The effect of spinal hypotension and anesthesia-to-delivery time interval on neonatal outcomes in planned cesarean delivery

Effect of esketamine on hypotension in women with preoperative anxiety undergoing elective cesarean section: a randomized, double-blind, controlled trial

To investigate the effect of low-doses esketamine on spinal anesthesia-induced hypotension in women with preoperative anxiety undergoing elective cesarean section, the randomized controlled trial enrolled 120 women aged 18-35 years who preoperative State-Trait Anxiety Inventory State scores > 40, conducted from September 2022 to August 2023 in Xuzhou Central Hospital, China. Women in the esketamine group received a single intravenous injection of 0.2 mg/kg esketamine after sensory block level achieved. The incidence of hypotension in the esketamine group was significantly lower than the control group at T2 (10% [6 of 60]; P < 0.001), T3 (5.0% [3 of 60]; P = 0.007) and T4(5.0% [3 of 60]; P = 0.004). Despite being higher in the esketamine group, the overall rates of hypertension (11.7% [7 of 60]; P = 0.186), tachycardia (23.3% [14 of 60]; P = 0.246), and bradycardia (0.0% [0 of 60]; P = 0.079) were no significantly difference between the two groups. STAI-S scores was significantly lower in the esketamine group (mean [SD] 37.52[7.14]) than in the control group (mean [SD] 41.03[9.66], P = 0.39) in postoperative day 1. Spinal anesthesia combined with intravenous low-doses esketamine infusion can significantly reduce the incidence of hypotension in women with preoperative anxiety undergoing elective cesarean section.

Comparison of Prophylactic Phenylephrine Infusion and Rescue Bolus Administration for Maintaining Blood Pressure During Spinal Anaesthesia for Caesarean Delivery in Obese Parturient: A Randomised Control Trial

Background

Phenylephrine (PE) is one of the vasopressor used to treat hypotension during anaesthesia. The primary aim of this study was to compare the effect of prophylactic infusion and rescue bolus of PE on the haemodynamic changes during spinal anaesthesia (SA) for Caesarean section (CS) in obese parturients.

Methods

A total of 74 obese parturients scheduled for elective CS under SA were randomised into two groups; Group A (n = 37) received prophylactic PE infusion starting at 50 μg min-1 and adjusted according to the given algorithm and Group B (n = 37) received 100 μg PE bolus to treat hypotension. The measured parameters were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), the total requirement of PE and neonatal Apgar score.

Results

Six patients were excluded from the analysis due to missing data and only 68 were analysed. Group A showed significantly higher SBP, DBP and MAP than Group B (P < 0.05). The requirement of PE was higher in Group A than Group B [817.7 (265.7) μg versus 360.6 (156.0) μg; P = < 0.05]. Both groups had no difference in terms of the neonatal Apgar score.

Conclusion

Prophylactic PE infusion provided better haemodynamic control than therapeutic boluses in obese parturients undergoing CS under SA.

Left-lateral position versus phenylephrine prophylactic treatment for hypotension following combined spinal epidural anesthesia during elective cesarean section

Backgroud

Hypotension is one of the most common and dangerous complications following combined spinal epidural anesthesia during elective cesarean delivery. Many methods are used to prevent or treat the hypotension with pharmacological or non-pharmacological measures. Our aim was to assess left-lateral position and phenylephrine prophylactic treatment for the prevention or treatment of maternal hypotension.

Methods

A total of 127 pregnant women were enrolled to be analyzed. The primary outcome measure was the incidence of maternal hypotension and secondary outcome measures included maternal demographic characteristics, anesthesia-to-incision time interval, birthweight and Apgar scores.

