The Society of Critical Care Medicine (SCCM) recommends that all mechanically ventilated patients receive analgesia, sedation, and delirium assessment and management while intubated. SCCM reinforced these principles in their 2018 clinical practice guideline on the prevention and management of pain, agitation/sedation, delirium and immobility.[i] The SCCM has promoted the ABCDEF bundle for all mechanically ventilated patients and this bundle has become the standard of care for ventilated patients in the ICU.
A – Assessment of pain and management of pain with analgesics
B – Both SAT (spontaneous awakening trial) and SBT (spontaneous breathing trial) daily in all appropriate patients
C – Choice of sedative agents
D – Delirium assessment (with CAM-ICU assessments) and management
E – Early mobility
F – Family engagement
The most common sedative agent used for mechanically ventilated adult patients is propofol; however, propofol is not without its adverse reactions. Propofol can suppress the respiratory drive, cause oversedation as well as hypotension, bradycardia, hypertriglyceridemia and rarely propofol infusion syndrome. The ideal scenario is to have a patient comfortable, but interactive, on the ventilator so that they may even participate with early mobility training. For this reason, other sedative agents such as dexmedetomidine have been used in the effort to minimize days free of coma or delirium and increase ventilator-free days in the ICU.
A recent multicenter, double-blind trial (MENDS2 trial) was performed at 13 U.S. hospitals that randomized 432 patients with known or suspected sepsis and required mechanical ventilation. One group was placed on dexmedetomidine 0.2 – 1.5 mcg/kg/hr (median dose of 0.27 mcg/kg/hr) and the other group received propofol infused at 5-50 mcg/kg/min (median dose 10.2 mcg/kg/min) titrated to a RASS (Richmond Agitation Sedation Scale) score of 0 to -2. Analgesia was provided with intermittent opioid boluses or a fentanyl infusion. The incidence of hypotension and bradycardia were similar in both groups. The primary endpoint was days alive with delirium or coma. Secondary endpoints were ventilator-free days at 30 days and 90-day mortality. There was no statistically significant difference between the two groups in either the primary endpoint or the secondary endpoints.[ii]
Therefore, for patients with sepsis requiring mechanical ventilation, dexmedetomidine is equally efficacious as propofol for ventilator sedation. The benefits of dexmedetomidine are that it tends to have a less sedating effect compared with propofol so patients can be more interactive. In addition, dexmedetomidine can be beneficial for the prevention of and management of delirium (especially in patients with substance use withdrawal disorders – such as alcohol withdrawal, or sympathomimetic [cocaine or methamphetamine] withdrawal disorders). Some investigators also has anti-inflammatory and “bacterial clearance” properties that may be beneficial in septic patients.
[i] Devlin J et al. Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Crit Care Med. 2018; 46 (9): e825-e873.