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Biomedical subjects

K Marsál

Publications and source records attributed to K Marsál.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of umbilical-artery velocimetry and cardiotocography for surveillance of small-for-gestational-age fetuses.

Intrauterine growth retardation is associated with an increased risk of fetal asphyxia as well as greater perinatal morbidity and mortality. Ultrasound fetometry enables detection of fetuses that are small for gestational age. Doppler velocimetry of the umbilical artery has good predictive ability for fetal distress, but it is not yet clear whether it could replace cardiotocography in antenatal surveillance of small-for-gestational-age fetuses. We have done a randomised comparison of the two methods. At four obstetric departments in Sweden, women with fetuses found to be small on ultrasound examination at 31 completed weeks of pregnancy or later were randomly assigned to antenatal surveillance with either doppler velocimetry (doppler; 214) or cardiotocography (CTG; 212). Pregnancies in the doppler group were managed according to a protocol based on blood-flow classes deriving from the semiquantitative evaluation of umbilical-artery velocity waveforms; unless the pregnancy was complicated by any other disorder, no antenatal cardiotocography was done. By comparison with the CTG group, the doppler group had fewer monitoring occasions (mean 4.1 [SD 3.1] vs 8.2 [6.2], p < 0.01), antenatal hospital admissions (68 [31.3%] vs 97 [45.8%], p < 0.01), inductions of labour (22 [10.3%] vs 46 [21.7%], p < 0.01), emergency caesarean sections for fetal distress (11 [5.1] vs 30 [14.2%], p < 0.01), and admissions to neonatal intensive care (76 [35.5%] vs 92 [43.4%], p = 0.10). The groups did not differ in gestational age at birth, birthweight, Apgar scores, or total number of caesarean deliveries. Umbilical-artery doppler velocimetry of small-for-gestational-age fetuses allows antenatal monitoring and obstetric interventions to be aimed more precisely than does cardiotocography.

Adolescent↗
PubMed1992

Randomised controlled trial of atenolol and pindolol in human pregnancy: effects on fetal haemodynamics.

OBJECTIVE: To compare the effects of uteroplacental circulation of two beta adrenoceptor blockers, atenolol (cardioselective) and pindolol (non-selective with intrinsic sympathomimetic activity). DESIGN: Controlled double blind double dummy study. SETTING: Departments of obstetrics and gynaecology in two Swedish university hospitals. SUBJECTS: 29 women with pregnancy induced hypertension in the third trimester, 13 randomised to atenolol and 16 to pindolol. MAIN OUTCOME MEASURES: Pulsatility index in fetal aorta, umbilical artery, and maternal arcuate artery. Volumetric blood flow in fetal aorta and umbilical vein. RESULTS: Mean arterial blood pressure decreased by 9.0 (95% confidence interval -13.0 to -5.0) mm Hg in the atenolol group and by 7.8 (-11.4 to -4.2) mm Hg in the pindolol group. During atenolol treatment the pulsatility index increased significantly from 1.82 (SD 0.20) to 2.07 (0.32) in the fetal thoracic descending aorta, from 1.44 (0.28) to 1.79 (0.27) in the abdominal aorta, and from 0.93 (0.17) to 1.05 (0.19) in the umbilical artery; the volumetric blood flow in the umbilical vein decreased from 106 (28.8) to 84 (22.6) ml/min/kg. No such changes were seen after treatment with pindolol. Birth weight was similar in the two groups but placental weight was significantly different (529 (122) g in atenolol group v 653 (136) g in pindolol group; p = 0.03). CONCLUSION: The hypotensive effect was similar with both drugs, but only the beta 1 blocker atenolol had significant effects on fetal haemodynamics, although within normal ranges. The implications of these findings can be only speculative, but negative fetal consequences of beta 1 adrenoceptor blockade cannot be excluded.

Atenolol↗
PubMed1992

Doppler velocimetry in cerebral vessels of small for gestational age infants.

