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Biomedical subjects

R K Freeman

Publications and source records attributed to R K Freeman.

At least 91 records · Page 5Linked to original sources
PubMed1977

The significance of fetal heart rate reactivity with a positive oxytocin challenge test.

This study reviews 27 patients with positive OCTs who were subsequently allowed a trial of directly monitored labor. Of these, 19 patients (70%) developed FHR signs of fetal distress and 8 (30%) tolerated labor without late decelerations. These patients were evaluated for signs of fetal reactivity (acceleration of the FHR associated with fetal movement of contractions) during the OCT. Those with a reactive pattern during the OCT (15 patients) uniformly had a good fetal outcome (unless there was birth trauma or premature delivery), but 8 of these 15 patients showed fetal distress during monitored labor. If the positive OCT was associated with a nonreactive baseline FHR recording, a trial of labor uniformly resulted in FHR signs of fetal distress. It is therefore concluded that a patient with a nonreactive positive OCT is unlikely to tolerate subsequent labor without fetal distress.

Apgar Score↗
PubMed1976

Umbilical cord compression associated with amniotomy: laboratory observations.

Impairment of umbilical cord blood flow has been associated with periodic fetal heart rate changes termed "variable decelerations." These patterns may be observed after amniotomy. A chronic fetal rhesus monkey preparation has been used to investigate this clinical observation. Loss of amniotic fluid produced variable deceleration patterns, while restoration of amniotic fluid volume eliminated such changes. These experimental data demonstrate that amniotic fluid may be critical in protection of the cord and maintenance of normal umbilical cord blood flow.

Amniotic Fluid↗
PubMed1976

Estriol in pregnancy. IV. Normal concentrations, diurnal and/or episodic variations, and day-to-day changes of unconjugated and total estriol in late pregnancy plasma.

Normal values of unconjugated, total, and immunoreactive (measured without extraction) plasma estriol (E3) have been determined from radioimmunoassay data obtained in 217 uncomplicated third-trimester pregnancies. Small but significant diurnal variations in unconjugated and total plasma E3 have been observed in a study comprising 12 women who were hospitalized during late pregnancy for diabetes, toxemia, or placenta previa. The late morning decreases in unconjugated and the afternoon/evening decreases in total plasma E3 concentrations, averaging some 10 to 15 per cent, were overshadowed by considerable episodic fluctuations and may thus be clinically irrelevant. Day-to day changes of unconjugated and total plasma E3 concentrations in late pregnancy were similar and smaller than changes in urinary E3 measurements. The urinary E3/creatinine ratio, however, reducing inadequacies of 24 hour urine collections, varied less than unconjugated or total plasma E3. The data suggest that a decrease in unconjugated or total plasma E3 must exceed 40 to 45 per cent of the mean of the three preceeding determinations if it is to be considered a signal of fetal distress.

Activity Cycles↗
PubMed1976

Ritodrine HCL for the prevention of premature labor in twin pregnancies.

The perinatal mortality rate for twin gestation is in the range of 15%, and this is due predominantly to prematurity, although twins may also be born growth retarded. Ritodrine HCl, a beta sympathomimetic drug, has been shown to be effective, both in stopping premature labor and in preventing intrauterine growth retardation. With this in mind, a double-blind study using ritodrine HCl or placebo was begun in order to study its effect on premature labor, intrauterine growth retardation, and the perinatal mortality rate in twins. Thus far, 30 patients have delivered and have been followed to 6 weeks postpartum. Although the results on individual patients have remained blinded to the investigators, an initial evaluation of the ritodrine and placebo groups have revealed no difference with respect to gestational age, birth weight, or perinatal mortality. These preliminary results are not significant. However, it appears that ritodrine HCl is a safe oral agent for the antepartum gravida and her fetus. The study will be continued until approximately 100 patients have been enrolled.

Clinical Trials as Topic↗
PubMed1976

An evaluation of the significance of positive oxytocin challenge test.

Sixty-six of 390 patients studied at LAC/USC Women's Hospital between 1970 and 1973 had positive oxytocin challenge tests (OCT). Twenty-four percent of patients who were allowed direct monitored labor after a positive OCT showed no late deceleration and must be assumed to have had false-positive tests. Patients with positive OCT's had significantly increased incidences of perinatal mord late deceleration in labor when compared to patients with no positive OCT. The combination of a positive OCT and abnormal 24-hour urinary estriol excretion should be considered ominous.

Evaluation Studies as Topic↗
PubMed1975

The use of the oxytocin challenge test for antepartum clinical evaluation of uteroplacental respiratory function.

Over the last 4 years at Los Angeles County-University of Southern California Medical Center, Women's Hospital, clinical interest in antepartum fetal monitoring has increased considerably. As a result of approximately 1,500 tests in some 600 patients at high risk for placental insufficiency, we have reached several conclusions regarding the methods for antepartum fetal monitoring, criteria for interpretation of the results obtained, and the role of antepartum monitoring information in clinical management. In this paper, the results of "stress" monitoring (monitoring in the presence of uterine contractions) are presented. The term "oxytocin challenge test" is used in reference to "stressed" monitoring even though sometimes the contractions were spontaneous, or without oxytocin stimulation.

Cesarean Section↗
PubMed1975

Clinical experience with the oxytocin challenge test. II. An ominous atypical pattern.

Three cases have been observed over the past 3 years at Los Angeles County-USC Medical Center, Women's Hospital, which have shown an unusual fetal heart rate response to induced uterine contractions during the antepartum period. All 3 cases resulted in perinatal death apparently due to asphyxia. This report describes this unusual pattern and presents a discussion of its possible significance.

Adult↗
PubMed1975

Pregnancy and delivery in a woman with hemophilia B.

Hemophilia B (Factor IX deficiency, Christmas disease) may cause excessive bleeding in women. The obstetric and hematologic management of the pregnancy and delivery of a woman with a Factor IX level of 4% is presented and discussed.

Adult↗