Comparative maternal, fetal, and neonatal effects of chloroprocaine with and without epinephrine for epidural anesthesia in obstetrics

The effects of epidural chloroprocaine with and without 1:200,000 epinephrine during labor and delivery on uterine activity, progress of labor, fetal heart rate, maternal blood pressure, newborn Apgar scores, neonatal acid-base status, and the Neurologic and Adaptive Capacity Scoring System (NACS) were compared in 28 parturients. Patients in group I (n = 14) received 2% chloroprocaine with 1:200,000 epinephrine and patients in group II (n = 14) received 2% plain chloroprocaine. Addition of epinephrine to chloroprocaine had no significant effects on uterine activity, duration of first or second stages of labor, or fetal heart parameters. Apgar scores, neonatal acid-base status, and the NACS were equally good in the two groups. Duration of analgesia was significantly longer in group I than in group II patients (76 +/- 3.8 vs 42.9 +/- 1 min, P less than 0.001). We conclude that addition of epinephrine to chloroprocaine during epidural anesthesia in the normal parturient has no adverse effects on mother, fetus, neonate, or the progress of labor and that it significantly prolongs the duration of anesthesia.     

Maternal, fetal, and neonatal effects of lidocaine with and without epinephrine for epidural anesthesia in obstetrics

The effects of epidural lidocaine with and without 1:300,000 epinephrine on uterine activity, progress of labor, fetal heart rate, maternal blood pressure and heart rate, newborn Apgar scores, neonatal acid-base status, and the Neurologic and Adaptive Capacity Scoring System were compared in 30 parturients during labor and delivery. Patients in group I (n = 16) received 1.5% lidocaine with 1:300,000 epinephrine and those in group II (n = 14) 1.5% lidocaine alone. Addition of epinephrine to lidocaine did not have any significant effects on uterine activity, duration of first or second stages of labor, fetal heart rate variability, or the incidence of abnormal fetal heart rate patterns. Maternal heart rate and the incidence of hypotensive episodes did not differ significantly between the two groups of patients. Apgar scores, neonatal acid-base status, and the NACS were equally good in the two groups. Duration of analgesia was significantly longer in group I as compared to group II patients (106.9 +/- 6.6 vs 66.2 +/- 4.4 min, P less than 0.001). Umbilical venous concentrations of lidocaine and umbilical vein to maternal vein ratios of lidocaine were significantly higher in group II patients (P less than 0.05). It is concluded that addition of epinephrine to lidocaine during epidural anesthesia in the normal parturient has no adverse effects on mother, fetus, neonate, or the progress of labor and it significantly prolongs the duration of anesthesia and limits the placental transfer of lidocaine.     

Safety and efficacy of epinephrine added to bupivacaine for lumbar epidural analgesia in obstetrics

The effects of epidural bupivacaine with and without 1:300,000 epinephrine on uterine activity, progress of labor, fetal heart rate, maternal blood pressure and heart rate, newborn Apgar scores, neonatal acid-base status, and Neurologic and Adaptive Capacity Scoring System (NACS) were compared in 32 parturients during labor and delivery. Patients in group I (n = 16) received 0.5% bupivacaine with 1:300,000 epinephrine and those in group II (n = 16) received 0.5% bupivacaine alone. Addition of epinephrine to bupivacaine had no significant effects on uterine activity, duration of first or second stages of labor, fetal heart rate and variability, or the incidence of abnormal fetal heart rate patterns. Maternal hypotension occurred less frequently in group I than in group II patients (P less than 0.05). Apgar scores, neonatal acid-base status, and the NACS were equally good in the two groups. Duration of analgesia was significantly longer in group I than in group II (186.8 +/- 11.6 vs 85.3 +/- 6.1 (mean +/- SEM) min, P less than 0.001). It is concluded that adding epinephrine to bupivacaine during epidural anesthesia in the normal parturient has no adverse effects on either mother, fetus, neonate, or the progress of labor; and that it significantly prolongs the duration of anesthesia and decreases the incidence of maternal hypotension.     

