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Biomedical subjects

A Huch

Publications and source records attributed to A Huch.

At least 145 records · Page 8Linked to original sources
PubMed1987

Skin reactive hyperemia recorded by a combined TcPO2 and laser Doppler sensor.

The tcPO2 electrode used at 37 degrees C monitors changes in cutaneous PO2 which at this temperature is mainly determined by the changes in blood flow. Laser Doppler velocimetry (LDV) measures the product of red cell number times their velocity. A comparison of these methods for the detection of skin reactive hyperemia has been made with a combined tcPO2 and laser Doppler sensor. The two parameters increased and decreased in parallel, the tcPO2 signal being delayed 10-20 s compared to the LDV signal. A significant correlation between the two signals was obtained (r = 0.73-0.93). In contrast, no significant correlation existed between the postocclusive peaks of the two signals recorded in 12 duplicate experiments. Comparing the peak amplitudes from the repeated recordings the tcPO2 signal showed a higher correlation coefficient (r = 0.91) and smaller intercept than the LDV signal (r = 0.74). Both methods can be used for non-invasive recordings of skin reactive hyperemia. The tcPO2 signal at 37 degrees C reflects changes in blood flow of the most superficial capillaries and reactive hyperemia can be monitored with high reproducibility. Only this signal can be used for calculation of skin blood flow. The LDV signal conveys information of blood flow changes mainly of deeper dermal vascular beds and reacts virtually instantaneously, but is less reproducible.

Blood Gas Monitoring, Transcutaneous↗
PubMed1987

[Is Indian version a successful method for decreasing the incidence of breech presentation?].

In a prospective randomized study involving 30 gravidae with breech presentation the efficacy of a maternal positioning exercise--raising of the pelvis, abduction of the thighs, relaxed abdominal breathing--for the purpose of spontaneous version of the fetus into vertex presentation was investigated. The results were compared with the rate of uninfluenced, spontaneous version in a further 31 gravidae with the same initial conditions. In view of the low numbers involved no statistical statements can be made; however, version in 21 out of 30 positioned subjects (70%) as opposed to 17 out of 31 spontaneous versions indicates some degree of success. Considering the risks of breech presentation during pregnancy and at birth on the one hand and the absence of risk and good acceptance of the positioning exercise on the other, the method can be recommended.

Adult↗
PubMed1987

[Effects of compression stockings on blood circulation in late pregnancy].

The effect of Class II compression stockings on maternal and fetal circulation was studied in left lateral position and standing in 21 patients with uterovascular syndrome in late pregnancy. The effect of different compression pressures was analyzed in further seven women also suffering from uterovascular syndrome in late pregnancy. It was shown that the use of compression stockings causes a measurable improvement in maternal and fetal circulation. The most favourable compression pressure for the maternal circulation parameters measured is 40 mm Hg.

Adaptation, Physiological↗
PubMed1987

[Obstetric-perinatologic data collection using a personal computer].

A concept covering the collecting and processing of obstetrical and perinatological data is described. Collecting of patient data is effected on the basis of a case history that has been drawn up in an EDP-adequate manner, which, however, can also be used in the conventional way. This procedure was chosen because for some time to come one cannot do without a document for handwritten notes to avoid duplication of work by "double tracking" and to eliminate transmission errors, and also to continue the present procedure of dealing with the patient. A commercial data base system was chosen for data collection and storage (dBase III by Ashton Tate). This relational data base has its own programming language with very powerful macro calls. Data input is effected by means of programme masks which the user can solicit via menu monitoring. The requisite hardware configuration consists of a computer with a main storage comprising 640 KB, system MS-DOS, and a hard disk of at least 20 MB. This data collection system operates in an obstetric hospital with annually more than 1,600 births and more than 1,200 entries during early pregnancy, to the satisfaction of the users. Besides compiling the usual statistical analyses and formulating research problems, the system automatically prepares the discharge reports. This rationalisation procedure compels the user to collect the data with care and also completely. On the whole, such a data collection system offers to hospitals of any size quick and easy access to data at any time, as well as optimised patient care, without additional effort and at a reasonable cost level.

Computers↗
PubMed1987

The effect of position and delay on stroke and minute distance in late pregnancy.

Stroke and minute distance were measured in 12 women in late pregnancy using Doppler ultrasound. In each patient two sets of measurements were made every 2 min for 20 min in the supine and left lateral positions, the sequence of positions being reversed on the second occasion. Within each of the four 20 min measurement periods there were no significant changes with time in stroke distance, heart rate, or minute distance, or in their coefficients of variation. From this evidence there is no justification for delaying the measurement of cardiac output until a 'steady state' is reached. The measurements were influenced both by the sequence and the position in which they were taken, the effects being additive. Overall, stroke distance was 5.1% greater in the left lateral than in the supine position, heart rate was 3.7% less and minute distance not significantly different. Independent of posture, stroke distance was 6.5% greater in the second period of measurement than in the first, heart rate was 3% less and minute distance 2.8% more. In late pregnancy the relative magnitude of cardiac output in the left lateral and supine positions has to be interpreted in the light of a stepwise increase of aortic blood flow with change of posture.

Adult↗
PubMed1987

Combined electronic fetal heart rate and fetal movement monitor--a preliminary report.

We have tested a new Doppler ultrasound apparatus which registers both fetal movements and fetal heart rate with a single transducer. To evaluate the reliability of the recognition of movements we also observed them simultaneously by real time ultrasound. In 20 patients with normal pregnancies between the 30th and 42nd week of gestation, taking the real time ultrasound as reference the positive predictive value was 0.93 and the sensitivity 0.94. Maternal hiccups or coughing were recorded as fetal movements. Neither gestational age, the amount of amniotic fluid or the position of the placenta influenced the recognition of movement; nor did fetal breathing, maternal breathing, speaking or laughing.

Female↗
PubMed1987

Blood flow velocity waveforms in human fetal intracranial arteries.

Blood flow velocity waveforms were recorded by pulsed Doppler examination from fetal intracranial arteries in 83 normal and 84 high-risk pregnancies. The normal cases showed a decreasing resistance index of the waveform toward the end of pregnancy, and a continuous forward flow that was always present in these arteries. A low resistance index predicted the birth of a small-for-dates newborn and/or the appearance of subsequent cardiotocographic abnormality, with 57% sensitivity and 94% specificity. Two hydrocephalic fetuses had abnormally high resistance index values. An abnormal fetal intracranial arterial velocity waveform can be seen as a sign of increased perinatal risk.

Blood Flow Velocity↗
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↗