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Biomedical subjects

N J Secher

Publications and source records attributed to N J Secher.

At least 109 records · Page 6Linked to original sources

The precision and accuracy of symphysis--fundus distance measurements during pregnancy.

We studied the precision and accuracy of SF measurements. Five trained obstetricians made three measurements of SF on each of 33 patients in the third trimester. The intraobserver variation varied from 0 cm to 8 cm, and comprised on average 1.5 to 2 cm (95th centiles 2.5 to 4 cm). The interobserver variation varied from 1 to 13 cm, and comprised on average 4 cm (95th centile 8 cm). The accuracy of SF measurements was estimated by comparison with ultrasound-guided measurements, which showed a very high precision. Two of the investigators differed significantly, by -1.56 cm and -1.97 cm, from the other 3.

Clinical Competence↗

Intrauterine growth in twin pregnancies: prediction of fetal growth retardation.

In 80 consecutive twin pregnancies, prenatal measurements of fetal biparietal diameter (BPD) and abdominal diameter were made and growth curves were calculated using routine ultrasound examinations. Nineteen percent of the infants were growth retarded. Growth retardation was found in both fetuses in four pregnancies and in one fetus in 22 other pregnancies. Linear regression analysis between birth weight and gestational age showed the standard deviation of birth weight to be proportional to gestational age. A more linear growth curve also was found when the mean fetal weight was calculated by use of the BPD and abdominal diameter measurements in the formula developed for singletons. The estimated weight compared with birth weight in 62 twins who had ultrasound examinations less than seven days before delivery showed a significant correlation (r = 0.89, P less than .001) with a coefficient of variation of 12.4%. The identification of intrauterine growth retardation (IUGR) in twin pregnancies by ultrasound had a sensitivity of 62%, a specificity of 98%, and a predictive value of positive and negative test of 93% and 83%, respectively.

Abdomen↗

Transcutaneous carbon dioxide measurements in the fetus during labor.

Transcutaneous partial pressure of carbon dioxide (transcutaneous PCO2) was measured in 55 fetuses during labor with a carbon dioxide electrode applied to the fetal scalp by a suction ring. The application procedure was simple and reliable, with reapplication required only 0.6 times per patient. The transcutaneous PCO2 recordings were of good quality and were correlated to carbon dioxide tensions in the umbilical artery (r = 0.60, p less than 0.001) and vein (r = 0.69, p less than 0.001) as well as to capillary PCO2 obtained by fetal scalp blood sampling (r = 0.96, p less than 0.001). If fetal distress occurred, transcutaneous PCO2 was significantly higher than in the uncompromised fetus. Although transcutaneous PCO2 monitoring might be useful for surveillance of the fetus during labor, it must still be reserved for scientific purposes for the time being.

Carbon Dioxide↗

A randomized trial of external cephalic version with tocolysis in late pregnancy.

The effect of external version under tocolysis with intravenous ritodrine during the 37th week of gestation was studied in a prospective randomized trial comprising 130 consecutive women with a fetus in breech presentation. Version was successful in 41% of the patients, all of whom had a cephalic vaginal delivery. Of the 56 women in the control group in whom version was not attempted; 8 (14%) converted to the vertex presentation spontaneously. Failure of version was significantly correlated with primiparity, location of the placenta on the anterior uterine wall, and maternal weight. The caesarean section rate was significantly lower in the version group (27%) than in the control group (46%) (P less than 0.05). The overall caesarean section rate for a fetus in breech presentation was 50%. There were no serious complications associated with version and the condition of the infants at birth was better in the version group than in the control group. We advise external version under tocolysis in late pregnancy to reduce the frequency of breech presentation in labour.

Breech Presentation↗

Submucous paracervical blockade compared with intramuscular meperidine as analgesia during labor: a double-blind study.

A double-blind study was carried out to compare the effect of submucous paracervical blockade using 12 mL 0.25% bupivacaine (55 women) to the effect of intramuscular injection of 75 mg meperidine (62 women) during the first stage of labor. All 117 were normal primiparous pregnancies. Seventy-eight percent of the women in the paracervical blockade group achieved full or acceptable pain relief against 31% in the meperidine group (P less than .01). Transient fetal bradycardia occurred in two cases in the paracervical blockade group and one in the meperidine group; all infants were born in good condition. Fetal distress, defined as an umbilical artery pH of 7.15 or less and/or a one-minute Apgar score of 7 or less was more frequent in the meperidine group (16 infants) than in the paracervical blockade group (six infants) (P less than .05). Submucous paracervical blockade is superior to intramuscular meperidine as pain relief during labor. Furthermore, meperidine results in more infants with asphyxia as compared with paracervical blockade.