Lidocaine hydrocarbonate and lidocaine hydrochloride for cesarean section: transplacental passage and neonatal effects

Twenty-six patients, ASA physical status 1, scheduled for elective cesarean section, were divided at random into two groups and received via an epidural catheter 20 ml of 2.2% lidocaine hydrocarbonate (17.3 mg.ml-1 lidocaine base) with 5 micrograms.ml-1 epinephrine freshly added (Group CO2 = 13 patients) or 20 ml of 2% lidocaine hydrochloride (17.3 mg.ml-1 lidocaine base) also with 5 micrograms.ml-1 epinephrine freshly added. Following clampage of the umbilical cord (at 40.1 +/- 4.9 min after the injection of lidocaine for the CO2 group and at 41.0 +/- 5.4 min for the HCl group), serum concentrations of lidocaine were measured both in the mother and in the umbilical vein. All newborns were examined by the same blinded pediatrician with Apgar scores at 1, 5 and 10 min and with Neurobehavioral Adaptive Capacity Scores (NACS) at 15 min, 2 h and 24 h. The concentrations of lidocaine in the serum were comparable in both groups: in the mothers 8.61 +/- 1.48 mumol.l-1 for the CO2 group vs 8.04 +/- 2.36 mumol.l-1 for the HCl group and in the newborns 3.86 +/- 0.84 mumol.l-1 for the CO2 group vs 3.92 +/- 0.95 mumol.l-1 for the HCl group. The ratio of umbilical vein to maternal vein concentrations of lidocaine was also similar in both groups: 0.45 +/- 0.07 for the CO2 group vs 0.54 +/- 0.24 for the HCl group. The percentage of newborns with a normal NACS (score > or = 35/40) was equal in both groups, i.e. 91% at 15 min and 2 h of life and 100% at 24 h of life.(ABSTRACT TRUNCATED AT 250 WORDS)     

Phenylephrine in the prevention of hypotension following spinal anesthesia for cesarean delivery

STUDY OBJECTIVE: Phenylephrine and ephedrine were compared in the prevention of maternal hypotension following spinal anesthesia for elective cesarean delivery. DESIGN: Randomized, double-blind trial. SETTING: Obstetric suite at a university-affiliated hospital. PATIENTS: Sixty healthy patients electively scheduled for cesarean delivery under spinal anesthesia. INTERVENTIONS: Patients were randomly assigned to receive either ephedrine (n = 29) in 10 mg intravenous (IV) bolus injections or phenylephrine (n = 31) in 80 microgram IV bolus injections to maintain systolic blood pressure (SBP) above 100 mmHg. MEASUREMENTS AND MAIN RESULTS: Maternal venous, umbilical artery, and umbilical vein blood gases were measured, and neonatal Apgar scores and Early Neonatal Neurobehavior Scale scores were assessed. In the ephedrine group, umbilical artery pH was 7.28 +/- 0.01 (mean +/- SEM), umbilical artery partial pressure of carbon dioxide (PCO2) was 56.6 +/- 1.4 mmHg, and umbilical artery base deficit was 2.2 +/- 0.04 meq. In the phenylephrine group, umbilical artery pH was 7.32 +/- 0.01, umbilical artery PCO2 was 52.1 +/- 1.3 torr, and umbilical artery base deficit was 0.38 +/- 0.35 meq. There were significant differences between the groups in mean umbilical artery pH, PCO2, and base deficit, although all values obtained were within normal limits. There were no significant differences between the groups in the remaining acid-base values, neonatal Apgar scores, Early Neonatal Neurobehavior Scale scores, or frequency of maternal nausea and vomiting. CONCLUSIONS: Phenylephrine is as effective as ephedrine in the treatment of maternal hypotension, and when used in small incremental bolus injections, it appears to have no adverse neonatal effects in healthy, nonlaboring parturients.     

