A prospective audit of regional anaesthesia failure in 5080 Caesarean sections

Anaesthesia for Caesarean section was audited over a 5 year period: 5080 cases were performed using spinal 63%, epidural top-up 26%, combined spinal-epidural 5% and primary general anaesthesia 5%. The rate of general anaesthesia conversion of regional anaesthesia was 0.8% for elective and 4.9% for emergency Caesarean section compared to Royal College of Anaesthetists targets of 1% and 3%. The rate of conversion of regional to general anaesthesia in category 1 Caesarean section was 20%. A total of 8% of women had general anaesthesia when both primary general and conversion of regional anaesthesia were combined. The rate of failure to achieve a pain-free operation was 6% with spinals, 24% with epidural top-up and 18% with combined spinal-epidural. Besides the type of anaesthesia and operative urgency, other factors associated with pre-operative failure of regional anaesthesia included body mass index, no previous Caesareans, and indication for Caesarean of acute fetal distress or maternal medical condition. Inadequacy of pre-operative anaesthetic block and duration of surgery were important risk factors for intra-operative failure. For spinal anaesthesia, use of a spinal opioid was associated with less pre-operative failure. For epidural top-up anaesthesia, lower epidural top-up volume was associated with less pre-operative failure, and use of adrenaline was associated with both less pre-operative and intra-operative failure. The rate of serious adverse incidents was 1 : 126 with general anaesthesia and 1 : 501 with regional anaesthesia.     

Combined epidural/spinal anaesthesia for Caesarean section

An evaluation of a 30 gauge spinal needle in a combined epidural/spinal anaesthetic technique for Caesarean section revealed a 25% failure rate of the spinal element. In this unit, no more than 4% of spinal anaesthetics might be expected to fail. One of the reasons for the higher failure rate was that, when using the Tuohy needle as an introducer, the dura was not identified. This prompted us to compare the 'through-the-Tuohy' or needle within needle approach for combined epidural/spinal anaesthesia, with a technique that involved siting the epidural and spinal sequentially in separate spaces. One hundred women requiring elective Caesarean section under spinal anaesthesia were randomised into single or double space groups. The technique failed in 16% of through-the-needle cases, and in 4% of sequential sitings. Combined spinal/epidural anaesthesia for Caesarean section is more successful if each procedure is performed using separate spaces.     

Regional anaesthesia for caesarean section in severe preeclampsia: spinal anaesthesia is the preferred choice

Standard textbooks advocate epidural rather than spinal anaesthesia for caesarean section in severe preeclampsia. The basis for this recommendation is the theoretical risk of severe hypotension but no published scientific studies have been identified to support this assertion. We therefore designed a prospective study to compare spinal versus epidural anaesthesia in severely pre-eclamptic patients requiring hypotensive therapy. Following ethics committee approval, 28 women with preeclampsia requiring hypotensive medication who were scheduled for urgent (not emergency) or elective caesarean section consented to receive epidural or spinal anaesthesia by random assignment. Seven patients were excluded due to protocol violations. Four of these were in the epidural group of which two were excluded due to inadequate analgesia. No spinal patient was excluded because of inadequate analgesia. Mean ephedrine dosage was 5.2 mg (range 0-24 mg) in the spinal group and 6.3 mg (range 0-27 mg) in the epidural group. Six of the 11 patients in the spinal group required no ephedrine as did five of 10 in the epidural group. One patient in the spinal group suffered from mild intraoperative pain. By contrast in the epidural group three patients had mild pain and four others had pain severe enough to warrant intraoperative analgesia. There were no differences in neonatal outcomes. These findings support recent studies suggesting the safety and efficacy of spinal anaesthesia in this group of patients.     

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

Elective Caesarean section deliveries over a 5-year period were studied to compare the effect of epidural block with general anaesthesia on the condition of the infant at birth. The Apgar score and umbilical arterial acid-base status were used as determinants of the latter. Epidural block was used in 139 (22.8%) mothers while 471 (77.2%) were performed under general anaesthesia. No babies in the epidural group were severely depressed (Apgar less than 4), compared with 6.2% in the general anaesthesia group. Only 4.3% of the epidural sections were moderately depressed (Apgar 4-6), compared with 15.4% of the others. These differences remained highly significant when infants of less than 2500 g were excluded, and when matched groups were compared. Mean umbilical arterial pH was similar within the two groups (pH 7.28), and was not consistent with asphyxia in almost 90% of the depressed infants. The findings suggest that general anaesthesia, rather than asphyxia or aortocaval compression, is responsible for most of the depressed infants born by elective Caesarean section. This may involve over 20% of babies delivered in this manner, so greater use of epidural block for elective Caesarean section is recommended. Further investigations are required to improve results with general anaesthesia.     

