Effect of maternal oxygen supplementation for parturient undergoing elective cesarean section by high-flow nasal oxygen compared with room air on fetal acidemia: study protocol for a randomized controlled trial.

BACKGROUND: Maternal oxygen supplementation is usually used as an intrauterine resuscitation technique to prevent fetal hypoxia and acidemia during delivery. However, there has been a great deal of controversy regarding the effects of prophylactic maternal oxygen during cesarean section, during which the incidence of fetal acidemia seems to be higher compared with that during labor. High-flow nasal oxygen (HFNO) can improve oxygenation better in patients with high-flow oxygen airflow. The purpose of this study is to determine whether maternal oxygen supplementation with HFNO has a positive effect on fetal acidemia during cesarean section through umbilical arterial blood gas analysis. METHOD: This prospective, single-center, randomized, double-blinded trial will enroll 120 patients undergoing cesarean section. Participants will be randomly assigned to the HFNO group or air group at a 1:1 ratio. For parturients in the HFNO group, the flow rate is 40L/min, and the oxygen is heated to 37℃ with humidity 100% oxygen concentration through the Optiflow high-flow nasal oxygen system. And for the air group, the flow rate is 2 L/min with an air pattern through the same device. The primary outcome was umbilical artery (UA) lactate. Secondary outcomes include UA pH, PO2, PCO2, BE, the incidence of pH < 7.20 and pH < 7.10, Apgar scores at 1 and 5 min, and neonatal adverse outcomes. DISCUSSION: Our study is the first trial investigating whether maternal oxygen supplementation with HFNO can reduce the umbilical artery lactate levels and the incidence of fetal acidemia in cesarean section under combined spinal-epidural anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov NCT05921955. Registered on 27 June 2023.

Heterogeneity in management of category II fetal tracings: data from a multihospital healthcare system.

BACKGROUND: Electronic fetal monitoring is widely used to identify and intervene in suspected fetal hypoxia and/or acidemia. Category II fetal heart rate tracings are the most common class of fetal monitoring in labor, and intrauterine resuscitation is recommended given the association of category II fetal heart rate tracings with fetal acidemia. However, limited published data are available to guide intrauterine resuscitation technique selection, leading to heterogeneity in the response to category II fetal heart rate tracings. OBJECTIVE: This study aimed to characterize approaches to intrauterine resuscitation in response to category II fetal heart rate tracings. STUDY DESIGN: This was a survey study administered to labor unit nurses and delivering clinicians (physicians and midwives) across 7 hospitals in a Midwestern healthcare system spanning 2 states. The survey posed 3 category II fetal heart rate tracing scenarios (recurrent late decelerations, minimal variability, and recurrent variable decelerations) and asked participants to select first- and second-line intrauterine resuscitation management strategies. The participants were asked to quantify the level of influence certain factors have on their choice using a scale from 1 to 5. Intrauterine resuscitation strategy selection was compared by clinical role and hospital type (nurses vs delivering clinicians and university-affiliated hospital vs non-university-affiliated hospital). RESULTS: Of 610 providers invited to take the survey, 163 participated (response rate of 27%): 37% of participants from university-affiliated hospitals, 62% of nurses, and 37% of physicians. Maternal repositioning was the most selected first-line strategy, regardless of the type of category II fetal heart rate tracing. First-line management varied by clinical role and hospital affiliation for each fetal heart rate tracing scenario, particularly for minimal variability, which was associated with the most heterogeneity in the first-line approach. Previous experience and recommendations from professional societies were the most influential factors in intrauterine resuscitation selection overall. Of note, 16.5% of participants reported that published evidence did not influence their choice at all. Participants from a university-affiliated hospital were more likely than participants from a non-university-affiliated hospital to consider patient preference when selecting an intrauterine resuscitation technique. Nurses and delivering clinicians differed significantly in the rationale for management choices: nurses were more often influenced by advice from other healthcare providers on the team (P<.001), whereas delivering clinicians were more influenced by literature (P=.02) and ease of technique (P=.02). CONCLUSION: There was significant heterogeneity in the management of category II fetal heart rate tracing. In addition, motivations for choice in intrauterine resuscitation technique varied by hospital type and clinical role. These factors should be considered when creating fetal monitoring and intrauterine resuscitation protocols.

The "30-minute rule" for expedited delivery: fact or fiction?

