Severe Maternal Hypotension Research Articles

Maternal pulse pressure before labor epidural and risk of severe maternal hypotension after epidural

Decreased intravascular volume on admission, defined as a pulse pressure (PP) < 45 mm Hg, has been associated with increased risk of new onset severe maternal hypotension (SMH) after epidural (Obstet Gynecol 2017;130:1366) and related fetal heart rate (FHR) changes (AJOG 2013;209:382.e1). However, interventions between admission and epidural may affect PP. We have evaluated whether the last PP recorded before epidural placement is an independent predictor of SMH post-epidural.

Do significant adverse reactions to labor epidural anesthesia affect interval to delivery?

Epidural anesthesia during labor may lead to maternal hypotension and changes in fetal heart rate (FHR). We have evaluated whether occurrence of such adverse reactions affect the interval to delivery after anesthesia. Cohort study of all laboring women who underwent epidural anesthesia during labor for the period October 1, 2020-December 31, 2020. Excluded were cases of elective CD, non-cephalic presentation, twins or multiples, fetal death, and gestational age < 37.0 weeks. Significant adverse reactions included severe maternal hypotension (defined as systolic blood pressure < 100 mm Hg in the 60 minutes after epidural or decreasing by >20% compared with before epidural) or presence of severe (prolonged or recurrent late) decelerations in the 60 minutes after epidural. Occurrence of any significant adverse reaction was related to the interval-to-delivery after completion of epidural anesthesia using linear regression analysis (SPSS 28). Among the 438 women in the cohort, significant adverse reactions to epidural occurred in 172 (39.2%), including severe maternal hypotension in 149 (34%) and severe FHR decelerations in 50 (11.4%). Interval-to-delivery after labor epidural anesthesia was associated with maternal age (P=0.007), body mass index (P< 0.001), cervical dilation at epidural (P< 0.001) as well as occurrence of severe adverse reactions to epidural (P=0.019), cesarean delivery (CD) (P< 0.001) and CD for non-reassuring FHR (P=0.009). Linear regression demonstrated that only cervical dilation at epidural (P< 0.001) and CD (P< 0.001) were related to interval-to-delivery after epidural, whereas adverse reactions to epidural were not (P=0.22). Although significant adverse reactions to labor anesthesia were not uncommon in our cohort, they did not independently affect interval-to-delivery after completion of anesthesia.

Predicting spinal hypotension during Caesarean section

Hypotension under spinal anaesthesia for Caesarean section remains a common problem, with attendant maternal and foetal morbidity. This review examines some of the issues surrounding the prediction of spinal hypotension, including concerns about current evidence, the debate on the mechanism of hypotension and the utility of prediction in this group of patients. It then covers some of the more conventional and established preoperative predictors of hypotension. Particular attention is paid to the assessment of autonomic function and some of the novel methods being used as predictors of severe maternal hypotension. The implications of autonomic dysfunction and areas for future research are discussed.

Colloid Preload Versus Coload for Spinal Anesthesia for Cesarean Delivery: The Effects on Maternal Cardiac Output

BACKGROUND:Spinal anesthesia for cesarean delivery may cause severe maternal hypotension, and a decrease in cardiac output (CO) and blood flow to the placenta. Fluid preloading with crystalloid is ineffective due to rapid redistribution. A “coload” given at the time of cerebrospinal fluid identifica

Comparison of quality of life, satisfaction with surgery and shoulder-arm morbidity in breast cancer survivors submitted to breast-conserving therapy or mastectomy followed by immediate breast reconstruction

OBJECTIVES:This study was designed to compare the prevalence of shoulder-arm morbidity, patient satisfaction with surgery and the quality of life of women submitted to breast-conserving therapy or modified radical mastectomy and immediate breast reconstruction.METHODS:This study was a cross-sectional study of women who underwent breast-conserving therapy (n = 44) or modified radical mastectomy and immediate breast reconstruction (n = 26). Quality of life was evaluated with the SF-36 Health Survey Questionnaire.RESULTS:No differences were found in the prevalence of lymphedema. The movements that were most commonly affected by these procedures were abduction, flexion and external rotation. When the two groups were compared, however, we only found a statistically significant difference for the prevalence of restricted internal rotation, which occurred in 32% of women in the breast-conserving therapy group and 12% of those in the modified radical mastectomy and immediate breast reconstruction group (OR: 7.23; p = 0.03 following adjustment for potential confounding factors). No difference in quality of life or satisfaction with surgery was found between the two groups.CONCLUSIONS:These data suggest that the type of surgery did not affect the occurrence of lymphedema. Breast-conserving therapy, however, increased the risk of shoulder movement limitation. No differences were found between the two surgical techniques with respect to quality of life or satisfaction with surgery.

