STAN Monitoring Research Articles

Change in practice: a qualitative exploration of midwives\u2019 and doctors\u2019 views about the introduction of STan monitoring in an Australian hospital

BackgroundThe present study examines the introduction of an innovation in intrapartum foetal monitoring practice in Australia. ST-Analysis (STan) is a technology that adds information to conventional fetal monitoring (cardiotocography) during labour, with the aim of reducing unnecessary obstetric intervention. Adoption of this technology has been controversial amongst obstetricians and midwives, particularly as its use necessitates a more invasive means of monitoring (a scalp clip), compared to external monitoring from cardiotocography alone. If adoption of this technology is going to be successful, then understanding staff opinions about the implementation of STan in an Australian setting is an important issue for maternity care providers and policy makers.MethodsUsing a maximum variation purposive sampling method, 18 interviews were conducted with 10 midwives and 8 doctors from the Women’s and Children’s Hospital, South Australia to explore views about the introduction of the new technology. The data were analysed using Framework Analysis.ResultsMidwives and doctors indicated four important areas of consideration when introducing STan: 1) philosophy of care; 2) the implementation process including training and education; 3) the existence of research evidence; and 4) attitudes towards the new technology. Views were expressed about the management of change process, the fit of the new technology within the current models of care, the need for ongoing training and the importance of having local evidence.ConclusionsThese findings, coupled with the general literature about introducing innovation and change, can be used by other centres looking to introduce STan technology.

A pilot exploratory investigation on pregnant women\u2019s views regarding STan fetal monitoring technology

BackgroundWomen’s views are critical for informing the planning and delivery of maternity care services. ST segment analysis (STan) is a promising method to more accurately detect when unborn babies are at risk of brain damage or death during labour that is being trialled for the first time in Australia. This is the first study to examine women’s views about STan monitoring in this context.MethodsSemi-structured interviews were conducted with pregnant women recruited across a range of clinical locations at the study hospital. The interviews included hypothetical scenarios to assess women’s prospective views about STan monitoring (as an adjunct to cardiotocography, (CTG)) compared to the existing fetal monitoring method of CTG alone. This article describes findings from an inductive and descriptive thematic analysis.ResultsMost women preferred the existing fetal monitoring method compared to STan monitoring; women’s decision-making was multifaceted. Analysis yielded four themes relating to women’s views towards fetal monitoring in labour: a) risk and labour b) mobility in labour c) autonomy and choice in labour d) trust in maternity care providers.ConclusionsFindings suggest that women’s views towards CTG and STan monitoring are multifaceted, and appear to be influenced by individual labour preferences and the information being received and understood. This underlies the importance of clear communication between maternity care providers and women about technology use in intrapartum care. This research is now being used to inform the implementation of the first properly powered Australian randomised trial comparing STan and CTG monitoring.

Breech labour is not a particular indication for STAN monitoring.

Breech labour is not a particular indication for STAN monitoring.

Value of Non-Invasive Fetal Monitoring Techniques in Detection of Fetal Metabolic Acidemia at Birth

Abstract Objective. Purpose of the study was to evaluate the diagnostic accuracy of fetal pulse oximetry (FPO) and STanalysis of the fetal ECG (STAN) in prediction of fetal acidemia at birth. Methods. A prospective clinical study was conducted at the Department of Obstetrics and Gynaecology, Jessenius Faculty of Medicine, Martin, Slovakia. In total, 63 out of 70 women with non-reassuring CTG patterns in labour were enrolled. Fetal surveillance during the labour continued with simultaneous CTG plus FPO and STAN monitoring. A receiver operating curve (ROC) analysis was performed to ascertain diagnostic accuracy of individual methods. Results. The study confirmed FPO has a significant ability to detect fetal acidemia at birth (UA-pH ≤ 7.2). The optimum diagnostic cut-off value of SpO2 was 33%, with FPO’s diagnostic sensitivity 60%, and specificity 85.2%. The diagnostic accuracies of STAN + CTG and CTG alone were inferior to that of FPO. Conclusions. FPO has an ability to predict fetal birth acidemia (UA-pH ≤ 7.2), and its diagnostic accuracy is superior to STAN + CTG, or CTG alone monitoring. Condensation.FPO has ability to predict fetal birth acidemia (UA - pH≤7.2), and its diagnostic accuracy is superior to STAN + CTG, or CTG alone monitoring.

