The optimal anesthesia mothod for external cephalic version (ECV): a randomized controlled trial

Background: The aim of the study is to investigate the success rate of ECV and relevant complications with intrathecal analgesia for singleton breech pregnancy.Methods: Sixty pregnant women received obstetrical regular prenatal care were randomly divided into EA group( epidural anesthesia, n = 30), CSEA group( combined spinal-epidural anesthesia, n = 30), control group(no analgesia, n = 30). The primary outcome of our study was the success rate of ECV confirmed by ultrasound. Visual analogue scale,, the rate of cesarean section and relevant side effect were recorded.Results: The success rate of spontaneous inversion to cephalic version was 76.7% in EA group, which was higher than that in CSEA group (53.3%) and control group (46.7%) (p = 0.058 and p = 0.017, respectively). The rate of cesarean section in EA group was 33.3%, which was also lower than that in CSEA group (53.3%) and control group (50.0%), however, the difference was not statistically significant between CSEA group and EA group(p = 0. 19). The VAS scores in the EA group and the spinal group were respectively 1.87 ± 2.94 and 1.73 ± 2.71 ,obviously better than that of the control group (6.84 ± 3.08) (p = 0.001 and p = 0.001).It was no significant difference between EA group and Control group ( p = 0. 118). The incidence of hypotension, nausea and vomiting, and fetal heart rate deceleration in CSEA group was significantly higher than that in control group (p = 0.000, p = 0.161, p = 0.129). The occurrence rate of spontaneous fetal heart rate deceleration in the EA, CSEA and control group were 6.7%, 20% and 6.7%, respectively, the differences were not statistically significant.Conclusions: EA can be more effective to enhance the success rate of spontaneous inversion to cephalic version than CSEA, and CSEA is accompanied with more side effects. Meanwhile, EA or CSEA don’t affect the rate of cesarean section of ECV for breech single pregnancy. (Registration number: ChiCTR1800017124)Trial registration: Name of the registry: Comparison of epidural analgesia with dexmedetomidine or sufentanil combined with ropivacaine: an observational study of multi-center ; Trial registration number: ChiCTR1800017124; Date of registration: 07-13-2018; URL of trial registry record: http://www.chictr.org.cn/edit.aspx?pid=29087&htm=4

Freezing of gaze during action preparation under threat imminence

When confronted with threatening stimuli, animals typically respond with freezing behavior characterized by reduced movement and heart rate deceleration. Freezing-like responses during threat anticipation have also been observed in humans and are associated with anxiety. Recent evidence yet suggests that freezing does not necessarily reflect helpless immobility but can also aid the preparation of a threat escape. To investigate which further behavioral responses human freezing encompasses, we presented 50 young adults (10 male) with aversive stimuli that could sometimes be avoided while measuring gaze, cardiovascular and electrodermal activity. In trials in which the threat could be escaped, participants displayed reduced heart rate, increased electrodermal activity and reduced visual exploration. Furthermore, heart rate deceleration and restricted visual exploration predicted the speed of flight responses. These results provide evidence for freezing behavior in measures of visual exploration and suggest that such responding is adaptive in preparing the subsequent escape of approaching threats.

Freezing as Flight Preparation: Evidence from Electrodermal, Cardiovascular and Gaze Recordings

When confronted with threatening stimuli, animals typically respond with freezing behavior characterized by reduced movement and heart rate deceleration. Freezing-like responses during threat anticipation have also been observed in humans and are associated with anxiety. Recent evidence yet suggests that freezing does not necessarily reflect helpless immobility but can also aid the preparation of a threat escape. To investigate whether preparatory freezing can also be discerned in gaze behavior, we presented participants with aversive stimuli that sometimes could be avoided while measuring gaze, cardiovascular and electrodermal activity. In trials in which the threat could be escaped, participants displayed reduced heart rate, increased electrodermal activity and reduced visual exploration. Furthermore, heart rate deceleration and restricted visual exploration predicted the speed of flight responses. These results provide first evidence for freezing behavior in measures of visual exploration and suggest that such responding is adaptive in preparing the subsequent escape of approaching threats.