Frank C. Miller

Hemodynamic observations in severe pre-eclampsia with a flow-directed pulmonary artery catheter☆☆☆

Ten patients with severe pre-eclampsia were studied throughout labor and delivery and during the early puerperium with a flow-directed pulmonary artery catheter. Cardiac output was higher than previously described in normal patients. Pulmonary artery pressures were not significantly altered from the normal pregnant values. The usual increase in cardiac output occurring in the early puerperium was not observed in the patients with severe pre-eclampsia. Central venous pressure and pulmonary artery wedge pressure did not correlate in three of the nine patients studied. Left ventricular stroke work index was elevated in the patients with severe pre-eclampsia, suggesting a hyperdynamic state. The pulmonary artery catheter provided important new information in patients with severe pre-eclampsia and may be a useful clinical adjunct in patients with hemorrhage or oliguria and in patients needing a regional or general anesthetic.

Significance of meconium during labor.

Continuous fetal heart rate (FHR) monitoring and routine fetal scalp blood sampling was utilized in the evaluations of 366 fetuses during labor. One hundred and six patients had meconium in the amniotic fluid at some time during labor. A total of 26,110 uterine contractions were monitored during these 366 labors. The incidence of FHR patterns as a percentage of uterine contractions was calculated for the meconium and nonmeconium groups. Although there was a 3 1/2-fold increase in the incidence of low five-minute Apgar scores (less than 7) in the meconium group, signs of fetal distress were, with rare esception, not significantly different from those in the nonmeconium group. The presence of meconium in the amniotic fluid without signs of fetal asphyxia (late decelerations and acidosis) is not a sign of fetal distress and need not be an indication for active intervention. The combination of fetal asphyxia and meconium staining of the amniotic fluid, however, does enhance the potential for meconium aspiration and a poor neonatal outcome. Universal fetal heart rate monitoring and appropriate fetal acid-base evaluation is recommended for following patients with meconium in the amniotic fluid during labor.

The scalp stimulation test: A clinical alternative to fetal scalp blood sampling

Intrapartum fetal heart rate response to various scalp stimuli and its correlation with scalp pH was studied in a prospective manner. One hundred fetuses with heart rate tracings judged by the resident responsible for the patient to be suggestive of fetal asphyxia were entered into the study. Each fetus was subjected to firm digital pressure on the head followed by a gentle pinch of the scalp with an atraumatic clamp. Scalp blood sampling was then performed in the usual manner. Response to either of these stimuli by an acceleration of the fetal heart rate of 15 bpm lasting at least 15 seconds was uniformly associated with a scalp blood pH of greater than or equal to 7.19. Fifty-one fetuses so stimulated responded with an acceleration. Of the remaining fetuses, 19 had a scalp pH less than 7.19 and 30 were associated with a pH greater than 7.19. Clinical application of such a scalp stimulation test could, therefore, reduce the necessity for scalp blood sampling by approximately 50% in the presence of a fetal heart rate pattern suggesting acidosis. Such a provocative test may also be very useful with an abnormal fetal heart rate pattern suggestive of acidosis when the cervix is sufficiently dilated to permit scalp blood sampling.

Intrapartum assessment of the postdate fetus.

Continuous monitoring of fetal heart rate (FHR) and routine sampling of fetal scalp blood were utilized to evaluate the intrapartum performance of 82 fetuses of postdates pregnancies. A comparison was made between this group and 260 term pregnancies. The incidences of abnormal FHR patterns were not different between the postdates group and the control group. All of the postdates neonates with low 5 minute Apgar scores had passed meconium. The mean pH values of the postdates fetuses with meconium were significantly lower than those of the control group at each sampling interval (i.e., early labor, late labor, and umbilical artery). Those fetuses with thick meconium had significantly lower pH values in late labor than did those with thin meconium. Continuous electronic FHR monitoring is recommended for intrapartum surveillance of all postdates patients. Because of the increased incidence of fetal acidosis in the presence of thick meconium, sampling of fetal scalp blood is not unreasonable even with a normal FHR pattern.

Hyperventilation during labor.

Abstract The effect of maternal hyperventilation during labor was studied in 20 patients. Fetal scalp blood samples were analyzed for pH, pO 2 , pCO 2 , and base excess and compared with maternal free-flowing venous blood samples taken at the same time. Samples were obtained for baseline values and repeated during and following a period of active hyperventilation. Both maternal and fetal pH rose with hyperventilation. No fetal acidosis was observed even in the 5 cases of severe maternal hypocarbia. Maternal pCO 2 during labor was low even prior to intentional hyperventilation. Both maternal and fetal pCO 2 decreased, the maternal change being greater than the fetal. There was a slight but statistically significant decrease in the fetal pO 2 during hyperventilation. However, fetal oxygen levels remained within physiologic range throughout the study.

