Showing papers in "Obstetric Anesthesia Digest in 1982"
TL;DR: In vitro, prostaglandin production by the decidua, but not by the myometrium, was increased by the addition of oxytocin, and Oxytocin may stimulate uterine contractions by acting both directly on theMyometrium and indirectly on decidual prostaglandsin production.
Abstract: The concentration of oxytocin receptors increased in the myometrium of pregnant women and reached maximum levels in early labor. Concentrations of oxytocin receptors were also high in the decidua and reached a maximum at parturition. In vitro, prostaglandin production by the decidua, but not by the myometrium, was increased by the addition of oxytocin. Oxytocin may therefore stimulate uterine contractions by acting both directly on the myometrium and indirectly on decidual prostaglandin production. Oxytocin receptors are probably crucial for the onset of human labor, and the stimulus for the increase in uterine prostaglandins may be oxytocin originating from the fetus.
102 citations
66 citations
TL;DR: The data suggest that ketamine is a mild depressant of cerebral metabolic rate and has no other cerebral vascular effects, as well as small doses of ketamine injected directly into the cerebral circulation.
Abstract: The effects of kelamine on cerebral blood flow (CBF), cerebral metabolic rate (CMRo2) and intracranial pressure (ICP) were evaluated in ventilated or spontaneously breathing goats after peripheral administration of 5mg.kg-1 and central administration of 0.1 -2.0 mg.
47 citations
TL;DR: The data showed that pulse rate rose throughout pregnancy, and stroke volume and cardiac output rose shortly after conception, the increase over the prepregnancy level being statistically significant by 12 wk.
Abstract: Systemic blood pressure (measured with a zero-randomized sphygmomanometer), stroke volume and heart-rate (measured with a Minnesota Impedance Cardiograph), hematocrit, and their derivatives -- cardiac output and peripheral vascular resistance--have been assessed in three groups of subjects. First, a control group of 19 nonpregnant women were matched for age and weight with the subjects in the second group, which consisted of 19 patients who were seen at regular intervals on 12 to 15 occasions from 8 to 11 wk of pregnancy until 6 wk postpartum. The third group consisted of 8 patients seen from before conception, throughout pregnancy and to several months postpartum. Readings were made with the subject in each of six positions: supine, reclining, left and right lateral, left and right tilt. This paper concerns the readings obtained in the left lateral position. The data showed that pulse rate rose throughout pregnancy. Stroke volume and cardiac output rose shortly after conception, the increase over the prepregnancy level being statistically significant by 12 wk. Thereafter both values fell throughout the rest of pregnancy and were below prepregnancy levels by about term, taking some weeks to regain the prepregnancy value. There were irregular fluctuations in the level of systolic blood pressure; diastolic blood pressure fell during the first 16 wk and then rose to reach almost the prepregnancy value by term. Peripheral resistance fell during the first trimester, then increased markedly throughout the remainder of pregnancy.
39 citations
TL;DR: It is concluded that the alpha-adrenergic system is important in maintaining the redistribution of cardiac output that occurs in hypoxic fetal sheep.
Abstract: During hypoxemia there is a redistribution of cardiac output in the sheep fetus associated with increased vascular resistance in some fetal organs. The role of the alpha-adrenergic blocking drug to eight chronically instrumented hypoxemic sheep fetuses. We measured arterial blood pressure and heart rate, determined cardiac output and organ blood flows by means of radionuclide-labeled microspheres, and calculated vascular resistances in fetuses before and during hypoxia, and after injection of phenoxybenzamine 15 mg into the inferior vena cava of the hypoxemic fetus. Hypoxemia resulted in an increased vascular resistance in certain vascular beds. Alpha-adrenergic blockade during hypoxia abolished the increase in vascular resistance of the fetal body and caused an increase in the blood flow to some tissues which had a hypoxia-induced vasoconstriction. After alpha-adrenergic blockade during hypoxia, mean arterial blood pressure decreased from 48 +/- 6 to 42 +/- 6 mm Hg (p less than 0.05) and heart rate increased from 128 +/- 19 to 235 +/- 51 beats per minute (p less than 0.001). Cardiac output increased 23% and blood flow to the brain was maintained. We conclude that the alpha-adrenergic system is important in maintaining the redistribution of cardiac output that occurs in hypoxic fetal sheep.
39 citations
TL;DR: The effects of lorazepam on neonates indicate that its intravenous use at any stage in pregnancy and oral use before 37 weeks should be restricted to hospitals with facilities for neonatal intensive care.