Initially developed from hospital feasibility data from the 1980s, the "30-minute rule" has perpetuated the belief that the decision-to-incision time in an emergency cesarean delivery should be <30 minutes to preserve favorable neonatal outcomes. Through a review of the history, available data on delivery timing and associated outcomes, and consideration of feasibility across several hospital systems, the use and applicability of this "rule" are explored, and its reconsideration is called for. Moreover, we have advocated for balanced consideration of maternal safety with rapidity of delivery, encouraged process-based approaches, and proposed standardization of terminology regarding delivery urgency. Furthermore, a standardized 4-tier classification system for delivery urgency, from class I, for a perceived threat to maternal or fetal life, to class IV, a scheduled delivery, and a call for further research with a standardized structure to facilitate comparison have been proposed.

The Application of Intrauterine Resuscitation Maneuvers in Delivery Room: actual and expected Use.

BACKGROUND: In case of suspicious CTG in labor a conservative attitude is recommended, when possible, through intrauterine resuscitation maneuvers. AIMS: This study aims to evaluate the use of intrauterine resuscitation maneuvers (IRM) at two Italian hospitals; the secondary outcome is the assessment of the agreement in their application. MATERIALS AND METHODS: Retrospective analysis was performed on the data of 80 deliveries (40 vs 40) from two different Italian hospitals, located in Novara (group 1) and in Borgomanero (group 2). In order to evaluate a varied series of CTG traces (normal and pathological), we randomly extracted 13 cases of neonatal asphyxia (2015-2020). The normal CTG traces were identified among the deliveries of the same day of these cases, in a ratio of 1: 4. One gynecologist and one midwife for the group 1 and one other gynecologist and one midwife for the group 2 were given a file with anonymous patient's clinical data, and the CTG registered during labor. Then, they classified the CTG trace, and they stated what they would have done if they had been present. RESULTS: Maternal position was changed for 58 patients, especially in group 2 (25/40 vs 33/40) (p = 0.046). Intravenous fluid administration was performed for 35 patients, more in group 2 (8/40 vs 27/40) (p < 0.001). Oxytocin was used for 21/80 patients: in 7/21 cases were discontinued (p = 0.241). Clark's test was used only in 2 cases, in group 2. No one used tocolysis, oxygen, or amnioinfusion. The concordance rate among operators showed poor agreement regarding the use of IRM, group 2 showed increased general concordance rates. CONCLUSIONS: The use of IRM in labor is recommended but underused and with poor concordance rate in the application, based on our results.

The effect of intrauterine resuscitation by maternal hyperoxygenation on perinatal and maternal outcome: a randomized controlled trial.

BACKGROUND: Maternal hyperoxygenation is widely used during labor as an intrauterine resuscitation technique. However, robust evidence regarding its beneficial effect and potential side effects is scarce, and previous studies show conflicting results. OBJECTIVE: To assess the effect of maternal hyperoxygenation upon suspected fetal distress during the second stage of term labor on fetal heart rate, neonatal outcome, maternal side effects, and mode of delivery. MATERIALS AND METHODS: In a single-center randomized controlled trial in a tertiary hospital in The Netherlands, participants were randomized in case of an intermediary or abnormal fetal heart rate pattern during the second stage of term labor, to receive either conventional care or 100% oxygen at 10 L/min until delivery. The primary outcome was the change in fetal heart rate pattern. Prespecified secondary outcomes were Apgar score, umbilical cord blood gas analysis, neonatal intensive care unit admission, perinatal death, free oxygen radical activity, maternal side effects, and mode of delivery. We performed subgroup analyses for intermediary and abnormal fetal heart rate, and for small for gestational age fetuses. RESULTS: From March 2016 through April 2018, a total of 117 women were included. Fetal heart rate patterns could be analyzed in 71 women. Changes in fetal heart rate (defined as improvement, equal, or deterioration) in favor of maternal hyperoxygenation were significant (odds ratio, 5.7; 95% confidence interval, 1.7-19.1) using ordinal logistic regression. Apgar score, umbilical cord blood gas analysis, free oxygen radicals, and mode of delivery showed no significant differences between the intervention and control group. Among women with an abnormal fetal heart rate, there were fewer episiotomies on fetal indication in the intervention group (25%) than in the control group (65%, P < .01). CONCLUSION: Maternal hyperoxygenation has a positive effect on the fetal heart rate in the presence of suspected fetal distress during the second stage of labor. There was no significant difference in the mode of delivery or neonatal outcome; however, significantly fewer episiotomies on fetal indication were performed following maternal hyperoxygenation in the subgroup with abnormal fetal heart rate pattern.

The effect of intrapartum oxygen supplementation on category II fetal monitoring.

