A Comparison Between Dexmedetomidine And Lidocaine For The Assessment On Quality Of Recovery From General Anesthesia In Patients With Thyroidectomy

Objectives: To evaluate the efficacy of perioperative administration of dexmedetomidine and lidocaine on the quality of recovery from general anesthesia in patients with thyroidectomy. Method: This trial was conducted on 114 women for selective thyroidectomy, aged 18 to 60, BMI between 18 to 25 kg/m2, ASA I or II, with presence of normal physical status and thyroid function. All study subjects were randomly allocated into three groups(n=38), and received the individual medication until the last suture. In Group D, intravenous bolus of 0.5mg/kg dexmedetomidine(over 10min) was administered 15 min before the induction of general anesthesia, and maintained with continuous infusion at 0.2mg·kg-1·h-1(4mg/ml). Group L was given intravenous bolus of 1.5mg/kg lidocaine at 5min before the induction of general anesthesia, and maintained with continuous infusion at 1.5mg·kg-1·h-1(20mg/ml); Group C was administered with comparative amount of normal saline in identical time period. Induction of anesthesia using total intravenous anesthetic technique was applied with sufentanil 0.5mg/kg, cis-atracurium 0.2mg/kg, propofol(1~2)mg/kg in sequence. Tracheal intubation was performed when reached sufficient depth of anesthesia, then mechanical ventilated with tidal volume of 6~10ml/kg, respiratory rate of 12 bpm, and PETCO2 of 35~45mmHg. General anesthesia was maintained with 2-3 vol% sevoflurane in oxygen/air, with fresh gas flow at 2L/min, and bispectral index(BIS) within 40~60. Sevoflurane inhalation was terminated at 10 minutes before the anticipated end of surgery. Postoperative analgesia was provided by patient-controlled intravenous analgesia(PCIA) pump, which contained sufentanil 1mg/kg and tropisetron 5mg in 100 ml normal saline. The PCIA device was setup without background infusion, bolus dose of 5ml, lockout interval of 10 minutes and an hour limit of 32 ml. Outcome measures: 1. Quality of recovery score(QoR-40) in preoperative and in 24 hours postoperative. 2. Postoperative 1hr, 2hr, 4hr, and 8hr of Visualized Analogue Scale(VAS) pain score at rest and during motor(swallowing movement) stimulation. 3. Changes in HR, BP, and SpO2 when patients were entering(T0), before induction(T1), before tracheal intubation(T2), immediately after tracheal intubation(T3), at the beginning of surgical incision(T4), during traction of the upper pole of thyroid lobe(T5), at the end of surgical procedure(T6), before tracheal extubation(T7), instantly after tracheal extubation(T8), at discharge from post-anesthetic care unit(T9). 4. The occurrence of coughing when extubation, postoperative nausea or vomiting(PONV), and analgesic consumptions during first 24 hours. Result: 1. The preoperative quality of recovery(QoR-40) score has no significant difference between groups. The overall assessment with QoR-40 was superior higher in Group D, when compared with patients in Group L and Group C, and which differences have statistical significance(P < 0.05). 2. In comparisons for VAS pain score at rest, patients in Group D and Group L scored lower at 1hr, 2hr, and 4hr after surgery, with statistical significant differences when comparing with the Group C(P < 0.05). As to the VAS pain score during motor stimulation by swallowing movement, Group D and Group L were significant lesser than Group C at 1hr, 2hr, and 4hr after surgery(P < 0.05). And VAS pain score during movement was also significantly decreased in Group D at 8hr, 24 hr after surgery in comparison with the other two groups(P < 0.05), while no statistical significant difference with the other observational time. 3. The hemodynamic parameters, including SBP, DBP, and MAP have generally presented a downward trend in Group D and Group L during anesthetic and surgical interventions, especially at T3 and T9, the differences have statistical significance, when compared with Group C(P < 0.05). In contrast with Group D, the collected data of Group L and Group C revealed the elevated SBP, DBP, and MAP have significant difference at T5 and T8(P < 0.05).The average level of SBP, DBP, and MAP in Group D were significantly below that of the Group C at T7(P < 0.05), however, no difference has been found within Group C and Group L, whereas no statistical significance in difference among the other observational time. 4. The coughing reflex has been significantly reduced in Group D, when compared with the other two groups(P < 0.05). Postoperative analgesic consumption, as with the cumulative amount of patient-controlled analgesia in Group D and Group L has decreased sharply, in their comparison with Group C(P < 0.05). As for the incidence of nausea and vomiting in postoperative 24 hr, both Group D and Group L has significantly fewer cases than in the Group C(P<0.05), even though fewer cases in Group D when compared with Group L, their difference has been without statistical significance(P < 0.05). Conclusion: Both dexmedetomidine(0.5μg/kg,0.2μg·kg-1·h-1) and lidocaine(1.5mg/kg,1.5mg·kg-1·h-1), especially dexmedetomidine, can reduce intraoperative anesthetic consumption and postoperative analgesic requirement by intravenous administration perioperatively. They improve the overall assessment by QoR-40 scale, and promote better quality in recovery from surgery.