Anaesthetic technique for elective caesarean section and neurobehavioural status of newborns

Ninety healthy parturients undergoing elective caesarean section were randomly allocated to receive either general (n = 30), epidural (n = 30) or spinal (n = 30) anaesthesia. Acid-base status, Apgar score and neurobehavioural status, using the neurologic and adaptive capacity scoring (NACS) system, were studied in the newborn. Apgar scores and acid-base parameters were similar in all the three groups. NACS testing revealed significantly more vigorous babies in the spinal anaesthesia group than in the other two groups at 15 min and 2 h interval after delivery, despite a higher incidence of maternal hypotension. We conclude that newborns tend to have a better neurobehavioural status in the early post-delivery period if their mothers receive spinal anaesthesia rather than general or epidural anaesthesia for caesarean section.     

Residual curarization in the neonate after Caesarean section

The transplacental transfer and the neonatal effects of atracurium 0.3 mg.kg-1 (ED95) were compared with those of d-tubocurarine at the usual clinical dose of 0.3 mg.kg-1 (ED90) in 46 patients undergoing elective Caesarean section. The atracurium group (25 patients) was similar to the d-tubocurarine group (21 patients) as far as age, parity and time intervals between precurarization, induction, skin incision, muscle relaxant administration, hysterotomy and birth. The transplacental transfer of atracurium was lower than that of d-tubocurarine, with a feto-maternal ratio of 9 +/- 3% for atracurium and 12 +/- 5% for d-tubocurarine (P less than 0.05). The transplacental transfer of laudanosine was low at 14 +/- 5%, with blood levels of 0.101 +/- 0.032 microM.L-1 in the umbilical vein. Newborns in the two groups were comparable in terms of Apgar scores at one, five and ten minutes, as well as for NACS scores (neurological and adaptive capacity scoring test) at two and 24 hours after birth. However, at 15 min after birth, only 55% of newborns in whom the mothers received atracurium had a normal NACS score (greater than or equal to 35/40) compared with 83% of newborns in whom the mothers received d-tubocurarine (P less than 0.05). Further analysis of the five variables related to active muscle tone revealed that the modal score for active extension of the neck of newborns from the atracurium group was lower than for newborns from the d-tubocurarine group (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Perioperative maternal and neonatal acid-base status and glucose metabolism in patients with insulin-dependent diabetes mellitus.

Maternal and neonatal acid-base status and glucose metabolism were studied in 20 patients with insulin-dependent diabetes mellitus (group 1) undergoing elective cesarean section under lumbar epidural anesthesia. All patients were given glucose/insulin infusion before delivery. Fifteen healthy patients with iatrogenic hyperglycemia (group 2) and 15 healthy euglycemic patients (group 3) served as controls. Results were expressed as mean +/- 1 SE and were analyzed using analysis of variance and chi 2 analysis at P less than 0.05. No significant differences were seen at delivery either in maternal arterial and neonatal umbilical venous and arterial blood acid-base status or in neonatal Apgar scores among the three groups. Patients in groups 1 and 2 had larger blood glucose concentrations than those in group 3 (P = 0.01). Diabetic mothers and their neonates had a 25%-50% reduction in pyruvate concentration in maternal venous, and neonatal umbilical venous and arterial blood compared with that in the other two groups (P = 0.001). Postpartum neonatal hypoglycemia (less than 30 mg/dL) developed in seven of the group 1 neonates (P = 0.05). Thus, epidural anesthesia in diabetic women is associated with normal acid-base status in the mother and in the neonate. The data also show an increased incidence of neonatal hypoglycemia and altered maternal and neonatal glycolysis in patients with diabetes mellitus.     

