Epidural versus general anaesthesia for elective caesarean section. Effect on Apgar score and acid-base status of the newborn

Comparison of the Effects of Anaesthesia Methods Used in Caesarean Delivery on Neonatal Cerebral and Renal Oxygenation: A Randomised Controlled Trial

Background: During a newborn's adaptation to extrauterine life, many changes take place that are influenced by various factors. The type of delivery and anaesthesia strategy utilised during labour can modify these adaptive modifications. In this regard, this study was designed to compare the effects of general and spinal anaesthesia on cerebral and renal oxygenation after elective caesarean deliveries. Methods: This randomised controlled study comprised sixty parturient women who were over 18 years old and had a gestational age between 37 and 41 weeks. All participants had an ASA (American Society of Anesthesiologists) classification of II. Neonatal cerebral (CrSO2) and renal (RrSO2) regional oxygen saturations were assessed using near-infrared spectroscopy. Additionally, the 1st-5th min Apgar scores, preductal and postductal peripheral oxygen saturation (SpO2), and perfusion index were recorded in both the general anaesthesia and spinal anaesthesia groups. Results: There was no statistically significant difference between the two groups in terms of CrSO2 or RrSO2 values. The values of CrSO2 and RrSO2 in both groups showed a significant rise from the 10th to the 15th min, respectively. Conclusions: General and spinal anaesthesia techniques used for cesarean delivery have similar effects on neonatal cerebral and renal oxygenation.

Maternal hypotension during elective cesarean section and short-term neonatal outcome

OBJECTIVE

To investigate the extent and risk factors for hypotension among women undergoing elective cesarean section, and whether maternal hypotension has any impact on perinatal infant outcome.

STUDY DESIGN

Retrospective analysis of data on 919 mother-infant pairs after elective cesarean section that involved the use of regional anesthetic. Data collection included information on maternal blood pressure during the cesarean section procedure and any infant perinatal complications.

RESULTS

Nearly one-half of the mothers underwent a decrease in their mean arterial blood pressure by > or =30%. The risk factors for hypotension included preoperative hypertension, older age, type of spinal anesthesia, and a higher infant birthweight. A drop in the maternal mean arterial blood pressure exceeding 30% or even 50% compared with the preoperative value was not found to predict any perinatal complications.

CONCLUSION

Despite a very high prevalence of maternal hypotension during cesarean sections, term infants tend to tolerate this placental blood perfusion challenge without any major sequel.

Pregnancy in carriers of haemophilia

The aim of the study was to review the complications, management and outcome of pregnancy in carriers of haemophilia over a 10-year period following the introduction of a multidisciplinary management guideline. Comparison was made to a 10-year cohort prior to implementation of the guidelines. A retrospective review of case notes of carriers of haemophilia (41 haemophilia A, 12 haemophilia B) who had received obstetric care at the Royal Free Hospital between 1995 and 2005 was conducted. There were 90 pregnancies (65 live births, 13 miscarriages, 12 terminations). Prenatal testing was taken up in 97% (63/65) of pregnancies where the mother was known to be a carrier of haemophilia. The majority (71%; 46/65) chose only to have non-invasive fetal sex determination. Seventeen (26%) had invasive testing (13 primarily for haemophilia and four primarily for chromosomal abnormalities). Termination of pregnancy was opted for in 67% (6/9) of pregnancies affected with haemophilia. Pregnancy was accompanied by a marked rise in factor VIII levels compared to only a small rise in factor IX levels. Invasive intrapartum monitoring techniques and instrumental deliveries were avoided in all pregnancies known to be at risk of haemophilia. Regional block was performed in 25 pregnancies for labour/delivery with no complications. The caesarean section rate was 47%. The incidence of primary and secondary postpartum haemorrhage was 19% and 2%, respectively. There were two neonatal head bleeding complications associated with prolonged labour or instrumental delivery. Availability of management guideline and care provided in a multidisciplinary approach can help to minimize bleeding complications in carriers of haemophilia and their newborns.

Anaesthesia for Caesarean section and neonatal acid-base status: a meta-analysis

Spinal anaesthesia is generally preferred for Caesarean section. Its superiority for the baby is often assumed. Umbilical artery acid-base status provides a valid index of fetal welfare. Twenty-seven studies reporting neonatal acid-base data with different types of anaesthesia were used to compare umbilical artery or vein pH and base deficit, using random-effect meta-analysis. Cord pH was significantly lower with spinal than with both general (difference: -0.015; 95% CI -0.029 to -0.001; 13 studies, 1272 subjects) and epidural anaesthesia (difference -0.013; 95% CI -0.024 to -0.002; 11 studies, 828 subjects). Larger doses of ephedrine contributed to the latter effect (p = 0.023). Sixteen studies reported a base deficit, which was significantly higher for spinal than for general (difference 1.109; 95% CI 0.434-1.784 mEq.l(-1); seven studies, 695 subject) and epidural anaesthesia (difference 0.910; 95% CI 0.222-1.598 mEq.l(-1); seven studies, 497 subjects). Spinal anaesthesia cannot be considered safer than epidural or general anaesthesia for the fetus.

