胎儿血氧饱和度监测在预测胎儿酸中毒中的应用

目的研究胎儿血氧饱和度（FSO2）预测胎儿酸中毒的阈值及准确性。方法2002—12—2004-06对广东省人民医院及青海红十字会医院的226例产妇在宫口开大3cm以上者行FSO，监测及电子胎儿监护仪监护，应用受试者工作特征曲线评估FSO2阈值；研究将30％作为FSO2阈值，评估其预测胎儿酸中毒的准确性。结果第二产程FSO2较第一产程下降，二者均值差异有显著性；脐动脉血气与FSO2呈相关性；将30％作为FSO2阈值，预测胎儿宫内缺氧的敏感性、特异性、阳性预测值、阴性预测值及准确性分别为88．9％、96．8％、84，2％、97．6％、95．6％。结论将30％作为FSO2的阈值是适宜的；FSO2可提高诊断胎儿宫内酸中毒的准确性。     

产程中胎儿血氧饱和度监测的临床研究

目的:研究产程中监测胎儿血氧饱和度(FSaO2)诊断胎儿窘迫的准确性及安全性,以及联合应用胎心电子外监护监测胎儿的合理途径。方法:对108例产妇在第一产程活跃期及第二产程中同时行胎心监护和胎儿血氧饱和度监测,动态观察胎儿血氧饱和度的变化,确定诊断胎儿窘迫的标准,依据分娩后Apgar评分及脐血血气分析结果,验证监测方法的敏感性、特异性、阳性预期值、阴性预期值与准确率。结果:(1)以胎儿血氧饱和度≤30%作为诊断胎儿窘迫的标准,对脐动脉血pH≤7.15预测的敏感性91.6%,特异性97.9%,阳性预期值84.6%,阴性预期值98.9%;(2)胎儿血氧饱和度≤30%持续5min以上预示胎儿有缺氧及酸中毒的可能;(3)胎心监护和胎儿血氧饱和度测定联合应用,可提高胎儿窘迫诊断的准确性。结论:胎儿血氧饱和度监测是一种理想的内监护方法;产程中常规应用胎心电子外监护,发现异常时可进一步进行胎儿血氧饱和度监测,是理想的监测方法。     

胎儿血氧饱和度的监测及临床意义

目前产程中胎儿监护主要采用胎心率外监护。由于该法敏感性较高而特异性较低 ,使假阳性率升高 ,导致剖宫产率增加。Dildy等[1] 复习文献指出 ,脉冲血氧测定仪可以进行无创性动脉血氧饱和度测定 ,己广泛应用于麻醉、重症监护及新生儿等学科领域。胎儿脉冲血氧测定 (fetalpulseoximetry)具有同样的优点 ,必将成为监测胎儿低氧血症的一项敏感措施。近 10余年来有关胎儿脉冲血氧饱和度监护的研究报道较多 ,现结合文献简介如下。1　监测指标血液中的氧绝大多数与血红蛋白结合 ,以氧合血红蛋白的形式存在 ,仅有小部分氧溶解于血浆中。因此 ,血氧…     

胎儿脉冲血氧监测法在产程中的应用价值

产时胎儿监护的主要目的是发现胎儿在分娩过程中有无缺氧,对胎儿宫内状况进行及时诊断并预测新生儿结局.随着围生医学的深入发展,监测仪器和技术的不断更新,对胎儿监护的手段越来越多,但目前还没有一种满意的方法能准确诊断胎儿窘迫.胎儿脉冲血氧测定法是近年国外兴起的一种新的产时胎儿监护方法,该方法可在产程中连续对胎儿进行血氧饱和度监测,及时发现胎儿缺氧.本文对胎儿脉冲血氧定量法的原理、发展及临床研究进展作一介绍.     

胎儿脉搏氧测定的临床价值

胎儿脉搏氧测定是国外近十年兴起的产程中胎儿监护技术,仪器探头直接与胎儿面部皮肤接触,无须采血即可实时观察胎儿的血氧饱和度,能较敏感和精确地反映胎儿宫内情况,减少不必要的产科干预,提高围生期预后,而且操作较简便,对母亲和胎儿均不会造成不良影响,是很有前途的胎儿监护技术.综述该技术的原理、基本操作、适应证与禁忌证及临床应用价值.     

