The Effects Of Different Low-dose Sufentanil Combined With Propofol On The Insertion Conditions Of Laryngeal Mask And Cardiovascular Responses In Children

Objective:To assess the effects of three kinds of low-dose sufentanil combined with standard dose of propofol on the insertion conditions of laryngeal mask and cardiovascular responses in children, and exploring an appropriate dose of sufentanil in clinic practice.Methods:Sixty children (39 males,21 females),aged 3 to 8 years old with body weight between 12 to 30 kg and American Society of Anesthesiologists (ASA) physical statusⅠ～Ⅱ, were recruited to the study. They were waiting for elective surgery i.e.15 cases with placement of Internal fixation of limb fracture and 6 cases of clavicular fracture; 18 cases with Internal fixation remove of fracture; 4 cases with malunion of orthopedic surgery; 7 cases with hernia repair surgery; 10 cases of foreskin restoration. They were randomly assigned into 3 groups with 20 children in each group. A bolus sufentanil in doses of 0.1,0.2 and 0.3μg/kg were intravenously administrated for groupⅠ-Ⅲrespectively, followed by propofol 2.5 mg/kg. Mean arterial pressure, electrocardiogram, heart rate, pulse oxygen saturation, endtidal CO2 pressure were continuously recorded in all patients. The size of LMA was determined according to the children's weight. The conditions for LMA insertion were evaluated using a three-point scale in six-categories:resistance to mouth opening (1:full,2: partial,3:nil), resistance to insertion (1:easy,2:difficult,3:impossible), head or body movement (1:nil,2:slight,3:gross), coughing and gagging (1: nil,2:slight,3:gross), swallowing (1:nil,2:slight,3:gross) and laryngospasm(1:nil,2:partial,3:complete). Head or body movement, coughing and gagging, swallowing and laryngospasm, were recorded and scored In all cases. The percentage of score in 2 or 3 on laryngeal mask airway insertion conditions were calculated, and to assess the satisfaction of laryngeal mask airway insertion conditions. MAP, HR were recorded before (baseline values To) and after anesthesia induction (postinduction values T1), at laryngeal mask airway insertion(T2) and 1 minute(T3),3 minute(T4), 5 minute(Ts) after insertion. MAP and HR related to baseline values at every measuring point and the percentage changes>25% of MAP and HR related to baseline values at every measuring point were calculated. Record the percentage of first successful LMA insertion, the time of LMA insertion, The duration of apnea, The number of Apnea> 5min cases. Record the complications such as muscle rigidity, bradycardia, retch, aspiration and the application of vasoactive agents.Results:1. Excepting the resistance to mouth opening and resistance to insertion,5 cases of 2 or 3 point were found in groupⅠ, the insertion conditions scores were both 4 in groupⅡand groupⅢ, No patient suffered head or body movement, coughing and gagging, swallowing and laryngospasm (p>0.05). The satisfaction rate of LMA insertion in three groups was 71%,100%,100% respectively. There were significant difference both in groupⅡand groupⅢcompared to groupⅠ(p<0.05).2. There were significant decreases of MAP and HR at T1 compared with To in three groups (p<0.05 or p<0.01), laryngeal mask airway insertion caused significant increases of MAP at T2 compared with To in groupⅠ(p<0.05) and there were significant differences in comparison of T2 in groupⅡand groupⅢ(p<0.05). There were significant increases of HR at T2 compared with T0 in groupⅠ(p<0.01) and significant differences compared with T2 in groupⅡand groupⅢ(p<0.01). There were no significant difference of MAP and HR at T2 compared with To in group II and groupⅢ(p>0.05).The percent increase of MAP and HR at T2 in groupⅠwere significant difference compared with group II and groupⅢ(p<0.05). The incidences of MAP and HR percent increases or decreases> 25% of baseline values were no difference among the 3 groups(p>0.05).3. There were no significant difference of the percentage of first successful LMA insertion and the time of LMA insertion in three groups(p>0.05). The time after the LMA placement to the return of spontaneous ventilation was prolonged as the increasement of the sufentanil. There were significant difference of the duration of apnea in three groups(p<0.01), The number of Apnea> 5min cases were significant difference in groupⅢcompared with groupⅠand groupⅡ(p<0.01).4. There were no complications such as muscle rigidity, bradycardia, retch, aspiration and the application of vasoactive agents(p>0.05).Conclusion:Sufentanil 0.2μ.g/kg combined with propofol 2.5 mg/kg are effective in facilitating insertion of the laryngealmask airway and can completely abolish the cardiovascular insertion response without causing more hemodynamic side effects and have fewer adverse effects.