BACKGROUND: Maternal oxygen administration is a widely used intrauterine resuscitation technique for fetuses with category II electronic fetal monitoring patterns, despite a paucity of evidence on its ability to improve electronic fetal monitoring patterns. OBJECTIVE: This study investigated the effect of intrapartum oxygen administration on Category II electronic fetal monitoring patterns. STUDY DESIGN: This is a secondary analysis of a randomized trial conducted in 2016-2017, in which patients with fetuses at ≥37 weeks' gestation in active labor with category II electronic fetal monitoring patterns were assigned to 10 L/min of oxygen by face mask or room air until delivery. Trained obstetrical research nurses blinded to allocation extracted electronic fetal monitoring data. The primary outcome was a composite of high-risk category II features including recurrent variable decelerations, recurrent late decelerations, prolonged decelerations, tachycardia, or minimal variability 60 minutes after randomization to room air or oxygen. Secondary outcomes included individual components of the composite high-risk category II features, resolution of recurrent decelerations within 60 minutes of randomization, and total deceleration area. The outcomes between the room air and oxygen groups were compared using univariable statistics. Time-to-event analysis was used to compare time to resolution of recurrent decelerations between the groups. Paired analysis was used to compare the pre- and postrandomization outcomes within each group. RESULTS: All 114 randomized patients (57 room air and 57 oxygen) were included in this analysis. There was no difference in resolution of recurrent decelerations within 60 minutes between the oxygen and room air groups (75.4% vs 86.0%; P=.15). The room air and oxygen groups had similar rates of composite high-risk category II features including recurrent variable decelerations, recurrent late decelerations, prolonged decelerations, tachycardia, and minimal variability 60 minutes after randomization. Time to resolution of recurrent decelerations and total deceleration area were similar between the room air and oxygen groups. Among patients who received oxygen, there was no difference in the electronic fetal monitoring patterns pre- and postrandomization. Similar findings were observed in the electronic fetal monitoring patterns pre- and postrandomization in room air patients. CONCLUSION: Intrapartum maternal oxygen administration for category II electronic fetal monitoring patterns did not resolve high-risk category II features or hasten the resolution of recurrent decelerations. These results suggest that oxygen administration has no impact on improving category II electronic fetal monitoring patterns.

Response to category II tracings: Does anything help?

Electronic fetal monitoring (EFM) is the most commonly used tool to screen for intrapartum fetal hypoxia. Category II EFM is present in over 80% of laboring patients and poses a unique challenge to management given the breadth of EFM features that fall within this category. Certain Category II patterns, such as recurrent late or recurrent variable decelerations, are more predictive of neonatal acidemia than others. A key feature among many published algorithms for Category II management is the use of intrauterine fetal resuscitation techniques including maternal oxygen administration, amnioinfusion, intravenous fluid bolus, discontinuation of oxytocin, and tocolytic administration. The goal of intrauterine resuscitation is to prevent or reverse fetal hypoxia. This is most likely to be successful if the etiology of the Category II EFM pattern is identified and targeted resuscitative measures are performed.

Safely lowering the emergency Cesarean and operative vaginal delivery rates using the Fetal Reserve Index.

Objective: The cardiotocograph (CTG) or electronic fetal monitoring (EFM) was developed to prevent fetal asphyxia and subsequent neurological injury. From a public health perspective, it has failed these objectives while increasing emergency operative deliveries (emergency operative deliveries (EODs) - emergency cesarean delivery or operative vaginal delivery) for newborns, who in retrospect, actually did not require the assistance. EODs increase the risks of complications and stress for patients, families, and medical personnel. A safe reduction in the need for EOD will likely reduce both the overall Cesarean section rate as well as the risk of fetal neurological injury during labor to which it is related. We have developed the fetal reserve index (FRI), which is more comprehensive than CTG as a new screening method for early identification of the fetus at-risk of both neurological harm and the need to "rescue" by means of an EOD. Here, we compare prospectively the need for EOD in two groups of parturients undergoing a trial of labor at term. One group was managed conventionally, the other by the principles of the FRI.Study design: We compared the need for EOD of 800 parturients with singleton cases undergoing a trial of labor at term entering with normal CTG patterns (ACOG category 1). Patients were either treated routinely (400 - "early cases") or in a second group seen later actively managed using the principles of the FRI (400 - "late cases"). The FRI includes measurements of five components of the CTG: rate, variability, decelerations, accelerations, and abnormal uterine activity combined with the presence of medical, obstetrical, and fetal risk factors. The 8-point metric categorizes cases as "green", "yellow", and "red" with the latter being at risk.Results: All 800 patients delivered babies, who were discharged in the usual time course with no untoward outcomes noted. The incidence of red zone scores was comparable in the two groups (≈25%), but the use of intrauterine resuscitation (IR) when reaching the red zone in the late group (47%) was more than double the incidence in the early group (20%) (p < .001). Despite (or because of) this, EODs were significantly reduced in the late group, from 17.3 to 4.0% (p < .001). Further, the late group spent less time in the red zone without increasing overall time in labor. Overall, EOD cases averaged >1 h in the red zone versus 0.5 h for non-EODs.Conclusions: The FRI may provide a metric to reduce EODs and by extension also reduce the risks of both cesarean delivery and adverse fetal/neonatal outcomes. The safe avoidance of EOD would seem to be an important metric to assess the quality of intrapartum management. This study represents the first attempt to apply the principles of the FRI "live" for the concurrent management of patients during labor. These promising results, if confirmed, in larger sample sizes, set the stage for our computerization of the FRI for widespread study. Benefits appear to come from identification and early, conservative management of fetal deterioration before the need to "rescue" the fetus by EOD.