Results

The incidence of hypotension was 65.4 % in sequential reactive treatment and only 11.3 % achieved complete anesis after left-lateral position, significantly higher than 17.4 % in left-lateral position combined phenylephrine prophylactic treatment (P < 0.001). The increasing in gestational age may decrease the hypotension risk (P < 0.001). There were no significantly differences with maternal age, gravidity, parity, BMI before pregnancy, BMI before cesarean section, anesthesia-to-incision time interval, birthweight and Apgar scores (P > 0.05). The univariate logistic regression analysis revealed a significant association between treatment and hypotension (OR 0.11, 95 % CI 0.05-0.27). After adjusting for confounding variables, the risk of hypotension was decreased in subjects with treatment (OR 0.1, 95 % CI 0.04-0.25; OR 0.15, 95 % CI 0.05-0.43; OR 0.16, 95 % CI 0.05-0.46). The results of stratified and interaction analyses of the association between treatment revealed no interactive role from maternal age, gravidity and BMI before cesarean section (P > 0.05).

Conclusions

Single use of left-lateral position had limited effective and left-lateral position combined prophylactic phenylephrine used may be much better to prevent or treat hypetension, but larger studies with more robust data are needed to confirm these findings.

Spinal Hypotension and Time from Spinal-to-Delivery in Scheduled Cesarean Deliveries: Association with Neonatal Acidosis

OBJECTIVE

This work aimed to study the effect of sustained hypotension after spinal on neonatal acidosis and adverse outcomes in those undergoing scheduled cesarean delivery (CD) with universal prophylactic vasopressor exposure and to examine differences in spinal-to-delivery time by neonatal acidosis status.

STUDY DESIGN

 This retrospective cohort study conducted at a quaternary care center from January 2019 to December 2021 included singleton, term, nonanomalous pregnancies, with scheduled CD under spinal anesthesia. Hypotension was defined as a systolic blood pressure (SYS-BP) < 100 mm Hg (SYS-BP100) or a >20% drop from baseline blood pressure (SYS-BP20). Both the occurrence of hypotension and its magnitude and duration were studied; the latter through the development of a hypotension index. The 90th and 95th percentiles of the hypotension index for SYS-BP20 and SYS-BP100, respectively, were used to define sustained hypotension. The primary outcome was neonatal acidosis (umbilical artery pH ≤ 7.1 or base excess ≤ -12 mmol). Secondary outcomes were composites of neonatal (CNAO) and maternal (CMAO) adverse outcomes. Multivariable Poisson regression models with robust error variance analysis was used to estimate adjusted relative risks (aRRs) and 95% confidence intervals (CIs).

RESULTS

 Our study included 332 individuals who underwent scheduled CD; among them 330 (99.4%) received prophylactic vasopressors. The rate of neonatal acidosis was 4.2%. Sustained hypotension after spinal anesthesia, which occurred in 12.3% of the cohort, was associated with increased risk for neonatal acidosis (aRR 3.96, 95% CI 1.21-12.98), but was not associated with CNAO or CMAO. Time from spinal-to-delivery was not different in those with and without neonatal acidosis.

CONCLUSION

 Despite universal exposure to prophylactic vasopressors, sustained hypotension after spinal anesthesia was still associated with neonatal acidosis, but no other adverse perinatal outcomes. Our findings may provide additional support for the adoption of prophylactic vasopressors to reduce spinal hypotension and downstream effects on the neonate from intraoperative hemodynamic instability.

KEY POINTS

· Despite prophylactic vasopressors during scheduled CD, neonatal acidosis occurred in 4% of subjects.. · Sustained hypotension after spinal anesthesia was associated with neonatal acidosis, but not adverse neonatal outcomes.. · Spinal-to-delivery time was not associated with neonatal acidosis in scheduled CD..

Umbilical cord gas analysis: clinical implications of a comprehensive, contemporary determination of normal ranges

BACKGROUND

Umbilical cord gases are often used to assess the impact of labor and delivery on the fetus. However, no large series exists that reflects contemporary obstetrical practice or that analyzed blood gas ranges by route of delivery. Baseline, prelabor acid-base status in the human fetus is also poorly defined, rendering the assessment of blood gas changes during labor difficult.

OBJECTIVE

This study aimed to define normal umbilical cord gas and lactate values, stratified by mode of delivery, in a large contemporary series in which universal umbilical cord gas evaluation was dictated by protocol.