Effects of four anaesthetic protocols on the neurological and cardiorespiratory variables of puppies born by caesarean section

Twenty-four bitches which had been in labour for less than 12 hours were randomly divided into four groups of six. They all received 0.5 mg/kg of chlorpromazine intravenously as premedication, followed 15 minutes later by either 8 mg/kg of thiopentone intravenously (group 1), 2 mg/kg of ketamine and 0.5 mg/kg of midazolam intravenously (group 2), 5 mg/kg of propofol intravenously (group 3), or 2.5 mg/kg of 2 per cent lidocaine with adrenaline and 0.625 mg/kg of 0.5 per cent bupivacaine with adrenaline epidurally (group 4). Except for group 4, the bitches were intubated and anaesthesia was maintained with enflurane. The puppies' heart and respiratory rates and their pain, sucking, anogenital, magnum and flexion reflexes were measured as they were removed from the uterus. The puppies' respiratory rate was higher after epidural anaesthesia. In general the puppies' neurological reflexes were most depressed after midazolam/ketamine, followed by thiopentone, propofol and epidural anaesthesia.

Short-term outcome of newborn infants: spinal versus general anesthesia for elective cesarean section. A prospective randomized study

OBJECTIVE

To compare general and spinal anesthesia with respect to the short-term outcome of newborns born by elective cesarean deliveries.

METHODS

Pregnant women admitted to our hospital from January 1999 to July 2000, for whom elective repeat cesareans were planned after 37 weeks gestation, were allocated randomly after their informed consent to spinal anesthesia or general anesthesia. Maternal age, gestational age, birth weight, Apgar's score, hospital stay duration, and duration of cesarean section time were all noted. The rate of the neonatal respiratory depression, perinatal asphyxia, and admittance to the neonatal intensive care unit of the infants were documented. We also studied arterial samples withdrawn from the cord for the pH, bicarbonate, PaO(2) (oxygen pressure, arterial), and PaCO(2) (carbon dioxide pressure, arterial). The serum levels of creatine kinase with myocardial-specific isoform, aspartate aminotransferase, alanine aminotransferase, and total cortisol levels of the newborns were measured and served in ruling out perinatal stress and in confirming the diagnosis of perinatal asphyxia (and of myocardial damage). Statistical analyses was performed with the use of an unpaired Student's t-test, Chi-square test, and a power calculation was done.

RESULTS

From the randomly selected patients, we had 38 (45.2%) infants for general anesthesia and 46 (54.8%) for spinal anesthesia. None of our primary endpoints favored any of the study groups, and the clinical short-term outcome of the infants was similar in the neonates born both by spinal and general anesthesia (P>0.05). The biochemical assays did not rule out or confirm any differences in the occurrence of perinatal stress (P>0.05).

CONCLUSION

Anesthesia type does not seem to influence the short-term outcome of the newborn infants for the elective cesarean deliveries. We believe that both spinal and general anesthesia could be performed in elective term cesarean deliveries without any risk to the newborn infants.

National obstetric anaesthetic practice in the UK 1997/1998

In the United Kingdom, the Royal College of Obstetricians and Gynaecologists requires maternity units recognised for training to complete annual statistical returns. Analysis of these data revealed that anaesthetists were directly involved in more than 251 000 procedures in the peripartum period in 1997/1998. There had been an increase in the number of women delivered by Caesarean section (18. 5% of all deliveries) compared with previous reports. The proportion of Caesarean sections performed under regional anaesthesia had increased for both elective and emergency Caesarean section deliveries (85.5% and 70.2%, respectively). For pain relief in labour, there had been neither an increase nor a decrease in the uptake of regional analgesia (23.6%). There were limited training opportunities for anaesthetists in general anaesthesia for Caesarean section and for obstetricians in vaginal breech delivery. The known admissions to intensive care units equated to over 100 women per month in the United Kingdom requiring intensive care as a result of childbirth.

Spinal anaesthesia for caesarean section: current clinical practice

Spinal anaesthesia has evolved as the preferred anaesthetic technique for most cases of caesarean section. Having been extensively studied and refined over the years, there are few situations where a spinal is absolutely contraindicated. While general anaesthesia will always have a place in obstetrics, in experienced hands a spinal offers safety, efficacy and an improvement in maternal morbidity.

