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Biomedical subjects

R Huch

Publications and source records attributed to R Huch.

At least 145 records · Page 8Linked to original sources
PubMed1988

Postpartum blood flow velocity waveforms of the uterine arteries.

Uterine arterial velocity waveforms, recorded by pulsed Doppler technology, demonstrated a significant increase in vascular resistance after the first postpartum day until the fourth to sixth postpartum week. In patients with an isthmic postcesarean hemorrhage, partial placental retention and puerperal endometritis, the corresponding waveforms presented higher diastolic velocity components than was the case for normal puerperal courses, indicating that lower uterine vascular resistance might be associated with these complications.

Arteries↗
PubMed1987

Is pulse oximetry reliable in detecting hyperoxemia in the neonate?

We tested the hypothesis that hyperoxemia defined as arterial PO2 above 12 kPa can be detected by pulse oximetry using 95% oxygen saturation as the upper limit. Thirty artificially ventilated neonates with an indwelling arterial catheter were studied registrating transcutaneous oxygen saturation (Ohmeda Biox 3700 Pulse Oximeter) and transcutaneous PO2 continuously during a 4-hour period and measuring arterial oxygen saturation and PO2 intermittently. 46 episodes of arterial hyperoxemia were observed. Pulse oximetry had a sensitivity of 30%, detecting 14 of these 46 hyperoxemic episodes, and a specificity of 93%. The accuracy for separating hyperoxemia from normoxemia by pulse oximetry could be improved by shifting the cut-off point from 95% to 92%. With this optimal cut-off point sensitivity was 70% and specificity 62%. We conclude that pulse oximetry is not reliable for detection of hyperoxemia.

Blood Gas Monitoring, Transcutaneous↗
PubMed1987

A simple method for HbF analysis.

Spectrophotometric methods with CO-oxymeters for measurements of carboxyhemoglobin and/or oxygen saturation in human blood include a systematic error depending on the percentage of fetal hemoglobin. It is of clinical importance to estimate the fetal hemoglobin to correct HbCO and SO2 values respectively. The described method is simple and less time consuming than conventional methods like HPLC or electrophoresis. The two measurements of oxy- and carboxyhemoglobin in the same blood sample with different oxygen saturation are needed for the estimation of the HbF and can be performed, including the deoxygenation procedure, in about 40 minutes.

Adult↗
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↗