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Biomedical subjects

W F Rayburn

Publications and source records attributed to W F Rayburn.

At least 73 records · Page 4Linked to original sources
PubMed1995

A statewide, toll-free telephone service to improve obstetric care.

The University of Oklahoma Health Sciences Center began in 1993 to provide a statewide, toll-free telephone service for pregnancy counseling to primary care physicians. The service was available 24 hours each day, and responses were made by the on-call maternal-fetal medicine specialist. This report summarizes our first full year of operation. Inquiries came from 34 (63%) of the state's 54 counties having physicians who provide obstetric care. One hundred twenty-eight physicians made 523 inquiries (median 3, range 1-15). Information was sought about prenatal genetic disorders, risks from drugs, exposure to infection, environmental hazards, and active obstetric or medical complications. Funds from targeted ultrasounds, genetic amniocenteses, more detailed counselling, and maternal transfers provided support for this expanding educational resource.

Female↗
PubMed1995

Umbilical cord length and acid-base balance at delivery.

An abnormally short or long umbilical cord is associated with a greater risk of cord compression, variable fetal heart rate decelerations and fetal demise. The purpose of the present investigation was to determine whether any relation exists between an abnormal length of the umbilical cord and acid-base imbalance at delivery. Cord lengths were measured routinely in 3,019 consecutive pregnancies undergoing labor beyond 34 weeks. Short cords (13-35 cm) were found in 61 (2.0%) cases and long cords (80-121 cm) in 112 (3.7%) cases. Umbilical blood pH and base deficit values averaged the same for those pregnancies with short (7.35 +/- 0.09 and 3.1 +/- 2.7 mEq/L, mean +/- SD), normal length (7.36 +/- 0.03 and 3.8 +/- 1.7, mEq/L) and long (7.34 +/- 0.06 and 3.7 +/- 3.1 mEq/L) cords. A blood pH < 7.20 was very uncommon in the presence of a short (two cases, 3.3%) or long (five cases, 4.5%) cord and was accompanied by an abnormal fetal heart rate pattern, such as severe variable decelerations or bradycardia. Finding an abnormally short or long umbilical cord at birth is not by itself associated with an increased risk of acid-base imbalance at delivery and does not require routine cord blood gas determination.

Acid-Base Imbalance↗
PubMed1995

Off-label drug prescribing on a state university obstetric service.

Off-label drug use occurs when physicians prescribe a drug recommended for indications other than those listed on the prescription labeling. The purpose of the present investigation was to describe patterns of off-label drug use during pregnancy, including the types of drugs and their timing of use. All study pregnancies had to receive prenatal care at our state university clinics before 14 weeks' gestation and deliver at our institution during a five-month period. Prenatal records were reviewed, and subjects were interviewed after delivery. A total of 165 (22.6%) of the 731 eligible subjects took > or = 1 (average 1.7, 95% confidence interval 1.3-3.8) drugs for off-label indications. Nearly all drugs were taken for a short term during the third trimester. The primary purposes were to avoid an obstetric complication (premature labor and delivery, preeclampsia/eclampsia) or improve the capacity for eventual postnatal adaptation. Despite discussions with patients, on no occasion was it recorded on the chart that the patient was informed that the drug was recommended for an off-label indication. Results from this study should help drug manufacturers, insurance companies and federal regulatory agencies understand the common use of recommending certain drugs for off-label indications during pregnancy.

Drug Labeling↗
PubMed1994

Double-blind comparison of intravenous butorphanol (Stadol) and fentanyl (Sublimaze) for analgesia during labor.

OBJECTIVE: Our purpose was to compare the analgesic properties, effect on labor, and maternal-fetal side effects of intravenous butorphanol and fentanyl. STUDY DESIGN: One hundred patients with uncomplicated term pregnancies were enrolled during early active labor. Each patient received standard doses of either fentanyl (50 to 100 micrograms) or butorphanol (1 to 2 mg) hourly on request in a double-blind manner. Pain was scored independently by the nurse and patient with a 10-point visual analog scale. Categoric and measurement data were collected for comparison of the effects on uterine activity, maternal and fetal well-being, and neonatal outcomes. RESULTS: The fentanyl (n = 50) and butorphanol (n = 50) groups were identical with respect to maternal age, race, parity, and weight. Greater improvement in pain relief was found after the first dose of butorphanol than after fentanyl (p < 0.05). When fentanyl was given, either more doses were necessary (3.2 +/- 1.3 vs 2.1 +/- 1.1, p < 0.01) or epidural analgesia was requested more often (16%, 32% vs 9%, 18%, p < 0.05). Uterine contraction patterns for the first hour after dosing were unchanged, and the duration of the first and second stages of labor were not different between the two groups. No differences in maternal or newborn adverse effects were observed. CONCLUSIONS: Both drugs were equally safe and without effect on active labor. Butorphanol provided better initial analgesia than fentanyl with fewer patient requests for more medication or epidural analgesia.

