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C Nickelsen

Publications and source records attributed to C Nickelsen.

36 records · Page 2Linked to original sources
PubMed1988

Computer assessment of the intrapartum cardiotocogram. II. The value of compared with visual assessment.

The chief aim of our work has been to create a computer Cardiotocographic Assessment System (CAS) and thus eliminate the intra- and inter-observer variability of the visual assessment of the cardiotocogram (CTG), and to improve the assessment of the CTGs to the standard of the most experienced obstetricians. The purpose of this paper is to present the accuracy of the prediction of fetal outcome obtained by the CAS and to compare it with 4 experienced obstetricians' accuracy. Fifty CTGs from the last 30 min. of labor were assessed as normal or pathological by the computer and by the obstetricians. The condition of the newborn was evaluated from the one-minute Apgar score, the umbilical artery pH and standard base excess, and the need for resuscitation. The accuracy of the CAS was significantly better than the accuracy of the obstetrician obtaining the best result. We conclude that the development of a computer-aided cardiotocographic assessment system is worthwhile.

Cardiotocography↗
PubMed1987

Acid-base evaluation of umbilical cord blood: relation to delivery mode and Apgar scores.

Acid-base status of umbilical artery and vein blood was measured immediately after delivery in 300 cases. A slight acidosis of mixed respiratory/metabolic type was found in newborns delivered following a second stage of 10-30 min duration. After a second stage of more than 30 min the metabolic contribution to the acidosis was predominating. With Apgar scores lower than 10 the pH was found to decrease and carbon dioxide tension to increase. Induction or augmentation of labor by oxytocin did not influence the acid-base status of umbilical cord blood. Delivery by vacuum extraction or low forceps resulted in lower pH and higher carbon dioxide tension in umbilical cord blood, but the changes were associated with the indication for instrumental delivery and not with mode of delivery. A large arterio-venous difference between the acid-base parameters was usually connected to vigorous newborns and a small difference to depressed infants. The carbon dioxide tension was usually increased in newborns with decreased pH, and a close correlation between these parameter was found. No case of acidosis (pH below 7.15) was found in this population at carbon dioxide tensions below 7.2 kPa; at higher Pco2 values only 25% of the newborns were acidotic. A Pco2 level of 7.7 kPa might be used at transcutaneous carbon dioxide monitoring during labor, although the sensitivity and specificity of this parameter will have to be decided in a prospective study.

Acid-Base Equilibrium↗
PubMed1987

Suction fixation of the tcPco2 electrode for fetal monitoring.

The fixation ring for suction fixation is made of a soft plastic material and is measuring 24.5 mm in diameter and 5.8 mm in height. The electrode is mounted into the center of the ring and kept in position by the elasticity of the material. A polyethylene catheter is glued into the ring connecting it to the vacuum pump (-20 kPa). The soft plastic material will be deformed by heating, and sterilization should be performed by gamma radiation or by fluid aldehydes. The electrode mounted in the suction ring is attached to the fetal head during vaginal examination without amnioscopy or the use of application tools. The suction fixation technique was evaluated in relation to the glue fixation technique by simultaneous measurements with two electrodes. In adult monitoring no differences in stabilization times and Pco2 values were found. In fetal monitoring a little difference (0.3 kPa) in mean values was found at a cervical dilatation of less than 8 cm, but no difference was found at a cervical dilatation of more than 8 cm. Calibration may be performed by either two-point or one-point calibration. One-point calibration is usually sufficient, but the sensitivity of the electrode should be checked regularly. Electrode sterilization by fluid aldehydes following the calibration does not influence electrode drift. A close correlation was found between the transcutaneous carbon dioxide tension just before delivery and the Pco2 of umbilical artery blood (r = 0.77, n = 64). Stabilization time was short (2.1 min.) and the electrode drift usually low (mean -0.14 kPa or 2.7%) independent of the duration of the monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Gas Monitoring, Transcutaneous↗
PubMed1987

Intra- and inter-observer variability in the assessment of intrapartum cardiotocograms.

The diagnostic value of a test depends on the variability of the test results and the accuracy of the test. The object of this investigation was to estimate the observer variability and the accuracy, when intrapartum CTGs were assessed by experienced obstetricians. Fifty CTGs were evaluated twice by four obstetricians. They were asked to identify the CTGs belonging to the compromised infants. They were told the criteria for a compromised infant and the incidence (one-third). Eleven (22%) of the CTGs were assessed in the same way of all the obstetricians in both evaluations. Between the obstetricians, the accuracy ranged from 50 to 66%. We conclude that the considerable observer variability found in this and other investigations must severely impair the clinical value of electronic fetal monitoring (EFM). The variability must be reduced before the "true" predictive value and the cost/benefit of EFM can be estimated.

