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Biomedical subjects

C Donner

Publications and source records attributed to C Donner.

At least 19 recordsLinked to original sources

Sleep-related oxygen desaturation and daytime pulmonary haemodynamics in COPD patients.

It has been hypothesized that in chronic obstructive pulmonary disease (COPD), sleep-related hypoxaemia could lead to pulmonary hypertension (PH) and cor pulmonale, even in patients with only mild daytime hypoxaemia. We investigated the relationships between sleep variables and daytime pulmonary haemodynamics in 40 COPD patients with daytime arterial oxygen tension (PaO2) between 60-70 mmHg (8-9.3 kPa). Patients were considered as desaturators if they spent at least 30% of the sleep recording time with a transcutaneous O2 saturation (StcO2) less than 90%. Daytime arterial blood gases and pulmonary volumes could not discriminate desaturators "D" (n = 18) from non-desaturators "ND" (n = 22), but awake baseline StcO2, measured just prior to the onset of sleep, was lower in group D. Pulmonary artery mean pressure was significantly higher in group D (19.1 +/- 4.7 vs 16.8 +/- 1.9 mmHg, p less than 0.05) and all patients with PH (6 out of 40) belonged to group D. PH was observed in 6 of the 15 patients whose mean nocturnal StcO2 was less than 90% but in none of the 25 with a mean nocturnal StcO2 greater than 90%. The PH patients (n = 6), all desaturators, differed from the desaturators with no PH (n = 12), and from ND (n = 22) in having higher numbers of desaturation dips, longer durations of dips, and lower mean nocturnal arterial oxygen saturation (SaO2). We conclude that a causal relation between nocturnal desaturation and permanent PH is very likely. Further studies are needed to see whether oxygen therapy can prevent PH in these patients.

Blood Gas Monitoring, Transcutaneous

[Collection of fetal cord blood for karyotyping].

Cordocentesis was performed in 234 pregnancies (241 fetuses) for rapid karyotyping. The indication was in 86% of cases: abnormal ultrasound. The abnormality encountered were IUGR (85 fetuses) or morphologic abnormality of the pregnancy (130 fetuses). The other indications were maternal mosaicism, mosaicism in cultured amniotic cells, maternal age (late booking), fragile X syndrome, confirmation of abnormal karyotype obtained by amniocentesis. The fetal karyotype was established in 97.5% (6 failures), 18 karyotypes were abnormal in the group "abnormal ultrasound" (208 pregnancies, 8.6%; 215 fetuses, 8.3%). No maternal complication were observed, there were 6 fetal losses (2.5%).

Blood Specimen Collection

[Fetomaternal alloimmunization: role of cordocentesis].

Twenty one pregnancies complicated by alloimmunization were managed by the use of intravascular method on an outpatient basis. One group was made of 9 women having had at least one pregnancy with a severely affected fetus. The other group was composed of 12 women without a previously affected infant; in 5 cases a situation at risk, either a transfusion (4 cases) or a severe obstetrical hemorrhage (1 case), was evidenced. Knowledge of fetal blood type (2 cases) and hematocrit determination obtained by fetal blood sampling allowed treatment individualized to the specific needs of each patient. In total 59 cordocenteses were performed, including 19 intrauterine transfusions.

Blood Transfusion, Intrauterine

Oxygen measurements in endometrial and trophoblastic tissues during early pregnancy.

Placental and endometrial partial pressures of oxygen (PO2) were measured using a polarographic oxygen electrode during the first trimester of pregnancy. Between 8-10 weeks' gestation, placental PO2 levels were significantly lower (P less than .001) than endometrial levels. A significant (P less than .001) increase was observed for placental PO2 values measured at 12-13 weeks compared with those obtained at 8-10 weeks. We suggest that the increase of placental PO2 at the end of the first trimester is related to the establishment of continuous maternal blood flow in the intervillous space.

Endometrium

Multifetal pregnancy reduction: a Belgian experience.

Multifetal pregnancy reductions were performed during the first trimester of pregnancy in 26 patients. Transabdominal intrathoracic KC1 injections were performed in 23 cases, and transcervical aspirations in 3 cases. There were 4 miscarriages (15%) during the second trimester, 18 pregnancies ended in 33 births, 4 pregnancies are going on uneventfully and are beyond 32 weeks. There was no maternal morbidity related to the procedure; fetal morbidity has been mild.

Abortion, Induced

[Chorionic villi sampling: experience of the initial 500 samples].