产时胎儿监护的评价

产时胎儿监护可减少围产儿死亡率，但不能减少新生儿脑瘫的发生，电子胎儿监护和胎儿血氧测量法是目前应用最好的两种监护方法，两者联合应用可明显减低围产儿死亡率，并将分娩中不必要的手术干预降到最低程度，脉搏血氧定量法（ｐｕｌｓｅｏｘｙｍｅｔｒｙ）可提供连续的胎儿生化监测，将来有可能成为产时胎儿监护的警报系统。     

产程中的胎儿监护

目前产程中的胎儿监护主要手段为外监护,其敏感性虽高,但特异性较低,导致剖宫产率增加。有必要寻找一种安全、直接、持续、无创并有一定敏感性、特异性的方法,在减少过度干预的前提下,预防新生儿窒息的发生。胎儿血氧饱和度(FSaO_2)探头直接接触胎儿面部皮肤,实时反映FSaO_2,血氧分压稍有变化即可引起明显的SaO_2变化,能敏感地反映胎儿宫内状况。     

产程中的胎儿监护

目前产程中的胎儿监护主要手段为外监护,其敏感性虽高,但特异性较低,导致剖宫产率增加.有必要寻找一种安全、直接、持续、无创并有一定敏感性、特异性的方法,在减少过度干预的前提下,预防新生儿窒息的发生.胎儿血氧饱和度(FSaO2)探头直接接触胎儿面部皮肤,实时反映FSaO2,血氧分压稍有变化即可引起明显的SaO2变化,能敏感地反映胎儿宫内状况.     

Fetal pulse oximetry: an adjunct to electronic fetal heart rate monitoring

Electronic fetal heart rate monitoring is routinely used as an indirect measure of fetal oxygenation, yet its value continues to be questioned. With a nonreassuring fetal heart rate pattern, the clinician often needs additional information about fetal oxygen status. Fetal pulse oximetry is a new fetal assessment technology. After consideration of the results of a multicenter randomized, controlled, clinical trial on fetal pulse oximetry in the United States, the U.S. Food and Drug Administration approved the technology for clinical use on May 12, 2000. The results of this trial are anticipated to be published in late 2000.     

Transabdominal fetal pulse oximetry with near-infrared spectroscopy

OBJECTIVE: The purpose of this study was to determine the feasibility of noninvasive fetal pulse oximetry in the human fetus with transabdominal continuous-wave near-infrared spectroscopy. STUDY DESIGN: The instrument has 3 wavelength light-emitting diodes (735, 805, and 850 nm) as light sources and a photomultiplier tube as a detector. This instrument was used in 6 pregnant women (>36 weeks of gestation). First, a fetal heart rate was obtained with a fetal heart rate monitor. Then, the depth of fetal tissue (head) from the maternal abdomen was determined by ultrasound examination; the distance between the optodes (light source and the detector) was set to be approximately twice the depth of the fetus (7-11 cm). The data analysis was based on the modified Beer-Lambert law and the use of optical densities at 735 and 850 nm to obtain the concentration changes of the oxyhemoglobin and deoxyhemoglobin. The saturation was expressed as the percent of oxygen saturation equal to 100 x oxyhemoglobin/(oxyhemoglobin + deoxyhemoglobin). We recorded the spectroscopy data and the fetal heart rate for approximately 3 to 10 minutes in each patient. RESULTS: The mean oxygen saturation values of each of the 6 individual fetuses ranged from 50% to 74% (overall mean saturation, 61% +/- 14.8% [SD]). CONCLUSION: This preliminary data indicate that transabdominal fetal pulse oximetry is feasible for human patient application. The measured values were similar to those that are obtained with transvaginal pulse oximetry. Future studies should correlate transabdominally obtained measurements with those measurements that are obtained by transvaginal fetal pulse oximetry.     