Abstract: Fifty-three neonates born to 51 mothers treated with lorazepam were followed up for five days after delivery. Lorazepam had been given by mouth to 35 mothers and intravenously to 16. In general, maternal plasma concentrations of lorazepam were higher than the corresponding cord plasma concentrations. Cord plasma concentrations exceeding 45 micrograms/l were associated with three-quarters of the infants requiring ventilation at birth. Neonates conjugate lorazepam slowly to the pharmacologically inactive glucuronide, which is then excreted in the urine, where it is detectable for over seven days. Though lorazepam was detectable in breast milk, the maximum amounts that an infant could absorb would be pharmacologically insignificant. Full-term neonates whose mothers had received oral lorazepam had no complications apart from slight delay in establishing feeding, which in seven out of 29 cases was associated with relatively large doses of lorazepam. Intravenous lorazepam for severe hypertension was associated with significantly low Apgar scores, need for ventilation, hypothermia, and poor suckling. Preterm babies whose mothers had been given lorazepam by either route had a high incidence of low Apgar scores, need for ventilation, hypothermia, and poor suckling. These babies had lower Apgar scores than those whose mothers had received diazepam, but the diazepam group were heavier and more mature. Lorazepam was an effective sedative and anxiolytic by either route, and there were no eclamptic fits among the lorazepam-treated patients. The effects of lorazepam on neonates indicate that its intravenous use at any stage in pregnancy and oral use before 37 weeks should be restricted to hospitals with facilities for neonatal intensive care.
36 citations
TL;DR: Fetal and maternal plasma levels of catecholamines were measured at birth in 40 women with normal term pregnancies who underwent elective cesarean section Twenty women were operated on under general anesthesia, and 20 under epidural anesthesia.
Abstract: Fetal and maternal plasma levels of catecholamines were measured at birth in 40 women with normal term pregnancies who underwent elective cesarean section Twenty women were operated on under general anesthesia, and 20 under epidural anesthesia For comparison, the same measurements were also made in 10 women who underwent vaginal delivery without signs of intrapartum fetal distress Maternal venous levels of catecholamines were elevated in all three groups as compared to values in the resting adult The highest levels were found in the vaginal delivery group (norepinephrine and epinephrine, 39 ± 21 and 11 ± 10 nmoles/L, respectively), and the lowest in the epidural cesarean section group Fetal outcomes were similar in all three groups, as judged by Apgar scores and by measurements of umbilical arterial blood gases In spite of that, neonates delivered vaginally showed a markedly higher sympathoadrenal activation (norepinephrine and epinephrine, 318 ± 241 and 51 ± 76 nmoles/L, respectively) than those born by elective cesarean section In the latter group, however, it was found that the type of maternal anesthesia influenced fetal sympathoadrenal activation, since neonatal levels of catecholamines were higher in the epidural section group (norepinephrine and epinephrine, 95 ± 64 and 40 ± 45 nmoles/L, respectively) than in the general anesthesia group (norepinephrine and epinephrine, 32 ± 27 and 10 ± 14 nmoles/L, respectively) These results may have a certain clinical relevance since fetal sympathoadrenal activation is thought to promote extrauterine adaptation
30 citations
TL;DR: Analgesia was most effective in group A, and at least in group C, both during labour and at delivery, although assessment by linear analogue score suggested that the differences between the three groups were slight.
Abstract: Five hundred and seventeen women in labour receiving extradural analgesia, using bupivacaine plain solution, were randomly allocated to one of three groups. Group A received 6-8ml of 0.5% solution, group B 10-14ml of 0.25% solution, and group C 6-8 ml of 0.25% solution. Spontaneous delivery occurred in 31.7% of patients in group A, 38.7% in group B and 53% in group C (P less than 0.001). The percentage of rotational forceps, ventouse and Caesarean section deliveries was similar in the three groups. Analgesia was most effective in group A, and at least in group C, both during labour and at delivery, although assessment by linear analogue score suggested that the differences between the three groups were slight. Motor block was most frequent and rapidly progressive in groups A, but was progressive in all groups, and after five or more top-up injections, was similar in the three groups. Difficulties with micturition following delivery were significantly more common in group A.
30 citations
TL;DR: Infants in newborn intensive and convalescent care units are exposed to large amounts of sensory stimulation of various sorts, but there is no diurnal rhythmicity in physical and social stimulation across days.