STUDY DESIGN

This was a retrospective cohort study. We analyzed the umbilical cord gas and lactate data of an unselected population of infants born between March 2012 and April 2022 at a large teaching hospital. These values were then analyzed by mode of delivery and, for cesarean deliveries, by indication for cesarean delivery and type of anesthesia. Umbilical cord gas values from infants delivered by elective cesarean delivey under general anesthesia without labor were considered representative of baseline, prelabor values.

RESULTS

Data were available for 45,475 infants. The median arterial pH values and interquartile ranges for vaginal births, elective cesarean deliveries without labor, and cesarean deliveries performed for fetal heart rate concerns were 7.27 (0.09), 7.27 (0.06), and 7.25 (0.09), respectively. Arterial lactate values for these same 3 groups were 4.1 (2.5), 2.5 (1.2), and 4.0 (2.8) mmoles/L, respectively. Because of the very large sample size, most comparisons yielded differences that were statistically significant, but clinically irrelevant. Of all the infants, 14% had an arterial pH <7.20; a pH value of 7.1 represents 2 standard deviations from the mean.

CONCLUSION

This large, population-based study of umbilical cord gas and lactate levels in an unselected population, stratified by delivery mode, represents a previously unavailable benchmark for the evaluation of umbilical cord gases. Arterial umbilical cord pH values for infants delivered by elective caesarean delivery without labor (median pH 7.28) reflect a lower prelabor fetal pH baseline than previously assumed. This finding, coupled with our determination that a 2 standard deviation below normal pH limit of 7.1, instead of the historic arbitrary pH of 7.2 threshold, helps to explain the poor positive predictive value of electronic fetal heart rate monitoring, a test designed to detect arterial pH levels that have fallen from an assumed baseline near pH 7.4 to an assumed potentially injurious pH level of <7.2. Uncomplicated labor, even when prolonged, does not generally lead to a clinically significant cumulative hypoxic stress to the human fetus. These findings, along with our determination that there is no difference in the acid-base status among infants delivered by cesarean delivery for fetal heart rate concerns, help to explain the failure of current approaches in labor and delivery management to reduce the rates of neonatal hypoxic-ischemic encephalopathy and cerebral palsy, conditions that almost always reflect developmental events rather than the effects of labor on the fetus.

Exploring factors influencing skin incision to the delivery time and their impact on neonatal outcomes among emergency cesarean deliveries indicated for non-reassured fetal heart rate status

Background

The time interval between skin incision and delivery (S-D) is crucial in determining neonatal outcome; however, little is known about the influencing factors and their impact on neonatal outcomes, particularly among emergency cesarean deliveries (ECD) indicated for fetal distress. This study investigated the factors influencing S-D time and their effects on neonatal outcomes among mothers who underwent ECD for non-reassured fetal heart rate status.

Methods

This retrospective cohort study involved 426 mother-infant pairs over four years. We retrieved data from the medical records, including baseline characteristics, perioperative data, and neonatal outcomes. Using multivariable logistic regression analysis, adjusted odd ratios, and a 95% confidence interval, potential factors influencing S-D time and their impacts on neonatal outcomes were assessed. A p-value of less than 0.05 was considered statistically significant.

Results

Factors independently associated with longer S-D time (>8 min) were mothers who had previous CD (AOR 5.9: 95% CI 2.2-16.1), obese mothers (AOR 6.2: 95% CI 1.6-24.5), and the second stage of labor (AOR 5.3: 95% CI 2.4-11.7). Adverse neonatal outcomes, including a 5th minute Apgar score of less than 7, the need for NICU admission, and neonatal death, were significantly higher in the longer S-D time interval [47.7% vs. 8.9%; p-value 0.001], [21.9% vs. 9.1%; p-value 0.001], and [32% vs. 11.8%; p-value = 0.004], respectively. Obese mothers and the second stage of labor, but not previous CD, adversely impact neonatal outcomes.

Conclusion

Longer S-D times are significantly associated with adverse neonatal outcomes. Factors that prolong the time interval between skin incision and delivery may or may not necessarily be associated with adverse neonatal outcomes. Considering surgical techniques that shorten the incision-delivery time and preparation for advanced neonatal care for risky subjects would help reduce detrimental neonatal consequences.

