Preeclampsia/eclampsia: hemodynamic and neurologic correlations

Three patients with eclampsia and four with severe preeclampsia underwent pulmonary artery catheterization before either labor or significant volume infusion. There was no difference in systemic or pulmonary vascular resistance, cardiac index, left ventricular stroke work index, or any other hemodynamic parameters between the eclamptic and severely preeclamptic patients. Despite the small numbers, plasma colloid osmotic pressures were significantly lower in the eclamptic patients. Factors other than the intensity of peripheral vasospasm may primarily affect the occurrence of grand mal seizures in patients with preeclampsia.

Labor and delivery in the presence of mitral stenosis: central hemodynamic observations

During a 1-year period, eight patients with New York Heart Association Class III or IV mitral stenosis were studied throughout the peripartum period with a pulmonary artery catheter. All patients were delivered vaginally. Intrapartum management was based upon cautious diuresis for preload optimization and heart rate control with propranolol. A mean increase in pulmonary capillary wedge pressure of 10 mm Hg was observed in the immediate postpartum period. Only two patients demonstrated a significant increase in cardiac output during this same time period. Central venous pressure correlated poorly with pulmonary capillary wedge pressure in seven of eight patients. Neonatal outcome was uniformly excellent. With the management approach described, no patient exhibited deterioration of cardiopulmonary status during the peripartum period.

The role of ultrasound in the aggressive management of obstructed labor secondary to fetal malformations

Eleven cases of major congenital anomalies were diagnosed in conjunction with arrest of dilatation or descent. In three cases, the diagnosis of fetal death was made. In the remainder, despite extensive counseling, the mothers refused cesarean section for an anomalous fetus. Fetal decompression resulted in prompt vaginal delivery in 10 of 11 cases.

Placenta previa/accreta and prior cesarean section

To assess the relationship between increasing numbers of previous cesarean sections and the subsequent development of placenta previa and placenta accreta, the records of all patients presenting to labor and delivery with the diagnosis of placenta previa between 1977 and 1983 were examined. Of a total of 97,799 patients, 292 (0.3%) had a placenta previa. The risk of placenta previa was 0.26% with an unscarred uterus and increased almost linearly with the number of prior cesarean sections to 10% in patients with four or more. The effect of advancing age and parity on the incidence of placenta previa was much less dramatic. Patients presenting with a placenta previa and an unscarred uterus had a 5% risk of clinical placenta accreta. With a placenta previa and one previous cesarean section, the risk of placenta accreta was 24%; this risk continued to increase to 67% (two of three) with a placenta previa and four or more cesarean sections. Possible mechanisms and clinical implications are discussed.

Experience with the pulmonary artery catheter in obstetrics and gynecology

Although traditionally the exclusive domain of other medical specialties, pulmonary artery catheterization may be of tremendous benefit to a variety of obstetric and gynecologic patients. Our experience with such invasive hemodynamic monitoring in 72 patients in an obstetrics and gynecology service is presented. In 86% of cases, catheter placement and primary management were carried out by residents in obstetrics and gynecology. Although many of the indications for pulmonary artery catheterization encountered are common to other areas of medicine, certain conditions such as severe preeclampsia or rheumatic heart disease in pregnancy involve pathophysiologic conditions unique to our specialty. On the basis of our experience, recommended indications for pulmonary artery catheterization in obstetric and gynecologic patients are presented. Insertion techniques, complications, and clinical outcome are discussed.

The role of external version in the intrapartum management of the transverse lie presentation

External version under tocolysis was applied and studied prospectively as an alternative to routine cesarean delivery in the laboring patient with a transverse lie presentation. After sonographic confirmation and signing of informed consent, 12 patients with a transverse lie presentation and intact membranes agreed to participate in the current investigation. For these 12 patients, 10 (83%) presentations were successfully converted to a longitudinal lie (nine cephalic, one breech) and two (17%) remained transverse. Of the 10 patients with successful conversions, six (60%) delivered vaginally while four required cesarean delivery. In two (20%) patients external version was unsuccessful and both patients were delivered by cesarean. With the exception of one infant with congenital anomalies, neonatal outcome was excellent in the study population. Overall, the use of external version in the laboring patient with a transverse lie presentation was associated with a 50% reduction in the cesarean section rate. While these results are encouraging, further experience is still needed to more clearly define the maternal and fetal risks associated with this procedure.

