Vecuronium Administration in ARDS: Bolus vs Infusion
For vecuronium specifically in ARDS, continuous infusion is the preferred method of administration, requiring significantly less total drug (approximately 40% less) while maintaining adequate neuromuscular blockade compared to intermittent boluses. 1
Primary Recommendation: Prefer Cisatracurium Over Vecuronium
Before addressing the bolus versus infusion question for vecuronium, it is critical to note that cisatracurium, not vecuronium, is the neuromuscular blocking agent with the strongest evidence for mortality benefit in ARDS. 2 The 2016 Critical Care Medicine guidelines recommend continuous IV infusion of an NMBA (specifically cisatracurium based on trial data) for 48 hours in early ARDS with PaO2/FiO2 < 150. 2
However, the 2020 Intensive Care Medicine Rapid Practice Guideline significantly revised this recommendation after the ROSE trial, now recommending against routine NMBA infusion in ARDS and suggesting it only for patients requiring deep sedation to facilitate lung-protective ventilation or prone positioning. 2
When Vecuronium Must Be Used: Infusion vs Bolus
Continuous Infusion is Superior
If vecuronium is selected as the NMBA in ARDS, continuous infusion should be used over intermittent boluses based on the following evidence:
Reduced total drug requirement: Continuous infusion requires approximately 0.79 mg/kg per 12 hours compared to 1.34 mg/kg per 12 hours with hourly boluses (41% reduction, p < 0.01). 1
Consistent neuromuscular blockade: Infusion maintains more stable blockade levels (average 87% twitch depression) compared to the fluctuating levels with bolus dosing. 3
Faster recovery: Despite lower total doses, continuous infusion allows for more predictable recovery times once discontinued. 4
Practical Dosing Algorithm for Vecuronium Infusion
Loading dose: 0.075-0.1 mg/kg IV bolus 3
Infusion rate: Start at 0.075 mg/kg/hour (approximately 1 μg/kg/minute) within 10 minutes of loading dose 3
Monitoring: Use train-of-four (TOF) monitoring to titrate; target 1-2 twitches out of 4 1, 4
Duration: Limit to 48 hours if following ARDS protocols, with additional boluses permitted if plateau pressures exceed 32 cm H2O 2
Critical Caveats and Pitfalls
Drug Selection Matters More Than Delivery Method
Cisatracurium demonstrates superior outcomes compared to vecuronium in ARDS patients, with fewer ventilator days (-1.01 days, p = 0.005) and ICU days (-0.98 days, p = 0.028), though mortality was similar. 5 Cisatracurium has minimal cardiovascular effects and potential anti-inflammatory properties via nicotinic acetylcholine receptor blockade. 6
Context-Dependent Use
The benefit of any NMBA infusion in ARDS is highly dependent on sedation strategy:
Light sedation strategy: Avoid NMBA infusion; use intermittent boluses only if absolutely necessary 2
Deep sedation strategy: NMBA infusion for 48 hours is reasonable for patients requiring deep sedation for lung-protective ventilation or prone positioning 2, 6
Resistance Risk
Cross-resistance between vecuronium and other NMBAs can occur, requiring progressively higher doses (up to 2.3 mg/kg/hour) that may still produce inadequate blockade. 7 This supports using cisatracurium as first-line when available.
Monitoring is Essential
TOF monitoring is mandatory regardless of delivery method, as it reduces total drug dose, accelerates recovery of neuromuscular function, and shortens intubation times compared to clinical assessment alone. 2 Quantitative monitoring should continue until TOF ratio ≥0.9 is achieved. 8
ICU-Acquired Weakness
While earlier concerns existed about NMBA-associated weakness, 48-hour cisatracurium infusions do not increase ICU-acquired weakness risk compared to no NMBA. 2, 6 However, this data is specific to cisatracurium and may not apply to vecuronium.
Current Evidence Hierarchy
The evidence strongly favors: