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Biomedical subjects

W Rayburn

Publications and source records attributed to W Rayburn.

At least 19 recordsLinked to original sources
PubMed2000

Maintenance treatment of preterm labor with the oxytocin antagonist atosiban. The Atosiban PTL-098 Study Group.

OBJECTIVES: Patients admitted with an acute episode of preterm labor who respond to early intravenously administered tocolysis remain at risk of having subsequent episodes of preterm labor and preterm delivery. Several pharmacologic agents have been used in an attempt to reduce subsequent episodes of preterm labor, and all are associated with significant side effects. Atosiban, an oxytocin receptor antagonist, is effective in the treatment of an acute episode of preterm labor. This study was designed to compare the efficacy and safety of atosiban with those of placebo maintenance therapy in women with preterm labor who achieved uterine quiescence with intravenous atosiban. STUDY DESIGN: A multicenter, double-blind, placebo-controlled trial was designed for patients in preterm labor who responded to early intravenous treatment with atosiban. Five hundred thirteen patients were randomly assigned to receive maintenance therapy, 252 to receive atosiban, and 251 to receive matching placebo. Maintenance therapy was administered as a continuous subcutaneous infusion, via pump, of 30 microg/min to the end of 36 weeks' gestation. The primary end point was the number of days from the start of maintenance therapy until the first recurrence of labor. A secondary end point was the percentage of patients receiving subsequent intravenous atosiban therapy. RESULTS: The time (median) from the start of maintenance treatment to the first recurrence of labor was 32.6 days with atosiban and 27.6 days with placebo (P =.02). At least one subsequent intravenous atosiban treatment was needed by 61 atosiban patients (23%) and 77 placebo patients (31%). Except for injection site reactions, adverse event profiles of atosiban and placebo were comparable. There were 4 neonatal deaths reported in the atosiban group and 5 in the placebo group after the start of maintenance therapy. Infant outcomes (including birth weight) were comparable between maintenance and treatment groups. CONCLUSIONS: Maintenance therapy with the oxytocin receptor antagonist atosiban can prolong uterine quiescence after successful treatment of an acute episode of preterm labor with atosiban. Treatment was well tolerated.

Adult↗
PubMed1998

Attempted vaginal birth after cesarean section: a multicenter comparison of outpatient prostaglandin E(2) gel with expectant management.

Objective: To compare the clinical effectiveness and safety of outpatient administration of an intracervical prostaglandin (PG) E(2) gel with expectant management for women with an unfavorable cervix who wish to attempt a vaginal birth after cesarean section.Study Design: This outpatient study was a randomized, multicenter investigation involving pregnant women at term with one previous low transverse cesarean section. Each had an unfavorable cervix (Bishop score </=4) and was a candidate for vaginal delivery. Those randomly assigned to receive the gel, rather than expectant management, were given a 0.5 mg dose of PGE(2) (Prepidil) intracervically at 39 weeks gestation. This cervical ripening treatment was repeated at weekly office visits for up to 3 doses.Results: Of the 294 cases, 143 received the gel while 151 underwent expectant management. No differences between the two groups were found for maternal demographics, race, parity, or predose Bishop score. The rates of repeat cesarean section did not differ (P =.68) with use of the gel (61, 42%) or with expectant therapy (48, 45%). The onset of active labor, the duration of labor among those delivering vaginally, and the 1-minute and 5-minute Apgar scores were not different between the two groups. No uterine rupture was apparent, and adverse effects during labor were as likely to occur in the two groups.Conclusions: Although its safety was confirmed for outpatient use and for persons with a prior cesarean delivery, intracervical prostaglandin E(2) gel did not improve the chance of a vaginal birth after a cesarean delivery.

Journal Article↗
PubMed1994

Clinical experience with the Hewlett-Packard M-1350A fetal monitor: correlation of Doppler-detected fetal body movements with fetal heart rate parameters and perinatal outcome.