Spinal anaesthesia for obstetrics

For a long time, epidural anaesthesia has been considered the method of choice for Caesarean delivery. The increased incidence of hypotension by the rapid onset of sympathetic blockade under spinal anaesthesia has been associated with a decline in uteroplacental blood flow and significant fetal acidosis, which may compromise neonatal well-being. Nevertheless, a decrease in fetal pH has not been shown to reduce neonatal Apgar or neurobehavioural assessment scores. Maternal blood pressure can be preserved with little side effects with low doses of vasopressors. On the other hand, spinal anaesthesia conveys significant advantages over epidural anaesthesia such as the simplicity of its use and the speed of onset, which allows neuraxial anaesthesia in urgent Caesarean sections and thus reduces the necessity for general anaesthesia. The small doses of local anaesthetics required to perform spinal anaesthesia reduce the risks of systemic toxicity to zero. Spinal anaesthesia is now considered the method of choice for urgent Caesarean section. The use of intrathecal opioids has profoundly changed the quality of spinal anaesthesia, with improved analgesia, a reduction in local anaesthetic requirements and shorter duration of motor blockade. Preliminary studies indicate that spinal anaesthesia may be safely performed in patients with severe pre-eclampsia, in whom spinal anaesthesia was previously considered contraindicated.     

Spinal haematoma following epidural anaesthesia in a patient with eclampsia

A patient with a twin pregnancy required a Caesarean section for severe pre-eclampsia. Her platelet count was 71 x 10(9).l-1. Epidural anaesthesia was performed after platelet transfusion. A spinal epidural haematoma was diagnosed postoperatively. A generalised tonic-clonic seizure sparing the lower limbs enabled early diagnosis to be made. The patient recovered with no permanent neurological damage after laminectomy and clot removal. The risks and benefits of regional techniques require careful consideration, and postoperative monitoring for recovery of neural blockade is essential.     

Real-time ultrasonic observation of combined spinal-epidural anaesthesia

BACKGROUND AND OBJECTIVE: The quality of combined spinal-epidural anaesthesia mainly depends on accurate identification of the epidural space. The real-time ultrasound control of the procedure for puncture was therefore evaluated. METHODS: Thirty parturients scheduled for Caesarean section were randomized to three equal groups. Ten control patients received conventional combined spinal-epidural anaesthesia. Ten of the remaining patients received ultrasonic scans by an offline scan technique, and 10 received online imaging of the lumbar region during epidural puncture. The epidural space was identified and needle advancement was surveyed through the interspinal and flaval ligaments. The number of attempts to advance the needle to achieve a successful puncture was measured and compared, as well as the number of vertebral interspaces punctured before successful entry into the epidural space. RESULTS: There was no difference between patient characteristics in the three groups. The visualization of the epidural structures and of the needle manipulations was very effective. In the ultrasound group, the reduction in the number of attempts at puncture was significant (P < 0.036). The number of interspaces necessary for puncture was reduced (P < 0.036) in the ultrasound online group compared with controls. The number of spinal needle manipulations was significantly reduced (P < 0.036). CONCLUSIONS: Real-time ultrasonic scanning of the lumbar spine is an easy procedure. It provides an accurate reading of the location of the needle tip and facilitates the performance of combined spinal-epidural anaesthesia.     

Epidural anaesthesia for caesarean section in an achondroplastic dwarf

This report describes the anaesthetic management of an 18-yr-old achondroplastic dwarf who presented for elective Caesarean section. Epidural anaesthesia was performed without technical difficulty using 8 ml carbonated lidocaine 2% with epinephrine 1:200,000. Although the skeletal abnormalities of achondroplasia have been cited as contraindications to the use of epidural anaesthesia, clinical experience does not support this contention. Previous reports have described technical difficulties in these patients, such as dural puncture and inability to advance the catheter into the epidural space, but no serious complications resulted and epidural anaesthesia was successful on subsequent attempts. The existing literature on the anaesthetic management of achondroplasia for Caesarean section is reviewed and considerations are presented concerning the choice of local anaesthetic, the epidural test dose, and dose titration.     