Abstract: Infants in newborn intensive and convalescent care units are exposed to large amounts of sensory stimulation of various sorts. Although infants in these units do not lack visual, auditory, and tactile stimulation, they receive relatively infrequent coordinated sensory experiences. Furthermore, there is no diurnal rhythmicity in physical and social stimulation across days.
29 citations
TL;DR: It is concluded that neither enflurane nor nitrous oxide analgesia adversely affects neonatal neurobehavioral status at 15 min, 2 h, or 24 h of age.
Abstract: The authors studied the neonatal neurobehavioral effects of nitrous oxide: oxygen and enflurane: oxygen inhalation analgesia for vaginal delivery. Parturients were assigned randomly to receive no inhalation agent (Group 1, n = 21); enflurane, 0.3 to 0.8 per cent, and oxygen (Group 2, n = 22); or nitrous oxide, 30 to 50 per cent, and oxygen (Group 3, n = 18). Infants were tested at 15 min, 2 h, and 24 h of age using the Neurologic and Adaptive Capacity Score (NACS); and at 2 and 24 h using the Early Neonatal Neurobehavioral Scale (ENNS). No significant differences in neurobehavioral status occurred. For all groups, scores tended to be lowest at two hours of age. We conclude that neither enflurane nor nitrous oxide analgesia adversely affects neonatal neurobehavioral status at 15 min, 2 h, or 24 h of age.
29 citations
TL;DR: In patients with deficiencies of the immune system, herpetic endometritis may represent the initial step toward dissemination and warrants particular attention.
Abstract: Two cases of herpetic endometritis are reported. In both patients, the disease developed from documented herpetic cervicitis via transcervical ascension. One patient recovered spontaneously. Generalization and death occurred in the other patient, a renal transplant recipient treated with immunosuppressive agents. The histologic features of herpetic endometritis are illustrated. Intranuclear inclusions and ground-glass nuclei were found in endometrial glandular and stromal cells. Focal necrosis was prominent. Herpetic virus particles were demonstrated by electron microscopy in both cases. Ascending herpetic endometritis is a rare complication of a common disease. In patients with deficiencies of the immune system, herpetic endometritis may represent the initial step toward dissemination and warrants particular attention.
TL;DR: In a case-control study of 2,030 malformed infants, six selected birth defects were evaluated in relation to maternal ingestion, during pregnancy, of caffeine from tea, coffee, and cola.
Abstract: In a case-control study of 2,030 malformed infants, six selected birth defects were evaluated in relation to maternal ingestion, during pregnancy, of caffeine from tea, coffee, and cola: 380 infants with inguinal hernia, 299 with cleft lip with or without cleft palate, 277 with cardiac defects, 194 with pyloric stenosis, 120 with isolated cleft palate, and 101 with neural tube fusion defects were compared with 712 other malformed infants who served as controls. None of the point estimates of relative risk was significantly greater than unity. For ingestion of any caffeine relative to no ingestion, the upper 95% confidence bounds were of the order of three or less; for consumption of the equivalent of four or more cups of coffee per day relative to less than two cups, the upper bounds were two or less. Potential confounding factors did not explain the findings. The results suggest that caffeine is not a major teratogen with regard to the six defects evaluated. (JAMA1982;247:1429-1432)
TL;DR: There was no evidence of teratogenesis, but a delay in fetal maturation was suggested by reduced fetal weight and by an increase in bipartite or absent skeletal ossification centres.
Abstract: Thirty-two inbred wistar rats (study group) were exposed to trichloroethylene 100 p.p m. in air for 4h daily fro M. Day 8 to day 21 of pregnancy. A control group (31 rats) was exposed to the same experimental conditions but without the addition of trichloroethylene. All the rats were sacrificed on the 21st day of pregnancy and the ovaries, uterus, liver, lungs, heart and the fetuses were examined There was no evidence of teratogenesis, but a delay in fetal maturation was suggested by reduced fetal weight (P
TL;DR: It is concluded that morphine given extradurally has a greater initial rate of vascular absorption than morphine given intrathecally and is similar to that observed after i.m. administration.
Abstract: Seventeen patients received morphine 0.2 mgkg-1 in a 10% dextrose solution i.m. (n = 5), extradurally (n = 6) and intrathecally (n = 6) for pain after operation. Morphine was measured in plasma by radioimmunoassay. Plasma immunoreactive morphine concentration was significantly less after intrathecal administration after i.m. and extradural administration (P less than 0.05) at 2, 10, 15 and 30 min. We conclude that morphine given extradurally has a greater initial rate of vascular absorption than morphine given intrathecally and is similar to that observed after i.m. administration.