OBJECTIVE: Our purpose was to correlate measures of Doppler-detected fetal movements with standard fetal heart rate parameters and perinatal outcomes. STUDY DESIGN: This prospective, multiinstitutional trial used the Hewlett-Packard M1350A monitor to record simultaneous fetal heart rate baseline, variability, accelerations, decelerations, and number of fetal movements, and duration and percent of total time. These data were compared at 10- and 30-minute intervals during nonstress tests and were correlated with fetal heart rate baseline parameters and maternally perceived fetal movements and with outcomes of infants delivered within 7 days of the last test. RESULTS: At six centers 1704 actocardiograms from 884 third-trimester patients were analyzed. Doppler-detected fetal movement counts, durations, and percent of total time correlated weakly with all baseline fetal heart rate parameters (all values < 0.20). All fetal movement parameters increased significantly in successive 10-minute blocks and in periods of increased or normal fetal heart rate variability compared with those with fetal heart rate variability. The sensitivity, specificity, and predictive values of the percent of total movement time were comparable to those of standard nonstress test parameters. The risk of poor perinatal outcomes after nonreactive nonstress tests was lower in cases with fetal movements than in those without. CONCLUSIONS: Doppler actocardiography may help to discriminate fetal states during antepartum testing. It may prevent inappropriate diagnosis of fetal compromise when the nonstress test is nonreactive or nonreassuring.

Female↗
PubMed1991

Intravaginal prostaglandin E2 gel and cardiovascular changes in hypertensive pregnancies.

Prostaglandin E2 (PGE2) and its analogues may be potent vasodilators, and intravaginal PGE2 is known to be absorbed rapidly into the maternal circulation. This study investigated any cardiovascular effects from intravaginal PGE2 on 42 hypertensive pregnant women requiring preinduction cervical ripening. Declines in maternal diastolic, systolic, and mean arterial pressures were apparent during the first half hour. This trend was mild, was reversible without treatment, and did not influence the fetal heart rate baseline or patterns. Fear of clinically significant changes should not be a concern, but monitoring during the first hour is recommended.

Administration, Intravaginal↗
PubMed1990

[Incidence and therapy of hyperstimulation following local prostaglandin administration for labor induction].

A major cause of concern with respect to local prostaglandin (PG) E2 application is uterine hyperstimulation. The purpose of the present study was to evaluate the incidence of hyperstimulation and the possibility of treating this complication. A total of 181 cases were registered in two obstetric centres over a 51-month period. The rates of hyperstimulation were 7.3% in the group receiving intravaginal PG E 2 tablets (3 mg), 2.9% with intravaginal gel (2.5 mg), and 0.5% with intracervical gel (0.5 mg). In 178 cases (98.3%) the infusion of a beta-2 adrenergic drug (hexoprenaline or terbutaline) led, without adverse effects, to the rapid resolution of the alarming findings. Caesarean section was necessary in 3 patients. Depressed Apgar scores and an umbilical artery pH less than 7.20 were uncommon and, indeed, no more frequent than in PG E 2-treated cases without hyperstimulation. We conclude that uterine hyperstimulation is uncommon after low-dose PG E 2 therapy and is usually rapidly reversible, without apparent untoward intrapartum or neonatal effects.

Adolescent↗
PubMed1989

Fentanyl citrate analgesia during labor.

Fentanyl citrate is a potent short-acting narcotic reported to cause less nausea and sedation than morphine or meperidine hydrochloride. The purpose of this prospective investigation was to determine whether a safe but adequate intrapartum dosing schedule is possible. A total of 137 women with uncomplicated term pregnancies were offered a standard intravenous dose (50 mcg or 100 mcg hourly as needed) of fentanyl citrate during active labor. Temporary analgesia and mild sedation were apparent in each case. The cumulative dose varied in accordance with maternal needs (mean, 140 +/- 42 micrograms; range, 50 mcg to 600 micrograms). Apart from a brief decrease in fetal heart rate variability that lasted 30 minutes, no worrisome pattern was apparent from exposure to fentanyl citrate. Pediatric examinations were performed without knowledge of analgesic therapy on infants exposed to fentanyl citrate and those not exposed to analgesics. No differences were found in frequencies of newborn depressed respirations, low Apgar scores, or neurologic and adaptive capabilities at two hours and 24 hours postnatally. With the use of the described dosing schedule, fentanyl citrate was helpful during labor and did not cause immediate or prolonged hazards to the mother and unborn infant.

Adaptation, Physiological↗
PubMed1989

Initiation of labor with a moderately favorable cervix: a comparison between prostaglandin E2 gel and oxytocin.