Re-engineering the interpretation of electronic fetal monitoring to identify reversible risk for cerebral palsy: a case control series.

BACKGROUND: Even key opinion leaders now concede that electronic fetal monitoring (EFM) cannot reliably identify fetal acidemia which many vouch as the only labor mediated pathophysiologic precursor for cerebral palsy (CP). We have developed the "Fetal Reserve Index" - an algorithm combining five dynamic components of EFM (1. Rate, 2. Variability, 3. Accelerations, 4. Decelerations, and 5. Excessive uterine activity) considered individually that are combined with the presence of: 6. maternal, 7. obstetrical, and 8. fetal risk factors. OBJECTIVE: Here, we compare this 8-point fetal reserve index (FRI) against the performance of ACOG monograph criteria and ACOG Category systems for predicting risk for both CP and the need for emergency operative delivery (EOD). We then studied how varied management for screen positives (Red zone-defined below) impacts the outcome of such cases. STUDY DESIGN: Four hundred twenty term patients were studied: all entered labor with normal EFMs and no apparent cause of harm except events of labor and delivery. Sixty subsequently developed CP, and 360 were apparently normal controls. An FRI, normal on all eight parameters scored 100%, 4 of the 8 was 50%, etc. We divided cases into Green zone >50%, Yellow 50-26%, and Red ≤25%. An FRI in the Red zone was considered a positive screen. We then compared performance metrics for the three evaluation schemes and differences between controls that reached Red against those controls whose worst scores were Green/Yellow. RESULTS: For detection of injury during labor, the FRI performed much better than the ACOG Category criteria (sensitivity 28%), and Category III (45%) (p < .001). All CP cases reached Red zone and were Red for a minimum of 2 hours (mean = 5.35 hours). Twenty-four% of controls reached Red, but were only Red for average of 1 hr. The incidence of low Apgar's, pH, FRI, and Lowest FRI increased progressively from Green/Yellow controls to red controls to CP cases. Irrespective, CP cases met ACOG Monograph criteria for labor injury less than 50% of the time. Only half of CP babies had umbilical artery pH values <7.00, and less than 50% showed Category III patterns. The earlier in labor the Red zone was reached, the more likely for a baby to develop CP or the mother to require an EOD regardless of fetal outcome. Successful intrauterine resuscitations (IR) diminished time spent in the Red zone and the need for EODs. CONCLUSIONS: FRI shows better discrimination for adverse fetal outcome and EOD than traditional EFM interpretation. The Category system is a very poor, subjective screening method as the vast majority of CP babies never reach the "action point" result of Category III. While reaching the Red zone does not ordain a bad outcome, how it is managed, does. Compared to CP cases, Red controls were delivered faster, had higher FRIs, and often had prompt management including IR maneuvers, which improved the FRI and lowered the risk of EODs even for cases with normal outcomes. With further study and validation, the quantitative FRI approach may replace the current, very subjective interpretation with a quantitative "lab test" approach.

Refining the Prediction and Prevention of Emergency Operative Deliveries with the Fetal Reserve Index.

Electronic fetal monitoring (EFM) is a poor predictor of outcomes attributable to delivery problems. Contextualizing EFM by adding maternal, obstetrical, and fetal risk-related information to create an index called the Fetal Reserve Index (FRI) improves the predictive capacity and facilitates the timing of interventions. Here, we test critical assumptions of FRI as a clinical tool. Our conceptualization implies that the earlier one reaches the red zone (FRI ≤25) and the longer one spends in the red zone, the greater the likelihood of emergency operative deliveries (EOD). METHODS: We analyzed 1,402 patients using logistic regression predicting the probability of EOD and employed qualitative methodology techniques to refine predictive capabilities. RESULTS: Reaching the red zone early and staying there > 1 h increases the probability of EOD. When these risk factors are paired with intrauterine resuscitation (IR) in Stage 1, the reduction of EOD is substantial. CONCLUSION: FRI is a capable predictor of EOD because it accurately identifies the level of malleable risk. FRI analysis increases the risk of using IR in Stage 1. Matching risk and resources dramatically reduces the chances of EOD. Earlier IR improves the outcomes if the calculated risk is high.