TL;DR: The effect of maternal intravenous glucose infusion on the newborn's glucose, insulin, and neurobehavioral performance was studied prospectively in 56 normal mother-newborn pairs and there were no major differences in neurobehavior that distinguished hypoglycemic neonates.
Abstract: The effect of maternal intravenous glucose infusion on the newborn's glucose, insulin, and neurobehavioral performance was studied prospectively in 56 normal mother-newborn pairs. Maternal blood glucose levels at the time of delivery, umbilical venous blood glucose and insulin levels, and neonatal blood glucose levels were measured. Neurobehavioral assessment of the newborns was performed at 4 and 24 hours of life. The median value for total amount of glucose infused to the mother was 32.5 g, the median rate of glucose infusion was 8 g/h, and the median maternal blood glucose concentration at delivery was 110 mg/dl. Median umbilical venous blood glucose concentrations were 104 mg/dl and median insulin concentration was 15 microunits/ml. Six babies were hypoglycemic at 1 hour of age. Umbilical venous glucose and insulin levels correlated significantly (p less than 0.001) with the rate of glucose infusion to the mother and her blood glucose level. The incidence of neonatal hypoglycemia was significantly related (p less than 0.05) to a maternal blood glucose level greater than 120 mg/dl, to a glucose infusion rate of 20 g/hr or greater and to an umbilical venous insulin level of greater than 40 microunits/ml. There were no major differences in neurobehavior that distinguished hypoglycemic neonates. It is recommended that the normal parturient be given less than 20 g/hr of intravenous glucose before delivery and have a blood glucose level less than 120 mg/dl at the time of delivery. Newborns delivered to mothers with hyperglycemia or excessive glucose infusion should be tested for hypoglycemia at 1 and 2 hours of age.
TL;DR: This article studied the relationship between cerebral oxygen consumption and cerebral oxygen delivery in fetal, newborn, and adult sheep, relative to the amount of oxygen consumed, cerebral oxygen delivered in the fetus exceeds that in the lamb and adult by 70 percent, which may represent a protective advantage for the fetus or simply an adaptation to the low arterial oxygen pressure in the intrauterine environment.
Abstract: We studied the relationship between cerebral oxygen consumption and cerebral oxygen delivery (cerebral blood flow x arterial oxygen content) in fetal, newborn, and adult sheep, Relative to the amount of oxygen consumed, cerebral oxygen delivery in the fetus exceeds that in the lamb and adult by 70 percent. This may represent a protective advantage for the fetus or simply a necessary adaptation to the low arterial oxygen pressure in the intrauterine environment.
TL;DR: The results show that the blood concentration of lidocaine is low in spinal anaesthesia compared with other types of regional anaesthesia.
Abstract: In 32 patients undergoing spinal anaesthesia with lidocaine or lidocaine plus adrenaline, the concentration of lidocaine base was measured in repeated venous blood samples. Half of the patients were given 100 mg lidocaine alone and the other half 100 mg lidocaine with the addition of 0.2 mg adrenaline. The blood concentration of lidocaine was significantly higher in the lidocaine group than in the group that received lidocaine with adrenaline. The mean maximal concentrations in these two groups lay between 0.2 and 0.3 and between 0.1 and 0.2 micrograms/ml, respectively (P less than 0.01). The time required for the individual maximal concentration to be reached was independent of whether the anaesthetic contained adrenaline or not. The blood concentration showed no correlation to body weight, height, or body surface area. In the first 60 min after the spinal injection the extent of the sensory block was the same in the two groups, but at 120 min this extent was significantly greater in the lidocaine-adrenaline group (P less than 0.01). The results show that the blood concentration of lidocaine is low in spinal anaesthesia compared with other types of regional anaesthesia.
TL;DR: In this article, the authors assess the risks and benefits of vaginal delivery in patients with prior cesarean section, and the English literature on this subject from 1950 to 1980 was reviewed.
