Comparison of efficacy of different doses of dexmedetomidine for sedation in patients with Parkinson′s disease undergoing deep brain stimulation surgery

Abstract

Objective To compare the efficacy of different doses of dexmedetomidine for sedation in patients with Parkinson′s disease(PD) undergoing deep brain stimulation(DBS) surgery. Methods Seventy-five patients of both sexes with PD, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, aged 48-72 yr, with body mass index of 18-24 kg/m2, undergoing elective DBS surgery, were divided into 3 groups(n=25 each) using a random number table method: different doses of dexmedetomidine groups(D1-3 groups). Dexmedetomidine was intravenously infused in a loading dose of 0.5 μg/kg at 10 min before local infiltration anesthesia with 0.25 % ropivacaine 10-20 ml, followed by an infusion of 0.3, 0.5 and 0.8 μg·kg-1·h-1 in D1-3 groups, respectively.The infusion of dexmedetomidine was suspended during neurological test, the patients were awakened, and dexmedetomidine was infused at 0.3, 0.5 and 0.8 μg·kg-1·h-1 until the end of the surgery after the test.Bispectral index(BIS) value was recorded immediately before anesthesia(T0), immediately after administration prior to wake-up(T1) and during neurological test(T2). The wake-up time and adverse reactions such as requirement for rescue analgesics, pulse oxygen saturation(SpO2)<90% and snoring were recorded. Results Compared with group D1, the requirement for rescue analgesics and BIS value at T1, 2 were significantly decreased in D2 and D3 groups, and the wake-up time was significantly prolonged, and the incidence of SpO2<90% and snoring was increased in group D3 (P<0.05 or 0.01). Compared with group D2, the requirement for rescue analgesics and BIS value at T1 were significantly decreased, the wake-up time was prolonged, and the incidence of SpO2<90% and snoring was increased in group D3(P<0.05 or 0.01). Conclusion Dexmedetomidine 0.5 μg·kg-1·h-1 can produce good sedative efficacy and safety for DBS surgery in patients with PD. Key words: Dose-response relationship, drug; Dexmedetomidine; Conscious sedation; Parkinson disease; Electric stimulation