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Biomedical subjects

J C Morrison

Publications and source records attributed to J C Morrison.

At least 127 records · Page 7Linked to original sources
PubMed1995

Delivery of the nonvertex second twin: breech extraction versus external cephalic version.

OBJECTIVE: Our purpose was to compare the maternal and perinatal outcomes of twin gestations in which the nonvertex second twin was delivered by total breech extraction versus those delivered by external cephalic version. STUDY DESIGN: The intrapartum courses of 284 consecutive twin gestations were analyzed retrospectively. Once those with actual birth weight < 600 gm, unrecognized multifetal pregnancy, multiple congenital anomalies, cesarean delivery, and/or antepartum intrauterine fetal death were excluded, 23 mothers were delivered by total breech extraction and 21 underwent external cephalic version. RESULTS: The two groups were similar for mean (+/- SD) maternal age, gravidity, parity, gestational age at delivery, ultrasonographic estimate of birth weight for twin B, incidence of breech or transverse presentation for the second fetus, and actual birth weight of the first or second newborn. Suspected fetal distress that led to cesarean delivery occurred significantly more often in parturients who underwent attempted external version (4/21) than total breech extraction (0/23, p = 0.04). The incidence of eventual abdominal delivery was also significantly higher in patients who underwent attempted external cephalic version (10/21) rather than breech extraction (1/23, p = 0.001). For twin B the occurrence of low Apgar scores at 1 minute was significantly higher for infants after attempted external version (7/21) rather than breech extraction (1/23, p = 0.02), but the mean pH, number with Apgar scores < 7 at 5 minutes, and number of neonatal intensive care unit admissions were similar. No perinatal traumatic injury occurred in either group. CONCLUSION: On the basis of our experience, total breech extraction of the nonvertex second twin is preferable to external cephalic version because it appears to be associated with a significantly lower incidence of fetal distress and abdominal delivery with comparable neonatal outcome.

Adult↗
PubMed1995

Incidence of adverse cardiopulmonary effects with low-dose continuous terbutaline infusion.

OBJECTIVE: Our purpose was to determine the incidence of adverse cardiovascular effects of terbutaline sulfate when administered as a continuous subcutaneous infusion in women with arrested preterm labor. STUDY DESIGN: Over a 6-year period records from 8709 women prescribed this therapy for preterm labor that had previously been arrested with other intravenous tocolytics were reviewed. These women were assessed daily for cardiovascular complaints and tolerance of the medication, while either in the hospital or at the home (by telephone). The main outcomes studied were the occurrence of pulmonary edema, sustained cardiac arrhythmias, chest pain, or myocardial ischemia. Any maternal death regardless of cause was also reviewed. RESULTS: Of the 8709 subjects, 47 (0.54%) had one or more cardiopulmonary problems. Pulmonary edema developed in 28 patients (0.32%) while receiving continuous subcutaneous infusion of terbutaline, 5 at home and 23 in the hospital. Of the total, 17 women were being treated concurrently with large amounts of intravenous fluids and one to three other tocolytic agents. In the 11 remaining subjects, 4 were diagnosed with pregnancy-induced hypertension and/or multiple gestation. Nineteen patients experienced other adverse cardiovascular effects, including electrocardiogram changes, irregular heart rate, chest pain, or shortness of breath. CONCLUSIONS: Continuous terbutaline infusion for women with stabilized preterm labor is associated with much fewer adverse effects than previous literature regarding intravenous beta-adrenergic agonist therapy would suggest.

Adrenergic beta-Agonists↗
PubMed1995

Cervical ripening before medical induction of labor: a comparison of prostaglandin E2, estradiol, and oxytocin.