Using the duplex Doppler system, blood velocity was measured serially at two sites of the anterior cerebral artery (ACA) and in the middle cerebral artery (MCA) during the first 3 days of life, in eight term, small for gestational age (SGA) infants (birthweight, 2179 +/- 230 g; mean +/- S.D.), and 13 term, appropriate for gestational age (AGA) infants (3376 +/- 441 g). All infants in both groups had normal Apgar scores and none manifested signs of respiratory distress. At 1 h post partum, the average MCA mean velocity in the SGA group (25.8 +/- 6.9 cm/s) was higher than that in the AGA group (19.6 +/- 5.7 cm/s), whereas the average values of the two ACA sites did not differ between the groups. A significantly increased value of the average mean velocity as compared to the value at 4 h post partum was reached earlier in the AGA group at all three vessel sites. The pulsatility index (as defined by Gosling) was lower at all vessel sites up to 72 h in the SGA group. Pulse pressure was significantly lower in the SGA group due to increased diastolic blood pressure. We suggest the results imply a state of cerebral vasodilation in the SGA infants and a poor ability to respond with an increased perfusion in the frontal regions supplied by the ACA. Changes in blood pressure and cerebral haemodynamics appear to exist in SGA infants in the absence of postnatal hypoxia which might explain the vulnerability of the growth-retarded infant to perinatal hypoxia.

Cerebral Arteries↗
PubMed1992

Antenatal diagnosis of intrauterine growth retardation by ultrasound.

Ultrasound estimation of fetal weight or ultrasound measurement of fetal abdomen alone enables identification of small-for-gestational-age fetuses. A prerequisite for this is a reliable dating of pregnancy, which is provided by a routine ultrasound screening in the first half of gestation. The fetal growth can be followed by serial fetometric measurements. As a standard, charts of intrauterine growth based on the ultrasonic measurement can be used. As a secondary diagnostic test for monitoring fetal health in pregnancies suspected of intrauterine growth retardation, Doppler ultrasound evaluation of fetal and uteroplacental hemodynamics provided useful for early detection of imminent fetal distress.

Female↗
PubMed1992

Intrauterine blood flow and postnatal neurological development in growth-retarded fetuses.

Intrauterine growth retardation (IUGR) is associated with abnormal neuro-developmental outcome. Aortic blood flow velocity waveforms have been shown to predict fetal distress in IUGR. Fetal aortic blood flow velocity waveforms were correlated to neuro-developmental performance at 7 years of age. Results suggest that abnormal fetal aortic blood flow velocity waveforms are associated with neuro-developmental impairment.

Aorta↗
PubMed1992

Short-term effect of magnesium sulfate infusion on renal function in preeclamptic women.

Magnesium (Mg) plays an important role in cardiovascular homeostasis. A deficiency may be of importance for the etiology of disorders that have vasospasm in common. Mg administration can reduce the peripheral vascular resistance and thus enhance organ perfusion. We observed that Mg sulfate infusion could have a beneficial effect upon the serum urate concentration in preeclamptic women, presumably by affecting the renal function. A study comprising 10 preeclamptic women with a high serum urate level (413-788 umol/l) was carried out. Glomerular filtration rate (GFR) was measured by determination of iohexol clearance. 30 mmol Addex-Magnesium was then given i.v. during 12 h and a second GFR determination performed the next day. We had expected the GFR to increase, but to our surprise, it decreased (in mean, from 74.2 ml/[min x 1.73 m2] to 71.3; p < 0.05; Wilcoxon signed-ranks test). There were no significant changes of blood pressure, proteinuria, blood thrombocytes, transaminases, serum creatinine or serum urate. We conclude that in preeclamptic women with renal dysfunction, Mg infusion therapy had no favourable effect upon either blood pressure nor GFR in the short-term perspective.

Adolescent↗
PubMed1992

Doppler blood flow changes and placental morphology in pregnancies with third trimester hemorrhage.

Combined real-time ultrasound and pulsed Doppler ultrasound examinations were performed in 67 patients with third trimester hemorrhage and other symptoms related to placental abruption, starting from the onset of symptoms to delivery. In 52 of the cases, placental morphology was investigated by light microscopy. Thirteen patients were ultimately given the diagnosis abruptio placentae. None of the morphological placental changes considered had any statistical relationship to placental abruption. Patients with placental centrocotyledon hemorrhages and infarction more often had abnormal umbilical artery flow velocity waveforms at the onset of symptoms, and more frequent abnormal arcuate artery flow velocity waveforms were found among those with placental infarction alone. Abnormal flow velocity waveforms in the umbilical and arcuate arteries were associated with placental abruption, both at the onset of symptoms and at the final examination before delivery. The results indicate an increased risk for placental abruption if the arcuate and/or umbilical artery flow velocity waveforms are abnormal in patients with third trimester hemorrhage.

Adolescent↗
PubMed1991

Waveform pattern recognition--a new semiquantitative method for analysis of fetal aortic and umbilical artery blood flow velocity recorded by Doppler ultrasound.