Anesthesia, Obstetrical↗

Labor induction with prostaglandins.

Prostaglandins E2 and F2 alpha have been used for labor induction for more than 10 years. Many investigations have shown that these prostaglandins are effective, and within certain dosage schedules, safe oxytocics, even though the systemic administration is accompanied by side effects, mainly from the gastro-intestinal tract. Oral PGF2 appears to be the prostaglandin favored in recent years. It gives few side effects when administered in this manner. It is concluded from the present investigation and a study of the literature that oral PGE2 has certain advantages in comparison with other oxytocics for induction of labor at term, although it cannot entirely replace intravenous oxytocin. This, together with the relatively high cost of oral PGE2, will limit its use in the future for labor induction at term in normal cases.

Dinoprostone↗

Oral oxytocics for induction of labor. A randomized study of prostaglandin E2 tablets and demoxytocin resoriblets.

A randomized comparative study of 387 consecutive patients admitted for induction of labor was carried out using two orally administered oxytocics (prostaglandin E2 tablets (Prostin) or Demoxytocin resoriblets for buccal administration (Sandopart)), the results of which are reported here. One-hundred and twenty-three cases were suitable for primary amniotomy; of these 48 were given PGE2 tablets and 75 received demoxytocin resoriblets. In a further 264 cases, primary amniotomy was inadvisable and of these, 133 patients were allotted to the PGE2 treatment group and 131 to treatment with demoxytocin. A significantly higher success rate was observed (p less than 0.05) in the PGE2 group in cases where primary amniotomy had been carried out, as compared with the demoxytocin group. Parturition was successfully induced in 82.0% of the patients given PGE2 tablets, as against only 63.4% of those receiving demoxytocin following 2 days of stimulation without primary amniotomy. This difference is statistically significant at the 0.001 level, and presumably due to the highly significant difference (p less than 0.0001) between patients with a Bishop score of 5 or less, where induction was successful in 75.4% given PGE2 tablets, in contrast to a success rate of only 36.7% in patients receiving demoxytocin resoriblets. No difference was observed in the success rate between the two treatment groups when the Bishop score was 6 or more. No difference was recorded in the incidence of fetal distress, instrumental delivery or low Apgar score between the two treatment groups. However, a higher incidence of vomiting and diarrhea were observed in patients treated with PGE2 tablets (11%) as compared with those receiving demoxytocin (1.5%). There was no difference with regard to the induction-delivery time, nor to the different stages of labor between otherwise comparable treatment groups when the induction was successful. It is concluded in respect of induction of labor using orally administered oxytocics that PGE2 (tablets) are preferable to demoxytocin (resoriblets) as it is the more effective of the two.

Administration, Oral↗

Use of oral oxytocics for stimulation of labor in cases of premature rupture of the membranes at term. A randomized comparative study of prostaglandin E2 tablets and demoxytocin resoriblets.

The efficacy of oral PGE2 tablets and buccal demoxytocin (resoriblets) for the induction of labor in cases of premature rupture of the membranes (PROM) after the 37th week of gestation has been evaluated in a prospective, randomized investigation of 193 women. PGE2 tablets (Prostin) were given to 109 parturients and demoxytocin resoriblets (Sandopart) to 84. The former were given in increasing doses from an initial 0.5 mg to a maximum of 1.5 mg every hour. The demoxytocin was administered at a constant dosage of 50 I.U. every 30 min. The treatment was unsuccessful in 10 of the women treated with PGE2 tablets and in 19 women receiving demoxytocin resoriblets. In addition, the treatment had to be discontinued in 5 women in the PGE2 group due to gastrointestinal side effects. This gives a total success rate of 86.3% for treatment with PGE2 against 77.4% in respect of demoxytocin. This difference is not significant. No difference was observed between the two treatment groups as regards: the stimulation-delivery interval, duration of the various stages of labor, efficacy in primiparae and multiparae, efficacy in patients with a high/low Bishop score. A significantly higher frequency of gastro-intestinal side effects was seen in those treated with PGE2 (21.7%) as compared with demoxytocin (3.6%). The frequency of surgical intervention was 17% in the PGE2 group and 10% in the demoxytocin group. In 4 cases where the stimulation was successful, cesarean section was carried out for reasons unrelated to the drug therapy. Despite the fact that demoxytocin treatment results in fewer side effects than PGE2, the efficacy of the drug is not superior. Based on experience from previous investigations carried out in this department, where intravenous oxytocin was found to be clearly better than oral PGE2 for the induction of labor in cases of PROM, intravenous oxytocin will remain the method of choice due to the shorter period of treatment, which must take priority.

