Comparison between dexmedetomidine and propofol for sedation in the intensive care unit: patient and clinician...

The alpha2 agonist dexmedetomidine is a new sedative and analgesic agent which is licensed in the USA for post-operative intensive care sedation. We compared dexmedetomidine with propofol in patients requiring sedation in intensive care. Twenty adult patients expected to require a minimum of 8 h artificial ventilation after surgery were randomized to receive sedation with either dexmedetomidine or propofol infusions. Additional analgesia, if required, was provided by an alfentanil infusion. Depth of sedation was monitored using both the Ramsay sedation score (RSS) and the bispectral index (BIS). Cardiovascular, respiratory, biochemical and haematological data were obtained. Patients' perceptions of their intensive care stay were assessed using the Hewitt questionnaire. Sedation was equivalent in the two groups [median (interquartile range): RSS, propofol group 5 (4-5), dexmedetomidine group 5 (4-6) (P=0.68); BIS, propofol group 53 (41-64), dexmedetomidine group 46 (36-58); P=0.32], but the propofol group received three times more alfentanil compared with patients sedated with dexmedetomidine [2.5 (2.2-2.9) mg h(-1) versus 0.8 (0.65-1.2) mg h(-1) (P=0.004)]. No differences were found in arterial pressures between the groups, but heart rate was significantly lower in the dexmedetomidine group [mean (SD) 75 (6) vs 90 (4) beats min(-1)]. Extubation times were similar and rapid with the use of both sedative agents [median (range) 28 (20-50) and 29 (15-50) min (P=0.63) respectively for the propofol and dexmedetomidine groups]. No adverse events related to the sedative infusions occurred in either group. Despite ventilation and intubation, patients sedated with dexmedetomidine could be easily roused to cooperate with procedures (e.g. physiotherapy, radiology) without showing irritation. From the clinician's and patient's perspectives, dexmedetomidine is a safe and acceptable sedative agent for those requiring intensive care. The rate pressure product is reduced in patients receiving dexmedetomidine, which may protect against myocardial ischaemia. Dexmedetomidine reduces the requirement for opioid analgesia.