Intrauterine resuscitation during the second stage of term labour by maternal hyperoxygenation versus conventional care: study protocol for a randomised controlled trial (INTEREST O2).

BACKGROUND: Perinatal asphyxia is, even in developed countries, one the major causes of neonatal morbidity and mortality. Therefore, if foetal distress during labour is suspected, one should try to restore foetal oxygen levels or aim for immediate delivery. However, studies on the effect of intrauterine resuscitation during labour are scarce. We designed a randomised controlled trial to investigate the effect of maternal hyperoxygenation on the foetal condition. In this study, maternal hyperoxygenation is induced for the treatment of foetal distress during the second stage of term labour. METHODS/DESIGN: This study is a single-centre randomised controlled trial being performed in a tertiary hospital in The Netherlands. From among cases of a suboptimal or abnormal foetal heart rate pattern during the second stage of term labour, a total of 116 patients will be randomised to the control group, where normal care is provided, or to the intervention group, where before normal care 100% oxygen is supplied to the mother by a non-rebreathing mask until delivery. The primary outcome is change in foetal heart rate pattern. Secondary outcomes are Apgar score, mode of delivery, admission to the neonatal intensive care unit and maternal side effects. In addition, blood gas values and malondialdehyde are determined in umbilical cord blood. DISCUSSION: This study will be the first randomised controlled trial to investigate the effect of maternal hyperoxygenation for foetal distress during labour. This intervention should be recommended only as a treatment for intrapartum foetal distress, when improvement of the foetal condition is likely and outweighs maternal and neonatal side effects. TRIAL REGISTRATION: EudraCT, 2015-001654-15; registered on 3 April 2015. Dutch Trial Register, NTR5461; registered on 20 October 2015.

Reengineering Electronic Fetal Monitoring Interpretation: Using the Fetal Reserve Index to Anticipate the Need for Emergent Operative Delivery.

OBJECTIVE: The near-ubiquitous use of electronic fetal monitoring has failed to lower the rates of both cerebral palsy and emergency operative deliveries (EODs). Its performance metrics have low sensitivity, specificity, and predictive values for both. There are many EODs, but the vast majority have normal outcomes. The EODs, however, cause serious disruption in the delivery suite routine with increased complications, anxiety, and concern for all. METHODS: We developed the fetal reserve index (FRI) as multicomponent algorithm including 4 FHR components (analyzed individually), uterine activity, and maternal, obstetrical, and fetal risk factors to assess risk of cerebral palsy and EOD. Scores were categorized into green, yellow, and red zones. Here, we studied 300 patients by the FRI, all of whom had normal neonatal outcomes. We attempted to distinguish the clinical course of those cases which required an EOD versus controls which did not. RESULTS: 51 cases with EOD had FRIs much lower than 249 non-EOD cases. The red zone was reached more frequently ( P < .001) and lasted longer (1.06 vs 0.05 hours; P < .001). Reaching the red zone had a sensitivity of 92% for EOD, with a positive predictive value of 64% and a false positive rate of 10.4%. CONCLUSIONS: Our data suggest the FRI can significantly lower the incidence of EODs by identifying the opportunity for intrauterine resuscitation. Our approach can reduce the disruptive effects of EODs and their concomitant increased risks of complications. The FRI may provide a metric that can refine labor management to reduce CP and EODs.

The "Fetal Reserve Index": Re-Engineering the Interpretation and Responses to Fetal Heart Rate Patterns.

