Objective: To investigate effects of two doses of dexmedetomidine (Dex) on the recovery quality from general anesthesia undergoing thyroidectomy.
Methods: A prospective randomized controlled double-blind trial was conducted in 90 patients admitted to Shengjing Hospital of China Medical University who were scheduled for thyroidectomy. They were randomly divided into three groups: group D0.4 received Dex 0.4 μg/kg intravenously, group D0.8 received Dex 0.8 μg/kg intravenously, and control group with same volume of normal saline. There were 30 patients in each group, and all the patients received the above drug or saline 30 minutes after intubation. The heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded before Dex administration, at the end of surgery, time of eye opening and extubation, and 10 minutes after extubation. Time of eye opening after surgery and time of extubation after eye opening were recorded. End-tidal partial pressure of carbon dioxide (PETCO2) before and after operation as well as restlessness score (RS), Ramsay sedative score, and visual analogue pain scale (VAS) scores at 10 minutes after extubation were recorded. Events during extubation including cough, nausea and vomiting, respiratory depression were also recorded.
Results: (1) Compared with control group, in D0.4 and D0.8 groups incidence of lowering of HR, SBP and DBP was lower at time of eye opening and extubation, and 10 minutes after extubation. Compared with D0.4 group, D0.8 group had lower HR at the time of extubation and 10 minutes after extubation, SBP was lower at the time of eye opening and extubation, and lower DBP at the time of eye opening. (2) D0.4 and D0.8 groups showed lower RS and VAS scores than those of control group, Ramsay sedative score in groups D0.4 and D0.8 was higher than that in control group (RS: 1.40±0.51, 1.20±0.42 vs. 1.90±0.56; VAS: 1.50±0.52, 0.80±0.63 vs. 2.50±0.52; Ramsay: 2.10±0.56, 2.40±0.51 vs. 1.60±0.51, P<0.05 or P<0.01), and VAS score in group D0.8 was lower than that in D0.4 group (P<0.01). The time of eye opening and extubation were longer in group D0.8 as compared with those in control and D0.4 groups (12.50±1.08 minutes vs. 10.50±1.58 minutes, 10.40±1.26 minutes; 15.00±0.94 minutes vs. 13.00±1.63 minutes, 12.80±1.13 minutes, P<0.05 or P<0.01), but there was no significant difference between the latter two groups. No significant difference in PETCO2 was found among three groups before and after surgery. (3) The incidence rate of cough, nausea and vomiting in control group (16.7%, 13.3%) were significantly higher than those in groups D0.4 (3.3%, 0) and D0.8 (0, 0). There was no respiratory depression in the three groups.
Conclusions: Adjunctive infusion of Dex 0.4 μg/kg at 30 minutes after anesthesia induction was recommended as it may result in more steady hemodynamics, with shorter recovery time and extubation time after thyroidectomy.