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Biomedical subjects

R Huch

Publications and source records attributed to R Huch.

At least 163 records · Page 9Linked to original sources
PubMed1987

Peripherally detectable hormones--their relation to the increased uterine activity during standing in pregnant women.

Two-thirds of women in late pregnancy in standing position show marked cyclic accelerations in heart rate with concomitant increase in the uterine activity. As the regulating mechanism of these contractions has not been investigated the aim of the present study is to see if variations in the concentrations of peripheral venous circulating hormones could account for the accelerations of the heart rate and the uterine contractions. In four healthy pregnant women, 25 to 27 years old and in the 33rd-38th weeks of gestation, and in three healthy nonpregnant women, 29 to 30 years old, venous blood was intermittently collected from a cubital vein. The women were investigated in the left lateral as well as in the standing postures. The plasma concentrations of norepinephrine (NE), prostaglandin E2(PGE2), prostaglandin F2 alpha (PGF2 alpha), 6-k-prostaglandin F1 alpha (6-k-PGF1 alpha) thromboxane B2 (TxB2), aldosterone (A), and the plasma renin activity (PRA) were measured by specific and sensitive assays. Significant differences in level and dynamics of the various substances were found between pregnant and nonpregnant subjects. However, no correlation could be found between the fluctuations in the concentration of hormones and heart rate accelerations and the occurrence of uterine contractions, respectively. Local changes of these substances in the uterus may not be reflected in the peripheral venous blood. Therefore our measurements can neither prove nor disprove the hypothesis that these hormonal substances are involved in the regulatory mechanism of uterine contractions occurring in standing.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Transcutaneous oxygen monitors are reliable indicators of arterial oxygen tension (if used correctly).

The following recommendations should always be kept in mind: Each new transcutaneous equipment, or modification of equipment, must be adequately tested in vivo as well as in vitro. The users must have basic understanding of the principles and the major requirements for applying the tcPO2 technique. Calibration procedures must be carefully adhered to according to the manufacturer's instruction. The temperature of the electrode must be kept at 44 degrees C for premature infants and at 44 degrees or 45 degrees C for term infants if the clinical aim is to estimate arterial PO2 levels. Resetting of the electrode must then be done every two hours. For sick infants, this may be needed more frequently. Whenever there is cause to compare tcPO2 values with arterial ones, the latter must be obtained from an appropriate vessel. Great care must be taken when drawing and analyzing blood for PO2. The infant should not be crying. Significantly lower transcutaneous PO2 values than arterial PO2 values are due to either one or several of the errors indicated above or to an insufficient circulation under the electrode. In recent years, technical or clinical errors seem to have become more and more common. Thereby the technique has unjustly fallen into disrepute. Insufficient circulation under the electrode rarely occurs in the newborn infant and then only in those who are in overt shock.

Arteries↗
PubMed1986

Physiologic changes in pregnant women and their fetuses during jet air travel.

The physiologic reactions of pregnant women and their fetuses were studied during routine commercial flights. Ten healthy pregnant women (32 to 38 weeks of gestation) each undertook two flights. Maternal respiratory and heart rates, transcutaneous PO2 and PCO2, blood pressure, uterine activity, and fetal beat-to-beat heart rate variability were continuously monitored. During these flights, maternal heart rate and blood pressure increased, and PO2 decreased significantly while PCO2 remained unchanged. Respiratory rate showed a short increase during takeoff and landing but remained unchanged during the rest of the flight. Mean fetal heart rate was within normal limits during the whole flight. No bradycardia, prolonged tachycardia, or significant loss of heart rate variability was observed. This study indicates no hazards of commercial flights to the mother and the fetus in uncomplicated pregnancies.

Adult↗
PubMed1986

Effect of ritodrine and betamethasone on metabolism, respiration, and circulation.

In order to obtain information on pharmacologic side effects of the most commonly used betamimetic in obstetrics, ritodrine (R) was infused under standardized, controlled conditions in one male and four nonpregnant female volunteers in increasing doses from 0.9 to 7.2 micrograms/kg/min. In second series, the same was done after premedication with 12 mg betamethasone (B), intravenously, 30 minutes before the start of the R infusion. Ritodrine caused increases in cardiac and respiratory work that were associated with rises in energy requirements and impaired efficiency of breathing. Premedication with betamethasone potentiated all side effects with the exception of diffusion capacity.

Adult↗
PubMed1986

[Multicenter experiences with the intracervical administration of a new PGE2 gel in labor induction].

