Application Of Dexmedetomidine Combined With Remifentanil For Sedation And Analgesia During Therapeutic Endoscopic Retrograde Cholangio-Pancretography

Background and objective: The endoscopic retrograde cholangio-pancreatography（ERCP）describes a complex and uncomfortable endoscopic minimally invasive gastrointestinal procedure that requires moderate analgesia and sedation.Dexmedetomidine as a conscious sedative exhibits both analgesia and respiratory sparing effects.In this designed study,we evaluated and compared the efficacy and safety of a dexmedetomidine-remifentanil（DR）regimen with a midazolam-remifentanil（MR）combination in sedation and analgesia during ERCP.Patients and Methods: 198 patients subjected to ERCP were randomized.Sedation was induced with dexmedetomidine and remifentanil（DR,n = 109）or midazolam and remifentanil（MR,n = 89）.Routine nasal catheter oxygen uptake（4 L/min）was observed in all patients.The patients were injected intravenously（Ⅳ）with a bolus of midazolam(0.05 mg kg^-1)in the MR group and continuous intravenous pumping of dexmedetomidine(1 μg kg^-1)was applied for 10 minutes in the DR group.The dosage of midazolam and dexmedetomidine was reduced by 60%[33] and 50%[34] each for patients over age 65.Next,an initial loading dose of 1 μg kg^-1 and 0.05-0.2 μg kg^-1 min^-1 of remifentanil was administered in all patients via continuous Ⅳ infusion.Extra remedy dose of midazolam（0.02 mg/kg）was given to maintain sufficient sedation and analgesia,while increasing the pumping rate of remifentanil by 0.02 μg/kg·min,in case of abrupt irregular movement and difficult in endoscopic operation.Subsequently,hemodynamic（invasive blood pressure and pulse oxygen saturation）and respiratory parameters（pulse oxygen saturation,respiratory frequency）,Ramsay Sedation Scale（RSS）,Visual Analogue Scale（VAS）,endoscopist and patient satisfaction were assessed and reccorded.Furthermore,adverse events as well as recovery time and discharge time were rated.Results: Patient satisfaction scores were significantly higher in the DR group compared to the scores in the MR group（P < 0.05）.Furthermore,the overall operation time was significantly shorter in the DR group than in the MR group（P < 0.05）.The DR group was found to require a statistically significantly reduced occurrence of extra bolous of midazolam（P < 0.05）,so the occurrence of desaturation was higher in the MR group than in the DR group（P < 0.05）.Although nausea during catheterization of oropharynx was found to be more pronounced in the DR group（P < 0.05）,statistically significant values could not be determined between the two groups with regards to amnesia,agitation.Conclusions: The combined of dexmedetomidine and remifentanil protocol can provide a parallel sedative and analgesic effects of midazolam combined with remifentanil.Furthermore,the patient satisfaction is improved and the adverse effect of respiratory despression is significantly reduced.With the results obtained,these results show that the combination of dexmedetomidine and remifentanil can be used as a safer method of sedation and analgesia during ERCP procedures.