The pharmacokinetics and maternal and neonatal effects of epidural lidocaine in preeclampsia

The pharmacokinetics and maternal and neonatal effects of epidural lidocaine were compared in ten preeclamptic and five normotensive women undergoing cesarean section at 36-40 weeks of gestation. Lumbar epidural anesthesia was achieved using 15-20 ml of 2% lidocaine without epinephrine. Serial venous samples for lidocaine levels were drawn from all the mothers during the procedure and up to 6 hr after the initial injection. Umbilical venous and arterial samples were drawn at delivery for measurement of neonatal acid-base status and lidocaine levels. There were no significant differences between normotensive and preeclamptic patients in the total dose of lidocaine, peak maternal plasma concentration, volume of distribution, maternal elimination half-life and umbilical vein/maternal vein ratios. The calculated area under the concentration time curve in preeclamptic patients (18.5 +/- 4.7 micrograms X hr X ml-1) was significantly greater than in normotensive mothers (14.1 +/- 1.3 micrograms X hr X ml-1) (P less than 0.02). Total maternal body clearance in preeclamptic patients (24.5 +/- 7.1 L/hr) was significantly lower than in normotensives (31.1 +/- 4.4 L/hr) (P less than 0.05). Neonatal outcome as evaluated by Apgar scores, umbilical arterial and venous blood gas tensions, umbilical vein/maternal vein ratios, and early neonatal neurobehavior scores at 4 hr and 24 hr after birth were similar in the two groups. The results indicate that the total maternal body clearance of lidocaine is prolonged in preeclampsia, and repeated administration of lidocaine can result in higher blood levels than in normotensive parturients.     

曲马多对母婴乳酸盐和新生儿神经行为的影响

目的　研究曲马多对母婴血乳酸盐和新生儿神经行为与适应能力评分 (NACS)的影响。方法　 6 0例足月妊娠剖宫产产妇随机分三组 :T0 组 ,2 0例 ,肌注 0 9%氯化钠 2ml;T1组 2 0例 ,肌注曲马多 1 5mg/kg ;T2 组 ,2 0例 ,肌注曲马多 2mg/kg。各组肌注后开始麻醉 ,三组均采用脊麻与硬膜外联合阻滞。观察指标 :新生儿生后 15min的Apgar评分及新生儿生后 15min的NACS ;胎儿娩出时采脐动、静脉血和母体动脉血各 2ml,行血乳酸值测定及血气分析。结果　三组新生儿Apgar评分无明显差异 ,T0 组NACS明显高于T1组 (P <0 0 5 )和T2 组 (P <0 0 1) ;T2 组脐动、静脉血乳酸值明显高于T1组 (P <0 0 5 )和T0 组 (P <0 0 1) ;母体乳酸值三组间无明显差异 ;T2 组母体和脐动、静脉血PaCO2 明显高于T0 组 (P <0 0 1) ,T2 组脐动、静脉血SaO2 明显低于T0 组 (P <0 0 5 )。结论　剖宫产术前肌注曲马多 1 5mg/kg对新生儿无明显不良影响。但 2mg/kg曲马多肌注具有呼吸抑制作用 ,使脐动、静脉血乳酸盐增加 ,对新生儿NACS有一过性影响     

A randomized study of the effects of perioperative i.v. lidocaine on hemodynamic and hormonal responses for cesarean section

Purpose  Intravenous infusion of lidocaine attenuates the stress response to surgery. We aimed to evaluate the effects of perioperative lidocaine on the hemodynamic and hormonal responses for cesarean delivery. Methods  After the gaining of ethical approval, 90 patients scheduled for elective cesarean delivery were randomly allocated to receive either lidocaine 1.5 mg·kg⁻¹ i.v. bolus 30 min before induction, followed by an infusion of 1.5 mg·kg⁻¹·h⁻¹ until 1 h after surgery (n = 45), or saline placebo (n = 45). Anesthesia was maintained with 50% nitrous oxide in oxygen with 0.7% isoflurane. Hemodynamic variables, plasma cortisol, maternal and neonatal lidocaine concentrations, Apgar scores at 1 and 5 min, neonatal acid-base status, and the neurologic and adaptive capacity score (NACS) were recorded. Results  After induction, patients receiving lidocaine had a smaller increase in heart rate and mean arterial blood pressure (P < 0.02) and lower plasma cortisol concentrations (31.1 ± 9.91 vs 45.6 ± 8.43 μg·dL⁻¹; P < 0.001). There were no differences between the two groups in Apgar scores, NACS, or neonatal acid-base status. After delivery, maternal and umbilical venous concentrations and umbilical vein-to-maternal vein ratios of lidocaine were 2.05 ± 0.42 μg·mL⁻ and 1.06 ± 0.31 μg·mL⁻¹, and 0.52 ± 0.07, respectively. Conclusion  Perioperative lidocaine is safe and effective in attenuating the maternal stress response to surgery for cesarean delivery.     