Administration, Oral↗

Neonatal jaundice after labour induced or stimulated by prostaglandin E2 or oxytocin.

In a prospective study of neonatal jaundice 739 infants, delivered vaginally, in the vertex presentation, and without major complications, were examined. Labour was induced or stimulated after random allocation of the mothers to one of three oxytocics (prostaglandin E2 orally, oxytocin intravenously, or demoxytocin buccally). Oxytocics were unnecessary after primary amniotomy in 91 women. A linear logistic statistical analysis showed that gestational age has a highly significant influence on the risk of jaundice (defined by maximum serum level of bilirubin greater than or equal to 205 mumol/l). An apparent influence of birthweight could be explained by the correlation between birthweight and gestational age. The influence of the three oxytocic agents was not significant, although they may have had a slight effect; however, any such effect could be a consequence of the infants of mothers given oxytocics being less mature than those whom mothers did not receive oxytocics. The duration of labour and the mother's age also had no effect on risk of jaundice. Thus, neonatal jaundice after induced and stimulated labour seems to be primarily associated with fetal maturity; the pharmacological side-effect, if any, of oxytocics is of no importance.

Birth Weight↗

Effect of prostaglandin E2 and F2alpha on the systemic and pulmonary circulation in pregnant anesthetized women.

The hemodynamic effect of prostaglandin F2 alpha (PGF2 alpha) and of prostaglandin E2 (PGE2) was studied in 12 healthy volunteers admitted for suction abortion at 10--12 weeks of gestation. They were anesthesized using natrium thiomebumal, pethidine and pancuronium bromide. PGF 2 alpha was given as an intravenous infusion of 100 micrograms/min, the dose being increased by 100 micrograms every 10 min to a maximum of 300 micrograms/min. PGE2 was administered with 5 micrograms/min, the dose being increased by 5 micrograms every 10 min to a maximum of 15 micrograms/min. During infusion of 300 micrograms PGF2 alpha a significant increase iun cardiac output and femoral arterial pressure of 40% and 25% respectively was measured together with an increase in the pulmonary arterial pressure (125%). Pulmonary vascular resistance was doubled, with a concomitant decrease in systemic resistance (11%). These changes were followed by a significant decrease in pH and PaO2, whereas an increase in PaCO2 was found. During infusion of PGE2 a significant, 36% increase in cardiac output was measured during infusion of 15 micrograms/min PGE2, together with a decrease in systemic blood pressure (31%) and resistance (33%). Heart rate rose significantly, while stroke volume showed only a small increase, and pulmonary pressure was unchanged. These changes were followed by an increase in PaO2. PGF2 alpha seems to have a positive inotropic effect on the heart, whereas its response to PGE2 seems to be a result of the peripheral vasodilatation. The slight decrease in systemic blood pressure without change in pulmonary hemodynamics makes PGE2 suitable for induction in patients with cardiopulmonary diseases.

Abortion, Induced↗

Prelabor evaluation of inducibility.

Data were collected prospectively on 381 patients admitted for stimulation of labor because of premature rupture of the membranes and 808 patients for induction of labor. The induction was by primary amniotomy in 337 cases, and the remaining 471 cases, because of relatively unfavorable cervical conditions, were treated without primary amniotomy. Induction of labor failed on the first day in 181 of the cases with an unfavorable cervix. All patients were delivered vaginally of one living infant in cephalic presentation. The predictive value of the Bishop pelvic score and other factors regarding the duration of labor (induction-delivery time) and the inducibility of labor (latency period) were evaluated by multiple regression analyses. The influence of parity on duration of labor was found to be very constant and highly significant, whereas it seemed to have only little influence on inducibility. The only factor of significant importance to inducibility thus seems to be the prelabor cervical condition. Of the 5 components in the Bishop score, dilatation was found to be most important and should be weighted at least twice the value given it by Bishop. A new pelvic score for prelabor evaluation of inducibility is proposed on the basis of these results.

Adult↗

Induction of labor with and without primary amniotomy. A randomized study of prostaglandin E2 tablets and intravenous oxytocin.