Hemodynamic alterations associated with amniotic fluid embolism: a reappraisal

Experimental amniotic fluid embolism in animals produces profound pulmonary hypertension and acute cor pulmonale without evidence of left ventricular compromise. Authors reporting hemodynamic alterations associated with clinical amniotic fluid embolism have traditionally attempted to explain their findings within this experimental framework. A reanalysis of the five published cases of amniotic fluid embolism, which include hemodynamic data derived from pulmonary artery catheterization as well as a report of a sixth case suggests a hemodynamic interpretation different from the traditional one based on the animal model. Left ventricular failure is the only hemodynamic abnormality consistently observed in humans, and the published data are most readily explained on this basis alone. A theoretical model of hemodynamic changes accompanying amniotic fluid embolism that incorporates both experimental and clinical observations is presented. Therapeutic implications are discussed.

Transient ventricular dysfunction associated with cesarean section in a patient with hyperthyroidism

Pulmonary artery catheterization was performed prior to surgery in a severely hyperthyroid patient undergoing cesarean section. A transient but significant decline in left ventricular performance was observed in conjunction with the stress of operation. A parallel is suggested between this phenomenon and the documented exercise-induced reduction of left ventricular function in nonpregnant hyperthyroid patients.

Emergency hysterectomy for obstetric hemorrhage

From 1978 to 1982, 70 cases of emergency hysterectomy for obstetric hemorrhage were performed at Los Angeles County/University of Southern California Women's Hospital. Sixty hysterectomies followed cesarean section, and ten were performed for hemorrhage after vaginal delivery. The most common indication for hysterectomy was atony (43%) followed by placenta accreta (30%), uterine rupture (13%), extension of a low transverse incision (10%), and leiomyomata preventing uterine closure and hemostasis (4%). Hysterectomies performed for atony had a significant association with the following factors when compared to hysterectomies performed for other indications: 1) amnionitis, 2) cesarean section for labor arrest, 3) oxytocin augmentation of labor, 4) MgSO4 infusion, and 5) fetal weight. Fifty-seven percent of hysterectomies performed for placenta accreta were associated with a previous cesarean section. During the study period, 53% of all patients presenting at term with both a placenta previa and one or more previous cesarean sections, subsequently underwent hysterectomy for placenta accreta. Even with a broad inclusion of risk factors, only 74% of patients developing a hemorrhagic complication leading to hysterectomy can be identified before delivery.

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.

Previous cesarean birth. Trial of labor in women with macrosomic infants

Patients with previous cesarean births who delivered macrosomic infants (greater than or equal to 4,000 gm) during the study periods January 1 to December 31, 1980, and July 1, 1982, to June 30, 1983, were analyzed to determine the impact of fetal weight on a trial of labor (TOL). Of 140 women with macrosomic infants given a TOL, 94 (67%) delivered vaginally. The most common indication for cesarean delivery was cephalopelvic disproportion (CPD). The dehiscence rates were similar when patients who underwent a TOL were compared with those who did not. Factors associated with a successful TOL were a previous vaginal delivery after the original cesarean section, no oxytocin usage during the TOL and an indication for the previous cesarean section other than CPD. The risk associated with a TOL in a patient with a previous cesarean birth and a macrosomic infant appears to be no greater than that encountered in a similar group of patients without uterine scars.

Effect of indication for previous cesarean section on subsequent delivery outcome in patients undergoing a trial of labor

During the period January 1 through December 31, 1980, 308 patients who had undergone previous cesarean sections (C/Ss) underwent a trial of labor (TOL). Hospital records of these patients were examined retrospectively in an effort to correlate delivery outcome with the indication for the prior C/S. Patients with a previous C/S for breech had the highest incidence of subsequent vaginal delivery (81 of 94, or 86%), and patients with a previous C/S for cephalopelvic disproportion or failure to progress had the lowest (22 of 64, or 64%). However, the lower rate of vaginal delivery in the latter group was found only among the subpopulation who had never delivered vaginally. Fetal distress does not appear to be a significant recurring factor in patients given a TOL. Exclusion of patients from a TOL after a previous C/S for cephalopelvic disproportion/failure to progress does not appear to be justified.

Vaginal delivery after cesarean section in women with unknown types of uterine scar

Documentation of a prior cesarean and the type of uterine scar has been used as one criterion for permitting patients a trial of labor. In a highly mobile patient population such as ours, these medical facts are often difficult or impossible to obtain. As a result, we retrospectively examined the performance of patients with unknown types of cesarean scar and found no difference between them and a similar population with documented low cervical scars. Although obtaining an old record is useful, its absence probably should not interdict a trial of labor in a patient who desires to attempt vaginal delivery.