Perioperative Maternal-Fetal Outcomes in the Setting of Minimally Invasive Fetal Therapy for Complex Monochorionic Pregnancies with Monitored Anesthesia Care

INTRODUCTION

Fetoscopic selective laser photocoagulation (FSLPC) and selective cord occlusion with radiofrequency ablation (RFA) can improve fetal outcomes when vascular anastomoses between fetuses cause twin-to-twin transfusion syndrome (TTTS) or selective fetal growth restriction (sFGR) in multiple gestation pregnancies with monochorionic placentation. This study analyzed perioperative maternal-fetal complications and anesthetic management in a high-volume fetal therapy center over a 4-year period.

METHODS

Included patients received MAC for minimally invasive fetal procedures for complex multiple gestation pregnancies between January 1, 2015, and September 20, 2019. Maternal and fetal complications, intraoperative maternal hemodynamics, medication usage, and reasons for conversion to general anesthesia, if applicable, were analyzed.

RESULTS

A total of 203 (59%) patients underwent FSLPC and 141 (41%) had RFA. Four patients (2%; rate 95% CI: 0.00039, 0.03901) undergoing FSLPC had conversion to general anesthesia. No conversions to general anesthesia occurred in the RFA group. The incidence of maternal complications was higher in those who underwent FSLPC. No aspiration or postoperative pneumonia events were observed. Medication usage was similar in FSLPC and RFA groups.

CONCLUSION

A low rate of conversion to general anesthesia and no serious adverse maternal events were observed in patients receiving MAC.

What Is New in Obstetric Anesthesia: The 2021 Gerard W. Ostheimer Lecture

The Gerard W. Ostheimer lecture is given annually to members of the Society for Obstetric Anesthesia and Perinatology. This lecture summarizes new and emerging literature that informs the clinical practice of obstetric anesthesiologists. In this review, some of the most influential articles discussed in the 2021 virtual lecture are highlighted. Themes include maternal mortality; disparities and social determinants of health; cognitive function, mental health, and recovery; quality and safety; operations, value, and economics; clinical controversies and dogmas; epidemics and pandemics; fetal-neonatal and child health; general clinical care; basic and translational science; and the future of peripartum anesthetic care. Practice-changing evidence is presented and evaluated. A priority list for clinical updates, systems, and quality improvement initiatives is presented.

Difficulties in Adaptation of the Mother and Newborn via Cesarean Section versus Natural Birth-A Narrative Review

Birth is a physiological act that is part of the morpho-functional economy of the maternal body. Each stage in the act of birth has a predetermined pathway that is neurohormonally induced and morpho-functionally established through specific and characteristic adaptations. Like maternity, childbirth also has an important impact on the maternal body as a biological structure and psycho-emotional behavior. Cesarean section performed at the request of the mother with no medical underlying conditions besides the prolonged hospitalization risk can also cause breathing problems in children, delayed breastfeeding, and possible complications in a future pregnancy. Vaginal birth remains the path of choice for a physiological evolution pregnancy. Although erroneously considered safe and easy today, cesarean section delivery must remain an emergency procedure or a procedure recommended for pregnancies where birth is a risk to the mother and to the child, as cesarean section itself is a risk factor for negative outcomes for both mother and baby. This review summarizes the impact that both cesarean section and natural birth have on mother and newborn in their attempt to adapt to postpartum events and extrauterine life.

Phenylephrine versus cafedrine/theodrenaline (Akrinor) for the treatment of spinal anaesthesia-induced maternal hypotension during caesarean section: a retrospective single-centre cohort study

OBJECTIVE

The main objective of this study was to assess the impact of phenylephrine and cafedrine/theodrenaline on the mother and newborn after spinal anaesthesia for caesarean section.

SETTING

University teaching hospital.

DESIGN

A single-centre retrospective data cohort study.

PATIENTS

All obstetric patients who were scheduled for caesarean section in a 2-year period.

INTERVENTIONS

Administration of either intravenous phenylephrine prophylactically or cafedrine/theodrenaline (Akrinor) reactively to maintain blood pressure after spinal anaesthesia.