Pharmacokinetics, placental transfer, and neonatal effects of vecuronium and pancuronium administered during cesarean section

Vecuronium and pancuronium were compared for placental transfer, pharmacokinetic variables, and neonatal effects during cesarean section under general anesthesia. Eighteen women underwent rapid-sequence intravenous induction using d-tubocurarine, succinylcholine, thiopental, and oxygen. Immediately after tracheal intubation, an intravenous injection of vecuronium (n = 11) or pancuronium (n = 7), 0.04 mg/kg, was given. Maternal venous blood samples were obtained before induction and at frequent intervals for 4 h after administration of vecuronium or pancuronium. Also, maternal venous and umbilical-cord arterial and venous blood samples were obtained at delivery. To describe placental transfer and maternal pharmacokinetics of the drugs, serum drug concentrations were determined using single-ion-monitoring mass spectrometry. The Apgar score and Neurologic and Adaptive Capacity Score (NACS) were used to evaluate neonatal condition. Both drugs crossed the placenta, as demonstrated by low concentrations of vecuronium (8.5-26.4 ng/ml) or pancuronium (12.2-34.2 ng/ml) found in umbilical venous blood. At delivery, the ratio of the drug concentration in umbilical venous blood to that in maternal venous blood was 0.11 +/- 0.02 for vecuronium and 0.19 +/- 0.03 for pancuronium. Vecuronium had a more rapid clearance (6.4 +/- 0.4 ml X kg-1 X min-1, mean +/- SE) and a shorter elimination half-life (36 +/- 1.8 min) than pancuronium (3.0 +/- 0.1 ml X kg-1 X min-1 and 72 +/- 6 min, respectively). No other pharmacokinetic differences were found between the drugs. Neonatal outcome was not affected adversely by either muscle relaxant, as assessed by Apgar scores and NACSs . The short duration of action, the minimal placental transfer, and the apparent lack of clinical neuromuscular effects on the newborn suggest that vecuronium should be a useful muscle relaxant for cesarean section.     

Propofol infusion anaesthesia for Caesarean section

Two propofol infusion regimens and a standard general anaesthetic were compared in thirty Chinese women undergoing elective Caesarean section. After induction of anaesthesia with propofol 2 mg.kg-1, ten patients received propofol 6 mg.kg-1.hr-1 and nitrous oxide 50 per cent in oxygen while ten were given propofol 9 mg.kg-1.hr-1 with 100 per cent oxygen. The other ten patients received thiopentone 4 mg.kg-1 and nitrous oxide 50 per cent in oxygen with enflurane one per cent. Maternal recovery times and psychomotor performance were recorded. Neonates were assessed by Apgar scores, neurologic and adapative capacity scores (NACS) and umbilical cord blood gas analysis. Haemodynamic changes were similar immediately following induction but the low propofol infusion group had the best haemodynamic stability subsequently. Recovery times were fastest in the low-infusion group but there were no differences in later postbox testing. Neonatal Apgar scores and umbilical blood gas analysis were similar but NACS at two hours were poorer in the high infusion group. A propofol infusion coupled with nitrous oxide appears to be a satisfactory technique for Caesarean section.     