With the participation of four Swiss obstetric clinics, medically indicated inductions of birth (with living fetuses) were performed using a new, stable PGE2 gel, and documented according to a uniform protocol. The study was conducted to investigate the efficacy of 0.5 mg of PGE2, in 2.5 ml of a vehicle (Triacetin) not yet commercially available, for local cervical maturation (n = 41). Thirty-nine patients selected by prospective randomization, in whom birth was induced conventionally, served as a control group. The efficiency of the prostaglandin gel alone or respectively with additional administration of oxytocin was evaluated on the basis of the clear changes in the cervical findings observed within 12 or respectively 24 hours, the spontaneous births, or, in the case of cesarean deliveries, according to the pelvic score. Application of PGE2 alone led to impressive changes of the cervix score and, in 34 of the 41 cases, to regular contractions after an average time of 87 minutes. After 12 hours, prior to administration of oxytocin, 43% of the patients were already delivered. The combination of locally applied PGE2 gel with conventional oxytocin induction significantly increases the number of successful inductions. The percentage of unsuccessfully attempted inductions was reduced to 24% in the PGE2 gel group as compared to 44% in the control group.

Adolescent↗
PubMed1986

[Altitude exposure and staying at high altitude in pregnancy: effects on the mother and fetus].

In this paper we review some effects of acute and short-term exposure to altitude on maternal and fetal cardio-pulmonary function. These effects may be seen during commercial aircraft flight or mountain ascent in cablecars. In addition cardio-pulmonary changes during maternal exercise at altitude are discussed. Altitudes up to 2 500 m are well tolerated by mother and fetus in uncomplicated pregnancies. Slight maternal exercise does not provoke fetal heart rate changes. However, in pregnancies at risk, for example because of maternal smoking, precaution with exposure to altitude is justified. Particularly at risk may be stewardesses if they continue their strenuous work while pregnant. Living at high altitude (more than 2 500 m) the lower oxygen partial pressure has some well known negative effects on mother and fetus. The importance of the various mechanisms of acclimatisation and adaptation to hypoxaemia, and other factors influencing reproduction when living at high altitude are reviewed and discussed.

Acclimatization↗
PubMed1985

Influence of different prostaglandin applications on cervical rheology.

The softening effect of prostaglandin (PG) on cervical tissue prior to elective pregnancy termination is quantified by a new technique for the measurement of the elastance and relaxation of the cervix. The method is based on the pressure-volume relation of a compliant balloon placed in the cervical canal. These properties have been measured before and after different applications of prostaglandins in 58 patients electively terminating pregnancy. Application techniques used included high pressure jet application of PGE2 into the tissue of the portio uteri and the internal cervical os (120 micrograms), PGE2 and PGF2 alpha in Tylose gel (100 micrograms/0.5 ml); PGE2 as an intracervical tablet (150 micrograms) and PGE2 oral tablets placed into the posterior fornix of the vagina. Significant changes in cervical elastance were seen with the intracervically applied PGE2 in Tylose gel and the vaginally applied PGE2 tablets. The intracervically applied PGE2 gel also gave significant changes in cervical relaxation. No side effects other than mild cramping (2 patients) were seen with any of the applications in this study.

Abortion, Induced↗
PubMed1985

Premature contractions: are they caused by maternal standing?

In 33 out of 51 women studied in late gestation, the uterus was found to phasically compress the pelvic vessels and impede the venous blood flow during quiet standing. This caused a reduction of the cardiac stroke volume with resultant reduction of systemic blood pressure and a compensatory increased heart rate (range of increases 9-51 beats/min). In all cases uterine contractions (mostly subclinical) coincided with the phase of circulatory readjustment. Apparently, the contracting uterus, by changing its position and/or shape, relieves the venous obstruction and prevents decompensation. In the women displaying the uterine compression syndrome (UCS), uterine activity was markedly increased in standing compared to the left recumbent position. It was also investigated whether the UCS appeared more often and earlier in gestation in women with twins. In all 9 women with twin pregnancies (mean gestational age 28 5/7 weeks) the UCS associated with uterine contractions was apparent in the standing posture. Although at present no definite conclusions can be reached on the effect on the cervix of these contractions, quiet standing especially in twin pregnancies seems to provoke an increased uterine activity and should therefore be avoided.

Female↗
PubMed1985

Acute polyhydramnios complicating twin pregnancies.