MAIN OUTCOME MEASURE

Maternal hypotension, heart rate during caesarean section and after admission to IMC, fetal arterial cord pH and base excess levels, maternal volume resuscitation and the use of rescue medication.

RESULTS

852 data sets could be included: n=440 Akrinor, n=412 in the phenylephrine cohort. During caesarean section blood pressure was slightly higher in the phenylephrine group compared with the Akrinor group, while hypotension <100 mm Hg systolic blood pressure (SBP) occurred significantly more often during arrival at the IMC after surgery when phenylephrine was used. Heart rate was lower and rescue medication was significantly more frequently given in the phenylephrine cohort. Irrespective of the medication used, women with baseline levels of <120 mm Hg SBP had a high risk to develop hypotension <100 mm Hg after spinal anaesthesia for caesarean section. While there was no statistical difference in mean umbilical arterial pH levels, the incidence of acidosis, defined as pH <7.2, was significantly higher with phenylephrine.

CONCLUSION

Phenylephrine was not superior to Akrinor to treat spinal anaesthesia-induced maternal hypotension during caesarean section.

TRIAL REGISTRATION NUMBER

DRKS00025795.

Spinal hypotension in obstetrics: Context-sensitive prevention and management

Spinal hypotension during caesarean section remains a common complication, with important attendant maternal and fetal adverse outcomes. Research elucidating the mechanisms of spinal hypotension has led to the development and refinement of effective management strategies, with a particular emphasis on prophylactic vasopressor administration. This has proved effective in well-resourced settings, with maternal comfort and the elimination of nausea now considered the primary aim of treatment. In resource-limited settings, sophisticated strategies are not feasible due to insufficient equipment, staff, and expertise. Therefore, in these areas spinal hypotension remains an important cause of maternal and fetal morbidity and mortality. Translational, context-sensitive research in resource-limited settings has shown promise in implementing pragmatic strategies based on research from resource-rich environments. We review the current best practice for the prevention and treatment of spinal hypotension, with a special emphasis on effective strategies in resource-limited settings. We further suggest a research agenda to address the knowledge gap in specific contexts.

Appropriate Method of Administering Vasopressors for Maternal Hypotension Associated with Combined Spinal Epidural Anesthesia in Elective Cesarean Section: Impact on Postnatal Respiratory Support for Newborns

Background and Objectives: Vasopressors are used for treating maternal hypotension. However, the appropriate administration method and effects on newborns have not been reported. We evaluated maternal blood pressure fluctuation and neonatal findings in patients who received continuous vasopressor administration during elective cesarean sections and those who received bolus vasopressor administration upon onset of hypotension. Materials and Methods: We retrospectively analyzed the data of 220 patients scheduled for elective cesarean delivery under spinal anesthesia at Mie University Hospital between April 2017 and March 2021. The patients were classified according to the method of vasopressor administration. Maternal information, intraoperative maternal blood pressure fluctuation, and neonatal findings were examined. A multiple regression analysis was performed for the administration of postpartum neonatal respiratory support using maternal background information and other variables related to blood pressure changes as independent variables. Results: The Continuous group and the Bolus group were composed of 98 and 122 patients, respectively. No difference was observed in maternal background information between the groups. Significant changes were noted in several blood pressure parameters between both groups. As for neonatal parameters, newborns of Bolus group patients had lower pO2, 1 min and 5 min Apgar scores, and required more respiratory support than those of Continuous group patients. In the multiple regression analysis, the groups and maternal post-anesthesia diastolic blood pressure variability were considered explanatory variables. Conclusions: Maternal hypotension and the need for neonatal respiratory support associated with anesthesia administration in elective cesarean section may be improved by continuous vasopressor administration upon induction of combined spinal–epidural anesthesia.