Alfentanil given immediately before the induction of anesthesia for elective cesarean delivery

Opioids are routinely omitted at the induction of general anesthesia for cesarean delivery because of concerns about neonatal respiratory depression. The subsequent unmodified maternal stress response to tracheal intubation reduces placental perfusion. The short-acting opioid alfentanil may afford advantages at the induction, without subsequent neonatal depression. In this double-blinded study of elective cesarean deliveries, 40 patients were allocated randomly to receive either alfentanil 10 microg/kg (n = 18) or placebo (n = 22), 1 min before the induction of anesthesia with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg. Anesthesia was maintained with 50% nitrous oxide, 0.5% isoflurane in oxygen, and atracurium. Neonates were assessed by using Apgar scores, Neurologic and Adaptive Capacity Scores, and umbilical cord blood gas and catecholamine analysis. After intubation, mothers receiving alfentanil had a smaller increase in mean arterial blood pressure, (11 +/- 15 vs 31 +/- 13 mm Hg, P < 0.001) and lower plasma norepinephrine concentrations, (336 +/- 152 vs 486 +/- 241 pg/mL, P < 0.05). Neonates in the alfentanil group had greater umbilical arterial oxygen tensions (27.8 +/- 7.0 vs 22.6 +/- 7.4 mm Hg), slightly reduced Apgar scores (both P < 0.05), but similar Neurologic and Adaptive Capacity Scores. One neonate in the alfentanil group required naloxone. The maternal stress response was attenuated in the alfentanil group but at the cost of early neonatal depression. However, all neonates should be monitored for possible immediate, but transient, respiratory depression.     

Vasopressor therapy for hypotension due to epidural anesthesia for cesarean section

Maternal hemodynamic changes and neonatal acid-base status were assessed in 127 healthy patients undergoing elective cesarean section under epidural anesthesia. An impedance cardiograph was used to measure stroke volume (SV), ejection fraction (EF) and end-diastolic volume (EDV). In addition, neonatal umbilical venous and arterial PO2, PCO2, pH, base excess, lactate, pyruvate, excess lactate, and L/P ratio were measured at birth. Patients were divided into three groups. Group 1 (n = 53) required no vasopressor (normotensive controls). In Group 2 (n = 37), mean blood pressure (BP) decreased from 90 mmHg (13.3 kPa). In Group 3 (n = 37), BP decreased from 83 mmHg to 62 mmHg (11.1 to 8.2 kPa), and phenylephrine was administered in 100 micrograms increments to maintain systolic BP greater than 100 mmHg (13.3 kPa). In Groups 2 and 3 the SV and EDV decreased 43% and 33% respectively when hypotension developed. Both vasopressors restored BP, SV and EDV to near baseline values. Neonatal Apgar scores and acid-base profiles were not significantly different among the three groups of neonates, nor were they different between the two hypotensive groups. It is concluded that: 1) transient maternal hypotension does not affect neonatal acid-base status; 2) both ephedrine and phenylephrine increase cardiac preload; and 3) an alpha agent like phenylephrine does not cause fetal acidosis when used for treating maternal hypotension.     

Comparative Maternal and Neonatal Effects of Halothane and Enflurane for Cesarean Section