OBJECTIVE: Our purpose was to evaluate the effectiveness of oxytocin, prostaglandin E2 intracervical gel, and estradiol cream for ripening the very unfavorable cervix in patients requiring induction of labor at term. STUDY DESIGN: This prospective, randomized study was conducted in a population of women with a very unfavorable cervix (Bishop score < 4) requiring induction of labor. The patients received prostaglandin E2 gel (0.5 mg) intracervically (three doses 6 hours apart), 4 mg estradiol cream in the anterior fornix of the vagina (three doses 6 hours apart), or oxytocin at induction per protocol with an infusion pump. RESULTS: Ninety-nine women were recruited into this trial and evenly distributed among the three groups. The demographics of maternal age, race, parity, gestational age, initial Bishop score, and indication for induction were similar among the groups. The incidence of cesarean deliveries was similar in the three groups with approximately 59% of pregnancies delivered abdominally. For patients undergoing abdominal delivery the maximum cervical dilatation among the oxytocin, estradiol, and prostaglandin E2 groups was similar (3.90 +/- 3.02 cm, 3.63 +/- 2.79 cm, and 4.65 +/- 2.78 cm, respectively; p > 0.05). For all patients birth weight and Apgar scores at 1 and 5 minutes were comparable across all regimens (p > 0.05). In the subset of patients delivered vaginally patients receiving oxytocin for cervical ripening had the greatest improvement in Bishop score over baseline (p = 0.023) with an improvement of 7.08 +/- 2.42. CONCLUSION: No differences were detected among prostaglandin E2 gel, estrogen, and oxytocin in relation to cervical ripening in patients with an unfavorable cervix at term who require an induction of labor. Patients with a very unfavorable cervix at term who require delivery may benefit from serial ripening and inductions.

Adult↗
PubMed1995

Postpartum plasma exchange for atypical preeclampsia-eclampsia as HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome.

OBJECTIVE: Our purpose was to investigate the postpartum use of plasma exchange in patients considered to have atypical preeclampsia-eclampsia manifested as persistent HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome with or without evidence of other organ injury. STUDY DESIGN: During a 10-year period, 18 patients with HELLP syndrome were treated post partum with single or multiple plasma exchange with fresh-frozen plasma. Each patient was entered into the clinical trial either because of persistent evidence of atypical preeclampsia-eclampsia as HELLP syndrome > 72 hours after delivery (group 1) or with evidence of worsening HELLP syndrome at any time post partum in association with single- or multiple-organ injury (group 2). All procedures were performed with the IBM 2997 Cell Separator (IBM, Cobe Laboratories, Inc., Lakewood, Colo.) system. Maternal and perinatal outcomes were the main outcomes studied. RESULTS: In the absence of other disease conditions, the 9 patients in group 1 with persistent postpartum HELLP syndrome complicated only by severe clinical expressions of preeclampsia-eclampsia responded rapidly to one or two plasma exchange procedures with few complications and no maternal deaths. In contrast, in the 9 patients of group 2 with HELLP syndrome presentations complicated by other organ disease, the response to plasma exchange was variable and there were two deaths in this group. CONCLUSION: The current series of patients details the successful postpartum application of plasma exchange therapy for unremitting HELLP syndrome but reveals that a uniformly positive response to this therapy will not always be observed when there is additional single or multiple organ injury.

Adolescent↗
PubMed1995

Corticosteroid-induced arrest of HELLP syndrome progression in a marginally-viable pregnancy.

Corticosteroid therapy in preterm pregnancy complicated by severe pre-eclampsia as HELLP syndrome temporarily stabilizes the HELLP syndrome. One such patient complicated by extreme prematurity was treated with long-term high-dose corticosteroid therapy. The HELLP syndrome was temporarily stabilized and additional in utero fetal maturation was gained.

Adrenal Cortex Hormones↗
PubMed1995

Amniotic fluid volume of third-trimester diamniotic twin pregnancies.