Fetal pulse oximetry and wavelet analysis of the fetal heart rate in the evaluation of abnormal cardiotocography tracings

AIM: Previous studies indicate that the addition of wavelet analysis of the fetal pulse oximetry tracings (FSPO2) and fetal heart rate (FHR) variability to cardiotocography (CTG), for intrapartum fetal monitoring, provides useful information on the fetal response to hypoxia. We applied the new procedure in non-reassuring CTG patterns, in which cesarean section was performed, and tested its accuracy in the diagnosis of the intrapartum fetal compromise. METHODS: At the 'Aretaieion' University Hospital labor ward, 318 women with term fetuses in the cephalic presentation entered the trial during labor. They all were monitored with external CTG and fetal pulse oximetry. In the cases that cesarean section was applied, because of abnormal CTG tracings, we applied a method based on the multiresolution wavelet analysis and a self-organized map neural network on the first and second stage of labor. The main outcome parameter was the rate of cord metabolic acidosis at birth (pH < 7.05). Secondary outcomes included Apgar scores at 5 min, fetal transmission to neonatal intensive care unit (NICU) and neonatal encephalopathy. RESULTS: Fifty out of 318 cases delivered operatively because of abnormal CTG patterns (rate 15.72%). In 30 cases, cord pH was >7.05, while in 11 Apgar scores at 5 min were <7, while none of those neonates were transferred to NICU. In the rest 20 cases cord pH was <7.05; in all of these cases Apgar scores at 5 min were <7, while four neonates were transferred to NICU. In one of them, neonatal encephalopathy was diagnosed. After the offline application of wavelet analysis and neural networks to the pulse oximetry and FHR variability readings of the 50 cases, statistics calculated that the system showed a sensitivity of 85% and a specificity of 93%, while false negative and false positive rates were 15% and 7%, respectively. CONCLUSION: Computerized FHR and FSPO2 monitoring shows an excellent efficacy and reliability in interpreting non-reassuring FHR recordings.     

Intrapartum fetal pulse oximetry and fetal heart rate decelerations.

OBJECTIVES: To determine the behavior of fetal oxygenation (FSpO(2)) in different patterns of fetal heart rate decelerations (FHR). METHODS: A total of 787 decelerations were studied. RESULTS: FSpO(2) decreased significantly during decelerations, especially when the alteration was prolonged. CONCLUSIONS: Modifications in FHR occur simultaneously with alterations in FSpO(2), although the latter do not persist in time. Different degrees of FSpO(2) seen prior to deceleration are an expression of fetal respiratory status.     

Dystocia in nulliparous patients monitored with fetal pulse oximetry

OBJECTIVE: A critical analysis of the United States randomized controlled trial of fetal pulse oximetry concluded that nonreassuring fetal heart rate patterns used for study entry may have been a marker for dystocia. We prospectively studied nulliparous women in labor whose progress was monitored with fetal pulse oximetry to examine the relationship between nonreassuring fetal heart rate patterns and operative delivery for dystocia. STUDY DESIGN: A prospective nonrandomized observational cohort study compared two distinct classes of nonreassuring fetal heart rate patterns (class I: intermittent, mildly nonreassuring; class II: persistent, progressive, and moderate to severely nonreassuring) among nulliparous patients with the use of fetal pulse oximetry to confirm fetal well-being. Definitions of dystocia included the cessation of labor progress in the first (3 hours) or second (2 hours) stage of labor, despite adequate uterine activity that was assessed with an intrauterine pressure catheter. Independent review confirmed the classification of nonreassuring fetal heart rate patterns and study entry criteria. RESULTS: Two hundred seventy-four patients met study criteria and had sufficient information for fetal heart rate tracing interpretation. Two hundred thirty-seven patients (86.5%) were class II, and 37 patients (13.5%) were class I. The two classes of patients were comparable in a variety of obstetric, demographic, and perinatal variables. Twelve percent of all patients were delivered for nonreassuring fetal status. Significantly more class II patients (22%) were delivered by cesarean for dystocia than were class I patients (8%). Higher doses and a longer number of hours of oxytocin were required among class II patients. Significantly more occiput posterior positions were noted among all patients who underwent cesarean delivery for dystocia compared with other modes of delivery. CONCLUSION: Significantly nonreassuring fetal heart rate patterns predict cesarean delivery for dystocia among nulliparous patients with normally oxygenated fetuses in a setting of a standardized labor management protocol. This confirms the observations in the randomized controlled trial of fetal pulse oximetry in the United States and may provide insight into the treatment of nonprogressive labor in contemporary practice.     

Intrapartum cardiotocography and fetal pulse oximetry in assessing fetal hypoxia.

