[Study of comparing dexmedetomidine and remifentanil for conscious sedation during radiofrequency ablation of hepatocellular carcinoma].

Objective: This study aimed to compare dexmedetomidine with remifentanil for conscious sedation in patients undergoing radiofrequency ablation of hepatocellular carcinoma. Methods: Sixty patients, who were aged 41 to 73 years with American Society of Anesthesiologists (ASA) physical status Ⅰ-Ⅱ, and scheduled for elective radiofrequency ablation of hepatocellular carcinoma under conscious sedation in National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, from January 2014 to June 2016, were allocated randomly to receive dexmedetomidine maintenance regimen(group D, n =30)or remifentanil maintenance regimen(group R, n =30)by random digital table. Subjects in group D received dexmedetomidine at a loading dose of 0.5 μg/kg over 10 min followed by 0.2-1.0 μg·kg(-1)·h(-1) infusion until Ramsay sedation scale reached 3-4. Patients in group R received a loading dose of remifentanil 1 μg/kg followed by remifentanil 4-10 μg·kg(-1)·h(-1) infusion and propofol 1-2 mg·kg(-1)·h(-1) infusion until Ramsay sedation scale reached 3-4. Haemodynamic variables, respiratory rate(RR), pulse oxygen saturation (SpO(2))and numeric rating scales(NRS) in each group were collected at entrance(T(0)), puncturing(T(1)), 15 min after beginning of radiofrequency ablation(T(2)), the end of radiofrequency ablation(T(3)) and 30 min after operation(T(4)). Efficacy of anesthesia, incidences of intraoperative respiratory depression, postoperative nausea and vomiting, patient and surgeon satisfaction were evaluated. Results: Compared with group D, the arterial blood pressure and heart rate at T(2) [(92.2±15.7)mmHg vs (102.4±16.7)mmHg, (69.7±15.3) beats/min vs (79.4±17.7) beats/min] and respiratory rate at T(1), T(2) and T(3) [(10.1±1.9) breaths/min vs(12.3±1.7) breaths/min, (10.8±1.5) breaths/min vs(13.6±1.6) breaths/min, (13.4±1.6) breaths/min vs(14.5±1.4)breaths/min] were significantly lower in group R ( t =-2.437, -2.271, -4.726, -6.993, -2.834, all P <0.05). With less sulfentanil consumption(23.2±8.3)μg vs( 35.5±11.7)μg, group R got less NRS at T(2) and T(3)(2.4±1.1) vs(3.5±1.2), (2.4±1.3) vs(3.6±1.1), and higher NRS at T(4)(3.4±1.1) vs( 2.1±0.9) than group D( t =-4.696, -3.701, -3.860, 5.010, all P <0.05). Compared with group R, the incidence of intraoperative respiratory depression was significantly lower (23.3% vs 56.7%)and the incidence of inadequate anesthesia(20% vs 0) was significantly higher in group D(χ(2)=5.625, 4.630, both P <0.05). Conclusion: Both dexmedetomidine and remifentanil can be successfully used for conscious sedation in patients undergoing radiofrequency ablation of hepatocellular carcinoma. Remifentanil maintenance regimen provides better intraoperative analgesia and operative condition, while dexmedetomidine is superior to remifentanil in reducing intraoperative respiratory depression and postoperative pain.