OBJECTIVE: Electronic fetal monitoring (EFM) correlates poorly with neonatal outcome. We present a new metric: the "Fetal Reserve Index" (FRI), formally incorporating EFM with maternal, obstetrical, fetal risk factors, and excessive uterine activity for assessment of risk for cerebral palsy (CP). METHODS: We performed a retrospective, case-control series of 50 term CP cases with apparent intrapartum neurological injury and 200 controls. All were deemed neurologically normal on admission. We compared the FRI against ACOG Category (I-III) system and long-term outcome parameters against ACOG monograph (NEACP) requirements for labor-induced fetal neurological injury. RESULTS: Abnormal FRI's identified 100% of CP cases and did so hours before injury. ACOG Category III identified only 44% and much later. Retrospective ACOG monograph criteria were found in at most 30% of intrapartum-acquired CP patients; only 27% had umbilical or neonatal pH <7.0. CONCLUSIONS: In this initial, retrospective trial, an abnormal FRI identified all cases of labor-related neurological injury more reliably and earlier than Category III, which may allow fetal therapy by intrauterine resuscitation. The combination of traditional EFM with maternal, obstetrical, and fetal risk factors creating the FRI performed much better as a screening test than EFM alone. Our quantified screening system needs further evaluation in prospective trials.

Update on Fetal Monitoring: Overview of Approaches and Management of Category II Tracings.

Electronic fetal monitoring (EFM) is widely used to assess fetal status in labor. Use of intrapartum continuous EFM is associated with a lower risk of neonatal seizures but a higher risk of cesarean or operative delivery. Category II fetal heart tracings (FHTs) are indeterminate in their ability to predict fetal acidemia. Certain patterns of decelerations and variability within this category may be predictive of neonatal morbidity. Adjunct tests of fetal well-being can be used during labor to further triage patients. Intrauterine resuscitation techniques should target the suspected etiology of intrapartum fetal hypoxia. Clinical factors play a role in the interpretation of EFM.

Practice variation in the management of intrapartum fetal distress in The Netherlands and the Western world.

OBJECTIVE: Solid evidence on the effect of intrauterine resuscitation on neonatal outcome is limited, and superiority of one intervention over the others is not clear. We therefore surveyed the clinical practice variation in fetal monitoring and the management of fetal distress during labor, in Dutch labor wards. In addition, we have compared recommendations from international guidelines. STUDY DESIGN: We conducted a survey among all 86 Dutch hospitals, using a questionnaire on fetal monitoring and management of fetal distress. In addition, we requested international guidelines of 28 Western countries to study international recommendations regarding labor management. RESULTS: The response rate of the national survey was 100%. Labor wards of all hospitals use CTG for fetal monitoring, 98% use additional fetal scalp blood sampling, and 23% use ST-analysis. When fetal distress is suspected, oxytocin is discontinued and tocolytic drugs are applied in all hospitals. Nearly all hospitals (98%) use maternal reposition for fetal resuscitation, 33% use amnioinfusion, and 58% provide maternal hyperoxygenation. Management is mainly based on the Dutch national guideline (58%) or on local guidelines (26%). Eight international guidelines on fetal monitoring were obtained for analysis. Fetal scalp blood sampling facilities are recommended in all the obtained guidelines. Use of ST-analysis is recommended in three guidelines and advised against in three guidelines. Five guidelines also advised on intrauterine resuscitation: discontinuation of oxytocin and use of tocolytic drugs was advised in all guidelines, amnioinfusion was recommended in two guidelines and advised against in two guidelines, whereas maternal hyperoxygenation was recommended in two guidelines and advised against in one guideline. CONCLUSION: Nationwide clinical practice, and recommendations from international guidelines agree on the use of fetal scalp blood sampling in addition to cardiotocography during labor. The opinion on the use of ST-analysis differs per clinic and per guideline. Discontinuation of oxytocin, administration of tocolytic drugs and maternal repositioning are rather uniform, on national and international level. However, there is a large variation in the use of amnioinfusion and maternal hyperoxygenation, which may be explained by the contradictory recommendations of the different guidelines.

Doppler sonographic examination of uterine and placental perfusion in cows in the last month of gestation and effects of epidural anesthesia and isoxsuprine.

