Comparison between Dexmedetomidine and Fentanyl Infusion for Short-Term Sedation in Mechanically Ventilated Patients in Intensive Care Unit

Abstract

Background: Sedation and analgesia are essential components of care for mechanically ventilated patients in the ICU (Intensive Care Unit). Conventional sedative and opioid agents may be associated with prolonged sedation, respiratory depression and haemodynamic effects. Dexmedetomidine, a selective α2-adrenergic agonist, provides sedation and analgesia with preservation of arousability and minimal respiratory depression. This study compared dexmedetomidine with fentanyl for short-term sedation in mechanically ventilated ICU patients.

Methods: A prospective, randomized, double-blind study was conducted in a Tertiary Care Centre, South India for a period of one and half years. Sixty-two mechanically ventilated patients aged 20–60 years were enrolled and randomly allocated into two groups of 31 each. Group I received dexmedetomidine infusion and Group II received fentanyl infusion. Sedation was assessed using the RASS (Richmond Agitation-Sedation Scale), with haemodynamic parameters and 24-hour rescue midazolam requirements recorded. Statistical analysis was performed using the chi-square test and Student’s unpaired t test.

Results: The mean time to achieve RASS −1 was significantly shorter with dexmedetomidine than fentanyl (2.97 ± 1.278 vs. 6.29 ± 3.388 hours; p<0.001). The mean rescue midazolam requirement was also significantly lower with dexmedetomidine (0.39 ± 1.202 vs. 2.29 ± 1.657 mg/24 hours; p<0.001), representing an 87% reduction. The mean dexmedetomidine infusion rate required for effective sedation was 0.5 ± 0.1 µg/kg/hour. No significant differences in heart rate or mean arterial pressure were observed between the groups.

Conclusion: Dexmedetomidine provided faster and effective sedation with significantly lower rescue midazolam requirements compared with fentanyl, while maintaining a comparable haemodynamic profile. It may therefore be considered an effective sedative for short-term sedation during the first 24 hours of mechanical ventilation in ICU patients.