Colloid Preload Versus Coload for Spinal Anesthesia for Cesarean Delivery: The Effects on Maternal Cardiac Output

Spinal anesthesia for cesarean delivery may cause severe maternal hypotension, and a decrease in cardiac output (CO) and blood flow to the placenta. Fluid preloading with crystalloid is ineffective due to rapid redistribution. A "coload" given at the time of cerebrospinal fluid identification may be more effective. Our null hypothesis was that there would be no difference between the effect of a colloid preload (15 mL/kg hydroxyethyl starch (HES) 130/0.4 [Voluven 6%]) and an identical coload on maternal CO and the incidence of hypotension after spinal anesthesia for cesarean delivery. Secondary outcomes studied were neonatal acid- base status and predelivery vasopressor requirements. Forty ASA PS I and II women scheduled for elective cesarean delivery were recruited. Patients were randomized to Group P (preload of 15 mL/kg HES) or Group C (coload, given when cerebrospinal fluid identified). Heart rate, arterial blood pressure, stroke volume and CO measurements were recorded at baseline, every minute for 10 min, and every 2.5 min interval for 10 min with the USCOM ultrasonic CO monitor. Spinal anesthesia was performed at the L3/4 interspace in the right lateral position. Arterial blood pressure was maintained at 90%-100% of baseline values using IV phenylephrine boluses. Demographic, anesthetic, and surgical characteristics were similar. There were no between-group differences in baseline systolic blood pressure, heart rate, and colloid volume. CO and stroke volume were significantly increased in Group P (P = 0.01) in the 5 min after spinal anesthesia. This increase in CO was not sustained at 10 min. There were no significant between-group differences in the incidence of hypotension, absolute arterial blood pressure values (P = 0.73), predelivery median (range) phenylephrine requirements (300[0-1000] in Group P versus 150 [0-850]microg in Group C, P = 0.24), or neonatal outcome as measured by Apgar scores and umbilical arterial and venous blood gas values. Intravascular volume expansion with 15 mL/kg HES 130/0.4 given as a preload, but not coload, significantly increased maternal CO for the first 5 min after spinal anesthesia for cesarean delivery, however, maternal and neonatal outcomes were not different.

The use of a continuous infusion of epinephrine for anaphylactic shock during labor

Background Anaphylaxis is a potentially life threatening, acute, and severe systemic reaction that occurs after the reexposure to a specific antigen. This immunoglobulin E-mediated process is the result of the action of basophils and mast cell mediators, causing severe brochospasm, laringospasm, angioedema, urticaria, and cardiovascular collapse. Case We present a case of anaphylactic shock during labor secondary to administration of ampicillin for group B streptococcus prophylaxis. Generalized itching and hives were soon followed by severe maternal hypotension and tachycardia and prolonged fetal bradycardia. These symptoms responded partially to the administration of fluids and parenteral epinephrine. A continuous infusion of epinephrine was required for persistent maternal symptoms. The infusion did not result in further fetal compromise. The patient delivered a healthy fetus 4 hours after the start of the epinephrine infusion. Conclusion This case supports the use of parenteral (intravenous) epinephrine for the treatment of anaphylactic reactions during pregnancy.

Aortocaval compression syndrome

Aortocaval compression syndrome (supine hypotensive syndrome) represents a common complication mainly of late pregnancy, although the syndrome has been described to occur as early as 16 weeks of gestation. The nature and severity of symptoms range from unspecific complaints to severe maternal hypotension, loss of consciousness, cardiovascular collapse, and consecutive fetal depression. Predominantly, the syndrome is provoked by placing the parturient supine. Since supine positioning is required for diverse diagnostic and therapeutic procedures in obstetrics, these involve increased risk of aortocaval compression. For the anesthetist, cesarean section is most relevant, because of the coincidence of several risk factors. The following article begins by reviewing the pathophysiology of the syndrome, known risk factors and anesthesiological procedures that predispose to the syndrome. The second part is concerned with prophylactic measures and therapeutic options, together with the discussion of a clinically practicable algorithm.