The massive increase in size of the fetus and uterus in the last trimester is accompanied by an increasing demand for nutrients and oxygen, and it is assumed that this demand is met by increasing uterine and fetal perfusion. The goals of this study were to measure the perfusion of the uterine arteries and the placentomes in the last month of gestation and to investigate the effect of epidural anesthesia and isoxsuprine on perfusion. During the last month of gestation, eight Braunvieh cows underwent nine color Doppler sonographic examinations of the uterine arteries to determine diameter (DM), pulse rate (PR), resistance index, time-averaged maximum blood flow velocity (TAMV), and blood flow volume (BFV), and power-mode Doppler sonography was used to determine perfusion of placentomes. The PR increased (P < 0.001), and the BFV and TAMV of the ipsilateral uterine artery decreased between 4.5 and 0.5 weeks prepartum (BFV, 236.8 ± 65.80 and 208 ± 41.52 cm(3)/s, P < 0.01; TAMV, 140.0 ± 26.53 cm/s and 125.2 ± 18.46 cm/s, P < 0.05). After sonographic examination, the cows received epidural administration of local anesthetic (100-mg lidocaine) in the sacrococcygeal space or isoxsuprine (200 mg/cow, iv), and the sonographic measurements were repeated 30 minutes later. After epidural anesthesia, the TAMV and BFV of the contralateral uterine artery increased by 5.4% (P < 0.05) and 7.9% (P < 0.01). In the placentomes of the gravid uterine horn, the relative placentome perfusion and the color pixel grading (Cp) increased by 10.1% (P < 0.05) and 11.5% (P < 0.01) after epidural anesthesia. After isoxsuprine, the DM, PR, and BFV increased by 4.7%, 49.3%, and 16.9% in the ipsilateral uterine artery and by 10.8%, 48.7%, and 22.8%, respectively in the contralateral uterine artery. The TAMV of the ipsilateral uterine artery increased by 7.1% (P < 0.01), and the resistance index decreased in both uterine arteries (ipsilateral 24.2%, contralateral 14.9%, both P < 0.00001). Isoxsuprine increased the relative placentome perfusion and the Cp of the placentomes by 18.1% and 18.3% in the gravid horn and by 10.2% and 24.2% in the nongravid horn. Blood flow variables changed little in the last month of gestation. However, epidural anesthesia and isoxsuprine caused changes in uterine and placentome perfusion that suggest improvement of placental nutrient and oxygen supply to the fetus.

A simulation model to study maternal hyperoxygenation during labor.

OBJECTIVE: To investigate the effect of maternal hyperoxygenation on fetal oxygenation and fetal heart rate decelerations during labor, using a simulation model. DESIGN: Use of a mathematical model that simulates feto-maternal hemodynamics and oxygenation, designed in Matlab R2012a. SETTING: Clinical and engineering departments in the Netherlands. METHODS: We simulated variable and late fetal heart rate decelerations, caused by uterine contractions with a different contraction interval. We continuously recorded oxygen pressure in different feto-placental compartments and fetal heart rate, during maternal normoxia and during hyperoxygenation with 100% oxygen. MAIN OUTCOME MEASURES: Changes in oxygen pressure in the intervillous space, umbilical vein and arteries, fetal cerebral and microcirculation as well as fetal heart rate deceleration depth and duration. RESULTS: Maternal hyperoxygenation leads to an increase in fetal oxygenation: in the presence of variable decelerations, oxygen pressure in the intervillous space increased 9-10 mmHg and in the cerebral circulation 1-2 mmHg, depending on the contraction interval. In addition, fetal heart rate deceleration depth decreased from 45 to 20 beats per minute. In the presence of late decelerations, oxygen pressure in the intervillous space increased 7-10 mmHg and in the cerebral circulation 1-2 mmHg, depending on the contraction interval. The fetus benefited more from maternal hyperoxygenation when contraction intervals were longer. CONCLUSIONS: According to the simulation model, maternal hyperoxygenation leads to an increase in fetal oxygenation, especially in the presence of variable decelerations. In addition, in the presence of variable decelerations, maternal hyperoxygenation leads to amelioration of the fetal heart rate pattern.

Effect of xylazine, isoxsuprine, and lidocaine on Doppler sonographic uterine and umbilical blood flow measurements in cows during the last month of pregnancy.

The maternal portion of the bovine placenta receives blood mainly from the uterine arteries (AUT) and the fetal portion from the umbilical arteries (AUM). Placental perfusion is crucial for fetal development and undergoes adaptive changes during pregnancy according to the fetal requirements. One goal of this study was to investigate changes in Doppler sonographic measurements of blood vessels that supply blood to the placenta in cows during the last 4 weeks of pregnancy. Another goal was to examine how these measurements are affected by three drugs commonly used in cows at the time of parturition. Nine cows underwent Doppler sonographic examination of the AUT ipsilateral and contralateral to the pregnant horn and one AUM three times per week during the last 4 weeks of gestation. This was followed by the randomized administration of one of the three following experimental drugs per day: isoxsuprine (200 mg/cow, iv), xylazine (2 mg/100 kg, iv), and lidocaine for epidural anesthesia (100 mg/cow). Doppler sonographic examination was repeated 30 minutes after medication. Maternal pulse rate increased during the study period (P < 0.001), and the diameter of the contralateral AUT was smaller in the last week before birth than in the two preceding weeks. The resistance index (RI) of the ipsilateral AUT was smaller in the last week than in the first 2 weeks of the study period. Uterine blood flow volume increased after isoxsuprine by 5% and after epidural anesthesia by 6% (both P ≤ 0.05) and decreased after xylazine by 10% (P < 0.001). Isoxsuprine was the only drug that elevated the blood flow volume in the AUM (P ≤ 0.05). Xylazine increased the RI of both AUT (both P < 0.001) and significantly reduced maternal and fetal pulse frequencies, whereas isoxsuprine significantly reduced the RI of both AUT and the AUM and increased maternal and fetal pulse frequencies. The results reported that Doppler sonographic measurements of uterine and AUM change little in the last month of pregnancy in the cow. Isoxsuprine and epidural anesthesia with lidocaine have the potential to improve uterine perfusion.