We report our experience in first trimester antenatal diagnosis since 1984. Transcervical chorionic villus sampling (CVS) was performed in 498 pregnancies. The rate of abnormal pregnancies was 6%, the rate of chromosomal abnormalities (trisomy) in the indication group "maternal age" was 2%. The fetal loss rate (until 28 weeks) was 3.4% (17 cases), the procedure related loss plus the background loss was 2.4% (12 cases). For 92.8% of the patients a diagnosis was available after 1 CVS procedure. Ultimately an antenatal diagnosis was given to 99% of the women through a second CVS procedure or an amniocentesis or a cordocentesis. No maternal complication was observed.

Chorionic Villi Sampling

[Cordocentesis: experience in 391 initial samples].

The first diagnostic cordocentesis was performed in our unit in october 1985. Our 4-year experience is reported: 391 cordocentesis were performed in 360 patients during gestational weeks 14 to 42. The first attempt was successful in 90% of the procedures, 4 samplings failed, there were 4 fetal deaths within one week after diagnostic cordocentesis, one of them appears to be directly linked to the punction. A transient fetal bradycardia was observed in 9.9% of the cases, bleeding occurred in 19% of the cases. The indications for cordocentesis were: risk of fetal infection, karyotyping, hemopathy, search for paternity, assessment of fetal acid-base status, biochemical dosage. Our data confirm that cordocentesis is a safe and reliable diagnostic procedure providing guidelines for management of the pregnancy.

Chromosome Aberrations

[The value of prenatal chromosomal diagnosis in cases of fetal abnormalities: results obtained in 468 pathological pregnancies].

The authors report the results of 468 foetal karyotypes performed on amniotic fluid or foetal blood samples after ultrasound discovery of foetal anomalies. A total of 46 chromosomal aberrations (10%) were detected. The rates of anomalies vary considerably according to the alarm sign; very high (greater than 30%) in cases of multiple malformations, foetal hydrops or foetal death, low (less than or equal to 2%) in cases of poly- or oligohydramnios and foetal growth retardation without detectable malformation. In addition to these chromosomal diagnoses, further investigations enabled in 9 cases the diagnosis of genetic autosomal recessive disorders. Our results which are comparable with those reported in the literature, demonstrate the importance of prenatal diagnosis in cases of pathological pregnancies, with regard to obstetrical and perinatal management as well as to genetic counseling.

Chromosome Aberrations

Diagnostic cordocentesis: two years of experience.

The first diagnostic cordocentesis was performed in our unit in October 1985, our 2-year experience is reported. 144 samplings were performed in 137 patients (139 fetuses - 2 patients had twin pregnancies) during gestational weeks 14 to 42. The first attempt was successful in 80% of the procedures, 4 samplings failed. There were no fetal deaths within 3 days after diagnostic cordocentesis, a transient fetal bradycardia was observed in 12.2% of the cases, bleeding occurred in 13.6% of the cases. The indications for cordocentesis were: risk of fetal infection, karyotyping, hemophilia A, alloimmunisation, search for paternity, assessment of fetal acid-base status. Our data confirm that cordocentesis is a safe and reliable diagnostic procedure providing guidelines for management of the pregnancy.

Blood Specimen Collection

[Perinatal research on feto-maternal anti-Kell immunization].

Three cases of pregnancies complicated by feto-maternal anti-Kell iso-immunisation are presented, as well as a review of the literature. The evolution of new techniques for antenatal diagnosis has made it possible to have a new approach to this fetal pathology. Chorionic villus biopsy can be carried out in the first trimester of pregnancy when there has previously been a serious incidence of anti-Kell immunisation with a couple where the husband is heterozygous for the Kell antigen. In the second and third trimesters the surveillance of the patient is essentially dependent on ultrasound examination of the fetus and placenta, which makes it possible to detect hydropic changes, and also depends on blood sampling from the cord which makes it possible to assess by direct measurement the degree of fetal anaemia. Now pulsed Doppler must be added to these classical diagnostic techniques because it allows a gross estimation of fetal haematocrit levels.

Adult

Pathologic aspects of the umbilical cord after percutaneous umbilical blood sampling.

Percutaneous umbilical blood sampling (cordocentesis) appears to be a valuable new procedure for prenatal diagnosis. In order to evaluate whether focal injury of the umbilical vessels caused by the needle puncture is potentially harmful, we completely examined 50 umbilical cords collected between 1 hour and 20 weeks after cordocentesis. Macroscopic evidence of the needle entry was found in 37 cases, including one giant hematoma of the cord. Within 48 hours after the procedure, microscopic examination of transverse sections taken at the puncture site revealed distinct perforation of the vessel wall, associated in four cases with a small hematoma encircling the vessel. One week after cordocentesis, the vessel wall was partially reformed. There were no histologic differences between needle entry in a vein or in an artery. No thromboses of the umbilical vessels were found.

Blood Specimen Collection