Objective:To evaluate the cerebral blood flow during preincision hypotension (PIH ) in school‐age children by measuring the changes of blood flow in main supplying artery of right hemisphere such as internal carotid and vertebral artery . Methods :A total of 44 children ,aged 7‐13 years ,with American Society of Anesthesiology (ASA ) gradeⅠ‐Ⅱ ,who were scheduled for elective surgery ,were enrolled in this study .Patients with baseline hypotension ,cardiovascular diseases and cerebrovascular diseases were excluded .Heart rate ,systolic blood pressure ,mean arterial pressure ,pulse oxygen saturation were continuously monitored during the procedure .General anesthesia was induced with propofol 2 .5 mg/kg ,fentanyl 2 μg/kg , and rocuronium 0 .6 mg/kg .After intubation ,mechanical ventilation were used to control the breath .The patients received 1 minimum alveolar concentration(MAC) sevoflurane for maintaining the anestheia ,and the end tidal CO2 partial pressure was adjusted to 35‐40 mmHg .The change of blood flow in internal carotid and vertebral artery was evaluated by detecting the time averaged velocity and diameter with Doppler ultrasound .Blood flow index was measured before induction and at the time of PIH .Results:When PIH occurred ,in right side internal carotid artery ,the diameter reduced ,the time averaged velocity and the blood flow decreased ,and the resistance index increased(P<0 .01) .Meanwhile ,in vertebral artery ,the diameter restored (P>0 .05) ,the peak systolic velocity and the time averaged velocity decreased ,the blood flow reduced ,and the resistance index increased (P<0 .01) .The cerebral flow of right side decreased(P< 0 .01) ,and the internal carotid artery percentage contribution reduced(P<0 .01) .Conclusions :When PIH occurs in school‐age children ,although the mean arterial pressure is above the lower limit of autoregulation ,the blood flow of right side internal carotid and vertebral artery significantly decreases , and the cerebral flow of right side also decreases .

Objective:To compare the Application of the trapezius squeeze and jaw thrust in laryngeal mask airway (LMA) in-sertion in children under sevoflurane anesthesia .Methods:A total of 80 children aged 4 to 10 ,American Society of Anesthesiol-ogists(ASA) I-II and undergoing minor operation such as indirect hernia repair and orchiopexy were enrolled and randomly de-vived into trapezius squeezing group(Group T ,n= 40) and jaw thrusting group (Group J ,n= 40) .Anesthisia was induced with 6 L/min oxygen and 8% sevoflurane .When the chileren’s eyelash reflex lose ,jaw thrust/trapezius squeeze was applied every 10 s .The LMA was inserted immediately after the response of childern to trapezius squeeze or jaw thrust disppeared .The successful rates of LMA insertion ,LAM insertion time ,and blood pressure(BP) and heart rate(HR) before and after LMA in-sertion ,end-tidal sevoflurane concentrations (ETsev) ,minimum alveolar concentrations (MAC) in two groups were Recorded and compared .Results:The successful rate of the LMA insertion in Group T (95% ,38/40) was significantly higher than that in the Group J (75% ,30/40) ,there was statistical difference(P= 0 .013);The LMA insertion time in Group T was longer than that in Group J (P=0 .000);the untoward effects in Group T were less than those in Group J ;The BP ,HR ,ETsev ,MAC in two groups had not statistical differences .Conclusions :The trapezius squeeze is more sutable than jaw thrust for assessment of anaesthetic depth in LM A insertion in chilren under sevoflurane anesthesia .