Spinal Anaesthesia with 0.25% Hyperbaric Bupivacaine for Cesarean Section

Comment: This carefully done study demonstrates that adequate analgesia for cesarean section can be obtained from hyperbaric 0.25% bupivacaine when doses of 10 mg or more of the drug are injected in volumes of ≥4 mL. In general, other studies using hyperbaric solutions of either 0.5% or 0.75% bupivacaine have found a minimum of 10 mg and, ideally, higher milligram doses of subarachnoid bupivacaine are required for adequate analgesia. From the data of this study, it would appear that the increased volume of doses greater than 10 mg of 0.25% bupivacaine result in very high cervical sensory levels and a higher incidence of more severe maternal hypotension. Hence, I can see absolutely no reason to use 0.25% hyperbaric bupivacaine over 0.5% or 0.75% hyperbaric bupivacaine. Our experience is that 0.75% bupivacaine in 8.25% dextrose, 15 mg (2 mL) given in the sitting position or 12.5 mg (1.7 mL) given in the lateral position, reliably results in a T2 sensory level in the average Caucasian woman who is ≥162 cm in height. It appears that the lower volume of this more concentrated solution enables a dense block, and its upper level is more controllable.1 The authors commented that their higher doses of local anesthetic resulted in more hypotension, a 70% vs. 40% incidence. Because this hypotension can be effectively treated, I consider this a lesser problem when one considers 14 (70%) patients in group 1 had pain, 4 (20%) of whom required general anesthesia compared with only 2 (10%) patients in group 3, neither of whom required general anesthesia. In addition, the objective of good or excellent analgesia was achieved in only 6 (30%) patients of group 1 compared with 15 (75%) and 18 (90%) in groups 2 and 3, respectively. Cesareans, as they are performed today using a low transverse cervical incision, require marked abdominal retraction before birth. After birth, most obstetricians exteriorize the uterus from the abdominal cavity for repair. These maneuvers require a high (≥T4), solid block if considerable maternal discomfort from visceral pain is to be avoided. With a high concentration (0.5–0.75%) of hyperbaric bupivacaine, perhaps, the addition of 25 μg of fentanyl or 7.5 μg of sufentanil appears indicated.

Severe Maternal Hypotension and Fetal Bradycardia after a Combined Spinal Epidural Anesthetic

INTRATHECAL sufentanil alone or combined with bupivacaine is commonly administered via a combined spinal epidural (CSE) technique to provide analgesia for patients in labor. Although side effects of these agents have been reported, there is debate about whether spinal sufentanil used alone or with bupivacaine is associated with clinically significant hypotension. 1-6 We describe a case of severe maternal hypotension with associated fetal bradycardia after the intrathecal administration of 7.5 μg sufentanil and 2.5 mg bupivacaine.

Allergic Reaction to an Amide Local Anesthetic in Segmental Epidural Analgesia

Erkkola, R.; Kanto, J.; Mäenpää, J.; Kero, P.; Hovi-Viander, M.; Viander, M. Author Information

Survey of the Practice of Epidural Analgesia in a Regional Sample of Obstetric Units

Summary An investigation into practices of the epidural services in a regional sample of obstetric units was undertaken following recent reported disasters associated with epidural analgesia for labour pain. A questionnaire was completed by all 22 obstetric units in the region, which included six teaching, 14 district and two independent centres. In three units the epidural service was shared with the obstetricians. A continuous anaesthetic presence was provided in 16 of 22 units. There was considerable variation in the attendance upon epidural patients by the anaesthetists. Instructions to midwives for top-ups and subsequent care of patients followed no uniform pattern. Midwife in-service training in the initial management of serious epidural complications and in cardiopulmonary resuscitation was inconsistent. In some units, the avoidance of aortocaval compression was not emphasised in the management of serious complications such as severe maternal hypotension, total spinal blockade or cardiac arrest of the parturient. The results obtained in this survey suggest that there is a need to review the requirements in the provision of obstetric epidural services and consideration should be given to the establishment of a generally accepted standard of practice.

Survey of the practice of epidural analgesia in a regional sample of obstetric units.

An investigation into practices of the epidural services in a regional sample of obstetric units was undertaken following recent reported disasters associated with epidural analgesia for labour pain. A questionnaire was completed by all 22 obstetric units in the region, which included six teaching, 14 district and two independent centres. In three units the epidural service was shared with the obstetricians. A continuous anaesthetic presence was provided in 16 of 22 units. There was considerable variation in the attendance upon epidural patients by the anaesthetists. Instructions to midwives for top-ups and subsequent care of patients followed no uniform pattern. Midwife in-service training in the initial management of serious epidural complications and in cardiopulmonary resuscitation was inconsistent. In some units, the avoidance of aortocaval compression was not emphasised in the management of serious complications such as severe maternal hypotension, total spinal blockade or cardiac arrest of the parturient. The results obtained in this survey suggest that there is a need to review the requirements in the provision of obstetric epidural services and consideration should be given to the establishment of a generally accepted standard of practice.

