Patients in the intensive care unit (ICU) setting require invasive monitoring and treatments that often lead to anxiety and pain. In particular, use of mechanical ventilation may create a variety of physical and psychological stresses.1,2 The use of intravenous sedatives is considered integral in the care of mechanically ventilated ICU patients.
Dexmedetomidine, an α-2 agonist, produces sedation, anxiolysis, and partial analgesia. In addition, It is less sedating than the commonly used agents and does not suppress the respiratory drive.3 Although dexmedetomidine in clinical trials was associated with less episodes of acute brain dysfunction (delirium and coma) and improved patients ability to communicate while sedated, none of these studies assessed psychological outcomes.4-7 This is important because anxiety, depression, acute stress disorder (ASD), and posttraumatic stress disorder (PTSD) in ICU patients may be related to factors such as sedation regimen, the occurrence of delirium, the duration of mechanical ventilation, and the ability of patients to remember their ICU experiences.8,9
MacLaren and colleagues sought to assess the utility and safety of transitioning patients from benzodiazepines to dexmedetomidine once they qualified for daily awakenings and to specifically assess patient recall of their ICU experiences and the incidence of anxiety, depression, and ASD manifestations.10 The study was a randomized double-blind pilot study. All critically ill patients requiring mechanical ventilation and receiving a benzodiazepine infusion with an anticipated need of at least 12 additional hours of sedation at a Riker sedation agitation score of 3 to 4 were recruited once they qualified for daily awakenings. Patients with the following: age less than 18 or greater than 85 years; administration of benzodiazepines for purposes other than sedation (e.g., seizure control); administration of neuromuscular blockers for more than 12 hours; administration of epidural medications; active myocardial ischemia; second- or third-degree heart block; hemodynamic instability; active neuromuscular disease; Childs-Pugh class C liver disease; alcohol abuse within 6 months of study eligibility; baseline dementia; solid organ transplant; pregnancy; moribund state with planned withdrawal of life support; enrollment in another therapeutic study; or known or suspected severe adverse reactions to any benzodiazepines, dexmedetomidine, or clonidine were excluded.
A total of 469 patients were screened and only 23 patients met the inclusion and exclusion criteria and were accordingly enrolled. Within 24 hours of qualifying for daily awakenings, patients were randomized to receive dexmedetomidine (n=11) or midazolam continuous infusion (n=12). Both agents were titrated by the bedside nurse for a Riker score of 3 to 4. Dexmedetomidine was started at 0.15 mg/kg/ h and adjusted by 0.15 mg/kg/h to a maximum of 1.5 mg/kg/h, while midazolam was started at 1 mg/h and adjusted by 1 mg/h to a maximum of 10 mg/h. All patients received fentanyl by continuous infusion at baseline. Open-label midazolam or fentanyl were permitted according to the sedation and analgesia protocol if agitation or pain were present or if the ...