Seitchik J, Amico J A, Castillo M
Am J Obstet Gynecol. 1985 Mar 15;151(6):757-61. doi: 10.1016/0002-9378(85)90514-9.
A regimen is described in which the time from the start of a large dose of oxytocin to a myometrial response was used for selection of a maintenance dose. The method is based on our experience that continuous intravenous doses of oxytocin in the therapeutic range for the augmentation of labor require about 40 minutes of intravenous infusion to achieve a steady-state plasma concentration of oxytocin. The method effectively identified the proper maintenance dose on the first attempt in 43 of 59 patients (73%) and on the second in 58 of 59. The doses selected effected cervical dilatation in 55 of 59 cases (93%). Comparison of the timed dose method with an arithmetic progression regimen revealed the former method to select the minimum effective dose more rapidly, but that method had no advantage in shortening the time from the start of oxytocin to complete cervical dilatation. Examination of the plasma concentration of oxytocin by radioimmunoassay demonstrates that the maintenance dose selected by the duration of the interval from the start of infusion to a myometrial response sustains the plasma oxytocin concentration obtained by the initial dose. These data lend additional evidence that any particular dose of oxytocin in the therapeutic range requires approximately 40 minutes to achieve a steady-state plasma concentration.
本文描述了一种方案，即从开始给予大剂量缩宫素到子宫肌层出现反应的时间用于选择维持剂量。该方法基于我们的经验，即在治疗范围内持续静脉输注缩宫素以加强宫缩时，大约需要40分钟的静脉输注才能达到缩宫素的稳态血浆浓度。该方法在59例患者中，有43例（73%）在首次尝试时有效确定了合适的维持剂量，59例中的58例在第二次尝试时确定了合适的维持剂量。所选剂量在59例中有55例（93%）实现了宫颈扩张。将定时剂量法与算术级数方案进行比较发现，前一种方法能更快地选择最小有效剂量，但该方法在缩短从开始使用缩宫素到宫颈完全扩张的时间方面没有优势。通过放射免疫分析法检测缩宫素的血浆浓度表明，根据从开始输注到子宫肌层出现反应的间隔时间选择的维持剂量能够维持初始剂量所获得的血浆缩宫素浓度。这些数据进一步证明，治疗范围内的任何特定剂量的缩宫素大约需要40分钟才能达到稳态血浆浓度。