Abstract: To assess the risks and benefits of vaginal delivery in patients with prior cesarean section, the English literature on this subject from 1950 to 1980 was reviewed. The following conclusions were reached: 1) Properly conducted vaginal delivery after cesarean section is relatively safe, with a 0.7% incidence of uterine rupture, 0.93 perinatal mortality, and no maternal deaths due to uterine rupture. 2) Of those patients allowed a trial of labor, 66.7% were successfully delivered vaginally. Successful vaginal delivery occurred in 74.2% of those patients with a nonrecurrent indication for their previous cesarean section and in 33.3% of those patients whose indication for previous cesarean section was cephalopelvic disproportion. Sixty-seven percent of those patients with a prior vaginal delivery versus 47.1% of those patients without a prior vaginal delivery subsequently delivered vaginally. 3) A classic uterine scar clearly increases the probability of uterine rupture. However, the precise magnitude of the increased risk cannot be accurately determined. 4) Certain basic safety requirements such as available operating room facilities and adequate personnel for careful observation are mandatory, but other management policies that remain controversial include use of regional anesthesia, oxytocin administration, timing of hospital admission, artificial rupture of membranes, mode of delivery, proper method to evaluate the uterine scar, and delivery of fetuses in breech presentation and twins. 5) A policy of selective vaginal deliveries among patients with prior cesarean sections will result in cost reductions due to decreased postpartum hospitalization.
TL;DR: It is nevertheless likely that aortocaval compression will interfere markedly with uteroplacental vascular dynamics and hence pose a hazard to the fetus.
Abstract: Systemic blood pressure (measured with a zero-randomized sphyngmomanometer), stroke volume and heart-rate (measured with a Minnesota Impedance Cardiograph), hematocrit and their derivatives--cardiac output, pulse pressure, mean arterial blood pressure and peripheral vascular resistance, were assessed in 19 nonpregnant women of child-bearing age and in 27 patients who were examined at regular intervals on 12 to 15 occasions from 8 to 11 wk of pregnancy until 6-wk postpartum. Readings were made with the subjects in each of six positions: supine, reclining, left and right lateral, left and right tilt. The purpose of this paper is to compare the results of these different postures. Systolic and diastolic blood pressure readings were lowest in the left lateral and second lowest in the left tilt. We suggest that this reflects a hydrostatic pressure difference. Stroke volume and cardiac output were lowest in the right lateral and second lowest in the right tilt. Thus, the derived values of peripheral resistance were lowest when subjects were turned towards the left and highest when turned towards the right. The rank orders of values were maintained with impressive consistency between subjects (pregnant and nonpregnant) and throughout pregnancy, reaching levels of statistical significance in almost all instances. No evidence was found that aortocaval compression led to a change in the measured attributes of central cardiovascular dynamics. For the 'normal unembarrassed parturient' it is suggested that aortocaval compression is rapidly succeeded by a restablization of these attributes to their previous levels, reflecting the prompt establishment of a suitably diminished circulating blood volume within a reduced vascular capacity. It is nevertheless likely that aortocaval compression will interfere markedly with uteroplacental vascular dynamics and hence pose a hazard to the fetus.
TL;DR: Fetal breathing movements and gross fetal body movements were studied subsequent to the intravenous injection of either 25 gm of glucose or an equal volume of normal saline solution to suggest a useful strategy for clinical measurement of fetal breathing activity near term.
Abstract: Fetal breathing movements and gross fetal body movements were studied subsequent to the intravenous injection of either 25 gm of glucose or an equal volume of normal saline solution in 10 healthy women with uncomplicated pregnancies at 38 to 40 weeks' gestation. The incidence of fetal breathing increased from 17.5% during the control period to 54.9% after glucose injection. Neither glucose nor saline solution had any effect on the incidence of gross fetal body movements. All fetuses made some breathing movements during any 15-minute interval between 30 and 75 minutes after glucose injection. These data suggest a useful strategy for clinical measurement of fetal breathing activity near term.
TL;DR: The conclusion is that the response of fetal heart rate to a transient reduction in uterine blood flow is related to the duration of the reduction and to the status of fetal oxygenation prior to the decrease in uterines blood flow.
Abstract: The responses of fetal heart rate and blood pressure to a transient reduction in uterine blood flow were studied in normoxemic and chronically hypoxemic lambs. In normoxemic fetuses, a reduction in uterine blood flow, if prolonged sufficiently, produced reflex bradycardia mediated through chemoreceptors and was associated with a decrease in carotid arterial PO2 to below 20 torr. The bradycardia was associated with a marked decrease in left ventricular output as measured by electromagnetic flowmeter; both were abolished by atropine. In chronically hypoxemic fetuses, a reduction in uterine blood flow produced a delayed deceleration of the heart rate which consisted of three components: reflex bradycardia due to chemoreceptor stimulation; baroreceptor-mediated reflex bradycardia which involved the slow and late recovery of the heart rate; and nonreflex bradycardia which was probably secondary to hypoxic myocardial depression. Quantitative analysis revealed a relationship between the components of delayed deceleration and the status of fetal oxygenation prior to the reduction in uterine blood flow. The lower the carotid arterial PO2, the shorter was the delay in the onset of bradycardia, the greater the decrease in heart rate, and the more prolonged the duration of bradycardia. The conclusion is that the response of fetal heart rate to a transient reduction in uterine blood flow is related to the duration of the reduction and to the status of fetal oxygenation prior to the decrease in uterine blood flow.
