Department of Obstetrics & Gynaecology, Southmead Hospital, Bristol, UK.
School of Clinical Sciences, University of Bristol, Bristol, UK.
BJOG. 2017 Sep;124 Suppl 4(Suppl 4):10-18. doi: 10.1111/1471-0528.14759.
To investigate (1) the placement of the BD Odon Device on the model fetal head and (2) perineal distention during simulated operative vaginal births conducted with the BD Odon Device.
Observational simulation study.
North Bristol NHS Trust, UK.
Four hundred and forty simulated operative vaginal births.
Three bespoke fetal mannequins were developed to represent (1) bi-parietal diameter of the 50th centile at term, (2) bi-parietal diameter at the 5th centile at term, and (3) 50th centile head with 2 cm of caput. Siting of the BD Odon Device on model heads was determined before and after 400 simulated operative vaginal births. Variables were analysed to determine their effect on device siting and movement during birth. The fetal mannequins were placed inside a maternal mannequin and the BD Odon Device was placed around the fetal head as per the instructions for use. The location of the air cuff was determined before and after the head was delivered. Perineal distension was determined by recording maximum perineal distention during a simulated operative vaginal birth using the same procedure, as well as scenarios employing an inappropriately non-deflated air cuff (for the BD Odon Device), the Kiwi ventouse and non-rotational forceps.
Site and displacement during birth of the BD Odon Device on a model head. Maximal perineal distension during birth.
The BD Odon Device was reliably sited in a standard over the fetal head position (approximately 40 mm above the fetal chin) for all stations, head sizes and positions with no significant displacement. In occipito-posterior births, compared with occipito-anterior or transverse, the BD Odon Device routinely sited further down the fetal head (toward the chin). The BD Odon Device was not associated with more perineal distension compared with forceps or Kiwi ventouse (respectively 21, 26 and 21 mm at posterior fourchette).
The BD Odon Device reliably sited over a safe area of the fetal head in 400 simulated births representative of clinical practice. The BD Odon Device generates similar levels of perineal distension compared with Kiwi ventouse when used correctly.
Location of the BD Odon Device on a fetal head in simulation.
（1）研究 BD Odon 装置在模型胎儿头部的放置位置，（2）使用 BD Odon 装置进行模拟阴道分娩时的会阴扩张情况。
观察性模拟研究。
英国北布里斯托尔国民保健信托基金会。
440 例模拟阴道分娩。
开发了三个定制的胎儿模型，分别代表（1）足月时第 50 百分位的双顶径，（2）足月时第 5 百分位的双顶径，以及（3）50 百分位头加 2 厘米头盖骨。在 400 次模拟阴道分娩前后，确定了 BD Odon 装置在模型头部上的位置。分析了变量，以确定它们对分娩过程中装置位置和移动的影响。将胎儿模型放置在母体模型内，然后按照使用说明将 BD Odon 装置放置在胎儿头部周围。分娩后确定空气袖带的位置。使用相同的程序，以及在使用不当的未放气空气袖带（用于 BD Odon 装置）、Kiwi 吸引器和非旋转产钳的情况下，记录模拟阴道分娩过程中的最大会阴扩张，确定会阴扩张程度。
模型头部上 BD Odon 装置在分娩过程中的位置和位移。分娩时的最大会阴扩张程度。
BD Odon 装置在所有胎方位、头大小和位置上，都可靠地位于标准的胎儿头部上方位置（大约位于胎儿下巴上方 40 毫米处），且无明显位移。在后枕位分娩中，与前枕位或横位相比，BD Odon 装置通常位于胎儿头部下方（朝向下巴）。与产钳或 Kiwi 吸引器相比，BD Odon 装置不会导致更大的会阴扩张（分别在后部四叉处为 21、26 和 21 毫米）。
BD Odon 装置在 400 次代表临床实践的模拟分娩中可靠地放置在胎儿头部的安全区域。当正确使用时，BD Odon 装置与 Kiwi 吸引器产生的会阴扩张程度相似。
BD Odon 装置在胎儿头部的放置位置。