Clinical Competence↗
PubMed1986

Continuous standard base excess monitoring during human labour.

Previously, the various components of fetal acid-base state during labour could only be estimated discontinuously by fetal blood sampling, or continuously by monitoring of a single component. This is the first report describing simultaneous continuous monitoring of the tissue pH, the transcutaneous carbon dioxide tension and on-line calculation of the tissue-standard base excess (t-SBE) of the human fetus during labour. In seven uncomplicated deliveries t-SBE was increasing or constant, thus indicating no fetal hypoxia. When a more reliable tissue pH electrode becomes available, t-SBE calculation may become a valuable tool in the management of high-risk labours.

Acidosis↗
PubMed1986

Fetal carbon dioxide tension during human labour.

Fetal carbon dioxide tension during labour is elevated in both metabolic and respiratory acidosis, but intermittent fetal blood analyses often fail to detect PCO2 changes during acute complications. Transcutaneous carbon dioxide monitoring is continuous and the possibility of diagnosing PCO2 changes is therefore better. The theoretical background for transcutaneous measurements and methods for clinical monitoring are described. Close correlations with capillary and arterial blood values have been found, and the atraumatic principle with a simple electrode application indicates a promising new method for acid-base assessment during human labour.

Acidosis↗
PubMed1986

Fetal transcutaneous carbon dioxide monitoring--the effect of different fixation methods.

Fetal transcutaneous carbon dioxide tension (tc-Pco2) was monitored simultaneously by two electrodes fixed with glue or suction during 10 deliveries. There were no differences in success rate, tc-Pco2 readings or stabilization time between the two fixation methods, but the glue fixation method was more time consuming, caused more discomfort to the patient and generally did not permit reapplication of the electrode.

Blood Gas Monitoring, Transcutaneous↗
PubMed1986

The effect of electrode compression during fetal transcutaneous carbon dioxide monitoring.

The influence of electrode compression by the cervix on transcutaneous CO2 measurements (tc-Pco2) was studied during 20 deliveries by simultaneous measurements with two electrodes, one positioned under the cervical edge and the other free of the cervix. At a cervical dilation of less than 8 cm, significantly higher values were measured by the electrode exposed to cervical compression, and tc-Pco2 fluctuations with uterine contractions were observed. This study confirms that the tonsure effect usually does not interfere with tc-Pco2 monitoring.

Blood Gas Monitoring, Transcutaneous↗
PubMed1986

Diagnostic and curative value of uterine curettage.

One hundred and eighty-one consecutive patients admitted for curettage because of irregular uterine bleeding were classified preoperatively as having postmenopausal bleeding, intermenstrual bleeding, menorrhagia, or metrorrhagia. They were followed up at 3 and 9 months after curettage with regard to diagnosis and cure. Fifty-seven per cent were cured; the lowest curative effect was found in patients suffering from menorrhagia. An etiological diagnosis was made in 90 patients; in the menorrhagia and postmenopausal groups, the lowest diagnostic value was found. Next to the histological report basal body temperature measurement was the best test to determine the etiology of the irregular uterine bleeding; hormone analyses and coagulation factors revealed the etiology in only a few cases. Intrauterine diseases were not diagnosed in patients below the age of 35 and it is suggested that curettage should not be used as first treatment in these patients.

Adult↗
PubMed1985

Continuous acid-base assessment of the human fetus during labour by tissue pH and transcutaneous carbon dioxide monitoring.

Simultaneous monitoring of fetal tissue pH (t-pH) and transcutaneous carbon dioxide (Tc-PCO2) was performed in 30 labours. Both t-pH and Tc-PCO2 at delivery were positively correlated with pH (r = 0.69) and PCO2 (r = 0.68) of the umbilical artery blood. A tissue/transcutaneous standard base excess (t-SBE) was derived from the t-pH and the Tc-PCO2 and calculated for 13 fetuses at delivery; there was a correlation with standard base excess of umbilical artery blood. An analysis of t-pH and Tc-PCO2 changes during the last hour of labour revealed that only infants who were born with decreased pH of the umbilical artery blood had decreasing t-SBE, while all others had a constant t-SBE.

Acid-Base Equilibrium↗