[Different doses of dexmedetomidine for quiet extubation during anesthesia recovery in hypertensive patients].

OBJECTIVE: To explore the feasibility of different doses of dexmedetomidine for quiet extubation during anesthesia recovery in hypertensive patients monitored with Narcotrend. METHODS: A total of 120 hypertensive patients scheduled for thyroid surgery from August 2012 to June 2014 in the Second Affiliated Hospital of Wenzhou Medical University, were randomly divided into 6 groups (n=20 each). Dexmedetomidine 0.4 (group M1), 0.6 (group M2), 0.8 (group M3) or 1.0 (group M4) µg·kg(-1)·h(-1), remifentanil 0.1 µg·kg(-1)·min(-1) (group R) and normal saline (group S) were infused for half an hour before the end of surgery, and extubation was carried out when Narcotrend index (NI) values were ≥80 in each group. Data of heart rate (HR), systolic blood pressure (SBP) and minimal alveolar concentration (MAC) of sevoflurane were observed and recorded at the time of baseline (T0), half an hour (T1) and 15 min (T2) before the end of surgery, stopping sevoflurane (T3), before extubation (T4), 1 min (T5), 5 min (T6) and 10 min (T7) after extubation. Extubation time, recovery time and related adverse reactions were also recorded. RESULTS: Compared with T0, SBP and HR at T4 to T7 in four M groups were significantly lower (all P<0.05). SBP and HR at T6, T7 in group R were significantly lower than at T0 (all P<0.05). SBP at T6, T7 and HR at T4 to T7 in group R were significantly lower than that of group S (all P<0.05). SBP and HR at T4 to T7 in four M groups were significantly lower than that of group S and group R (all P<0.05). The values of MAC of sevoflurane at T2 and T3 in group R and M2-4 were significantly lower than at T1 and that of group S (all P<0.05). Recovery time in group M3 [(19.1±2.8) min] and group M4 [(20.6±4.1) min] were significantly longer compared with other four groups (all P<0.05). The percentage of cough grade at level I and II in each M group and group R during extubation was significantly higher than that in group S (85%, 85%, 90%, 95%, 80% vs 45%, all P<0.05). CONCLUSIONS: Dexmedetomidine could be safely used in hypertensive patients monitored with Narcotrend for quiet extubation during anesthesia recovery, but larger doses of dexmedetomidine may prolong the recovery time.