A semiquantitative computerized waveform pattern recognition system for analysis of the fetal descending aortic and umbilical artery Doppler flow velocity waveforms is presented. Based on empirically and manually selected clinical recordings from both vessels, 11 computerized and normalized standard curves for the aorta (type curves A to K), and 10 curves for the umbilical artery (type curves a to j) were constructed. The best match between the normalized waveform and the standard curve was based on either the degree of absent diastolic flow or, in cases with positive diastolic flow, on the calculation of the least square sum of the difference. The pattern recognition was tested against conventional waveform indices and our older semiquantitative Blood Flow Class (BFC) system in 472 clinical consecutive Doppler recordings. A good correlation was found. This new relatively simple computer-based method for waveform analysis is now prospectively applied in clinical studies.

Aorta, Thoracic↗
PubMed1991

Aortic diameter pulse waves and blood flow velocity in the small, for gestational age, fetus.

An ultrasound phase-locked, echo-tracking system was used for noninvasive measurements of pulsatile diameter changes in the descending aorta of 60 small, for gestational age (SGA), fetuses and of 60 fetuses appropriate for gestational age (AGA). Pulsed Doppler ultrasound was used for the recording of blood flow velocity in the aorta and in the umbilical artery of the SGA fetuses. In the SGA fetuses, a weight-related higher end-diastolic diameter and a lower relative pulse amplitude suggest that diastolic blood pressure was increased; a less steep rise of the initial ascending part of the pulse wave and a lower relative pulse amplitude suggest that the absolute stroke volume was decreased. Except for a positive correlation between relative pulse amplitude and mean velocity in the aorta, no correlation was found between diameter pulse waves and blood flow velocity. Aortic diameter pulse waves apparently yield no unequivocal information as to peripheral resistance, for which purpose blood flow velocity waveform analysis would seem, at least at present, to be the only available method.

Adult↗
PubMed1991

Blood velocity waveforms in the fetal aorta and umbilical artery as predictors of fetal outcome: a comparison.

In 139 pregnancies in which intrauterine growth retardation (IUGR) was suspected at routine ultrasound screening at 32 weeks of gestation, blood velocity in the fetal aorta and umbilical artery was recorded by a pulsed Doppler ultrasound every second week until delivery. The maximum blood flow velocity waveforms (FVWs) were analyzed for pulsatility index (PI) and blood flow class (BFC). In both vessels, an abnormal PI (greater than mean + 2 SD of the normal population) and abnormal BFC at the final antenatal examination were significantly associated with the occurrence of IUGR (birthweight less than or equal to mean - 2 SD) (p less than 0.001), operative delivery for fetal distress (p less than 0.001), and a low 1-minute Apgar score (less than or equal to 7). PI in the umbilical artery was a better predictor of fetal outcome than was the aortic PI, but the BFC was similarly predictive of fetal outcome in both vessels. The data indicate that a simple umbilical artery examination, which can be performed blindly with the Doppler ultrasound instrument without the help of a real-time scanner, is a reliable method for monitoring fetal status in pregnancies when IUGR is suspected.

Aorta, Thoracic↗
PubMed1991

Receiver operating characteristic curves of fetal, umbilical and uteroplacental blood velocity waveforms as predictors of fetal outcome.

The maximum blood flow velocity waveforms (FVW) were recorded by a pulsed Doppler ultrasound from the fetal aorta, umbilical artery and arcuate artery in 142 pregnancies suspected of intrauterine growth retardation (IUGR) according to ultrasound fetometry. The FVW were analysed for pulsatility index (PI) and Blood Flow Class (BFC). The aim of the study was to find the optimal parameter and cut-off level for predicting the outcome of pregnancy. Receiver operating characteristic curves were used for the analysis. The umbilical artery PI and BFC shows the strongest relationship to IUGR. The optimal cut-off point was found at 2 SD above the mean PI of the normal population. The aortic PI had a relatively low predictive value for IUGR, but the absence of aortic end-diastolic velocities (BFC 2 and 3) was the best parameter for predicting fetal distress. The arcuate artery PI had low predictive capacity for fetal outcome. The data indicate that the absence of diastolic velocities in the fetal aorta and the umbilical artery PI, with the cut-off level of 2 SD above the mean for the normal population, are the best and comparable blood flow parameters, which can be used for monitoring fetuses suspected of IUGR.

Blood Flow Velocity↗
PubMed1991

Diameters of the common carotid artery and aorta change in different directions during acute asphyxia in the fetal lamb.