OBJECTIVE: To define the normal range of amniotic fluid (AF) volume in third-trimester diamniotic twin gestations. METHODS: The AF volume of third-trimester diamniotic twin pregnancies was measured prospectively. An AF sample was drawn from both amniotic cavities of diamniotic twins either for diagnosis of subclinical chorioamnionitis with preterm labor and/or assessment of fetal lung maturity. Actual AF volume was determined in each amniotic cavity by a dye-dilution technique. RESULTS: The AF volume of 45 diamniotic twin pregnancies of 27-38 weeks' gestation was assessed. The AF volume per amniotic sac ranged from 155-5430 mL, with a mean (+/- standard deviation) of 877 +/- 860 mL. The AF volume in individual amniotic cavities and the total of both cavities in a diamniotic twin pregnancy were unchanged across the entire gestational age range (27-38 weeks). Neither fetal positioning within the uterus (lower twin versus upper twin) nor fetal weight were determining factors in the AF volume variability (P = .846 and P = .726, respectively). Based on absolute volumetric differences between the larger- and smaller-sac AF volume, we observed that as the AF volume of the larger sacs increased proportionately (P < .001), the AF volume of the smaller sacs remained relatively constant across the entire range of differences (P = .687) between 27-38 weeks. CONCLUSIONS: The average AF volume of 877 mL for each diamniotic twin is similar to the AF volume reported for third-trimester singletons. The AF volumes of diamniotic twin gestations relate neither to fetal position nor fetal weight, but instead develop independently without relation to the other amniotic cavity. Ninety percent of the AF volumes were 215-2500 mL.

Adolescent↗
PubMed1995

A randomized study to assess the efficacy of the amniotic fluid index as a fetal admission test.

OBJECTIVE: To determine whether there is a difference in the incidence of abdominal delivery for presumed fetal distress in women who have an intrapartum fluid index assessment and those who do not. METHODS: Over a 7-month period, parturients at 26-42 weeks' gestation and in early labor were randomized to the study (measured amniotic fluid index [AFI] on admission) or a control group (no sonographic assessment of amniotic fluid [AF] volume). The labor and delivery staff were aware of the AFI results of the study subjects. All patients had continuous electronic fetal monitoring, and none had an abnormal tracing on admission. Student t test or chi 2 was used for statistical analysis. P < .05 was considered significant. RESULTS: The study (N = 447) and control groups (N = 436) had similar maternal demographics as well as medical and obstetric complications. In the study group, the incidence of abdominal delivery for fetal distress (29 of 447) was significantly higher than among controls (14 of 436) (P = .02; relative risk 1.3, 95% confidence interval 1.1-1.7). Among parturients who had abdominal delivery for fetal distress, the decision-to-incision times (mean +/- standard deviation) were similar for parturients who had undergone assessment of AFI and those who had not (38.5 +/- 14.7 versus 32.5 +/- 14.7 minutes, respectively; P = .47). Mean birth weight, incidence of low birth weight, macrosomia, Apgar scores less than 7, and the number of admissions to the neonatal intensive care unit were not significantly different in the two groups. CONCLUSIONS: Patients having an intrapartum assessment of AFI as a fetal admission test are significantly more likely to have abdominal delivery for presumed fetal distress. However, the decision-to-incision time is not decreased and the perinatal outcome is not improved if the status of AF volume is known for patients in early labor.

Adult↗
PubMed1995

Acute tocolysis for suspected intrapartum fetal distress: maternal effects of terbutaline versus magnesium sulfate.

This study was undertaken to determine the maternal hemodynamic impact of terbutaline versus magnesium sulfate in the acute treatment of fetal distress prior to cesarean delivery. Forty-six women were prospectively randomized to receive 0.25 mg subcutaneous terbutaline or 4.0 g intravenous magnesium sulfate for in utero fetal resuscitation before cesarean delivery. There were no significant differences between groups in baseline mean arterial pressure, arterial pressure before and after induction of anesthesia, maternal heart rate, maternal oxygen saturation, estimated blood loss, and pre- and postoperative hematocrits. Magnesium sulfate-treated women received significantly more intraoperative intravenous fluids (2365 +/- 877 ml) than the terbutaline group (1624 +/- 564 ml; P < 0.001). However, mean urine output was significantly greater in the terbutaline group (88 +/- 42 ml/h) than in those treated with magnesium sulfate (61 +/- 26 ml/h; P < 0.03). Terbutaline, the superior agent for acute tocolysis, is not associated with an increase in maternal cardiovascular side effects during anesthesia.