Adolescent↗
PubMed1994

Double-blind comparison of intracervical and intravaginal prostaglandin E2 for cervical ripening and induction of labor.

OBJECTIVE: Our purpose was to compare the safety and effectiveness of prostaglandin E2 delivered sequentially as an intracervical (0.5 mg) or intravaginal (2.5 mg) gel. STUDY DESIGN: Hospitalized patients with an unfavorable cervix (Bishop score < or = 4) at > or = 35 weeks and requiring induction of labor were assigned to receive two 2.5 ml doses of gel intracervically and intravaginally in a double-blind, placebo-controlled manner. Second and third doses were given at 6-hour intervals until there were either regular uterine contractions or a Bishop score change > 3 points. RESULTS: The 100 evaluable cases received prostaglandin E2 either intracervically (n = 52) or intravaginally (n = 48). Difficulty with exact gel instillation was present with intracervical gel only, where spillage occurred in 85% of cases. Compared with intracervical therapy prostaglandin E2 given intravaginally was more likely to significantly change the Bishop score (60.4% vs 40.4%, p = 0.04) and stimulate regular contractions (72.9% vs 48.1%, p = 0.01). Uterine hyperstimulation was present in one case in each group. CONCLUSION: Although each was safe, instillation of prostaglandin E2 gel was better at a higher intravaginal dose than a lower intracervical dose because of its greater ease of administration and higher likelihood of cervical change.

Administration, Intravaginal↗
PubMed1994

Short-term effects of inhaled albuterol on maternal and fetal circulations.

Short-term circulatory effects with the maximum recommended dose of inhaled albuterol (Proventil) were studied on 12 asthmatic patients between 33 and 39 weeks' gestation. The mean maternal blood pressures and heart rates, systolic/diastolic ratios of the uterine arcuate and umbilical arteries, and fetal heart rates and aortic velocities were unaffected during the first 2 hours after dosing.

Adolescent↗
PubMed1994

Ambulatory blood pressure monitoring during pregnancy with a new, small, easily concealed monitor.

Before establishing the utility of ambulatory blood pressure monitoring during pregnancy, we evaluated the accuracy of a small, easily concealed monitor. The 59 normotensive pregnant patients were between 13 and 26 gestational weeks. For each monitor reading, two trained observers independently and simultaneously recorded blood pressures using a mercury manometer connected to the monitor cuff. Seven readings in three positions (sitting upright, semirecumbent, standing) were performed on each patient. Averaged differences between the observers' and monitor readings varied from -2.2 to -0.9 mm Hg (systolic) and from -2.8 to -0.6 (fifth-phase diastolic), indicating slight but clinically unimportant overestimation by the monitor. Correlations between averaged observers' readings and the monitor ranged from 0.79 to 0.92 (systolic) and from 0.85 to 0.92 (fifth-phase diastolic). Overall, the observers agreed with the monitor within 5 mm Hg on 94% of systolic readings and 99% of fifth-phase diastolic readings. There was no statistically significant difference in accuracy with changes in body position. We conclude that this small, quiet, noninvasive device accurately determined blood pressures during pregnancy.

Adolescent↗
PubMed1994

Intravaginal prostaglandin E2 for cervical ripening and initiation of labor. Comparison of a multidose gel and single, controlled-release pessary.

A study was conducted to compare the efficacy and safety of two methods of delivering prostaglandin E2 (PGE2) as a low-dose gel delivered in up to two sequential, 2.5-mg doses and as a single-dose, controlled-release, 10-mg pessary. A cervical change was present in both groups, but a Bishop score > or = 8 occurred in more nulliparous patients in the pessary than in the gel group by 12 hours after dosing. Labor was initiated without oxytocin more frequently in the pessary than gel group for nulliparas and multiparas. Reversal of uterine hyperstimulation was possible by removal of the pessary without tocolytic therapy. The controlled-release PGE2 pessary was more effective in changing the cervix in nulliparas and in initiating labor and offered the advantage of removal when desired.

Administration, Intravaginal↗
PubMed1993

In utero drug therapy.