Use of Peripartum ST Analysis of Fetal Electrocardiogram Without Blood Sampling: A Large Prospective Cohort Study

Abstract Objective Fetal peripartum surveillance with ST analysis of fetal electrocardiogram (STAN) alone or in combination with fetal blood sampling (FBS) is a worldwide debate. STAN monitoring without FBS support was implemented in 2000 in the authors’ department when it took part in a European multicentre project. The aim of this study was to evaluate neonatal outcomes associated with peripartum STAN monitoring without FBS support in a large prospective cohort of patients at high risk of peripartum fetal asphyxia. Study design This prospective cohort study included all consecutive high-risk women monitored with STAN technology over a 77-month period, excluding fetuses with congenital anomalies. Outcome variables were fetal metabolic acidosis, umbilical pH ≤ 7.05 and normal extracellular base deficit, transfer to a neonatal intensive care unit, neonatal encephalopathy and neonatal death related to peripartum asphyxia. Cases with metabolic acidosis were reviewed by a referent midwife and referent obstetricians to check whether or not labour management was consistent with the STAN guidelines. Results In total, 3112 women were included in the study. The caesarean section rate for suspected fetal distress was 9.5% [95% confidence interval (CI) 8.5–10.5]. Acid–base status was available for 3067 (98.5%) neonates. There were 14 cases of fetal metabolic acidosis (0.45%; 95% CI 0.2–0.7), 62 cases with umbilical pH ≤ 7.05 and normal extracellular base deficit (2%; 95% CI 1.5–2.5), 27 neonates with 5-min Apgar scores ≤ 7 (0.87%; 95% CI 0.54–1.20) and 16 neonates were transferred to the neonatal intensive care unit (0.51%; 95% CI 0.26–0.76) due to peripartum asphyxia. No cases of neonatal encephalopathy, or fetal or neonatal death occurred. Out of the 14 cases of fetal metabolic acidosis, 11 were not managed in accordance with the STAN guidelines. Specificity was 80.5% and the negative predictive value was 99.9%. Sensitivity was highly affected by medical staff interpretation, varying from 9.1% in the authors’ experience to 90.9% with appropriate labour management according to the STAN guidelines. Conclusions STAN monitoring without FBS support was associated with a low rate of fetal metabolic acidosis. Most cases of fetal metabolic acidosis were not managed in accordance with the STAN guidelines. This study not only supports STAN usage without FBS support, but also warns of possible guideline violations and subsequent adverse neonatal outcomes.

Use of peripartum ST analysis of fetal electrocardiogram without blood sampling: a large prospective cohort study

Objective Fetal peripartum surveillance with ST analysis of fetal electrocardiogram (STAN) alone or in combination with fetal blood sampling (FBS) is a worldwide debate. STAN monitoring without FBS support was implemented in 2000 in the authors’ department when it took part in a European multicentre project. The aim of this study was to evaluate neonatal outcomes associated with peripartum STAN monitoring without FBS support in a large prospective cohort of patients at high risk of peripartum fetal asphyxia. Study design This prospective cohort study included all consecutive high-risk women monitored with STAN technology over a 77-month period, excluding fetuses with congenital anomalies. Outcome variables were fetal metabolic acidosis, umbilical pH ≤ 7.05 and normal extracellular base deficit, transfer to a neonatal intensive care unit, neonatal encephalopathy and neonatal death related to peripartum asphyxia. Cases with metabolic acidosis were reviewed by a referent midwife and referent obstetricians to check whether or not labour management was consistent with the STAN guidelines. Results In total, 3112 women were included in the study. The caesarean section rate for suspected fetal distress was 9.5% [95% confidence interval (CI) 8.5–10.5]. Acid–base status was available for 3067 (98.5%) neonates. There were 14 cases of fetal metabolic acidosis (0.45%; 95% CI 0.2–0.7), 62 cases with umbilical pH ≤ 7.05 and normal extracellular base deficit (2%; 95% CI 1.5–2.5), 27 neonates with 5-min Apgar scores ≤ 7 (0.87%; 95% CI 0.54–1.20) and 16 neonates were transferred to the neonatal intensive care unit (0.51%; 95% CI 0.26–0.76) due to peripartum asphyxia. No cases of neonatal encephalopathy, or fetal or neonatal death occurred. Out of the 14 cases of fetal metabolic acidosis, 11 were not managed in accordance with the STAN guidelines. Specificity was 80.5% and the negative predictive value was 99.9%. Sensitivity was highly affected by medical staff interpretation, varying from 9.1% in the authors’ experience to 90.9% with appropriate labour management according to the STAN guidelines. Conclusions STAN monitoring without FBS support was associated with a low rate of fetal metabolic acidosis. Most cases of fetal metabolic acidosis were not managed in accordance with the STAN guidelines. This study not only supports STAN usage without FBS support, but also warns of possible guideline violations and subsequent adverse neonatal outcomes.