Journal Article↗
PubMed1995

Sonographic assessment of birth weight among breech presentations.

The objective in this study was to determine whether there was a difference in the accuracy of sonographically determined birth weight estimate in fetuses presenting by the breech as compared to the vertex. Prospectively, 104 consecutive singleton fetuses presented by the breech presentation were identified who also had a sonographic estimate of birth weight within 72 h of delivery. The control group (n = 104) consisted of fetuses presenting by the vertex of women who had the following hospital number and who were of similar demographic characteristics; the birth weight estimate in the control group had to be within 100 g of that of the women with the breech fetus. The estimate of the birth weight was derived for both groups using seven published models. Prediction limits were calculated for an estimated vs. actual birth weight for parturients with breech presentation. Among the study group, the mean standardized absolute error was similar for the seven models (range 120 +/- 104 to 138 +/- 118 g/kg; p = 0.08). For six of the models, the mean standardized absolute error was significantly higher for fetuses in the breech presentation than for fetuses in vertex presentation (range 80 +/- 63 to 112 +/- 95 g/kg; p = 0.02 to < 0.0001). Prediction limit calculations indicate that 99% of the time the actual birth weight was between 1500 and 3999 g if the estimate of birth weight was 2400-2900 g. We conclude that, for fetuses in a breech presentation, the error with most models is significantly higher than for a singleton in the vertex position.

Abdomen↗
PubMed1995

Factors adversely affecting pregnancy outcome in the military.

This prospective study was undertaken to identify the significant risk factors associated with adverse pregnancy outcome in active-duty women. The deliveries of 300 consecutive pregnancies of active-duty women were assessed for maternal-fetal outcome. The risk factors evaluated were: marital status, parity, race, smoking and alcohol consumption while pregnant, maternal weight gain during pregnancy, maternal height, and educational level. Two-thirds of these women were junior enlisted personnel (rank E-4 or below) and worked under demanding job conditions over which they had little control. Increased age as a risk factor was associated with a significant increase in pregnancy-associated complications of cesarean birth, operative vaginal delivery, pregnancy-induced hypertension, preterm labor, maternal transport for fetal indications, intrauterine growth restriction, intrauterine fetal death, postpartum hemorrhage, placenta previa, and 5-minute Apgar scores < 7 (p = 0.039). In gravidas more than 65 inches in height with a weight gain more than 42 pounds, there was a significant increase in the complications of pregnancy (p = 0.022). Interactions of these risk factors yielded a significant age (p = 0.025), maternal height (p = 0.007), and height times weight gain interaction (p = 0.006) association with pregnancy complications. The risk factors of advancing maternal age and tall stature with a maternal weight gain of more than 42 pounds are associated with increased pregnancy complications of active-duty women.

Adult↗
PubMed1995

Intrapartum detection of a macrosomic fetus: clinical versus 8 sonographic models.

The purpose of this study was to determine whether clinical or sonographic models have 1) the highest accuracy in differentiating newborns with birth-weights > or = 4,000 g (macrosomia) versus < or = 3,999 g, and 2) among macrosomics which method of predicting birth-weight has the lowest percentage error. Prospectively, 602 consecutive parturients at term had a clinical estimate of birth-weight followed by sonographic measurement of fetal parts. The sonographic prediction of birth-weight was derived using 8 different models that utilize either 1 measurement or a combination of 2 to 4 parameters. The incidence of macrosomia was 11.1% (67 of 602). Analysis of ROC curves indicated that clinical predictions (w = 0.85) were significantly better than 4 of the 8 sonographic models. The mean standardized absolute error among macrosomic newborns is significantly lower when predictions are derived clinically (99 +/- 70 g/kg) than using 1 or 2 fetal parts. Sonographic assessment of birth-weight is not significantly more accurate in the detection of a macrosomic fetus than clinical predictions.