The effects of placental transfer of enflurane and halothane were studied in 81 women undergoing cesarean sections. All patients had rapid sequence induction using thiopental, succinylcholine, and endotracheal intubation. They were then randomly assigned to one of five groups: Group I (n = 16) received N2O and oxygen, Group II (n = 16) N2O, oxygen, and 0.25% halothane, Group III (n = 18) N2O, oxygen, and 0.5% halothane, Group IV (n = 18) N2O, oxygen, and 0.5% enflurane, Group V (n = 13) N2O, oxygen, and 1% enflurane. At delivery, blood was drawn from the maternal artery, umbilical vein and artery for measurement of the halogenated agents using gas chromatography. The neonates were evaluated by Apgar scores, umbilical artery and vein acid base status and the Early Neonatal Neurobehavioral Scores (ENNS) at 2 and 24 h of age. Blood loss and the incidence of maternal awareness were also determined. The umbilical vein to maternal vein ratio was approximately 0.5 and 0.6 for enflurane and halothane, respectively. The umbilical artery to umbilical vein ratio was 0.5 with both agents; higher inspired anesthetic concentrations produced higher blood levels. All neonates had Apgar scores of 8 or more at 5 min with the exception of one neonate in the N2O group. Maternal and neonatal acid base status, blood loss, and ENNS were not affected by the addition of the halogenated agents. Of the patients who had N2O alone, 12% had awareness versus none in the other groups. These data demonstrate that low dose halothane or enflurane decreases the incidence of maternal awareness and does not adversely affect the neonate.     

Addition of epinephrine to epidural ropivacaine during labour--effects on onset and duration of action, efficacy, and systemic absorption of ropivacaine

Addition of epinephrine to epidural anaesthetic solutions may enhance efficacy and duration of analgesia. We postulated that addition of epinephrine 5 microg.mL(-1) to epidural ropivacaine would improve efficacy, decrease systemic absorption and reduce neonatal effects. Twenty-one multiparous women were studied. An initial dose of ropivacaine 30 mg followed by an infusion of ropivacaine 10 mg.h(-1) was given via a lumbar epidural catheter. According to random allocation, epinephrine 5 microg.mL(-1) was added to ropivacaine. Ropivacaine concentrations were measured in maternal venous plasma after one hour of infusion and in both umbilical venous and maternal plasma at delivery. Neonatal neurologic and adaptive capacity score (NACS) tests were performed at 2 and 24 h postpartum. All women delivered vaginally. The groups had similar ropivacaine dose requirements, epidural-delivery intervals and satisfaction scores. Bromage scores for motor block were greater in the epinephrine group (2; range: 1-3) than controls (1; range: 0-2). Mean plasma ropivacaine concentrations (+/-SD) were less in the epinephrine group (0.17 +/- 0.05 mg.L(-1), n = 10) than controls (0.31 +/- 0.14 mg.L(-1), n = 11; P < 0.05) after one h of infusion but not at delivery. UV ropivacaine concentrations and NACS scores were similar in the two groups. The addition of epinephrine to ropivacaine decreases maternal plasma concentrations after one h of epidural infusion but also increases motor block.     

Supplemental maternal oxygen therapy during caesarean section under epidural anaesthesia: a comparison of nasal prongs and facemask

Forty healthy parturients at term, undergoing elective Caesarean section, were divided into two groups to receive supplemental oxygen by either simple facemask (Group FM, 8 L.min-1) or nasal prongs (Group NP, 4 L.min-1) during the procedure. Anaesthesia was provided by epidural block to equivalent dermatomal levels in all patients. Maternal oxygen saturation was measured continuously with pulse oximetry and supplemental oxygen was provided to the mother after administration of the epidural test dose and continued until the end of the procedure. Following delivery of the infant and concurrent with Apgar scoring, the umbilical cord was double-clamped and arterial and venous samples were drawn. The pH, partial pressures of O2 and CO2 and O2 saturations were measured. There was no difference in the clinical condition of the neonates, as assessed by Apgar scores, or in the acid-base and oxygenation status, as assessed by blood gas analyses between the two groups. Mean umbilical vein oxygen saturation, a measure of fetal oxygen delivery, was 46 +/- 18% (95% confidence interval 39% to 54%) for Group NP and 54 +/- 17% (95% confidence interval 46% to 62%) for Group FM, again not different. We conclude that when the clinical condition, acid-base and oxygenation status of neonates, delivered by elective Caesarean section to healthy, low-risk parturients with normal placental function under epidural anaesthesia, are evaluated, it makes no difference whether the mothers received supplemental oxygen by nasal prongs or simple facemask.     