Congenital Hypothyroidism Can Dictate the Mode of Delivery and Intra-Labor Medication Usage

Background: Pregnancy and parturition reflect the complex interaction between physiological conditions of the mother and her offspring, and fetal health characteristics may affect maternal health throughout pregnancy and delivery. We aimed to investigate the characteristics of the mother-infant dyad of term infants detected as having congenital hypothyroidism (CH). Methods: A retrospective cohort study of 108,717 term infants delivered liveborn at Lis Maternity and Women's Hospital between 2010 and 2017. Infants were detected by the National Newborn Screening Program as having CH (131, 0.12%). Three years of surveillance in the Pediatric Endocrine Clinic revealed that 65 infants had transient CH and 66 had permanent CH. Data on maternal, pregnancy, delivery, and perinatal characteristics of the mother-infant dyads were retrieved from the hospital's electronic database. Results: Mode of delivery differed: a higher proportion of deliveries of CH infants required vacuum assistance, and more infants with CH were born through a cesarean section compared with the general population (p < 0.001). Medication during labor also differed, with higher rates of oxytocin (p < 0.001) and antibiotics (p = 0.008) administered to mothers of CH infants. A multivariate logistic regression model revealed an increased demand for oxytocin administration during the labor of a CH infant in a hypothyroidism severity-dependent manner, expressed as a threefold risk associated with permanent but not transient CH. Conclusions: Our findings of increased utilization of medical interventions during the labor and delivery of CH infants suggest that the prenatal fetal thyroid function may affect the development and progress of labor and delivery, in response to oxytocin.

Anesthetic management in cesarean delivery of women with placenta previa: a retrospective cohort study

Background

The incidence of placenta preiva is rising. Cesarean delivery is identified as the only safe and appropriate mode of delivery for pregnancies with placenta previa. Anesthesia is important during the cesarean delivery. The aim of this study is to assess maternal and neonatal outcomes of patients with placenta previa managed with neuraxial anesthesia as compared to those who underwent general anesthesia during cesarean delivery.

Methods

A retrospective cohort study was performed of all patients with placenta preiva at our large academic institution from January 1, 2014 to June 30, 2019. Patients were managed neuraxial anesthesia and general anesthesia during cesarean delivery.

Results

We identified 1234 patients with placenta previa who underwent cesarean delivery at our institution. Neuraxial anesthesia was performed in 737 (59.7%), and general anesthesia was completed in 497 (40.3%) patients. The mean estimated blood loss at neuraxial anesthesia of 558.96 ± 42.77 ml were significantly lower than the estimated blood loss at general anesthesia of 1952.51 ± 180 ml (p < 0.001). One hundred and forty-six of 737 (19.8%) patients required blood transfusion at neuraxial anesthesia, whereas 381 out of 497 (76.7%) patients required blood transfusion at general anesthesia. The rate neonatal asphyxia and admission to NICU at neuraxial anesthesia was significantly lower than general anesthesia (2.7% vs. 19.5 and 18.2% vs. 44.1%, respectively). After adjusting confounding factors, blood loss was less, Apgar score at 1- and 5-min were higher, and the rate of blood transfusion, neonatal asphyxia, and admission to NICU were lower in the neuraxial group.

Conclusions

Our data demonstrated that neuraxial anesthesia is associated with better maternal and neonatal outcomes during cesarean delivery in women with placenta previa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01472-w.

Association Between Hyperbaric Bupivacaine Dose and Maternal Hypotension: Retrospective Database Study of 8226 Women Undergoing Cesarean Delivery Under Spinal Anesthesia

BACKGROUND

Low-dose (≤8 mg) hyperbaric bupivacaine for spinal anesthesia during cesarean delivery results in reduced efficacy, yet as a secondary outcome was associated with reduced frequency of spinal-induced hypotension. Our primary aim was to investigate the relationship between hyperbaric bupivacaine dose and the occurrence of spinal-induced hypotension for cesarean delivery.

METHODS

Retrospective study of cesarean delivery under spinal or combined spinal anesthesia with hyperbaric bupivacaine in 1 academic institution (2 centers-tertiary and district) from 2012 to 2018. Data were retrieved from the anesthesia information management systems (Metavision, iMDsoft, Tel Aviv, Israel) and the hospital information system, including potential confounding factors, maternal age and weight, hypertensive disease of pregnancy, single/multiple gestation, gestational age, vasopressor administration, planned/urgent surgery, position during anesthesia placement (sitting/lateral), and anesthesiologist seniority. Spinal-induced hypotension was defined as systolic blood pressure that either dropped >20% from baseline or <100 mm Hg. The primary outcome of interest was the incidence of spinal-induced hypotension according to hyperbaric bupivacaine dose. Logistic regression was used to characterize the association between the dose of hyberbaric bupivacaine and spinal-induced hypotension after adjusting for confounding factors.