Adult↗
PubMed1995

Long-term non-invasive measurement of intraocular pressure in the rat eye.

To study the optic neuropathy associated with glaucoma, a system for accurate, reliable, and non-invasive monitoring of intraocular pressure (IOP) is required. Of particular interest is the effect of sampling frequency on IOP. To address this issue, ten adult male brown Norway rats (group 1) were acclimatized to a 12-h/12-h light/dark cycle. On 20 days over a 30-day period, rats were anesthetized with short-acting isoflurane (Forane) inhalant anesthesia and IOP for each eye was determined by averaging 15 valid individual readings obtained with a TonoPen 2 tonometer. The last 12 measurement sessions were performed on a daily basis. To determine the minimum tolerable interval between IOP measurement sessions, a second group of 10 animals (group 2) was acclimatized in the same manner as group 1, and IOP was measured every 4 days over a period of 80 days. Next, IOP was measured every 4 days over a period of 28 days, and finally, every 2 days over a period of 19 days. For all group 1 measurements, there was no statistically significant difference between the right and left eye IOP, 14.75 +/- 1.08 (SEM) and 14.90 +/- 1.09 mm Hg, respectively. However, daily measurements produced a steady decrease in IOP and gradual weight loss. For group 2, overall mean right and left eye IOPs were 15.24 +/- 1.28 (SEM) and 15.12 +/- 1.26, respectively and were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetics, Inhalation↗
PubMed1995

Accuracy of ultrasonography in evaluating amniotic fluid volume at less than 24 weeks' gestation.

The purpose of this investigation was to evaluate the accuracy of common sonographic techniques in assessing the amniotic fluid volume in pregnancies of less than 24 weeks' gestation. Patients at less than 24 weeks' gestation undergoing an amniocentesis for the placement of prostaglandin F2 alpha for termination (because of genetic or fetal anomalies, or both) were assessed for amniotic fluid volume. All fetuses were alive at the time of prostaglandin instillation. The amniotic fluid index and two-diameter pocket were used to determine the amniotic fluid volume. Prior to the prostaglandin instillation, the amniotic fluid volume was determined with para-aminohippurate using a diazo dye reaction with spectrophotometric analysis. The amniotic fluid volume was determined in 21 pregnancies between 15 and 24 weeks' gestation, yielding volumes ranging from 189 to 1840 ml. Using published standards for amniotic fluid volume in singleton pregnancies, oligohydramnios was present in three gestations, the volume was found to be normal in 15, and hydramnios complicated three pregnancies. The two-diameter pocket identified the amniotic fluid volumes correctly more often (18 of 21 [85.7%]) than the amniotic fluid index (10 of 21 [47.6%]) (P = 0.02). Normal amniotic fluid volume was identified in nine of 15 (60%) pregnancies by the amniotic fluid index and in 14 of 15 (93.3%) by the two-diameter pocket (P = not significant). Abnormal amniotic fluid volumes, oligohydramnios, and hydramnios were recognized more often by the two-diameter pocket (66.7%) than by the amniotic fluid index (1 of 6 [16.7%], P = not significant).

Abortion, Induced↗
PubMed1995

Intrapartum amniotic fluid index for predicting fetal acidemia. Results of receiver operating characteristic curve analysis.