The relative significance of spinal and supraspinal actions in the antinociceptive effect of morphine in the dorsal horn: an evaluation of the microinjection technique

Large quantities of morphine injected directly into the brainstem of spinal anaesthetized cats inhibited the noxious heat-evoked excitation of dorsal horn neurones. The amounts required were similar to those that were required intravenously in cats with the spinal cord intact or transected. When the spinal cord was intact the amount of morphine microinjected into the brainstem required to inhibit the excitation of dorsal horn neurones was about ten fold less than it was in spinal animals. It is concluded that large, but not small doses of morphine microinjected into the brainstem can exert effects on the spinal cord after first entering the circulation. The effects of small doses are attributed to a local action in the brainstem which causes inhibition of spinal neurones either by activating descending inhibitory neuronal systems or by liberating endogenous substances which reach the spinal cord via the cerebro-spinal fluid. The concentrations of morphine achieved at various distances from the site of injection by the microinjection of microgram quantities and the time courses of the concentration changes were calculated from diffusion equations, assuming diffusion coefficients of 3 or 5 X 10(6) cm2 s-1. The curves obtained closely approximated those obtained experimentally. The concentrations achieved at distances up to 2 mm from the site of injection of 10 micrograms of morphine were calculated to exceed 10(-4)M and the time-courses of these concentration changes were compatible with the time course of inhibition of spinal neurones, or the production of analgesia after microinjection. Such concentrations are vastly in excess of those achieved in the brain after the systemic administration of morphine in analgesic doses. It is concluded that the local effects in the brainstem produced by the microinjection of microgram quantities of morphine have no relevance to the mechanism of analgesia produced by systemic administration.

Simultaneous bilateral tubal pregnancy. A case report

A woman was treated for a simultaneous bilateral tubal pregnancy that had an unusual presentation and unusual diagnostic problems. The diagnosis of ectopic pregnancy may be overlooked in a semiconscious patient if a proper history and examination are not carried out. During surgery for ectopic pregnancy it is important to look at both adnexae.

The antinociceptive action of etorphine in the dorsal horn is due to a direct spinal action and not to activation of descending inhibition

1--Etorphine, microinjected into the brainstem or administered intravenously, inhibited the firing of dorsal horn neurones to noxious heat in spinal or non-spinal anaesthetized cats and in decerebrate, non-anaesthetized cats with intact spinal cords. 2--Small doses of etorphine sometimes caused facilitation, especially when the cord was intact, but this was invariably followed by inhibition at higher doses. 3--The ED50 for inhibition (mean 3.9 micrograms/kg) after microinjection into nucleus raphe magnus, nucleus reticularis magnocellularis or the lateral tegmental field was similar at all sites in anaesthetized, non-spinal cats. 4--The ED50 for microinjection was not increased by spinal transection in anaesthetized cats (mean ED50, 2.6 micrograms/kg) and was similar to the ED50 in decerebrate, non-anaesthetized cats. 5--Intravenous administration was 2 to 3 times more effective than microinjection and the time course of inhibition was faster after intravenous administration than after microinjection. 6--It is concluded that etorphine inhibits dorsal horn neurones after microinjection or intravenous administration by a direct action on the spinal cord and not by activating a descending inhibition. After microinjection it rapidly enters the general circulation and subsequently distributes into the spinal cord. 7--It is also concluded that naloxone readily gains entry to the circulation from the brain because microinjection antagonized the effects of systemic etorphine on dorsal horn neurones in spinal cats.

Fetal heart rate response to scalp blood sampling

Fetal heart rate acceleration in response to various stimuli has long been considered to be a reliable sign of fetal well-being in both the intrapartum and antepartum periods. In an effort to define the correlation between fetal heart rate response and fetal blood pH, we analyzed 200 fetal heart rate tracings of fetuses who had undergone scalp blood sampling in early labor. Data in regard to fetal heart rate response to endoscope placement, scalp puncture, and resultant scalp pH were then analyzed. In no case did a fetus with a scalp blood pH less than 7.20 respond to scalp puncture with an acceleration (defined as an elevation above the baseline of 15 bpm for at least 15 seconds). Among fetuses with a scalp blood pH greater than 7.28, 142 of 144 responded to scalp puncture with an acceleration. Exception occurred in one fetus who was 32 to 33 weeks' gestation, and in one fetus who was moderately Rh isoimmunized. Fetuses with scalp pH in the range of 7.21 to 7.28 showed a variable response. The correlation noted between a reassuring fetal heart rate pattern and the absence of acidosis in conjunction with the inverse (73% of fetuses in whom no acceleration occurred were acidotic) is further verification of both the reliability and complementary nature of intrapartum fetal assessment by both biophysical and biochemical techniques.