Drug therapy directed toward the fetus would be intended for either treating a fetal disorder or improving the capacity for later intrauterine or postnatal adaptation. Most reported trials involve single cases or small numbers of fetuses receiving the drug transplacentally after the first trimester, but before attaining maturity. Studies usually involve a single drug administered shortly before delivery. Treatments that are more direct or begun earlier in gestation are being attempted, but our limited understanding of fetal pharmacokinetics forces us to proceed cautiously. Studies to date have shown no risks to the mother and newborn infant, but long-term follow-up is necessary.

Animals↗
PubMed1993

Effect of low intravaginal doses of prostaglandin E2 on the closure time of the ductus arteriosus in term newborn infants.

Seventeen term newborn infants (control subjects) and 17 whose mothers had been given intravaginal doses of prostaglandin E2 (PGE2) were examined serially by color Doppler echocardiography to determine whether maternal PGE2 prolonged ductal patency. No clinically relevant differences in closure times were found. Low-dose intravaginal PGE2 therapy was not associated with prolonged ductal patency in term infants.

Administration, Intravaginal↗
PubMed1993

A physician's prerogative to prescribe drugs for off-label uses during pregnancy.

Physicians frequently prescribe drugs for indications other than those on the product label. Reasons for such off-label use during pregnancy include: prevention of repetitive abortion, inhibition of premature labor, reduction of fetal or neonatal infection, reduction in development of preeclampsia and its complications, and ripening of the cervix or induction of labor. A physician has a legal right to prescribe for off-label indications despite regulatory, manufacturer, and cost constraints. Such prescribing habits would not be considered experimental if based on sound scientific evidence. Adequate and well-controlled studies are difficult to perform during pregnancy. Evidence of widespread use and support from another qualified clinician are methods of justifying off-label prescribing. Each patient is entitled to know why she and her fetus would benefit from the treatment and whether any unnecessary risk is anticipated. Legible documentation of these discussions in the medical records is important.

Cost Control↗
PubMed1992

Prenatal exposure to phenobarbital and quantifiable alterations in the electroencephalogram of adult rat offspring.

OBJECTIVE: Our purpose was to measure central nervous system insult from prenatal phenobarbital by quantified electroencephalographic evaluation of mature rat offspring. STUDY DESIGN: Twenty-four adult female rats were given phenobarbital as 0, 20, 40, or 60 mg/kg/day subcutaneously between 9 and 10 AM for 28 days before breeding and throughout gestation. The electroencephalograms of 90-day-old offspring were sampled over 24 hours and converted to the power spectra. RESULTS: Female offspring exposed prenatally to 20 mg and males exposed prenatally to 40 mg displayed an increase in delta and a decrease in alpha and middle-beta waveform activities. Females exposed prenatally to 40 mg and males exposed prenatally to 60 mg displayed decreases in delta, theta, alpha, and middle-beta activities. CONCLUSIONS: Prenatal phenobarbital exposure produced dose- and sex-dependent changes in the electroencephalogram of mature offspring consistent with a generalized deficit in the neuronal synchronization mechanisms that are critical for normal sleep and learning.

Animals↗
PubMed1992

Characterization of fetal body movement recorded by the Hewlett-Packard M-1350-A fetal monitor.

OBJECTIVE: The purpose of this study was to evaluate the ability of a commercially available monitor, the Hewlett-Packard M-1350-A fetal monitor, to record and discriminate between various fetal body movements. STUDY DESIGN: Twenty-four patients between 29 and 42 weeks' gestation were monitored over a 20 to 30 minute period simultaneously by the Hewlett-Packard instrument and ultrasonography. RESULTS: All 593 single or clustered fetal movements recorded by the monitor were seen ultrasonographically as being extremity movements that were either isolated or combined with trunk motion. Discriminating between these two types of movements was not possible on the basis of the duration of recorded movements. All adequate fetal heart rate accelerations were attributed to combined trunk and extremity movements. Detection of fetal hiccups was less exact, and recording of fetal hand, mouth, breathing, and rapid eye movements was beyond the sensitivity of the monitor. Signal artifacts were attributable to either motion of the maternal abdomen or Doppler transducer and became less of a problem with experience. CONCLUSION: Fetal extremity movements were recorded with accuracy by this new fetal monitor.

Adult↗
PubMed1992

Effects of analgesia on labor.

