Objective To evaluate the effect of sevoflurane on the electrophysiological stability of i-solated rat hearts subjected to hypothermic perfusion. Methods Clean-grade healthy adult male Sprague-Dawley rats, weighing 280-360 g, were heparinized and anesthetized with pentobarbital sodium. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95％ O2-5％CO2 at 37℃. Twenty-four Langendorff-perfused hearts were divided into 4 groups ( n=6 each) using a ran-dom number table method: control group ( C group ) , sevoflurane group ( S group ) , 32 ℃ hypothermia group ( H group) and 32℃ hypothermia plus sevoflurane group ( HS group) . After 15 min of equilibration, the isolated hearts were continuously perfused for 30 min with K-H solution at 37℃, with K-H solution con-taining 2. 3％ sevoflurane at 37 ℃, with K-H solution at 32 ℃, and with K-H solution containing 2. 3％sevoflurane at 32℃ in C, S, H and HS groups, respectively. Heart rate and monophasic action potential in three layers of the left ventricular anterior wall were recorded at 15 min of equilibration ( T0 ) and 30 of con-tinuous perfusion ( T2 ) , the transmural dispersion of repolarization ( TDR) were calculated, and the occur-rence of arrhythmia was observed. Results Compared with C and S groups, the heart rate was significantly decreased and TDR was enlarged at T1 , and the incidence of arrhythmia was increased in H and HS groups ( P<0. 05) . Compared with H group, TDR was significantly reduced at T1 , and the incidence of arrhythmia was decreased in HS group ( P<0. 05) . Conclusion Sevoflurane can improve the electrophysiological in-stability of isolated rat hearts subjected to hypothermic perfusion, and thus decrease the development of ar-rhythmia.

Objective To evaluate the effect of esketamine for cesarean section under epidural an-esthesia and maternal and fetal outcome.Methods The parturients all were singleton pregnancies at term and scheduled for elective cesarean delivery.Ninety parturients undergoing elective cesarean delivery under epidural anesthesia,aged 20-40 years,BMI 18-35 kg/m2,ASA physical status Ⅱ,were randomly alloca-ted into two groups:esketamine group(group K)and control group(group C),45 cases in each group.When the targeted upper sensory block level was achieved,esketamine 0.15 mg/kg was administered intra-venously for 1 minute before skin incision in group K,the same volume of normal saline was intravenously injected in group C.Visceral traction reaction during the operation was recorded.Apgar score was assessed 1 minute and 5 minutes after birth.The pH value,partial pressure of carbon dioxide,oxygen partial pressure,and lactic acid value of the neonatal umbilical vein blood were recorded.Adverse events such as nausea,vomiting,hallucination,dizziness and nightmare were monitored in the two groups.Results Compared with group C,visceral traction reaction was significantly lower in group K(P＜0.05).The neonatal Apgar score,pH value,carbon dioxide partial pressure,oxygen partial pressure,and lactic acid value of the neo-natal umbilical vein blood did not differ between the two groups.There were no differences in the incidence of nausea,vomiting and dizziness between the two groups.Hallucinations and nightmares were not encoun-tered in either group.Conclusion Esketamine 0.15 mg/kg can effectively reduce visceral traction reaction during cesarean delivery under epidural anesthesia.There was no significant effect on neonatal Apgar score and blood gas analysis,with no noticeable maternal and neonatal adverse effect.

Objective:To investigate the normal range of exhaled nitric oxide (FeNO) in 6-18-year-old children in China, so as to provide a data base for the establishment of FeNO standards for Chinese children.Methods:A multi-center study was conducted on 5 949 children aged 6-18 (3 101 males and 2 848 females) in 16 pro-vinces of 7 administrative districts in China.According to the technical standard recommended by American Thoracic Society/European Respiratory Association, FeNO was measured, and the relationship of FeNO with the sex, age, height, weight, body mass index and region was discussed.Results:The geometric mean FeNO value of Chinese children aged 6-18 was 14.1 ppb, and its 95% confidence interval (skewness distribution) was 1.0-38.2 ppb.The geometric mean FeNO values of children aged 6-11 and 12-18 were 13.1 ppb and 15.7 ppb, respectively, and their 95% confidence intervals (skewness distribution) were 1.0-38.1 ppb and 2.0-38.2 ppb.For children at and under 11 years old, FeNO decreased with age, with a mean decline of 1 ppb per year.The multiple linear regression results suggested that there was a significant correlation between FeNO and age for children aged 6-11, and FeNO of children aged 12-18 was significantly correlated with the gender, height, and region(all P<0.01). Conclusions:FeNO values of Chinese children and adolescents in this study are higher than those obtained by the previous study conducted from 2010 to 2012.For children aged 12-18, 16 ppb is recommended as the clinical cut-off point.For children at or under 11 years old, the influence of age on FeNO should be considered, and the cut-off point of FeNO decreases by 1 ppb as the age is reduced by one year.