Efficacy of different dose of dexmedetomidine combined with remifentanil in colonoscopy: a randomized controlled trial

BACKGROUND: Dexmedetomidine has advantages during colonoscopy as it allows the patient to cooperate during the procedure. Few studies examined the dexmedetomidine-remifentanil combination. This study was to evaluate the effects of different doses of the dexmedetomidine-remifentanil combination in colonoscopy. METHODS: This was a prospective trial carried out at the Fourth Hospital of Hebei Medical University between 02/2018 and 10/2018. The patients were randomized: group I (dexmedetomidine 0.2 μg·kg(− 1)), group II (dexmedetomidine 0.3 μg·kg(− 1)), and group III (dexmedetomidine 0.4 μg·kg(− 1)), all combined with remifentanil. The primary outcomes were the patient’s body movements during the procedure and adverse events. RESULTS: Compared with at admission (T(0)), the SBP, HR, and RR at immediately after giving DEX (T(1)), at the beginning of the examination (T(2)), 5 min after the beginning of the examination (T(3)), 10 min after the beginning of the examination (T(4)), and at the end of the examination (T(5)) in the three groups were all reduced (all P < 0.05), but all were within the clinically normal range. SpO(2) remained > 98% in all patients during the examination. Compared with T(0), the BIS values of the three groups were decreased at T(1) and T(2) (all P < 0.05). There were no significant differences in BIS among the three groups (all P > 0.05). The minimum BIS value in group III was lower than in groups I and II (P < 0.05). The degree of satisfaction with the anesthesia effect was higher in groups II and III that in group I (P < 0.05). No hypotension occurred, seven patients had bradycardia, and four patients had nausea/vomiting. CONCLUSIONS: Dexmedetomidine 0.3 μg·kg(− 1) combined with remifentanil was effective for colonoscopy and had few adverse reactions. Chinese Clinical Trial Registry: ChiCTR2000029105, Registered 13 January 2020 - Retrospectively registered.