TL;DR: It is concluded that a T4 dermatomal level of analgesia combined with intramuscular administration of ephedrine 25 mg, provides more maternal comfort than a T7 level of opioid analgesia does, with or withoutEphedrine, and is without significant maternal or foetal side effects.
Abstract: We compared analgesia to the T4 dermatomal level with analgesia to the T7 level with and without prophylactic intramuscular administration of ephedrine 25 mg to determine the adequacy and side effects of such analgesia for caesarean section. Unmedicated patients were prehydrated (727 +/- 303 ml of saline solution) and kept in a left lateral tilt position. Sufficient three per cent chloroprocaine was given to obtain analgesia to the T7 (T6-T8) dermatomal level (455 +/- 128 mg) or to the T4 (T3-T5) dermatomal level (758 +/- 168 mg). Patients who received analgesia to the higher level required less narcotic than those who received analgesia to the lower level (21 per cent versus 48 per cent) (p less than 0.05). The incidence of hypotension in patients with analgesia at the T4 level was 21 per cent for those receiving ephedrine and 64 per cent for those who did not receive ephedrine (p less than 0.05). Intramuscular administration of ephedrine 25 mg was not associated with increased plasma levels of norepinephrine, epinephrine or dopamine. There was no difference in Apgar score, behavioural test scores, neonatal acid-base status or oxygenation in children of mothers in the different groups. We conclude that a T4 dermatomal level of analgesia combined with intramuscular administration of ephedrine 25 mg, provides more maternal comfort than a T7 level of analgesia does, with or without ephedrine, and is without significant maternal or foetal side effects.
TL;DR: It is concluded that progesterone is not responsible for the reduction in halothane MAC, which was determined in nonpregnant, 10 days pregnant, term, and postpartum lactating rats.
Abstract: Near-term pregnancy is associated with a decrease in the minimum alveolar concentration (MAC) for halothane in ewes. Although increased progesterone levels might account for this change, a correlation between MAC and the known variations of progesterone levels which occur throughout gestation and the postpartum period has not been performed. Therefore, MAC for halothane was determined in nonpregnant, 10 days pregnant, term, and postpartum lactating rats. MAC values were significantly decreased by 19 per cent on the tenth day of pregnancy, and by 16 per cent at term, but they returned to control values 5 days postpartum. These changes did not correlate with the known changes in progesterone levels during pregnancy and lactation, and the authors conclude that progesterone is not responsible for the reduction in halothane MAC.
TL;DR: The contractile actions of prilocaine and bupivacaine on the human umbilical arteries are undesirable and might be hazardous if high concentrations are attained, e.g. during paracervical block.
Abstract: The smooth muscle effects on human umbilical arteries of four different local anaesthetic agents - lidocaine, etidocaine, prilocaine and bupivacaine - were studied. Lidocaine and etidocaine relaxed the arteries, etidocaine more profoundly than lidocaine. Prilocaine in the concentration range 10-1,000 micrograms/ml caused pronounced contractions. Bupivacaine consistently evoked a contractile response in the concentration range 5-25 micrograms/ml, but at lower and higher concentrations the response to this drug was inconsistent. The concentrations of lidocaine were determined in six human umbilical arteries following maternal epidural block with this agent and were found to be 0.1 - 1.7 micrograms/g tissue. The contractile actions of prilocaine and bupivacaine on the human umbilical arteries are undesirable and might be hazardous if high concentrations are attained, e.g. during paracervical block.
TL;DR: This study reviews the experience in 64 pregnancies managed at the Medical University Hospital over a 7 year period and found prophylactic exchange transfusion was not associated with improved pregnancy outcome and was associated with significant antibody formation.
Abstract: During the past decade, pregnancy outcome has improved among patients with sickle hemoglobinopathies. The role of prophylactic exchange transfusion in this improvement is uncertain. This study reviews the experience in 64 pregnancies managed at the Medical University Hospital over a 7 year period. Prophylactic exchange transfusion was not associated with improved pregnancy outcome and was associated with significant antibody formation. Exchange transfusion may best be reserved as a treatment modality when infection, crisis, or symptomatic anemia occurs in patients with a sickle hemoglobinopathy.