Effect of different doses of dexmedetomidine on blood pressure, heart rate and postoperative sedation in laparoscopic cholecystectomy / 医学研究生学报

ABSTRACT

Objective In laparoscopic cholecystectomy(LC), increased intra-abdominal pressure and carbon dioxide absorption may cause obvious sympathetic excitation and bring about increased blood pressure and heart rate. Effective control on such sympathetic responses can reduce complications, which is beneficial to timely recovery for patients. The study aimed to investigate the effect of different doses of dexmedetomidine on blood pressure, heart rate and postoperative sedation during perioperative period in patients undergoing LC.Methods Sixty patients enrolled in the study randomly were divided into three equal groups(20 patients each) control group(only equal amount of isotonic saline), low dose group and high dose group according to the injection of dexmedetomidine. At each time point including before anaesthesia(T0), before cutting(T1), pneumoperitoneum at 0min(T2), at 10min(T3), at 20min(T4), immediate deflation(T5), before extubation(T6), after extubation and before leaving operation room(T7), and entering recovery room(T8), records were made on the patient’s blood pressure, heart rate, SpO2, airway peak pressure, PetCO2 and Ramsay sedation score after extubation.Results Extubation time and PACU stay time were significantly longer in high dose group in comparison with control group and low dose group (F=12.669, P=0.000 and F=6.281, P=0.030 respectively). Compared with control group, the heart rates of high dose group and low dose group at T5, T7 and T8 decreased significantly(P<0.05). During T2-T5, airway peak pressure was significantly higher than those of control group and low dose group(P<0.05). At T7, the Ramsay score of high dose group was significantly higher than those of control group and low dose group(P=0.015).Conclusion Sustainable pumping of dexmedetomidine can keep stable heart rate. However, the increase of pumping rate and dose will deepen the depth of sedation after extubation and obviously extend extubation time and observation time in recovery room. Therefore, it is appropriate to infuse dexmedetomidine less than 0.5μg/(kg·h) in clinical anaesthesia.