A comparative study of labor induction has been performed on 471 consecutive patients. Primary amniotomy was performed in 227 cases, and 103 of these patients were stimulated, 57 patients with PGE2 tablets and 46 with oxytocin. In the remaining 124 cases labor was induced within 4 hours without medical stimulation. Primary amniotomy was omitted in 244 cases, as the head was not engaged and the cervix was unripe. After random allocation to the treatment groups 125 patients received PGE2 tablets (ProstinR), and 119 patients received oxytocin intravenously. After 2 days of stimulation without primary amniotomy, delivery was induced in 83 per cent of the patients receiving PGE2 and in 84 per cent of the patients receiving oxytocin. All patients on whom primary amniotomy had been performed were delivered on the first day. There was no difference in the success rate between PGE2 and oxytocin treatments in patients with the same Bishop score. The performance of amniotomy at the beginning of induction led to a significantly lower total dose as well as a lower maximal dose of PGE2 and oxytocin. There was no difference in the duration of active labor in patients receiving PGE2 or oxytocin. There were no differences in the incidence of fetal distress and low Apgar scores between the different groups. No serious side effects occurred. Vomiting and diarrhea in 14 patients (8 per cent) receiving PGE2 was in contrast to 3 patients with these symptoms (2 per cent) in the oxytocin group. Oral administration of PGE2 is a convenient, effective and safe alternative to oxytocin for the induction of labor; however, PGE2 was not found superior to oxytocin in cases with a low Bishop score.

Adult↗

Stimulation of labor in cases of premature rupture of the membranes at or near term. A consecutive randomized study of prostaglandin E2-tablets and intravenous oxytocin.

Prostaglandin E2-tablets were compared to intravenous oxytocin for the stimulation of labor in 201 patients at or near term, with premature spontaneous rupture of the membranes without labor activity for 6 hours after the escape of fluid. The patients were randomly allocated; 99 were treated with PGE2-tablets (0.5-1.5 mg/hr) and 102 with intravenous oxytocin (7.5-45 mIU/min). The treatment was ineffective in the PGE2 group in 3 cases; these were treated successfully with intravenous oxytocin. In the oxytocin group, 3 patients were delivered by cesarean section for reasons not associated with the drug. A significant difference was found in the stimulation-delivery time, in favor of intravenous oxytocin. Although PGE2 tablets are a safe and convenient alternative to intravenous oxytocin, the investigation showed that intravenous oxytocin is preferable in cases of premature rupture of the membranes with more than 6 hours without labor activity.

Adult↗

Transcutaneous fetal oxygen tension and fetal heart rate pattern preceding fetal death. Case report.

Simultaneous cardiotocography (CTG) and transcutaneous PO2 (tcPO2) measurements were made in a pregnancy complicated by membrane rupture and cord prolapse at 27 weeks gestation. A Caesarean section was not done because the fetus was judged to have little chance of survival and to be at very high risk of severe brain damage if it did. The fetus weighed 830 g and the CTG changes preceding fetal death were similar to those described by others. The tcPO2 was zero for periods of a few seconds to 20 minutes at 1 to 2 hours before fetal death, and the tcPO2 was constantly zero during the last 50 minutes of fetal life. Tracings showing the tcPO2/CTG changes preceding fetal death are reproduced.

Adult↗

Continuous measurement of transcutaneous fetal oxygen tension during labour.

Transcutaneous scalp oxygen tension (tcPO2) was measured during labour in 40 fetuses, using a modified Clark electrode (Radiometer, Copenhagen). In 24 of the fetuses the recordings were of good quality during the second stage of labour. After delivery the acid-base status and oxygenation of the umbilical cord blood was measured. A correlation was found between the tcPO2 and umbilical artery oxygen saturation (r = 0.56, p less than 0.01) and umbilical artery PO2 (r = 0.56, p less than 0.01). Furuthermore, a positive correlation was found between the area beneath the recorded tcPO2 curve during the last 10 minutes and the umbilical artery pH (r = 0.50, p less than 0.05). The data suggest that continuous transcutaneous PO2 measurement may be of value in monitoring high risk patients during labour.

Electrodes↗

Measurements of cardiac stroke volume in various body positions in pregnancy and during Caesarean section: a comparison between thermodilution and impedance cardiography.

A total of 220 simultaneous pairs of measurements of cardiac stroke volume were made in twelve women before and during Caesarean section in order to compare impedance cardiography with the thermodilution method. A significantly higher coefficient of correlation was found before (r = 0.77) than during anaesthesia (r = 0.55). Further, there was a significant difference in the slope of the regression lines: before anaesthesia the slope was 1.07 and during anaesthesia with thiopentone, nitrous oxide, oxygen and suxamethonium it was 0.45. Significant changes in the intercept on the Y-axis were found before (-13.9 ml) and during anaesthesia (33.4 ml). When the uterus was displaced upwards and to the left from the 15 degrees tilt position the stroke volume and the cardiac output were increased when measured by both methods to nearly the same values as in the left lateral position. It is concluded that the impedance method is reliable for measuring cardiac stroke volume in late pregnancy under physiological conditions in the conscious patient, but that it cannot replace the thermodilution method in pharmacological studies.

Adult↗