Comparison of epidural and general anaesthesia for elective caesarean delivery according to the effects of apgar scores and acid-base status

The objective of this study was to determine the effects of lumbar epidural anaesthesia on the Apgar score and acid-base status of the newborn. Umbilical artery blood gases were obtained in 85 singleton, term, uncomplicated pregnancies delivered by elective Caesarean section. The umbilical artery blood pH, PaCO2, PaO2 and HCO3 values and Apgar scores (1 and 5 minutes) were compared between lumbar epidural and general anaesthesia groups. General anaesthesia was used in 45 (52.9%) women and lumbar epidural anaesthesia in 40 (47.1%). Only 2 of the newborns exposed to epidural anaesthesia had umbilical artery blood pH values 7.19 or less. The mean umbilical artery blood pH was found to be significantly lower in the newborns exposed to lumbar epidural anaesthesia (p = 0.011). None of the newborns in the 2 groups were severely depressed (Apgar scores less than 4). The mean umbilical artery blood PaCO2, PaO2 and HCO3 values did not show any significant difference between the groups. In conclusion, lumbar epidural anaesthesia is associated with lower umbilical artery blood pH values, occasionally with severe fetal acidaemia.

A comparison of spinal and general anaesthesia for elective caesarean section: effect on neonatal condition at birth

The condition of 74 neonates delivered by elective caesarean section under general anaesthesia was compared with that of 63 neonates delivered under spinal anaesthesia. When the uterine incision - delivery interval was less than 3 min, neonates in the spinal group exhibited a higher Apgar score at 1 min (P < 0.002) and a higher mean umbilical venous pH (P < 0.05) than the equivalent general anaesthesia group; a significantly greater proportion of the neonates delivered under general anaesthesia had an umbilical venous pH<7.28 at delivery (P < 0.05), a fact which previous work suggests is important. Among anaesthetized mothers inspired oxygen concentration (33% or 50%) before delivery had no significant effect upon neonatal outcome. It is concluded that neonates delivered at elective Caesarean section under spinal anaesthesia are in better condition than those delivered under general anaesthesia.

A comparison of postoperative analgesia following spinal or epidural anaesthesia for caesarean section

Postoperative analgesia, using a patient-controlled analgesia system, was studied in 32 women after elective Caesarean section performed under either spinal or epidural anaesthesia. Patients who had spinal anaesthesia had significantly higher pain scores and morphine consumption during the first 4 h postoperatively than patients who had epidural anaesthesia. This situation was reversed between 4 to 8 h postoperatively with patients who had had epidurals having significantly higher pain scores despite higher morphine consumption. After 8 h there was little difference in pain scores or morphine use between the two groups. Total morphine consumption in the first 24 h postoperatively was not significantly different between the two groups.

Caesarean section anaesthesia and the Apgar score

Retrospective comparison of epidural and general anaesthesia by a multivariate analysis of 1 and 5 minute Apgar scores did not show that general anaesthesia improves operating conditions for Caesarean section or reduces fetal trauma for preterm and term infants.

Epidural anaesthesia for caesarean section in a patient with a cerebral artery aneurysm

A case is described of a 30-year-old insulin-dependent diabetic woman who presented at 25 weeks gestation with frontal headache. Contrast tomography revealed an aneurysm of the middle cerebral artery with no evidence of subarachnoid bleeding. Although elective caesarean section at term was planned, it was performed at gestational week 38 due to the onset of vaginal bleeding and premature labour. In contrast to previous reports, the cerebral aneurysm was not managed surgically at the same time as the delivery, but was treated conservatively. An epidural anaesthetic was performed successfully and postoperative analgesia maintained with a continuous infusion of local anaesthetic in the epidural space. Literature is reviewed and advantages of regional versus general anaesthesia are discussed.

A comparison of the effect of epidural, general, and no anesthesia on funic acid-base values by stage of labor and type of delivery

The effect of epidural anesthesia on neonatal acid-base status, before, during, and after labor, was determined by review of funic blood-gas values from 142 women with normal term pregnancies and normal fetal heart rate patterns. Funic acid-base parameters were compared by type of anesthesia when stratified by mode of delivery (vaginal, cesarean section in the active phase of labor, or elective cesarean section). Use of epidural analgesia for vaginal delivery was associated with significantly longer labor, lower umbilical arterial pH, higher arterial PCO2 and arterial bicarbonate values. In women who had cesarean section in the active phase of labor, use of epidural anesthesia was associated with significantly lower arterial and venous PO2 values when compared with women who received general anesthesia. Patients who had elective cesarean section with epidural anesthesia had funic acid-base values similar to women who had general anesthesia. Epidural analgesia-anesthesia offers no clear advantage to the uncompromised term fetus.