Objective To investigate the effects of hydrogen-rich saline on postoperative cognitive dysfunction (POCD) in aged mice and the possible mechanism.Methods Seventy-two male C57BL/6 mice,aged 18 months,weighing 45-55 g,were randomly divided into 4 groups (n =18 each):control group (group C),hydrogen-rich saline group (group H),POCD group and POCD + hydrogen-rich saline group (group PH).POCD was induced by open tibial fracture.Hydrogen-rich saline 10 ml/kg was injected intraperitoneally twice a day for 7 days before surgery.Six mice were chosen at day 1,3 and 7 after surgery and cognitive function was assessed by Morris water maze test.The mice were then sacrificed and hippocampus was isolated for determination of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) contents (by ELISA) and nuclear factor-κB (NF-κB) activity.Results Compared with group C,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,the frequency of crossing the original platform was decreased at 3 and 7 days after surgery,and the contents of NF-α and IL-1β and NF-κB activity were increased during 1,3 and 7 days after surgery in group POCD (P ＜ 0.05),and no significant change was found in the parameters mentioned above in group H (P ＞ 0.05).Compared with group POCD,the escape latency was significantly shortened,the time of staying at the original platform quadrant was prolonged,the frequency of crossing the original platform was increased at 3 and 7 days after surgery,and the contents of NF-α and IL-1β and NF-κB activity were decreased at 1,3 and 7 days after surgery.Conclusion Hydrogen-rich saline can alleviate POCD via inhibiting NK-κB activity in hippocampus and reducing inflammatory response.

Objective To evaluate the mechanism of external branch of the superior laryngeal nerve (EBSLN) injury during thyroid surgery as showed by intraoperative neuromonitoring.Methods 70 patients with 109 nerves at risk were enrolled in this study from March 2011 to October 2011.A positive signal is determined by observing contractions of the cricothyroid muscle.The relationship between EBSLN and the upper pole of the thyroid or the inferior constrictor muscle was studied.Results 108 nerves (99.1％) were located successfully,42 of which were visualized (38.9％).55 nerves (50.9％) crossed the superior thyroid artery more than 1 cm apart,while the other 53 nerves (49.1％) went less than 1 cm including 24 nerves(more than 0.5 cm,less than 1 cm) and 29 nerves (less than 0.5 cm) or coursed below the superior pole of the thyroid.The rate of the latter type was significantly elevated in patients with the top to botton diameter of the gland more than 5 cm.One patient suffered from impairing in the production of high tones postoperatively.Conclusions Intraoperative neuromonitoring is useful and helpful in providing instructive information for operations by locating EBSLN.

Objective To investigate the ultrasound imaging findings of anatomical relationship between femoral artery and vein in children of different ages.Methods Sixty-five children aged 4 months-7 years were enrolled in this study.The children were divided into 3 age groups: group Ⅰ＜ 1 yr;group Ⅱ 1-3 yr and group Ⅲ＞ 3,≤ 7 yr.A protable ultrasound machine was used.The probe was placed at the level of inguinal ligament and 2 and 4 cm below inguinal ligament.The children were placed in supine position.The legs were placed in 2 positions:(1)extended and in standard anatomical position and(2)flexed and 45° abducted and 45° laterally rotated.Results The examination showed that at the level of inguinal ligament,the femoral vein lay behind and lateral to femoral artery in 91% of children.At the level of 4 cm below inguinal ligament,the femoral vein lay posterior and lateral to the femoral artery in all children.When the leg was placed in abducted and laterally rotated,the depth of femoral vein was reduced and the vein was less overlapped by artery in all children,especially in preschool children.Conclusion At the level of 4 cm below inguinal ligament,the femoral vein lies posterior and lateral to the femoral artery in children.When the leg is placed in abducted and laterally rotated,the depth of femoral vein is reduced and the vein is less overlapped by artery.It is indicated that femoral vein puncture should be performed at the level of 4 cm below inguinal ligament with the leg flexed and abducted in all children,especially in preschool children.