The aim of this experimental ultrasound study on six fetal lambs was to evaluate how blood flow variables and vessel diameters of the descending aorta and the common carotid artery change during fetal asphyxia in the acute preparation. When acute asphyxia was induced by obstructing the maternal aortic blood flow all fetuses reacted with significant decrease in the aortic diameter and blood flow. In the common carotid artery vessel diameter and the blood flow increased significantly. The results support the theory of a brain sparing effect during fetal distress with significant changes of blood vessel diameters occurring in opposite directions in the aorta and the common carotid artery, thereby contributing to the centralisation of circulation.

Animals↗
PubMed1991

Umbilical artery Doppler velocimetry as a labor admission test.

Doppler ultrasound of the umbilical artery flow velocity waveform was studied prospectively as an admission test at the labor ward. Recordings were made in 575 women in various stages of labor before, during, and after uterine contractions, and evaluated in relation to intrapartum and fetal outcome variables. No association was found between abnormal flow velocity waveforms and cord complications, meconium-stained amniotic fluid, or abnormal fetal heart rate tracing, nor was there any association with operative delivery for fetal distress or low Apgar scores at 1 and 5 minutes. Small for gestational age fetuses had significantly more abnormal flow velocity waveforms than appropriate for gestational age fetuses, and so had those with umbilical artery acidemia compared with those with normal pH. The results indicate that Doppler recording of the umbilical artery flow velocity waveform as an admission test at the labor ward is not a good predictor of fetal distress in an unselected population.

Apgar Score↗
PubMed1990

Recording of blood flow velocity waveforms in the uteroplacental and umbilical circulation: reproducibility study and comparison of pulsed and continuous wave Doppler ultrasonography.

Reproducibility of the blood flow velocity waveforms (FVW) recorded from the umbilical artery and the arcuate arteries on the right and left side of the placenta was examined in 8 women with normal pregnancies and anterior placentas. The FVW were recorded using a 2-MHz pulsed Doppler ultrasound system in combination with a real-time linear-array scanner. The FVW were characterized by the pulsatility index (PI) and systolic/diastolic (S/D) ratio. For the PI, the mean coefficients of variation between six operator pairs in the umbilical artery and the left and right arcuate arteries were 8.4%, 26%, and 21.5%, respectively. These findings suggest that, in clinical practice, the umbilical artery FVW is reproducible, but the usefulness of arcuate artery FVW is limited by the wide variation of Doppler signals. Paired recordings of FVW were obtained from the umbilical, arcuate, and uterine arteries using pulsed wave and continuous wave Doppler ultrasonography in a randomized order in another 21 pregnant women with anterior placentas. There was no difference between the two Doppler modes for any of the measured waveform indices.

Arteries↗
PubMed1990

Cord blood gases and absence of end-diastolic blood velocities in the umbilical artery.

Umbilical artery and vein blood gases were compared in three groups of pregnant women delivered by elective caesarean section: group 1 (n = 21), normal controls; group 2 (n = 15), complicated pregnancies with normal umbilical artery blood flow velocity waveforms; and group 3 (n = 14), complicated pregnancies with absent end-diastolic blood velocity in the umbilical artery. Newborns in group 3 were found to be small for gestational age and to have significantly lower oxygen pressure and saturation. These fetuses were thus in a state of chronic hypoxia, which may predispose for development of intra-uterine distress. Doppler ultrasound examination can be useful in identifying this high risk group requiring intensified surveillance.

Bicarbonates↗
PubMed1990

Blood flow velocity and pulsatile diameter changes in the fetal descending aorta: a longitudinal study.

Blood flow velocity and pulsatile diameter changes in the fetal descending aorta were measured subsequently with pulsed Doppler ultrasonography and phase-locked echo-tracking technique, respectively. Blood flow velocity and pulse-wave curves with equal beat-to-beat intervals were synchronized by external fetal electrocardiogram. The systolic increase in blood flow velocity and in vessel diameter started simultaneously. The velocity peak preceded the diameter peak by a significant margin (p in the range 0.0001 to 0.0014). The time interval was more pronounced in the thoracic than in the abdominal part of the aorta and was slightly smaller near term. The effective diameter, calculated from the synchronized integrals of the blood flow velocity and the diameter curves, was significantly greater (p in the range 0.0001 to 0.0016) than the mean diameter. The difference tended to decrease with advancing gestational age and was more pronounced in the thoracic than in the abdominal aorta. The maximum error incurred by the use of nonsimultaneous measurements of blood flow velocity and vessel diameter when calculating volume blood flow was found to be less than 8% and thus probably of little practical importance.

Aorta, Thoracic↗