This study compares prostaglandin E2 (PGE2) gel and oxytocin for the initiation of labor in term pregnancies with a moderately favorable cervix (Bishop score 5-8). Compared with a matched group, 48 cases treated with PGE2 gel (2.5 mg intravaginally) required significantly less or no oxytocin, had shorter first stages of active labor, and had no increased risk of uterine hyperstimulation or cesarean section. Initiation of labor with low dose PGE2 when the cervix is moderately favorable is less labor intensive and meets with more patient satisfaction.

Adult↗
PubMed1989

Histologic examination of the placenta in the growth-retarded fetus.

This investigation was undertaken to determine whether histologic examination of the placenta contributed to a better understanding of the cause of intrauterine fetal growth retardation. Placentas were examined of 151 liveborn infants whose birthweights were in the lower 10th percentile for gestational age. One or more histologic aberrations were found in 139 (92%) cases, in contrast to one or more antenatal risk factors (primarily hypertension) in 77 (51%) cases or a gross placental abnormality (primarily abruption) in 46 (30%) cases. Compared with placentas belonging to appropriately sized fetuses, histologic signs of uteroplacental vascular insufficiency, chronic inflammation, and hemorrhagic endovasculitis were significantly more common in the study group. The primary histologic condition was supportive of prior clinical impressions in 61 (40%) cases, contradictory in 23 (15%) cases, or solely contributory to explaining the growth retardation in 55 (36%) cases. Placental histologic examination may clarify a cause for delayed fetal growth, especially after a normotensive pregnancy.

Female↗
PubMed1989

Intravenous meperidine during labor: a randomized comparison between nursing- and patient-controlled administration.

Preliminary reports about patient-controlled analgesia during labor have been promising. The purpose of this investigation was to compare our experience with meperidine given intravenously by the patient versus by a nurse. Sixty-four healthy women beginning active labor (cervical dilation 3 cm) at term were randomly assigned to either self-administer a 10-mg dose as often as every 20 minutes or have a nurse administer 25-50 mg every 3 hours as requested. The total meperidine dose and consumption rates were greater when administered by the patient than by a nurse. Maternal side effects occurred with similar frequency in both groups, and pain relief was judged to be equivalent. Maternal and umbilical serum concentrations of meperidine at delivery increased in the patient-controlled group if active labor lasted longer than 2 hours. Neonatal naloxone therapy was used more often when meperidine was administered by the patient than by a nurse (five of 31, 16%, versus three of 33, 10%, respectively). Self-administration of intravenous meperidine by the laboring patient was not found to be advantageous over nursing administration, and may pose an increased threat to the infant.

Adult↗
PubMed1989

Oral phenobarbital given antenatally to reduce neonatal intraventricular hemorrhage. A comparison between maternal and umbilical cord serum levels at delivery.

This investigation was undertaken to compare maternal and neonatal cord serum levels of phenobarbital given orally to mothers anticipated to deliver very low birthweight infants at risk for neonatal intraventricular hemorrhage (IVH). Fifty women anticipated to deliver between 26 and 34 weeks' gestation agreed to receive a daily oral dose of 90 mg of phenobarbital. The umbilical cord to maternal phenobarbital concentration ratio at birth was 1.05 and remained constant after the first day of maternal therapy. Cord phenobarbital concentrations increased rapidly during the first 3 days until reaching a steady state by the end of the first week of therapy. In contrast to recent promising reports using large doses of phenobarbital given parenterally shortly before delivery, lower doses of oral phenobarbital did not reach cord levels reported to be protective against IVH or therapeutic as an anticonvulsant.

Administration, Oral↗
PubMed1988

Outpatient cervical ripening with prostaglandin E2 gel in uncomplicated postdate pregnancies.

A double-blind, placebo-controlled, prospective investigation was undertaken to determine whether the outpatient administration of prostaglandin E2 gel was helpful for ripening the cervix in postdate pregnancies. One hundred eighteen women with an uncomplicated pregnancy at or beyond 42 weeks' gestation with an unripe cervix (Bishop score less than or equal to 5) were randomly administered a single dose of gel containing either 2.5 mg prostaglandin E2 (n = 55) or a placebo (n = 63) before induction of labor with Pitocin. No side effects were detected in these healthy mothers and fetuses. A distinct change in Bishop score after 12 hours occurred more often in the prostaglandin E2 than in the placebo group (42% versus 6%, p less than 0.0001). Forty-four women (80%) who had received prostaglandin E2 were admitted in early labor; they required little or no oxytocin for augmentation. The duration of labor and maximum dose of oxytocin infused were significantly decreased in the prostaglandin E2 group, and forceps delivery or primary cesarean sections were performed less often when prostaglandin E2 was used (24% versus 44%, p less than 0.05). The outpatient administration of a single dose of prostaglandin E2 gel is safe in the uncomplicated postdate pregnancy and was found to significantly change the unripe cervix, enhance the onset of labor, minimize the need for oxytocin administration, and encourage a spontaneous vaginal delivery.