Inhibition by substance P of some peripheral actions of acetylcholine in the cat

1 The effect of substance P on contractions of the nictitating membrane and pressor responses to acetylcholine (ACh) and dimethylphenyl-piperazinium (DMPP) which were mediated via nocotinic receptors was studied in cats anaesthetized with chloralose.2 Substance P (2-20 nmol) injected into the lingual artery giving estimated concentrations in arterial blood of 10(-6) to 10(-5) M, or intravenously giving estimated concentrations in blood of 10(-8) to 10(-7) M, reduced hexamethonium-sensitive but not atropine-sensitive responses.3 The pressor effects of ACh and DMPP injected intra-arterially in atropinized and non-atropinized cats respectively were consistently attenuated by substance P given intra-arterially or intravenously.4 The contractile effect of ACh in atropinized and of DMPP in non-atropinized cats was attenuated by substance P injected intra-arterially but only rarely when the polypeptide was injected intravenously.5 The depressor effects of substance P per se were variable in magnitude and duration as were the inhibitory effects upon nicotinic receptors. The depressor and inhibitory effects of substance P were unrelated.6 There was desensitization to all of these effects of substance P which probably contributed to the variation in the magnitude of the effects observed.7 Substance P had no effect on muscarinic actions of acetyl-beta-methylcholine on the nictitating membrane or blood pressure.8 The results are discussed in relation to the ubiquity of the modulatory actions of substance P on nicotinic receptors and in relation to the possible physiological significance of the action.

Development of clinical education sites in an area health education system

In 1974 the University of Kentucky was faced with two problems: 1) overburdening of local clinical facilities by students and 2) a large exodus of graduates from the state. The advent of the Area Health Education System offered the opportunity for the clinical education program to develop nontraditional clinical sites across the state. The development and use of these nontraditional sites in predominantly rural areas has become an integral part of the clinical education program. Local facilities are no longer inundated with students. The retention rate of graduates has improved in the seven years of the program from 36 percent to 1972 to 81 percent in 1979.

Incorporation of sulfate by the mouse thymus: its relation to secretion by medullary epithelial cells and to thymic lymphopoiesis

The thymus was examined in suckling mice during normal development and the involution and regeneration produced by injection of cortisol, in experiments designed to test the hypothesis that medullary epithelial cells secrete a ymphopoietic hormone responsible for controlling the magnitude of thymic lymphopoiesis. Cellular events were observed by light and electron microscopy. Lymphopoiesis was assessed, after injection of thymidine-(3)H, by counting the proportion of lymphocytes labeled in radioautographs of thymus. Cortical lymphopoiesis was distributed heterogeneously, being concentrated in the subcapsular region, but medullary lymphopoiesis was statistically homogeneous in distribution and similar in magnitude to the average level of cortical lymphopoiesis in suckling mice. Therefore counts of the labeling index in the medulla were used to estimate the size of the proliferating population of lymphocytes. Epithelial secretory activity was estimated by measuring the incorporation of (36)sulfate by the thymus, using gel filtration chromatography to isolate soluble macromolecular (35)sulfate-presumed on radioautographic evidence to represent the mucoid epithelial secretory product. Incorporated (35)sulfate accumulated rapidly for 4 hr, reached a peak at 12 hr, and had fallen to half that level by 24 hr after a single injection-as would be expected of a secretory product. During normal postnatal development the size of the proliferating population of lymphocytes and the magnitude of (35)sulfate incorporation increased in parallel. During acute involution induced by cortisol both parameters diminished greatly but rose to high levels during subsequent regeneration. Accordingly, lymphopoiesis and sulfate incorporation -as defined and measured in these experiments-correlated linearly over a wide range of variation, providing circumstantial evidence to support the hypothesis that medullary epithelial cells secrete a sulfated mucoid lymphopoietic hormone. This conclusion is discussed in terms of the roles of thymus and adrenal cortex in development of the lymphoid system and maturation of immunological competence.

Authoritarian attitudes and field dependence

This study sought to investigate further the dependency of authoritarian attitudes on field dependence by using a factor analytically derived measure of authoritarian attitudes, the F + D scale. 523 college Ss completed the F + D scale, and the high and low scorers were selected from the extreme ends of the male distribution of 264 Ss. 20 Ss in each extreme group were individually administered Jackson's Short Form of the Embedded Figures Test (EFT), a measure of field dependence. High F + D scorers required significantly more time to complete the EFT than did low F + D scorers. They also obtained significantly lower SCAT verbal and total scores than did low F + D scorers. These two sets of findings were interpreted as resulting from the contrasting cognitive styles of the two F + D groups. It was concluded that, as measured by the tests in this study, high F + D scorers were more field dependent and less intelligent than low F + D scorers.