravis → exaggerated effect
11. Monitoring in ICU
Train-of-Four (TOF)
- Target: 1–2 twitches out of 4
- Prevents over-paralysis
Clinical endpoints
- Ventilator synchrony
- Absence of spontaneous breathing
12. Reversal
Sugammadex
- Specific reversal agent for aminosteroid NMBAs
- Encapsulates rocuronium → rapid reversal
|
Dose |
Indication |
|
2 mg/kg |
Moderate block |
|
4 mg/kg |
Deep block |
|
16 mg/kg |
Immediate reversal (RSI) |
Advantage over neostigmine:
- Faster
- More predictable
- No cholinergic side effects