OBJECTIVES: A retrospective analysis of short-term variability (STV), a cardiotocography (CTG) parameter, in relation to fetal blood saturation values (FSpO(2)) obtained by fetal pulse oximetry. METHODS: The study included 26 healthy pregnant women monitored continuously during delivery with both cardiotocography and fetal pulse oximetry. RESULTS: Lower FSpO(2) values were observed in the group showing STV levels 6.0 ms (34.4+/-2.9% vs. 43+/-7.2%; P<0.001). A positive correlation was found between STV levels 相似文献   

Intrapartum management of nonreassuring fetal heart rate patterns: a randomized controlled trial of fetal pulse oximetry

OBJECTIVE: We tested if fetal pulse oximetry in addition to electronic fetal monitoring (CTG) and scalp blood sampling improves the accuracy of fetal assessment and allows safe reduction of operative deliveries (-50%) and scalp blood sampling (-50%) performed because of nonreassuring fetal status.Study design A randomized controlled trial was conducted in 146 patients with term pregnancies in active labor and abnormal fetal heart rate patterns: 73 had electronic fetal heart rate monitoring (CTG) and fetal scalp blood sampling (control group), 73 had CTG, fetal scalp blood sampling, and continuous fetal pulse oximetry (study group). RESULTS: There was a reduction of -50% in operative deliveries and fetal scalp blood sampling performed because of nonreassuring fetal status in the study group: operative deliveries, study versus control 25/49 (P 相似文献   

Alterations in Doppler velocimetry indices of the umbilical artery during fetal hypoxia in labor,in relation to cardiotocography and fetal pulse oximetry findings

Aim The aim was to investigate fetal peripheral blood flow using external cardiotocography (CTG), Doppler velocimetry, and pulse oximetry (PO) in normal labor compared with those complicated by hypoxia.Subjects During labor, 35 term fetuses with oxygen saturation values (FSPO₂) between 30 and 40%, and 25 term fetuses with FSPO₂ values 30% for a period of 20 s to 2 min were studied. Fetuses were assessed using simultaneous CTG, PO, and Doppler ultrasonography of the umbilical artery (UA). The pulsatility index (PI), resistance index (RI), and flow velocity integral (FVI) were recorded. Peripartum outcomes were compared with those of 30 fetuses with SPO₂ values >40%. All groups presented abnormal CTG patterns and were comparable with regard to maternal age and parity.Setting The Fetal Surveillance Unit of the 2nd Department of Obstetrics and Gynecology, Aretaieion Hospital, Athens University, Greece.Results Umbilical artery Doppler revealed an initial increase in the RI and the PI in the presence of decreased oxygen saturation. The differences observed in Doppler velocity and impedance indices correlated with PO values. Fetal outcomes correlated with UA Doppler findings.Conclusions Alterations in UA Doppler velocimetry indices were observed during labor-induced fetal hypoxia. PO readings of <40% provoked an increase in the RI and PI. When PO readings remained <30% for >2 min, both the PI and the RI were further increased in a more prominent way. UA velocimetry indices correlated with perinatal outcome.     

A cost-effectiveness analysis of the intrapartum fetal pulse oximetry multicentre randomised controlled trial (the FOREMOST trial)

OBJECTIVE: To report an economic analysis of the Australian intrapartum fetal pulse oximetry (FPO) multicentre randomised controlled trial (the FOREMOST trial), which examined whether adding FPO to conventional cardiotocographic (CTG) monitoring (intervention group) was cost-effective in reducing operative delivery rates for non-reassuring fetal status compared with the use of CTG alone (control group). DESIGN: Cost-effectiveness analysis of the FOREMOST trial. SETTING: Four Australian maternity hospitals, each with more than 4000 births/year. POPULATION: Women in labour at > or =36 weeks of gestation, with a non-reassuring CTG. METHODS: Costs were for treatment-related expenses, incorporating diagnosis-related grouping costs and direct costs (including fetal monitoring). Incremental cost-effectiveness ratio (ICER) and cost-effectiveness plane were calculated, and sensitivity analysis was conducted. The primary outcome was that of the clinical trial: operative delivery for non-reassuring fetal status avoided in the intervention group relative to that in the control group. MAIN OUTCOME MEASURES: The ICER. RESULTS: The ICER demonstrated a saving of $A813 for each operative birth for non-reassuring fetal status averted by the addition of FPO to CTG monitoring compared with the use of CTG monitoring alone. CONCLUSION: The addition of FPO to CTG monitoring represented a less costly and more effective use of resources to reduce operative delivery rates for non-reassuring fetal status than the use of conventional CTG monitoring alone.