Leung Tak Yeung, Sahota Daljit Singh, Chan Lin Wai, Fok Wing Yee, Law Lai Wa, Lau Tze Kin
Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong.
Acta Obstet Gynecol Scand. 2006;85(2):182-7. doi: 10.1080/00016340500408440.
To compare the degree of force applied during external cephalic version, between different patients' characteristic and outcomes of version.
It is a prospective observational study in a cohort of patients undergoing external cephalic version at or above 36 weeks of gestation. During external cephalic version, the operator wore a pair of pressure-sensing gloves which had ultra-thin piezo-resistive pressure sensors positioned on the palmer surface. Readings from each of the sensors were recorded in real time throughout each version attempt and analyzed by a computer program. The pressure exerted on individual sensors over time, the pressure-time integral (PTI; mmHg s), was calculated for each sensor from the start to the end of each version attempted. The degree of force applied for each attempt (PTI-A) was represented by the sum of pressure-time integrals across all sensors. PTI-A was analyzed in relation to different patients' characteristics and outcome of version.
Ninety-two patients were recruited, 73% of whom had a successful external cephalic version. The median PTI-A of the successful attempt in women who completed version after 1 and 2 attempts were 17,180 and 17,736 mmHg s, respectively. They were significantly lower than that of the women who required 3 or more attempts for a successful version (32,351 mmHg s), as well as the highest PTI-A among all attempts received by women who finally had a failed version (31,638 mmHg s) (p <0.05, Kruskal-Wallis Test and Dunn test). Within the same subject, there was no difference in PTI-A between the successful attempt and the preceding failed attempt, suggesting that the failure may not be due to insufficient force but rather to inefficient application of the force. Uterine tone was found to be the only clinical variable that was significantly associated with the degree of applied force during a version (p < 0.05). A tenser uterus was associated with a stronger applied force.
The degree of force required for a successful version is highly variable, being lowest when version can be completed within 2 attempts, but doubled when 3 or more attempts are required. Failure of version is usually not due to inadequate force but inefficient application of force. Uterine tone is significantly related to the degree of applied force, with stronger force being exerted when the uterus is tense.
比较不同患者特征及外倒转术结果时，外倒转术过程中施加的力的程度。
这是一项对妊娠36周及以上接受外倒转术的患者队列进行的前瞻性观察研究。在外倒转术过程中，操作者佩戴一副压力感应手套，其掌面设有超薄压阻式压力传感器。在每次倒转尝试过程中，每个传感器的读数实时记录，并由计算机程序进行分析。从每次倒转尝试开始到结束，计算每个传感器随时间施加的压力，即压力-时间积分（PTI；mmHg·s）。每次尝试施加的力的程度（PTI-A）由所有传感器的压力-时间积分总和表示。对PTI-A与不同患者特征及倒转术结果进行分析。
招募了92名患者，其中73%外倒转术成功。在1次和2次尝试后完成倒转术的女性中，成功尝试的PTI-A中位数分别为17,180和17,736 mmHg·s。它们显著低于需要3次或更多次尝试才能成功倒转术的女性（32,351 mmHg·s），以及最终倒转术失败的女性所有尝试中最高的PTI-A（31,638 mmHg·s）（p<0.05，Kruskal-Wallis检验和Dunn检验）。在同一受试者中，成功尝试与之前失败尝试之间PTI-A无差异，表明失败可能不是由于力量不足，而是由于力量应用效率低下。发现子宫张力是与倒转术过程中施加力的程度显著相关的唯一临床变量（p<...