Acceptability of the fetal electrocardiographic (STAN®) monitoring system by staff at a high-risk maternity unit

Sir, We read with great interest the article by Parisaei et al. w1x in which they presented the acceptability of the new fetal monitoring system STAN to a high-risk labor ward. We performed a similar, but a region-wide, questionnaire after the introduction of STAN in Flanders, Belgium. In October 2008, we send a questionnaire to 110 midwives and gynecologists who had 1–3 years previously received training in STAN fetal monitoring in our center. The response rate was 57% (ns63), the respondents were 12 (19%) gynecologists and 51 (81%) midwives. We asked whether they had the impression that after the introduction of STAN the number of artificial deliveries, both vaginally and by cesarean section, for fetal distress had decreased (ns36; 57%), increased (ns5; 8%), did not change (ns7; 11%) or they did not know (ns15; 24%). We also evaluated whether they found the method easy to learn and easy to use in practice (ns28; 44%), easy to use but difficult to learn (understand the theory, ns23; 36%), difficult to learn both in theory and to use in practice (ns2.3%) or easy to learn in theory but difficult to use in practice (ns10; 16%). The number of deliveries in which STAN was used in the respondents’ practices ranged from 10% to 80% (median 30%). When asked whether they felt that from a medicolegal point of view, STAN vs. CTG alone was experienced as safer (ns21; 33%), no difference (ns16; 25%), less safe (ns20; 32%) or do not know (ns6; 10%). We presented a theoretical case in which we asked if in a term primigravid nulliparous women in labor in the second stage of labor and with an abnormal cardiotocogram demonstrating complicated variable decelerations, they would wait for 60 min, unless further fetal deterioration, if no ST-events occurred, as advised by STAN guidelines; or intervene immediately based solely on the cardiotocogram. Of the respondents 44 (70%) would follow the STAN guidelines and wait. But 17 (27%) would intervene immediately, and 2 (3%) did not know. We did not offer the possibility of fetal scalp pH measurement as it was not available in these centers. This means that even in this purely theoretical situation, a high percentage of users would not follow the guidelines, which might be even higher in a real-life situation. For us this underscores the importance of training, retraining and continuous evaluation. We believe these data support and enlarge the conclusion drawn by Parisaei et al. w1x, namely that the introduction of this new monitoring system, not only to high-risk labor wards, but also to general labor wards, is possible but that easy to understand theoretical support and easy to reach practical solutions is necessary. Otherwise, the benefits of this new method might get lost. Both authors have give courses in STAN monitoring organized by Neoventa.

Intrapartum fetal monitoring by ST analysis at University Hospital of Wales: usage and outcome

ObjectiveReview usage and outcome of cases where STAN fetal monitoring was used at University Hospital of Wales over 6 months (June–November 2009).BackgroundSTAN monitoring was introduced in our unit in 2006....

Acceptability of the fetal electrocardiographic (STAN®) monitoring system by staff at a high risk maternity unit

To assess staff acceptability of STAN monitoring system. This was a prospective study of health care professionals involved in the first 18 months of STAN use at a high risk maternity unit. During the study period 75% of midwives and 80% of doctors questioned felt confident when interpreting STAN cases. A total of 88% of midwives and 90% of doctors felt adequately supported in their actual clinical use of the system. Of all the obstetricians who used the STAN, 95% felt it was an acceptable alternative to fetal blood sampling. One of the main complaints was poor signal quality which occurred in 16% of cases. As many as 97% of doctors and 96% of midwives considered STAN to be an acceptable way of monitoring high risk women after its introduction. Introduction of a new monitoring system to a high risk labor ward is possible, and acceptable to its staff. Constant practical and theoretical support and adherence to strict, easily understood guidelines is required.

