Effects of age factors on sedation induced by dexmedetomidine / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of age factors on sedation induced by dexmedetomidine.Methods One hundred and thirty-nine patients,aged 18-103 yr,with body mass index ≤ 30 kg/m2,scheduled for elective surgeries on lower abdomen or lower extremities,were divided into4 groups according to the agegroup Ⅰ (18 yr≤age≤44 yr,n=40);group Ⅱ (45 yr≤age≤59 yr,n=38);group Ⅲ (60 yr≤age≤89 yr,n=39);group Ⅳ (≥90 yr,n=22).A catheter was placed in the subarachnoid space at L3,4 interspace,and ropivacaine 10-20 mg was injected via the catheter.At 20 min after ropivacaine injection,dexmedetomidine 1 μg/kg was infused via a pump over 10 min.The onset time and duration of sedation were recorded,and the occurrence of adverse effects such as hypoxemia,bradycardia and hypotension was observed.Results There was no significant difference in the onset time of sedation and incidence of bradycardia among the 4 groups (P＞0.05).Compared with group Ⅰ,the duration of sedation was significantly prolonged in Ⅱ-Ⅳ groups (P＜0.05).Compared with Ⅱ and Ⅲ groups,the duration of sedation was significantly prolonged in group Ⅳ (P ＜ 0.05).The incidence of hypoxemia and hypotension was significantly higher in group Ⅳ than in Ⅰ-Ⅲ groups (P＜0.05).Conclusion Dexmedetomidine-induced sedation is influenced by age factors,the duration of sedation induced by dexmedetomidine is prolonged,and the occurrence of adverse effects is increased,especially if the patients ≥ 90 yr of age.