A study to compare the overall effectiveness between midazolam and dexmedetomidine during monitored anesthesia care: A randomized prospective study

BACKGROUND: Monitored anesthesia care (MAC) combines intravenous sedation along with local anesthetic infiltration or nerve block. Several drugs have been used for MAC, but all are associated with complications. Dexmedetomidine is a selective α2-adrenoceptor agonist with both sedative and analgesic properties and is devoid of respiratory depressant effects. Its short elimination half-life makes it an attractive agent for sedation during MAC. AIM: Comparative evaluation of dexmedetomidine and midazolam for MAC. METHODS: In this prospective, randomized, double-blind study, 50 American Society of Anesthesiologist I and II patients undergoing a surgical or diagnostic procedure of <1 h requiring MAC were enrolled. Dexmedetomidine-ketamine (Group “KD”) patients (n = 25) received intravenous (I.V.) dexmedetomidine 1 mcg/kg over 10 min followed by 0.5 mg/kg of I.V. ketamine. Midazolam-ketamine patients (n = 25) received I.V. midazolam 0.05 mg/kg over 10 min followed by 0.5 mg/kg of I.V. ketamine to get a targeted level of sedation (≤4 using Observer's Assessment of Alertness/Sedation Scale score). Inadequate sedation (e.g., 15% increase in mean arterial blood pressure or heart rate, decrease in degree of calmness, increase in respiratory rate, physical movement) was treated by a ketamine bolus of 0.5 mg/kg as a rescue analgesia. STATISTICAL ANALYSIS: The statistical tests used in the study are unpaired Student's t-test for continuous variables and Chi-square test for categorical variables. Mann–Whitney test was used to assess the patient and surgeon satisfaction. Data were expressed as mean ± standard deviation. Value of P < 0.05 is considered significant and P < 0.0001 as highly significant. RESULTS: Clinically desired sedation and analgesia was achieved earlier and better with dexmedetomidine. Patients and surgeons satisfaction were significantly higher with dexmedetomidine. The requirement of additional sedation and analgesia was less in dexmedetomidine (KD) group. CONCLUSION: During MAC dexmedetomidine provides better sedation and analgesia than midazolam.