Spinal myoclonus following combined spinal-epidural anaesthesia for Caesarean section

A nulliparous woman presented with pre-eclampsia at 39 weeks' gestation. A combined spinal-epidural anaesthesia was employed for Caesarean section but the spinal component produced no discernible block, so the epidural was topped up with 20 ml ropivacaine 0.75% without problem and surgery was uneventful. A week after delivery she developed twitching of her legs and opisthotonus, that was initially thought to be eclampsia but was subsequently diagnosed as spinal myoclonus. She was treated with oral carbamazepine and diazepam, with improvement over the next 4 days, and discharged home a week later taking oral carbidopa and levodopa. Her symptoms resolved completely 6 months after the initial event.     

Ephedrine requirements are reduced during spinal anaesthesia for caesarean section in preeclampsia

BACKGROUND: Despite controversy over the haemodynamically safest blockade for caesarean section in women with severe preeclampsia, an increasing number of anaesthetists now opt for spinal anaesthesia. In a previous study we found that spinal compared to epidural anaesthesia offered an equally safe but more effective option for these patients. The current study was designed to compare the hypotension induced by spinal anaesthesia, as measured by ephedrine requirement, between 20 normotensive and 20 severely preeclamptic but haemodynamically stabilised women. METHOD: Standardised spinal anaesthesia was instituted and ephedrine was given in boluses of 6 mg if the systolic pressure fell >20% from the baseline, or if the patient exhibited symptoms of hypotension. RESULTS: The mean ephedrine requirement of the normotensive group (27.9+/-11.6 mg) was significantly greater (P<0.01) than that of the preeclamptic group (16.4+/-15.0 mg). CONCLUSION: This suggests that the hypotension induced by spinal anaesthesia in women with severe but haemodynamically stabilised preeclampsia, is less than that of normotensive patients.     

Obstetrical anaesthesia in Ontario

The purpose of this study was to determine the availability of regional anaesthesia for Caesarean section, of epidural opioids and patient-controlled analgesia after Caesarean section, and of epidural and other forms of analgesia in labour. A mail survey was sent to the “Head Nurse, Department of Obstetrics” at each of the 142 hospitals in Ontario with designated obstetric beds. Responses were obtained from 100% of hospitals. For Caesarean Section, general anaesthesia was used in all hospitals, and was the only option in seven. Epidural anaesthesia was used in 93% of hospitals, and spinal anaesthesia in 48%. Postoperatively, patient-controlled analgesia was used in 31% of hospitals and spinal opioids in 28%. In 66 hospitals, im or iv opioids were the only types of analgesia available. For analgesia in labour, im or iv opioids were used in 96% of hospitals, nitrous oxide was used in 75%, epidural analgesia in 75%, transcutaneous electrical nerve stimulation in 52% and patient-controlled analgesia in 10%. The overall epidural rate was 38%. Although the average rate in the 73 hospitals with fewer than 500 births per year was only 6% 14 large hospitals had an epidural rate of 60% or higher. It is concluded that regional techniques for peripartum analgesia have been widely accepted. Analgesia after Caesarean section could be improved. Epidural analgesia should be more widely available, especially in the many small hospitals in Ontario.     

The impact of increasing the use of regional anaesthesia for emergency caesarean section

BACKGROUND AND OBJECTIVE: In 1991 general anaesthesia was used extensively for emergency Caesarean section at Haukeland University Hospital even in patients with an ongoing epidural infusion. With increased knowledge of the potential safety benefits of regional anaesthesia and increased experience with the technique, we decided to use indwelling epidural catheters for emergency Caesarean section. METHODS: We conducted a retrospective analysis of a full annual data set on emergency Caesarean section in parturients with ongoing epidural analgesia in 1997 and compared it with a similar data set from 1991. RESULTS: Epidural anaesthesia was used significantly more often in 1997 with 115 (78%) cases than in 1991 with five (12%) cases (P < 0.001). Elapsed time before adequate anaesthesia and the start of surgery was significantly shorter in 1991 (mean 8.3 min) compared to 1997 (mean 13 min) (P < 0.001). No deaths or major complications were observed in either group. Intraoperative minor complications were observed more frequently in 1997 with 70 cases (47%) than in 1991 with two cases (6%) (P < 0.001). The principal complications were hypotension and nausea. Postoperative complications in mother and neonate were similar in both groups. There was a significantly shorter mean hospital stay in 1997 (6 days), compared with 1991 (8 days) (P < 0.001). CONCLUSION: The increase in the use of indwelling epidural catheters for emergency Caesarean section has resulted in a significant increase in the use of regional anaesthesia. A modest increase in time elapsed before start of surgery was observed although there were no significant differences in the number of neonates with low Apgar scores. No major complications were observed, but there was an increased frequency of minor complications in 1997.     