Acute polyhydramnios in the second trimester is a typical complication in monozygous twin pregnancies. It is caused by a feto-fetal transfusion with anemia on the donor and polycythemia on the recipient twin. Contrary to the chronic hydramnios, there is no increase in malformations. In view of the high mortality rate (100%, according to most authors), the clinical management has to be reconsidered. During the years 1979 to 1983, 10 cases of acute polyhydramnios have been observed at the University Hospital in Zurich. This corresponds to an incidence of 9% in our twin population. All cases investigated were MZ twin pregnancies. With the exception of one patient, who underwent an abortion, all women were hospitalized, had bed rest and received recurrent removals of amniotic fluid and prophylactic tocolysis. The mean gestational age at the time of diagnosis was 23 4/7 weeks and at delivery 30 3/7 weeks. In two cases--one of which is presented in detail--with an unintentional puncture of a placental vessel, the recurrence of the hydramnios did not appear. Eight of 18 newborns survived. No malformations were found. Bed rest, tocolysis and recurrent amniocenteses seem to have a positive influence on the prolongation and outcome of the gestation in acute polyhydramnios.

Acute Disease↗
PubMed1985

[Accuracy of prenatal weight estimation using ultrasound in the case of birth weights less than 2000 grams].

In this study foetal weight as estimated by ultrasound was compared with the true birth weight of children having a birth weight of less than 2000 g (n = 105). The estimation of foetal weight was achieved using the authors' own diagram containing a curve for the biparietal and the thoracal diameter as well as for the foetal weight. The data for the weight curve were taken from two European populations (Bonn and Winterthur). There was a highly significant correlation between the ultrasonically estimated foetal weight and the true birth weight. Only in the group less than 1200 g a significant overestimation of foetal weight could be shown by using the weight curve of the population of Bonn, whereas the percentage deviation of both weight curves was comparable: when using the curve of Bonn 68% of readings had a deviation of less than 10%, whereas with the curve of Winterthur this was the case for 65% of the readings.

Embryonic and Fetal Development↗
PubMed1985

[Travel, sports and pregnancy].

This article is an attempt to review and to discuss critically the pros and cons of physical stress to which a pregnant woman is subjected by sports activities or by travel. The review is based on theoretical considerations as communicated in the article as well as on facts derived from casual observations or systematic studies. Besides the subjective feeling of well-being of the pregnant woman associated with sports activities, objective data favour the preservation or enhancement of fitness by training during pregnancy; other factors in favour of physical load, and the capacity to sustain such load, are the positive reports on the course of pregnancy, on birth, and on the influence exercised on the child by the sports activities of the pregnant mother, the often-quoted experiences collected during sports activities of competitive sportswomen who are pregnant, and the behaviour of pregnant animals. Risks consist in an increased danger of traumatization of mother and foetus resulting from certain types of sports requiring maintenance of balance or sudden changes of movement. Hyperthermia should be avoided, for example, excessively long-lasting sauna baths, or physical activity associated with high stress, such as marathon running, because thermoregulation is hampered during pregnancy in such a way that blood flow of the uterus is affected; besides, there is also the risk of teratogenic effects during the early stages of pregnancy. Excess physical stress leading to exhaustion of the pregnant woman (in animal experiments, in circulatory collapse) definitely exercises an adverse effect on the foetus.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1985

[Reaction of mother and fetus to physical stress at high altitude].

The objective of the study reported here was to investigate the reactions of mother and fetus to high-altitude hypoxia combined with physical exercise. The climb was passive, by means of scheduled journeys of the Grap Sogn Gion AG aerial cableway in Laax (Switzerland). The valley station is at an altitude of 1100 m, the mountain station at 2200 m. The mother exercised on a bicycle ergometer set to 25 watts for 3 minutes. The following were measured continuously and noninvasively: heart rate, respiratory rate, systolic and diastolic blood pressure, Po2 and Co2, uterus activity, and fetal heart rate. Twelve pregnant women with an average gestational age of 36 weeks (30th-39th week) took part in the study. Ten of the women were primiparae and two multiparae. During the trip up the mountain the barometric pressure dropped on average from 668 to 583 mmHg. This resulted in a maximum difference in Po2 between the valley and mountain stations of 18 mmHg. There were no systematic changes in Po2. Respiratory rate, heart rate, systolic and diastolic blood pressure remained unchanged during the trip up the mountain. The physical exercise at the mountain station led to an increase in respiratory rate from 12 to 20 min-1, while heart rate rose from 103 to 128 min-1, systolic blood pressure from 117 to 144 mmHg, and diastolic blood pressure from 70 to 90 mmHg. Six of the 12 women had regular contractions even during the trip up the mountain; these either remained unchanged or became less frequent in the course of the study. The mean fetal heart rate only changed slightly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