Ambulatory Care↗
PubMed1988

Antenatal phenobarbital and bilirubin metabolism in the very low birth weight infant.

Prior studies in term infants have suggested that in utero phenobarbital exposure may accelerate bilirubin metabolism by stimulating hepatocyte glucuronyl transferase activity. This report reviews our experience with maternal phenobarbital therapy and fetal bilirubin conjugation in the very premature fetus. Mothers with arrested premature labor between 26 and 33 weeks' gestation were randomly assigned to receive oral phenobarbital (90 mg daily) or not. Infants in the two groups were similar in race, birth weight, and gestational age. Conjugated bilirubin levels at birth were significantly higher for infants receiving several days of phenobarbital in utero than no therapy (0.31 +/- 0.03 vs 0.16 +/- 0.01 mg dl, p less than 0.01). A smaller portion of infants exposed to phenobarbital in utero required phototherapy (10/23, 43% vs 24/29, 83%, p less than 0.01), which was also more likely to be delayed beyond 48 hours after delivery. Antenatal phenobarbital enhances bilirubin conjugation before delivery of a very low birth weight infant.

Bilirubin↗
PubMed1988

Routine preoperative ultrasonography and cesarean section.

This prospective investigation was undertaken to determine whether routine ultrasound visualization of the gravid uterus shortly before cesarean section would provide useful information in determining the site for uterine incision. Complete data were gathered on 124 pregnancies using a portable real-time ultrasound machine. Determination of the placenta and umbilical cord locations, fetal presentation, and amniotic fluid volume were reliable. Compared with a matched group without ultrasonic visualization, the eventual site for uterine incision and morbidity to the mother and fetus were not significantly different. Although routine visualization of the intrauterine contents before surgery is not necessary, worthwhile information may be gained in select cases to confirm a previously suspected noncephalically presenting fetus or a low anterior placenta.

Cesarean Section↗
PubMed1988

Birth weights in term infants. A 50-year perspective.

An improvement in prenatal care over several generations could enhance the birth weights of term infants. We reviewed data on live-born, singleton infants born at our university medical center between 1935 and 1985. Our review of 42,185 such pregnancies revealed that the mean birth weight (3,279 g) of a term infant has not changed significantly during the past 50 years. The frequency of term infants' weighing less than 2,500 g has not changed, but there has been a significant increase in the percentage of macrosomic infants (greater than 4,000 g), from 3 to 14, in the last 15 years. White infants have been consistently heavier than black infants, by an average of 179 g (6.3 oz). Differences in mean birth weights have been consistently greater for male than female infants (123 g, 4.6 oz) and for multiparous than primiparous deliveries (79 g, 2.8 oz), regardless of race. Impressions from these data, spanning three generations, should be helpful for prenatal counseling.

Birth Weight↗
PubMed1987

Reversing severe hypoglycemia during pregnancy with glucagon therapy.

Glucagon therapy has been used to reverse severe hypoglycemia-induced unconsciousness, but no known study exists which reports its use during pregnancy. Pregnant diabetic women were eligible if they had either a prior hypoglycemic episode requiring intravenous glucose administration or had repeated capillary blood glucose determinations less than 40 mg/dl without any warning adrenergic symptoms. Of 51 insulin-dependent diabetic women, 16 were candidates for glucagon use during a recent 3 1/2-year period. Seven of these 16 persons required an injection on 12 occasions, and an immediate reversal of unconsciousness was encountered in 11 circumstances. No apparent short- or long-term maternal adverse effects were present. We conclude that glucagon therapy is needed infrequently for diabetic women during pregnancy but is helpful in reversing acute episodes of severe hypoglycemia.

Adult↗