[Propofol target controlled infusion plus a low concentration of sevoflurane inhalation induction anesthesia for the removal of foreign body from tracheobronchus in children].

OBJECTIVE: To explore the effects of propofol target controlled infusion (TCI) plus a low concentration of sevoflurane inhalation induction for the removal of tracheobronchial foreign body in children. METHODS: After the approval of the hospital ethics committee, a total of 90 patients, aged 9 - 36 months old and weighted 8 - 17 kg, were randomly divided into 3 groups: group A, group B and group C. Propofol TCI plus a low concentration of sevoflurane inhalation induction was administered in group A while ketamine or fentanyl plus propofol TCI in group B or C respectively. Effects of anesthesia, complications and recovery durations were observed. RESULTS: The incidence of severe breathholding and bucking during inserting bronchoscope was 1 case in group A, 7 in group B and 5 in group C. There were significant differences between groups A and B (P < 0.05). The minimal intra-operative SpO2 in group B or group C was lower than that in group A (P < 0.01). The cases for intra-operative SpO2 < 95% in group B or group C were more than that in group A (P < 0.01). And the maximal target concentration of propofol was significantly higher than that in group A (P < 0.01). Ten cases in group B had laryngeal stridor and dyspnea during inspirations post-operatively and occurred more frequently than those in group A or C (P < 0.01). As compared with group A and C, post-operative staying lengths and recovery durations were significantly longer in those in group B (P < 0.01). CONCLUSION: Propofol TCI plus a low concentration of sevoflurane inhalation induction is both safe and practical for the controlled removal of tracheobronchial foreign body in children.

[Optimal concentrations of sevoflurane and propofol for laryngeal mask airway insertion in Chinese boys of different ages].

OBJECTIVE: To investigate the optimal concentrations of sevoflurane and propofol for laryngeal mask airway (LMA) insertion in Chinese boys of different ages. METHODS: 200 boys with ASA status I weighting 7 - 53 kg undergoing inguinal operation were divided into 4 groups (n = 50) according to age: Group A (aged 7 m-1 yr), Group B (1 - 3 yrs), Group C (4 - 6 yrs), and Group D (7 - 11 yrs). No premedication was given. General anesthesia was induced with propofol intravenous infusion at target effect-site concentration by target controlled infusion (TCI) using children Marsh model (Subgroups As, Bs, Cs, and Ds, 25 cases for each subgroup) or sevoflurane inhalation combined with 50% N2O (Subgroups Ap, Bp, Cp, and Dp, 25 cases for each subgroup) the optimal concentration was predetermined according to the modification of Dixon's up-and-down method. The size of LMA was determined according to the boy's weight and reverse technique was used to place LMA. The insertion conditions were noted as satisfactory when the jaw was relaxed, lash reflex disappeared, no coughing, gagging, swallowing, and laryngospasm was seen, and limb movement was minimal. RESULTS: The levels of ED(50) of P(ET)-sevoflurane for LMA insertion in Subgroups As, Bs, Cs, and Ds were 2.96% (95% CI 2.58% - 3.44%), 2.62% (95% CI 2.31% - 2.90%), 2.16% (95% CI 1.97% - 2.33%), and 1.89% (95% CI 1.66% - 2.24%) respectively. The levels of ED(50) of target effect site concentration with propofol for LMA insertion in Subgroups Ap, Bp, Cp, and Dp were 4.74 microg/ml (95% CI 4.49 - 5.13 microg/ml), 4.33 microg/ml (95% CI 4.07 - 4.62 microg/ml), 4.10 microg/ml (95% CI 3.90 - 4.31 microg/ml), and 3.65 microg/ml (95% CI 3.24 - 3.98 microg/ml) respectively. CONCLUSION: The ED(50) level of P(ET)-sevoflurane or target effect site concentration with propofol for LMA insertion in Chinese boys decreases gradually along with the increase of age.