Table Tilt Versus Pelvic Tilt Position for Intrauterine Resuscitation during Spinal Anaesthesia for Caesarian Section.

BACKGROUND: This study was undertaken to compare the effects on intrauterine resuscitation by table tilt versus pelvic tilt position after spinal anaesthesia for Caesarian Section. PATIENTS #ENTITYSTARTX00026; METHODS: FIFTY ASA I AND II PATIENTS WHO FULFILLED THE ELIGIBILITY CRITERIA WERE ENROLLED IN THE STUDY AND WERE DIVIDED INTO TWO GROUPS: group W (Pelvic tilt with wedge under right hip and group L- (15(0)left lateral table tilt) and received spinal anaesthesia. The following parameters were recorded. Heart rate (HR), mean arterial pressure (MAP) at baseline, 2mins, 5 min and then 5 min thereafter. Mean height of block, Total no. of segments blocked, Onset Time of sensory block (in Minutes), ephedrine doses, incidence of hypotension & bradycardia, APGAR score at 1& 5 Minutes. RESULTS: The decrease in MAP was much more in wedged position as compared to table tilt position also the incidence of hypotension was 40% in wedged position as compared to 12% in table tilt position. Mean height of block, Total no. of segments blocked, and boluses of inj. ephedrine used were more in the wedged position than in table tilt position. CONCLUSION: Wedge placement caused increased incidence of hypotension and higher blockade after spinal anaesthesia as compared to left lateral table tilt position, there was no adverse effects on foetus and patients tolerated wedge better than left lateral table tilt position. Also surgery was easier to perform after wedge placement.

Efectividad de la hiperoxigenación materna y tocolisis aguda en monitoreo electrónico fetal intraparto alterado / Maternal hyperoxygenation and acute tocolysis in abnormal intrapartum electronic fetal monitoring

El trabajo de parto es un evento de riesgo para hipoxia fetal aguda, lo que puede detectarse en alteraciones del Monitoreo Electrónico Fetal Intraparto (MEFI). Frente a un MEFI sugerente de hipoxemia fetal, existen maniobras estándar de resucitación intrauterina como lateralización de la paciente, aporte de volumen intravenoso y suspensión de la infusión oxitócica. Se debate la utilidad de la hiperoxigenación materna y la tocolisis aguda. Revisamos la evidencia científica relevante sobre la utilidad y seguridad de estas dos maniobras. Encontramos sólo limitada evidencia respecto del efecto benéfico de la hiperoxigenación materna frente a alteraciones del MEFI, existiendo dudas de su inocuidad. La tocolisis aguda ha demostrado ser eficaz en lograr la normalización del MEFI, independiente de la presencia de hiperactividad uterina, con una efectividad cercana al 80 por ciento. La evidencia apoya el uso de B-miméticos y Nitroglicerina. Recomendamos incluir en la practica clínica habitual la tocolisis aguda y la hiperoxigenación materna sólo por lapsos breves, junto a las maniobras habituales de resucitación intrauterina frente a un MEFI alterado. (

Labor is a risk condition for acute fetal hypoxia, this hypoxia can be detected by using cardiotocography (CTG). When CTG suggest hypoxia, intrauterine resuscitation techniques must be implemented, such as lateral positioning of the mother, intravenous fluid administration and suspension of oxytocin administration. Among intrauterine resuscitation techniques it is discussed the use of maternal hyperoxygenation and acute tocolysis. Here we review the evidence supporting utility and safety of these two techniques. We found only limited evidence supporting the beneficial role of maternal hyperoxygenation after nonreassuring CTG, plus concerns about its safety. Acute tocolysis has proven to be efficient in normalizing CTG, independent of the presence of uterine hyperactivity, with an overall benefit of 80 percent. Evidence supports the use of B-mimetics and nitroglycerin. We recommend to include acute tocolysis and maternal hyperoxygenation (just for limited time), among intrauterine resuscitation techniques for abnormal CTG.