The Influence Of Dexmedetomidine On The Postoperative Analgesia Effect Of Incision Infiltration With Ropivacaine In Children

Objective:To investigate the influence of dexmedetomidine on the postoperative analgesia effect of incison infiltration with ropivacaine in children; to evaluate its safety and efficacy on postoperative sedation and analgesia in children undergoing laparotomy.Methods:75 patients suffering from elective laparotomy under general anesthesia, aged 1 to 6, the ASA class was Ⅰ-Ⅱ level and 10-24 kg weight were enrolled in our study. They were randomly divided into three groups. Fentanyl Group (Group F, n=25),1 μg/kg fentanyl was administered by an intravenous injection when closing the abdominal cavity; Ropivacaine Group(Group R,n=25),0.25% ropivacaine (1 mL/cm incision) for incision infiltration step by step before closing the abdominal cavity; Dexmedetomidine Group (Group D,n=25),0.25%ropivacaine (1 mL/cm incision) combined with 0.25 μg/kg dexmedetomidine for incision infiltration step by step before closing the abdominal cavity. The vital signs were recorded at six time points preanesthesia (TO), the extubation moment (T1),5 minutes after extubation (T2), 10 minutes after extubation (T3), the waking moment (T4) and when leaving the recovery room(T5). The length of incision, operative time, postoperative recovery time, extubation time and residence time in Postanesthesia Care Unit (PACU) were also recorded. Face legs activity cry consolation (FLACC) score was used to assess the postoperative pain score at the waking moment (T4),2 h(T6),4 h(T7),6 h(T8),12 h(T9),24 h(T10),48 h(T11),72 h(T12) after operation, agitation incidence, postoperative adverse reactions and Ramsay sedation score were also recorded. The number of children asked for postoperative analgesia in each period after the surgery, the incision healing, dressing changing times and postoperative hospitalization were counted.Results:(1)Three groups of patients with gender, age, height, weight, BMI, length of incision, operation time, recovery time, extubation time, PACU residence time, grading of surgical incision, frequency of dressing change, postoperative hospitalization and incision healing have no statistically significant difference(P> 0.05). (2)The comparison between groups:HR, SBP and DBP at T1 to T5 in Group D and Group R were significantly lower than those in Group F (P< 0.05); HR, SBP and DBP at T3-T5 in Group D were not only lower than those in Group F but also lower than those in Group R(P< 0.05). The RR at T4, T5 in Group D were lower than those in Group F(P< 0.05).The vital signs at TO and SPO2 at each time point in three groups were not statistically significant(P>0.05). The comparison within groups:Compared with T0, the HR and SBP at T1 to T5 and DBP at T1, T2, T4, T5 in Group F were increased; the HR at T3 to T5 in Group D were decreased(P< 0.05).(3)The emergence agitation in Group D(0%) were significantly lower than those in Group F(44%) and Group R(20%) (P< 0.05). The incidence of postoperative adverse reactions within 24 hours in Group D was significantly lower than those in Group F and Group R(P< 0.05). In 0-6 hours postoperative period, patients in Group D and Group R needed less postoperative analgesia than those in Group F(P< 0.05). Compared with Group F and Group R, the total number of children with additional analgesia within 72 hours after surgery in Group D were decreased significantly. The first time to use postoperative analgesia obviously prolonged in Group D(P< 0.05). (4)The Ramsay sedation score at any point of recovery period in Group D were higher than those in Group F and Group R, Ramsay sedation score at T4 and T8 in Group R was also higher than Group F(P < 0.05). At T4 to T8, the FLACC score in Group D and Group R were significantly lower than those in Group F,and the FLACC score at T4 to T8 in Group D were less than those in Group R. At T9, T10 the FLACC score in Group D were less than those in Group F (P< 0.05). The FLACC scores at T11 to T12 in three groups were not statistically significant(P> 0.05).Conclusion:(1)The incision infiltration with ropivacaine can provide good postoperative analgesia for children in 6 hours after surgery. (2) Dexmedetomidine combined with ropivacaine for incision infiltration can provide good sedation and analgesia for children in 24 hours after surgery, it can also reduce the agitation during recovery period and postoperative adverse reactions, it is a safe, convenient and effective method for postoperative analgesia and sedation in children.