Effects of hyperbaric spinal ropivacaine for caesarean section: with or without fentanyl

BACKGROUND AND OBJECTIVE: Adding various opioids to the local anaesthetic solution administrated intrathecally improves the analgesic potency of spinal analgesia. The purpose of this study was to evaluate the efficacy and safety of intrathecal fentanyl 10 microg added to 15 mg hyperbaric ropivacaine in patients undergoing caesarean section under spinal anaesthesia. METHODS: Thirty-seven healthy, full-term parturients were randomly assigned into two groups: Group S (saline group, n=17) received 15 mg hyperbaric ropivacaine in 2.5 mL + 0.5 mL saline; Group F (fentanyl group, n=20) received 15 mg hyperbaric ropivacaine in 2.5 mL + 10 microg fentanyl in 0.5 mL, intrathecally. Characteristics of spinal block, intraoperative quality of spinal anaesthesia, time to first feeling of pain (complete analgesia), time to first request of analgesics postoperatively (effective analgesia), side-effects and fetal outcomes were evaluated. RESULTS: Regression of sensory block to L5 was significantly prolonged in the fentanyl group compared with the saline group (P = 0.001). Time to the first feeling of pain (130.6 +/- 15.8 min vs. 154.3 +/- 31.1 min; P = 0.008) and the first analgesic requirement (161.2 +/- 32.6 min vs. 213.0 +/- 29.3 min; P < 0.001) were significantly shorter in the saline group compared with the fentanyl group. Side-effects, umbilical arterial and venous blood gases did not differ between the groups. Apgar scores were similar in both groups and no infants had an Apgar score < or =7 at 5 min. CONCLUSIONS: The addition of fentanyl 10 microg, to hyperbaric ropivacaine 15 mg, for spinal anaesthesia increased the duration of analgesia in the early postoperative period in patients undergoing caesarean delivery.     

Prospective,randomized trial comparing general with spinal anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace

BACKGROUND: There are no randomized studies on neonatal outcome after spinal versus general anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace. This study examined both markers of neonatal hypoxia and maternal hemodynamics. METHODS: Seventy patients were randomized to general (n = 35) or spinal anesthesia (n = 35). The general anesthesia group received thiopentone, magnesium sulfate, and suxamethonium intravenously before intubation, followed by 50% nitrous oxide in oxygen, 0.75-1.5% isoflurane, and morphine after delivery. The target end-tidal partial pressure of carbon dioxide (Pco2) was 30-34 mmHg. The spinal anesthesia group received 1.8 ml hyperbaric bupivacaine plus 10 microg fentanyl at the L3-L4 interspace. Heart rate and blood pressure were measured at specific time points. Hypotension was treated with ephedrine. Maternal arterial and neonatal umbilical arterial blood gas samples were taken at delivery. Resuscitation requirements were recorded. RESULTS: In both groups, hemodynamic measures remained within acceptable limits. Spinal anesthesia patients required more ephedrine (13.7 vs. 2.7 mg). Maternal Paco2 was lower in the spinal group (28.9 vs. 32.4 mmHg). One-minute Apgar scores were lower after general anesthesia. Base deficit was greater (7.13 vs. 4.68 mEq/l) and neonatal umbilical arterial pH was lower (7.20 vs. 7.23) after spinal anesthesia. Post hoc analysis showed that if maternal diastolic blood pressure on admission was greater than 110 mmHg, neonatal umbilical arterial base deficit was greater after spinal anesthesia. There was no difference in the number of patients with Apgar scores less than 7 at 1 or 5 min or umbilical arterial pH less than 7.2 or in the requirements for resuscitation. CONCLUSIONS: In preeclamptic patients with a nonreassuring fetal heart trace, spinal anesthesia for cesarean delivery was associated with a greater mean neonatal umbilical arterial base deficit and a lower median umbilical arterial pH. The clinical significance remains to be established. Maternal hemodynamics were similar and acceptable with either anesthetic technique.