Abstract

Background: Dexmedetomidine produces sedation while maintaining a degree of arousability and may reduce the duration of mechanical ventilation and delirium among patients in the intensive care unit (ICU).Data comparing Dexmedetomedine and Fentanyl as an effective sedation in mechanically ventilated patients are lacking.
Methods: In a prospective, bouble blind study, we randomly assigned newly mechanically ventilated patients  to receive  Dexmedetomidine (0.3 to 0.7mcg/kg/hr) or fentanyl (1 to 3mcg/kg/hr) with doses adjusted to achieve target sedation goals set by clinicians according to the Richmond Agitation–Sedation Scale (RASS, on which scores range from −5 [unresponsive] to +4 [combative]). Midazolam 0.002 mg/ Kg bolus was administered as rescue sedation if the target sedation score could not be achieved within the infusion range. Primary end points were to assess the total dose of the sedative drugs, time required to achieve target sedation as well as total dose of rescue sedation administered.
Results:  62 patients were included in the study, of which 31 received Dexmedetomidine, and 31 received fentanyl infusion. It was observed that there was a significant difference among the two groups with reference to the time required to achieve target Richmond Agitation Sedation score (RASS) of -1.The mean time to achieve target RASS of -1 in Dexmedetomidine group was 2.97 ± 1.278 hours whereas in Fentanyl group  6.29 ± 3.388 hours  (p<.001  vhs) . The mean rate of infusion required to achieve target RASS of -1 in Dexmedetomidine group was 0.5 ± 0.1 mcg/kg/min and in Fentanyl group 2.7 ± 0.8266 mcg/kg/hr. The mean dose of Midazolam as rescue sedation was higher in Fentanyl group (2.29 ± 1.657) as compared to Dexmedetomidine (0.39 ± 1.202) mg (P < 0.01).
Conclusion:  Dexmedetomidine group achieved adequate sedation in lesser time and in doses within the prescribed clinical range as compared to fentanyl group, in mechanically ventilated patients. Further, the 24 hour midazolam requirement was higher in fentanyl group.