Fetal RBCs Potential in Obstetric Protocols to Minimize Fetomaternal Hemorrhage

Background: During pregnancy a small number of fetal RBCs (Red Blood Cells) enter maternal blood without risk, and incidence of significant feto-maternal hemorrhage (FMH) and isoimmunization depends on how much fetal blood enters maternal circulation;the use of flow cytometer (FCM) in FMH detection is considered the best laboratory technique. Aims: To evaluate role of FCM in FMH estimation to optimize delivery protocols and decrease isoimmunization. Subject and Method: 100 pregnant women at labor were included, equally classified into early cord clamping (ECC) and delayed cord clamping (DCC) groups, each including 25 women delivered vaginally and 25 with caesarian section;the control groups included 20 non-pregnant females, 20 at 3rd trimester and 20 neonates. Fetal RBCs were done on Becton Dickinson (B.D) FCM, and the reagents used were 5-Glutaraldehyde 0.5% Sigma cat. G5882, flouroscine isothiocyanite (FITC) anti-hemoglobin F (Hb-F) cat. 555748, anti-carbonic anhydrase, Triton-X100 solution and Alsever’s solution cat. HFH-11, 0.1% phosphate buffer saline/bovine serum albumin (PBS/BSA). Statistical Analysis: Mann Whitney’s U-test, Chi-squared, Fischer’s Exact tests, and SPSS for windows version 15.0. Results: There was a significant increase in the volume of the FMH in the ECC compared to DCC groups (p < 0.0001), also in the vaginal delivery comparing to caesarian section subgroups within the DCC group (p < 0.01), and in the ECC compared to DCC within caesarian section subgroup (p < 0.02). Conclusion: Fetal RBCs estimation by FCM is good;perinatal laboratory test should be done in routine investigations, as a guide for obstetric techniques that can alter FMH volume and decrease subsequent isoimmunization.

向丙泊酚麻醉患者血管内注射含肾上腺素的硬膜外试验剂量观察灌注指数的预测效能

背景灌注指数是一种无创性的来自干血氧饱和度监测的反映外周循环灌注的指标。本研究评估了灌注指数做为探索成人丙泊酚麻醉过程中血管内注入包含15μg肾上腺素的硬膜外试验剂量药物后变化指标的有效性；同时将它与常规评估标准-心率（HR）（如果升高≥10bpm则为阳性）及收缩压（SBP）（如果升高≥15mmHg则为阳性）进行了可靠性比较。方法40例全静脉麻醉、择期行普外科手术的患者随机静脉注射3ml含5μg/ml肾上腺素浓度为15mg／ml的利多卡因或3ml生理盐水（每组n=20）。监测注射后5分钟的心率、收缩压和灌注指数（PI）。结果注射试验剂量在39±15秒后平均最大灌注指数降低65％±13％。心率和血压的最大增量分别为49±25秒后19±8bpm和102±34秒后17±7mmHg。用灌注指数作为血管内注射的评估指标（如果灌注指数较注射前降低≥10％则为阳性），其敏感性、特异性、阳性预期值和阴性预期值是100％（95％可信区间CI=83％-100％）。相对地，心率和血压指标的敏感性分别为95％（CI=76％-99％）和90％（CI=70％-97％）。结论灌注指数是评价成年丙泊酚静脉麻醉患者血管内注射硬膜外试验剂量药物后常规血流动力学变化的可靠的选用指标。