Effect of availability of fetal ECG monitoring on operative deliveries

The objective of our study was to test the hypothesis that the availability and selective use of STAN in conjunction with cardiotocography for intrapartum monitoring, lowers the incidence of operative deliveries for fetal distress. Observational study. Delivery suite of the National University Hospital, Singapore. The data regarding intrapartum cesarean sections and instrumental vaginal deliveries for presumed fetal distress and the condition of the neonate at birth (Apgar scores at one and five minutes and admission to neonatal intensive care unit (NICU) were collected over two consecutive three-year periods. In the first triennium, only external cardiotocography was used for intrapartum fetal surveillance and in the second triennium STAN monitoring was available for use in the delivery suite. With the availability and selective use of STAN monitoring, there was a significant decrease in the number of instrumental deliveries for fetal distress (from 66 out of 520 (0.9%) to 36 out of 474 (0.5%), p<0.025), the number of admissions to the NICU (from 418 (5.6%) to 311 (4.6%), p<0.01) and the number of neonates with Apgar score of seven or less at five minutes (from 192 (2.6%), p<0.001 to 113 (1.7%), p<0.001). There was no significant difference in the incidence of emergency cesarean sections for fetal distress during the two time periods. Intrapartum monitoring of term fetuses with cardiotocography combined with selective use of ST analysis leads to a significant reduction in the number of operative deliveries for suspected fetal distress with no adverse effect on neonatal outcome.

Review of the First 1502 Cases of ECG-ST Waveform Analysis During Labor in a Teaching Hospital

Although electronic fetal monitoring has lowered the rate of intrapartum stillbirth, intrapartum asphyxia still is a major cause of long-term deficits in survivors. A recent Cochrane review found less metabolic acidosis, fewer operative deliveries, and a significant reduction in neonatal encephalopathy (NNE) when performing cardiotocography with ST waveform analysis (CTG-ST). This prospective observational study, carried out at a tertiary referral labor ward, evaluated the STAN™ monitoring system of ST-segment analysis in 1502 women who had a suspicious or abnormal CTG or a high-risk pregnancy. Monitoring entails the application of a fetal scalp electrode that provides continuous CTG and fetal ECG analysis. The ST waveform reflects what takes place during ventricular repolarization. STAN analysis deals with the ability of the fetal heart to adapt to hypoxia, as opposed to fetal blood sampling, which is done to detect acidosis. STAN analysis indicated the need for some action in 358 of the 1502 women in the trial-nearly one-fourth of those studied. In 2.4% of cases, traces could not be interpreted. Cord blood gas values were available in 836 cases, in 23 of which (2.8%) metabolic acidosis was documented. STAN monitoring identified 16 of these cases (70%). In all, 14 cases of NNE were monitored by STAN. A retrospective analysis showed the most frequent reasons for a poor outcome to be delay in taking action when an ST event and CTG called for delivery, and lack of intervention after 90 minutes of active second-stage labor with an abnormal CTG trace despite a normal ST trace. In the authors' experience, the use of ECG-ST waveform analysis to monitor high-risk labors has not altered the frequency of either NNE or emergency operative delivery. More intensive training in CTG and ST analysis appears to be needed, emphasizing the need for prompt action when significant CTG and ST-segment changes are present.

Review of the first 1502 cases of ECG‐ST waveform analysis during labour in a teaching hospital

To assess the impact of introduction of the STAN monitoring system. Prospective observational study. Tertiary referral labour ward, St George's Hospital, London. High-risk term pregnancies. We report all consecutive cases of intrapartum monitoring using the STAN S 21 fetal heart monitor. Cases with adverse neonatal outcome were evaluated in relation to the ST waveform analysis and cardiotocography (CTG). Cord artery metabolic acidosis, neonatal encephalopathy (NNE) and reasons behind cases with poor outcome. Between 2002 and 2005, there were 1502 women monitored by STAN. Based on combined STAN analysis in the 1502 women, action was indicated in 358 women (23.8%), while in 1108 women (73.8%) no action was indicated. Traces were not interpretable in 36 women (2.4%). Of the 836 cases (55.7%) where cord blood gases were available, there were 23 cases (2.8%) of metabolic acidosis and 16 of these (70%) were identified by STAN. Overall, there were 14 cases of NNE monitored by STAN. Retrospective analysis of these highlights human errors, such as poor CTG interpretation, delay in taking appropriate action and not following the guidelines. Our experience suggests the need for more intense training on interpretation of CTG and strict adherence to guidelines.