OBJECTIVE: The objective of this study was to determine if the discriminatory intrapartum amniotic fluid index can reliably predict respiratory or metabolic acidosis in the newborn. STUDY DESIGN: Among 256 parturients at 37 weeks' gestation or more, the intrapartum amniotic fluid index was obtained in early labor, and umbilical arterial blood gas analysis was performed within 30 minutes of delivery. The mean (+/- SD) amniotic fluid indices in labor among newborns with no acidosis versus those with respiratory or metabolic acidosis were compared. A receiver operating characteristic curve was used to determine the best discriminatory intrapartum amniotic fluid index for respiratory and metabolic acidosis. RESULTS: Statistical analysis revealed that the mean intrapartum amniotic fluid index among 12 newborns with respiratory acidosis and 26 with metabolic acidosis was significantly lower than the mean index in 218 newborns without fetal acidemia. Despite the differences in the mean intrapartum amniotic fluid index in the three groups analyzed, the receiver operating characteristic curve indicated that an intrapartum amniotic fluid index alone is a poor test for predicting acidosis (respiratory or metabolic) in the neonate. CONCLUSION: The mean intrapartum amniotic fluid index in labor among newborns with respiratory or metabolic acidosis was significantly lower than that among nonacidotic newborns. The receiver operating characteristic curve indicated that the intrapartum amniotic fluid index cannot reliably distinguish nonacidotic infants from those with respiratory or metabolic acidosis.

Acidosis↗
PubMed1995

Infectious morbidity, operative blood loss, and length of the operative procedure after cesarean delivery by method of placental removal and site of uterine repair.

OBJECTIVE: This study was done to determine the impact of the method of placental removal and the site of uterine repair on postcesarean infectious morbidity rates in women receiving prophylactic antibiotics at cesarean delivery. STUDY DESIGN: This prospective study included 284 women who underwent cesarean delivery and who were randomly assigned to four groups based on the method of placental removal and the site of uterine repair: group 1, spontaneous placental removal and in situ uterine repair; group 2, spontaneous placental removal and exteriorized uterine repair; group 3, manual placental removal and in situ uterine repair; and group 4, manual placental removal with exteriorized uterine repair. Exclusion criteria were repeat cesarean deliveries without labor, active infection at the time of cesarean delivery, and patient refusal to participate. RESULTS: There was no significant difference among the groups in maternal age, race, parity, weight, the length of time from rupture of membranes (ROM) or the number of vaginal examinations from ROM to cesarean delivery, or preoperative hematocrit. Intraoperatively, the type of uterine incision, anesthesia administered, incidence of meconium-stained amniotic fluid, Apgar scores, and cord gases were similar between groups. The incidence of postcesarean endometritis was greater in group 4 (32 [45 percent] of 71, p = 0.003) compared with group 1 (17 [24 percent] of 71), group 2 (12 [30 percent] of 71); and group 3 (13 [18 percent] of 71). CONCLUSIONS: Manual placental removal and exteriorization of the uterus for repair of the surgical incision increases the infectious morbidity rate in women receiving prophylactic antibiotics at the time of cesarean delivery and increases the length of hospitalization.

Adult↗
PubMed1995

Emergent management of the patient in preterm labor.

Clinicians who treat PTL should realize that side effects rarely occur when tocolytic medications are properly used. The beneficial effects of tocolytic therapy vastly outweigh the risks associated with their use for the prolongation of gestation. Even a short extension of in utero life for a few days or weeks can significantly and positively affect neonatal survival and long-term outcome. Although the opponents of tocolytic therapy argue that no reduction in the PTB rate has occurred since their introduction, this argument does not consider that the large majority of PTBs are not eligible for tocolytic intervention. If patients with clear indications for tocolysis could be compared with those that were not treated (which most studies have not done), a substantial beneficial effect of tocolytic administration probably would be demonstrated. Based on available data, we consider MgSO4 and terbutaline to be first-line tocolytics. Magnesium is used more often because of its lower side-effect profile. Indomethacin and nifedipine should be reserved for difficult or refractory preterm labor, and should only be used for intervals of < or = 48 hours. We have attempted to present a method of decision analysis which should be followed for every patient who is admitted to the obstetric care unit for a presumptive diagnosis of premature labor. We realize that many of the issues included here are controversial, however, we hope that by developing a decision tree (see Fig. 1), a more complete management scheme will be created and lead to improved care of the patient undergoing premature labor.

Adrenergic beta-Agonists↗