Evaluation of the pharmacodynamics and pharmacokinetics of ritodrine when administered as a loading dose

Abstract Inhibition of labor during the intrapartum period has been suggested as a method of managing acute fetal distress. In such cases, rapid tocolysis is desirable but, in high doses, β-adrenergic-receptor agonists, such as ritodrine, may cause severe maternal hypotension that could aggravate the existing fetal distress, We undertook the present study to establish a safe infusion protocol for ritodrine that achieves high plasma concentration rapidly. Twelve nonpregnant female volunteers received, on separate days, three infusions of ritodrine, that is, 1, 2, and 3 mg, during a 2-minute period. The peak plasma concentration measured by high-performance liquid chromatography with electrochemical detection averaged 37, 74, and 100 ng/ml after the 1, 2, and 3 mg doses, respectively. Ritodrine concentrations decreased rapidly and with the 3 mg dose the ritodrine concentration was only 14 ng/ml after 15 minutes. The elimination phase half-life of ritodrine averaged 6.11 hours. None of the doses significantly affected systolic blood pressure but ritodrine increased heart rate and the plasma glucose level and decreased diastolic blood pressure and the plasma potassium concentration. Even at the highest infusion rate, the maximal changes in cardiovascular and metabolic variables were short-lived and clinically modest; heart rate increased 29 bpm, diastolic blood pressure decreased 8 mm Hg, glucose level increased 26 mg/dl, and potassium concentration decreased 0.6 mEq/L. These data indicate that high plasma concentrations of ritodrine can be achieved rapidly without serious side effects.

Evaluation of the pharmacodynamics and pharmacokinetics of ritodrine when administered as a loading dose: On establishing a potentially useful drug administration regimen in cases of fetal distress

Inhibition of labor during the intrapartum period has been suggested as a method of managing acute fetal distress. In such cases, rapid tocolysis is desirable but, in high doses, β-adrenergic-receptor agonists, such as ritodrine, may cause severe maternal hypotension that could aggravate the existing fetal distress, We undertook the present study to establish a safe infusion protocol for ritodrine that achieves high plasma concentration rapidly. Twelve nonpregnant female volunteers received, on separate days, three infusions of ritodrine, that is, 1, 2, and 3 mg, during a 2-minute period. The peak plasma concentration measured by high-performance liquid chromatography with electrochemical detection averaged 37, 74, and 100 ng/ml after the 1, 2, and 3 mg doses, respectively. Ritodrine concentrations decreased rapidly and with the 3 mg dose the ritodrine concentration was only 14 ng/ml after 15 minutes. The elimination phase half-life of ritodrine averaged 6.11 hours. None of the doses significantly affected systolic blood pressure but ritodrine increased heart rate and the plasma glucose level and decreased diastolic blood pressure and the plasma potassium concentration. Even at the highest infusion rate, the maximal changes in cardiovascular and metabolic variables were short-lived and clinically modest; heart rate increased 29 bpm, diastolic blood pressure decreased 8 mm Hg, glucose level increased 26 mg/dl, and potassium concentration decreased 0.6 mEq/L. These data indicate that high plasma concentrations of ritodrine can be achieved rapidly without serious side effects.

Spinal and epidural anesthesia, fetal and uterine response to acute hypo- and hypertension

1.1. Spinal or epidural anesthesia does not abolish uterine contractility as long as the blood pressure is maintained within normal limits. Factors associated with sensation of pain, bearing down, muscle rigidity, etc., which may enhance or inhibit uterine contractility, however, are abolished by spinal or epidural anesthesia. Although labor after spinal or epidural anesthesia may be altered, the intrinsic uterine work is preserved. In the clinical estimation of the duration of labor in patients with spinal or epidural anesthesia these factors should be considered.2.2. Acute postepidural hypotension resulted in a decrease of uterine contractility, fetal tachycardia, and oscillation of the fetal heart rate. Fetal bradycardia was encountered either with a severe maternal hypotension or more frequently with enhancement of uterine contractility following a posthypotensive period.3.3. Correction of an acute hypotension with one intravenous injection of 3 mg. of methoxamine hydrochloride resulted in 8 cases in tetanic uterine contraction and severe fetal distress.4.4. It is suggested in the management of postspinal hypotension by pressor amines that the intravenous drip should be used and the dose and effect individually followed by clinical monitoring of the fetal heart rate, uterine contractility, and the maternal hemodynamic status.