Objective To evaluate the effect of hypothermia on the endotracheal tube cuff pressure during cardiopulmonary bypass in the pediatric patients with congenital heart disease. Methods Forty pedi-atric patients of both sexes, of American Society of Anesthesiologists physical status Ⅱ-Ⅳ, aged 1 months-14 yr, weighing 3-58 kg, scheduled for elective surgery for congenital heart disease using cardiop-ulmonary bypass, were included in this study. All the pediatric patients were intubated with a cuffed endo-tracheal tube. After anesthesia induction and endotracheal intubation, the air was injected into the cuff to make the cuff pressure reach 20 cm H2 O ( baseline) . The endotracheal tube cuff pressure was recorded when the esophageal temperature was reduced to 34, 32, 30, 28 and below 28℃ and returned to 28, 30, 32, 34 and 36 ℃. Results The cuff pressure was significantly decreased when the esophageal temperature was reduced to 30 and 28 ℃ and below 28 ℃ and returned to 28, 30, 32 and 34 ℃ as compared with the baseline ( P<0. 05) . Conclusion Hypothermia can reduce the endotracheal tube cuff pressure during car-diopulmonary bypass, and it is recommended to routinely monitor the cuff pressure in the pediatric patients with congenital heart disease.

Objective To evaluate the effect of injecting alkalinized lidocaine into the tracheal tube cuff on the responses to extubation in pediatric patients.Methods One hundred and twenty-six pediatric patients,aged 3-13 yr,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective abdominal surgery under general anesthesia requiring oral tracheal intubation,were divided into 3 groups (n =42 each) using a random number table:control group (group C),normal saline group (group NS) and alkalinized lidocaine group (group L).Air was injected into the tracheal tube cuff in group C.Normal saline was injected into the tracheal tube cuff in group NS.Alkalinized lidocaine was injected into the tracheal tube cuff in group L.Cuff pressure was monitored and maintained below 20 cmH2O.The differences in mean arterial pressure (ΔMAP) and heart rate (ΔHR) immediately after stopping inhalation of anesthetics and immediately after extubation were calculated.The response to extubation was defined as Δ MAP or / HR＞20％ of the baseline value and/or development of moderate and severe bucking and agitation.The development of coughing,hoarseness and sore throat during the period in postanesthesia care unit and the period from being discharged from postanesthesia care unit until 8 h after extubation were recorded.Results Compared with group C and group NS,the incidence of response to extubation and sore throat was significantly decreased (P＜0.05),and no significant change was found in the incidence of coughing or hoarseness in group L (P＞0.05).The volume of the alkalized lidocaine solution in the cuff was (4.2±2.3) ml[(60±33) mg] in group L.No cuffdamage was found in three groups.Conclusion Injecting alkalinized lidocaine into the tracheal tube cuff can safely and effectively inhibit responses to extubation and is helpful in improving outcomes in pediatric patients.

Objective To evaluate the effect of positive end-expiratory pressure (PEEP) on lung atelectasis using lung ultrasound ( LUS) in the pediatric patients without high risk factors. Methods One hundred American Society of Anesthesiologists physical statusⅠor Ⅱ patients of both sexes, aged 1-6 yr, with body mass index in the normal range, scheduled for elective non-abdominal surgery, were divided into no PEEP group (group C, n=50) and PEEP group (group P, n=50) using a random number table meth-od. The animals were mechanically ventilated in volume-controlled mode after intravenously injecting propo-fol, with PEEP 5 cmH2 O, tidal volume 8 ml/kg, inspiratory/expiratory ratio 1 : 2, respiratory rate 20-25 breaths/min in group P. In group C, the animals received no PEEP, and the other treatments were similar to those previously described in group P . Lung ultrasound was carried out after anesthesia induction and at the end of surgery. The severity and development of lung atelectasis were recorded. Results Compared with group C, the severity of lung atelectasis was significantly reduced after anesthesia induction and at the end of surgery, and the incidence of lung atelectasis was decreased in group P ( P＜0. 05) . Conclusion Early application of PEEP 5 cmH2 O can reduce the occurrence of atelectasis for the pediatric patients with-out high risk factors for atelectasis.

Objective To investigate risk factors of postoperative pulmonary complications(PPCs)in children after video-assisted thoracoscopic lung resection.Methods Retrospective analysis of clinical data of 566 children,334 males and 232 females,aged≤6 years,ASA physical statusⅠorⅡ,enrolled for video-assisted thoracoscopic lung resection.The children were divided into two groups based on whether they developed PPCs within 7 days after surgery:the PPCs group and the non-PPCs group.Factors with P≤0.2 and perceived as potentially clinically meaningful,were included in the binary logistic regression model.The receiver operating characteristic(ROC)curve was drawn and the area under the curve(AUC)was calculated.Results A total of 123 children(21.7%)developed postoperative pulmonary compli-cations(PPCs).Multivariate logistic regression analysis showed longer duration of one-lung ventilation(OLV),faster respiratory rate during OLV and inexperienced surgeon were found to be independently risk factors of PPCs.Higher PEEP level was protective factors of PPCs(The maximum PEEP was 7 cmH2 O).The prediction model was Logit(P)=-4.41+0.006×OLV duration+0.063×OLV respiratory rate+0.569×inexperienced surgeon(yes = 1)-0.16×maximum PEEP value.The ROC curve showed a good accuracy with an area under the curve of 0.682(95%CI 0.631-0.734),and sensitivity was76.4%,and specificity was 69.6%.Conclusion Longer OLV duration,faster repiratory rate and less surgeon experience are found to be independently risk factors of PPCs.Higher PEEP level is protective factor of PPCs.