RESULTS

A total of 8226 women were identified. The hyperbaric bupivacaine dose administered was <9 mg for 2395 (29.1%), 9-9.5 mg for 1031 (12.5%), 10 mg for 4155 (50.5%), and >10 mg for 645 (7.8%). We used a cutoff (<10 vs ≥10 mg) to assess for the primary outcome, using multivariable logistic regression. The incidence of at least 1 spinal-induced hypotension episode was higher in patients who received ≥10 mg hyperbaric bupivacaine, 75.8% vs 62.9% for doses below 10 mg, P < .0001; however, even women with lower doses had hypotension. Hyperbaric bupivacaine dose <10 mg was associated with a lower incidence of spinal hypotension, adjusted odds ratio (OR) of 0.774, 95% confidence interval (CI), 0.669-0.897, and P = .0006, adjusted for confounding factors.Umbilical cord pH was available for 2684 (32.6%) cases. There were significantly more neonates with pH < 7.2, among women who received hyperbaric bupivacaine ≥10 mg (10.1%) versus women who received <10 mg (6.8%), P = .0032; however, in the adjusted model, hyperbaric bupivacaine dose ≥10 mg was not associated with pH < 7.2 and an OR of 0.955 (95% CI, 0.631-1.446, P = .829).

CONCLUSIONS

Our major finding was that hypotension occurred at all doses of hyperbaric bupivacaine, yet occurrence of spinal hypotension was significantly associated with doses ≥10 mg after adjustment for potential confounders.

Comparison of two vasopressor protocols for preventing hypotension post-spinal anesthesia during cesarean section: a randomized controlled trial

Background:

Norepinephrine infusion decreases hypotension after spinal anesthesia during cesarean section. This study aimed to compare the efficacy of norepinephrine infusion and ephedrine bolus against post-spinal hypotension in parturients.

Methods:

In this double-blinded, randomized controlled clinical trial, parturients scheduled for elective cesarean section were randomly allocated to receive norepinephrine infusion (0.05 μg·kg⁻¹·min⁻¹) just before spinal anesthesia continuing for 30 min or ephedrine bolus (0.15 mg/kg) just before spinal anesthesia. A rescue bolus (5 μg norepinephrine for the norepinephrine group, and 5 mg ephedrine for the ephedrine group) was administered whenever hypotension occurred. Our primary outcome was the incidence of hypotension within 30 min of spinal anesthesia administration. Secondary outcomes included maternal and neonatal outcomes 30 min after spinal block, and neonatal cerebral oxygenation 10 min after birth.

Results:

In total, 190 patients were enrolled; of these patients, 177 were included in the final analysis. Fewer patients suffered hypotension in the norepinephrine group than in the ephedrine group (29.5% vs. 44.9%, odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.28–0.95, P = 0.034). Moreover, the tachycardia frequency was lower in the norepinephrine group than in the ephedrine group (OR: 0.22, 95% CI: 0.11–0.44, P < 0.001), and patients suffered less nausea and vomiting (OR: 0.28, 95% CI: 0.11–0.70, P = 0.004). There was no difference in Apgar scores and umbilical arterial blood gas analysis between the two groups. However, neonatal cerebral regional saturations were significantly higher after birth in the norepinephrine group than in the ephedrine group (mean difference: 2.0%, 95% CI: 0.55%–3.45%, P = 0.008).

Conclusion:

In patients undergoing elective cesarean section with spinal anesthesia, norepinephrine infusion compared to ephedrine bolus resulted in less hypotension and tachycardia, and exhibited potential neonatal benefits.

Trial Registration:

ClinicalTrials.gov, NCT02542748; https://clinicaltrials.gov/ct2/show/record/NCT02542748