Uterine activity may be defined in terms of the frequency of contractions of the uterus and the pressure generated by these contractions. Most studies that report an effect of analgesia on labor are retrospective, and, if prospective, are nonrandomized. Drug effects on uterine activity and labor progress are probably dose related, but are also influenced by a myriad of other factors including, but not limited to, the mother's emotional state, degree of cervical change, uterine contractility pattern, phase of labor, and individual differences in pharmacokinetics and drug sensitivity. The latest phase of labor may be prolonged by excessive narcotic or inappropriate timing of regional analgesia. The normal active phase tends to be resistant to the inhibitory effects of the usual amount of any analgesia. A brief period of decreased uterine activity often follows institution of analgesia. This may effectually accelerate labor in some patients by decreasing maternal anxiety and serum concentrations of catecholamines. A combination of sedation epidural blockade, and subsequent oxytocin use may prove effective in correcting a dysfunctional or hyperstimulatory pattern during the active phase. The second stage of labor may be slightly prolonged by effective epidural analgesia, but this delay is not necessarily harmful as long as the fetal heart rate tracing is normal, maternal hydration is adequate, and maternal pain relief is sufficient.

Analgesia, Obstetrical↗
PubMed1992

An intravaginal controlled-release prostaglandin E2 pessary for cervical ripening and initiation of labor at term.

The purpose of this randomized, double-blind study was to evaluate the efficacy and safety of a new controlled-release hydrogel pessary for ripening the cervix and initiating labor. Subjects had an entry Bishop score of 4 or less and gestational age of 37 or more weeks. One hundred fourteen women received a placebo pessary and 101 received the hydrogel pessary, containing 10 mg of prostaglandin (PG) E2. Compared with the placebo group, those given the PGE2 pessary were more likely to have an increase in Bishop score of 3 or more (60 or 59% versus 21 or 18%; P less than .0001), change to a Bishop score of 6 or higher (59 or 58% versus 18 or 16%; P less than .0001), and active labor (68 or 67% versus 15 or 13%; P less than .0001). Including the crossover study, uterine hyperstimulation (28 of 182, 15%) and fetal heart rate abnormalities (18 of 182, 10%) in PGE2-treated subjects were reversed on removal of the pessary with no apparent harm to the mother or fetus. These temporary adverse effects appeared while the pessary was in place and after the onset of active labor. Oxytocin was unnecessary in 89 of 182 (49%) of the PGE2-treated cases and was used more often to augment than to induce labor. We conclude that the described controlled-release PGE2 vaginal pessary induces appreciable cervical ripening and frequently initiates active labor with little or no need for oxytocin. The pessary may cause uterine hyperstimulation or fetal heart rate abnormalities, but these would be expected to reverse on removal of the pessary.

Delayed-Action Preparations↗
PubMed1992

Relation of mild idiopathic polyhydramnios to perinatal outcome.

The relation between clinically obvious polyhydramnios and poor perinatal outcome has been described. Much less is known about mild, unexplained polyhydramnios, which usually is initially suggested by sonographic examination late in gestation. The purpose of the present investigation was to relate mild idiopathic polyhydramnios to perinatal outcome. Mild polyhydramnios was defined sonographically as an amniotic fluid index of 24.1-39.9 during fetal biophysical testing. All subjects had singleton gestations not complicated by conditions known to predispose to polyhydramnios. We diagnosed mild polyhydramnios in 97 of 1177 patients (8.2%) undergoing fetal testing at 26-42 gestational weeks. Premature delivery, intrapartum complications, and neonatal depression were no more frequent in the pregnancies complicated by mild, unexplained polyhydramnios than in a comparable control group with normal fluid volume. The mild polyhydramnios group showed a significantly higher incidence of birth weight greater than 4000 g than did the control group (18.6 versus 8.6%; P less than .05). We conclude that mild idiopathic polyhydramnios in late gestation is relatively common. Except for a higher incidence of large for gestational age fetuses, this condition by itself is not associated with an increased risk of adverse perinatal outcomes.

Female↗
PubMed1992

Transvaginal sonography of cervical width and length during pregnancy.

Transvaginal ultrasonography has been proposed as a reliable method of assessing dimensions of the cervix. The purpose of the current investigation was to establish normative data for cervical width and length during pregnancy. This information may be helpful in predicting patients at risk for preterm birth. A transvaginal 5 or 7.5 MHz transducer was used on 132 consecutive low-risk pregnant women undergoing evaluation for gestational dating purposes. Even in cases of patient obesity or an empty bladder, high resolution was possible and permitted cervical measurement in all but one case. The external cervical width at the vaginal fornices was found to increase with advancing gestation (R = 0.512, P < 0.005). The cervical length from internal os to external os was found not to change with advancing gestation (R = 0.11, P = 0.30). Using these normative data, investigation is recommended to determine whether measuring cervical width and length is useful in predicting preterm labor and delivery.

Anthropometry↗