Department of Medicine, University of Alberta.
Women and Children's Health Research Institute.
Blood Press Monit. 2024 Aug 1;29(4):167-172. doi: 10.1097/MBP.0000000000000700. Epub 2024 Mar 5.
Understanding of how oscillometric waveforms (OMW) vary between pregnant and nonpregnant individuals remains low. An exploratory analysis was completed to assess for quantitative and qualitative changes in OMW and oscillometric envelope features in pregnancy.
Eighteen pregnant individuals (over 20 weeks gestational age) and healthy, nonpregnant (HNP) women were recruited. Six HNP were matched to six healthy pregnant (HP) women, and six pregnant women with a hypertensive disorder of pregnancy (HDP) by age, arm circumference, and cuff size. Blood pressure measurements were completed per the International Organization for Standardization (ISO) protocol using a custom-built oscillometric device as the test device and two-observer mercury auscultation as the reference measurement. Auscultatory blood pressure and blood pressure derived from slope-based and fixed ratio algorithms were determined. OMW and envelope features were compared among groups.
In HNP, HP, and HDP groups respectively: mean auscultatory blood pressure (systolic mean ± SD/diastolic mean ± SD) was 103.4 ± 12.2/67.1 ± 7.9; 109.5 ± 3.1/58.1 ± 6.4; 135.6 ± 18.9/85.1 ± 14.2 mmHg. HDP had significantly higher auscultatory systolic and diastolic blood pressure than the HP group ( P = 0.001). The pregnant groups had a lower average pulse width (mean ± SD: HNP = 0.8 ± 0 s, HP = 0.6 ± 0.1 s, HDP = 0.6 ± 0.1 s; HP vs. HNP mean difference [adjusted P value]: 0.2 [ P = 0.004], HDP vs. HNP 0.1 [ P = 0.018]) compared with the HNP group. The HDP group had a larger area under the OMW envelope than the HNP group (mean ± SD: HNP = 22.6 ± 3.4; HDP = 28.5 ± 4.2; HDP vs. HNP mean difference [adjusted P value]: 5.9 P = 0.05).
In this exploratory work, differences in the OMW morphology and parameters were found in pregnancy and in hypertensive disorders of pregnancy compared with healthy controls. Even small differences may have important implications in algorithm development; further work comparing OMW envelopes in pregnancy is needed to optimize the algorithms used to determine blood pressure in pregnancy.
人们对孕妇和非孕妇的柯氏音（oscillometric waveforms，OMW）之间的变化了解甚少。本探索性分析旨在评估怀孕期间 OMW 和柯氏音包络特征的定量和定性变化。
招募了 18 名妊娠 20 周以上的孕妇和健康非妊娠（healthy nonpregnant，HNP）女性。根据年龄、臂围和袖带尺寸，将 6 名 HNP 与 6 名健康孕妇（healthy pregnant，HP）和 6 名患有妊娠高血压疾病（hypertensive disorder of pregnancy，HDP）的孕妇相匹配。使用定制的柯氏音设备作为测试设备，以国际标准化组织（International Organization for Standardization，ISO）协议完成血压测量，以两名观察者的柯氏音听诊作为参考测量。确定听诊血压和基于斜率和固定比值算法得出的血压。比较各组之间的 OMW 和包络特征。
在 HNP、HP 和 HDP 组中，分别为：平均听诊血压（收缩压平均值±SD/舒张压平均值±SD）为 103.4±12.2/67.1±7.9mmHg；109.5±3.1/58.1±6.4mmHg；135.6±18.9/85.1±14.2mmHg。HDP 的收缩压和舒张压明显高于 HP 组（P=0.001）。与 HNP 组相比，孕妇组的平均脉搏宽度更低（平均值±SD：HNP=0.8±0s，HP=0.6±0.1s，HDP=0.6±0.1s；HP 与 HNP 之间的平均差异[调整后的 P 值]：0.2[P=0.004]，HDP 与 HNP 之间的差异：0.1[P=0.018]）。与 HNP 组相比，HDP 组的 OMW 包络面积更大（平均值±SD：HNP=22.6±3.4mmHg；HDP=28.5±4.2mmHg；HDP 与 HNP 之间的平均差异[调整后的 P 值]：5.9[P=0.05]）。
在这项探索性工作中，与健康对照组相比，在怀孕期间和妊娠高血压疾病中发现了 OMW 形态和参数的差异。即使是微小的差异也可能对算法开发有重要意义；需要进一步比较妊娠期间的 OMW 包络，以优化用于确定妊娠期间血压的算法。
