UMEM Educational Pearls - By Zachary Wynne

The presence of an endotracheal tube by itself does not mandate sedation and many patients require no sedatives while intubated in the ICU. However, patients intubated in the emergency department usually require initial sedation while still paralyzed from RSI. Sedation can also help facilitate procedures and imaging in critically ill patients during initial management. 

Current literature has found increased mortality and length of ventilator requirement in oversedated ED patients. The target sedation level for the general population remains a goal RASS (Richmond Agitation-Sedation Scale) of 0 to -1. Society of Critical Care Medicine guidelines from early 2025 recommend dexmedetomidine over propofol as the preferred sedative for light sedation and reducing delirium risk in intubated critically ill patients. A recent trial re-examined other clinical outcomes between these two common sedative agents.

A2B Randomized Clinical Trial - JAMA 2025

Clinical Question: Does alpha 2 adrenergic receptor agonist sedation (dexmedetomidine or clonidine) reduce duration of mechanical ventilation in mechanically ventilated patients compared to a propofol based regimen (usual care)?

Where: 41 UK ICU’s from December 2018 to October 2023

Who: 1438 adults receiving mechanical ventilation for less than 48 hours, receiving propofol and opioid for sedation/analgesia, expected to require mechanical ventilation for greater than 48 hours

Intervention: protocol driven sedation to reach a RASS score of -2 to +1 (either dexmedetomidine, clonidine, or propofol). Of note, propofol could be added to achieve deeper sedation goal if deemed necessary by care team.

Outcomes:

• No significant difference in time to extubation between dexmedetomidine vs. propofol (HR of 1.09, p=0.2) OR clonidine vs. propofol (HR of 1.05, p=0.34)
• Higher rates of agitation in the dexmedetomidine group (HR of 1.54, CI 1.21-1.97) and clonidine group (HR of 1.55, CI 1.22-1.97) compared to propofol group
• Mortality at 180 days similar between all groups
• Severe bradycardia seen more frequently in dexmedetomidine and clonidine groups compared to propofol group although unclear if ongoing propofol administration had any effect on these groups
• Subgroup analysis showed a weak interaction with age as a continuous variable showing reduced benefit on time to extubation with dexmedetomidine vs. propofol at later decades of life (i.e. dexmedetomidine showing potential benefit at younger ages)

Bottom Line:

While either dexmedetomidine or propofol, with appropriate use of opiates for pain management, are appropriate agents in non-paralyzed mechanically-ventilated patients, propofol may be a more appropriate choice in patients with greater agitation while boarding in the emergency department. However, close attention is needed to avoid the overly deep analgosedation associated with increased mortality. Maintain a goal RASS of 0 to -1 with frequent re-evaluation of your ICU boarders.

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