Sinusoidal fetal heart rate pattern associated with massive fetomaternal transfusion

formity. As no undulating movements of the tongue were seen in this case, this finding may be more indicative of cleft palate . The ability to determine inner and outer orbital distances reliably has recently been established. This parameter is useful not only in assessment of gestational age but also in determining the presence of hypotelor ism or hypertelorism. In our patient both the inner and outer orbital distance were increased for gestational age. Inner and outer canthal distances correlate well with inner and outer orbital distances in the absence of primary telecanthus or other soft tissue abnormalities. At birth, these canthal measurements were markedly increased, confirming the diagnosis of hypertelorism. The reason for the association of median cleft face syndrome with severe hydrocephalus due to aqueductal stenosis in this case in unclear. It is uncommon to find either hypertelorism or any other manifestation of the median cleft face syndrome associated with hydrocephalus. In this case, the severe hydrocephalus led us to a more detailed examination of the head and face. This experience emphasizes the dictum that whenever fetal hydrocephalus is diagnosed, a thorough examinaCommunications in brief 97

Heart rate and blood pressure in infants of pre-eclamptic mothers during the first hour of life.

Neonatal heart rate (HR) and arterial blood pressure (BP) were recorded continuously for the 1st hour of life in term newborn infants of normotensive (control group) and pre-eclamptic (study group) primiparous mothers. Infants were matched for gestational age, birth weight, method of delivery, and Apgar scores. In infants of pre-eclamptic mothers, the HR was significantly lower for the 1st 50 min of life, and their mean arterial blood pressure (MAP) was significantly higher during the 1st 20 min of life.

The evaluation of uterine activity: A comparative analysis

In this study a comparison is made between the most widely accepted method of expressing uterine activity, Montevideo units, and an automated on-line method expressed as uterine activity units. Although the actual numerical expression differs, the percentage of variation when the two values are compared is small at various phases of labor. The variation between the methods for uterine activity required to progress from 4 to 6 cm cervical dilatation and from 6 to 10 cm cervical dilatation is less than 5%. Both methods closely agree on the actual expression of uterine activity or uterine work.

Intrapartum fetal heart rate monitoring.

Post term pregnancy ≥42 weeks Suspected or known Fetal Growth Restriction Oligohydramnios Preterm labour Multiple pregnancy Breech presentation Abnormal Umbilical Artery (UA) doppler studies Meconium stained liquor Prolonged membrane rupture>18 hours Induced or augmented labour (with oxytocin) Epidural anaesthesia Evidence of infection and/or chorioamnionitis Maternal pyrexia >38C Heavily blood stained liquor Dystocia in 1st or 2nd stage of labour Abnormal FHR on auscultation Antepartum haemorrhage Pre-eclampsia/hypertension Insulin requiring diabetes Cholestasis Previous caesarean/uterine surgery Other maternal medical conditions

21. Evaluation of continuous fetal scalp pH during labor

ZusammenfassungDie kontinuierliche Aufzeichnung des Gewebe-pH-Wertes in der fetalen Kopfschwarte von 35 Patientinnen war in 79,4% technisch befriedigend. Der Korrelationskoeffizient (r) zwischen den kontinuierlich aufgezeichneten pH-Werten und den diskontinuierlich gemessenen Werten betrug insgesamt 0,75. Die Genauigkeit konnte bei den letzten 23 Patientinnen deutlich verbessert werden. Dieses ist einmal auf eine verbesserte Applikationstechnik des Operateurs, zum andern aber auch auf eine Änderung der Eichtechnik zurückzuführen. Der Korrelationskoeffizient dieser letzten 23 Patientinnen betrug 0,82 und 87% der Aufzeichnungen waren einwandfrei. Die durchschnittliche Registrierdauer betrug 2,39 Std und bei acht Feten wurde sowohl während der Geburt als auch postpartal gemessen. Obwohl die Ergebnisse dieser Versuchsserie zufriedenstellend waren, sollte die Methode weiterhin verbessert werden, um klinisch brauchbare Ergebnisse zu erhalten.SummaryContinuous monitoring of fetal scalp tissue pH was technically acceptable in 79.4% of 35 patients sequentially studied. Overall, the correlation coefficient (r) between the continuous pH readings and the intermittent pH values was 0.75. The accuracy improved greatly in the latter 23 patients. This was probably due to improved skills of the operators but also to a revision of the calibration technique. The correlation coefficient in these 23 patients was 0.82, and 87% of the records were accurate. The mean monitoring time was 2.39 h and eight infants were monitored throughout delivery and post natal. Although good results were obtained in this study, the method still demands technical skill in order to achieve clinically useful results.