Study on the appropriate dose of dexmedetomidine leading analgesia combined with transverse abdominal plane block for postoperative analgesia in colon cancer

Objective:To explore the suitable dosage of dexmedetomidine preemptive analgesia combined with transverse abdominal muscle block for postoperative analgesia of colon cancer.Methods:From March 2018 to October 2019,120 patients undergoing laparoscopic radical resection of colon cancer in our hospital were randomly divided into control group(group C,without dexmedetomidine),low-dose group(group L,0.5μg/kg),medium-dose group(group M,1μg/kg)and high-dose group(group M,0.5μg/kg)The Mean arterial pressure,MAP),Heart rate,HR)and visual analog scale(vas)pain were compared at 2 h(T0),4 h(T1),8 h(T2),12 h(T3),24 h(T4)and 48 h(T5)after operation The pain sensitive area of mechanical stimulation was measured at T4,T5 and 72 h(T6)after operation.The adverse reactions of patients after operation were compared.Results:Compared with C group,MAP and HR of L,M and H groups decreased in different degrees at each time point.MAP and HR of m and h groups were lower than those of l group at different time points(P<0.05).The VAS score and pain sensitive area of T4-T6 in l,m and h groups were significantly lower than those in c group(P<0.05),but there was no significant difference in Ramsay score among groups(p>0.05).The vas score and pain sensitive area of m and h groups were lower than those of l group(P<0.05).Incidence of postoperative adverse reactions in l,m and h groups was lower than that in c group(P<0.05).Conclusion:Dexmedetomidine at doses of 1μg/kg and 1.5μg/kg has a good analgesic effect without increasing the incidence of adverse reactions.It is recommended that 1μg/kg Dexmedetomidine be used as an auxiliary drug dose of ropivacaine during TAP block.At the same time,it is necessary to strengthen monitoring to avoid adverse reactions such as hypotension and bradycardia.