Prophylactic intravenous bolus ephedrine for elective Caesarean section under spinal anaesthesia

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and optimal dose of prophylactic intravenous ephedrine for the prevention of maternal hypotension associated with spinal anaesthesia for Caesarean section. METHODS: After patients had received an intravenous preload of 0.5 L of lactated Ringer's solution, spinal anaesthesia was administered in the sitting position with hyperbaric bupivacaine 2.5 mL 0.5% combined with 25 microg fentanyl. A total of 68 patients were randomized to receive a simultaneous 2 mL bolus intravenously of either 0.9% saline (Group C, n = 20), ephedrine 6 mg (Group E-6, n = 24), or ephedrine 12 mg (Group E-12, n = 22). Further rescue boluses of ephedrine 6 mg were given if systolic arterial pressure fell to below 90 mmHg, greater than 30% below baseline, or if symptoms suggestive of hypotension were reported. RESULTS: There was a significantly higher incidence of hypotension in Group C (60% patients) compared to Group E-12 (27%), but not in Group E-6 (50%). The 95% Confidence Interval for the difference in proportions between Groups C and E-12 was 6-60%, P < 0.05. Fewer rescue boluses of ephedrine were required in Group E-12 compared with Group C (1.8 +/- 1.2 vs. 3.3 +/- 2.1, P < 0.05). There were no significant differences in the incidence of maternal nausea or vomiting, or of neonatal acidaemia between groups. CONCLUSION: A prophylactic bolus of ephedrine 12 mg intravenously given at the time of intrathecal block, plus rescue boluses, leads to a lower incidence of hypotension following spinal anaesthesia for elective Caesarean section compared to intravenous rescue boluses alone.     

Emergency Caesarean section: best practice

Good multidisciplinary communication is crucial to the safe management of women requiring non-elective Caesarean section. Anaesthetists should participate actively in resuscitation of the fetus in utero; relief of aortocaval compression is paramount. Epidural top-up with levobupivacaine 0.5% is the anaesthetic of choice for women who have been receiving labour epidural analgesia. If epidural top-up fails to provide bilateral light touch anaesthesia from S5 - T5, a combined spinal-epidural technique with small intrathecal dose of local anaesthetic is a useful approach. Pre-eclampsia is not a contra-indication to single-shot spinal anaesthesia, which is the technique of choice for most women presenting for Caesarean section without an epidural catheter in situ. Induction and maintenance doses of drugs for general anaesthesia should not be reduced in the belief that the baby will be harmed. Early postoperative observations are geared towards the detection of overt or covert haemorrhage.     

Intravenous ketoprofen and epidural sufentanil analgesia in children after combined spinal-epidural anaesthesia

BACKGROUND: Epidural opioid analgesia has become more popular for postoperative pain treatment in children. Epidural opioids are associated with adverse effects such as respiratory depression, excessive sedation, protracted vomiting, urinary retention and pruritus. Following minor surgery, ketoprofen has a synergistic effect with opioids, resulting in an improved analgesia without increase in incidence of adverse effects. To see whether this is also true following major surgery, we compared the effect of i.v. ketoprofen and placebo as an adjuvant to epidural sufentanil analgesia. METHODS: A prospective, randomised, double-blind, placebo-controlled, parallel-group study design was used in 58 children, aged 1-15 years, receiving a standardised combined spinal-epidural anaesthesia. Intravenous ketoprofen or saline was provided as a bolus and a continuous infusion in addition to epidural sufentanil infusion, which was adjusted as clinically required. Epidural bupivacaine was used for rescue analgesia. The study drug infusion was discontinued when pain scores were <3 on a 0-10 scale for 6 h with an epidural sufentanil infusion rate of 0.03 microg kg(-1) h(-1). RESULTS: Children in the ketoprofen group received less rescue analgesia (none/29 vs. 8/29 children in the placebo group). In the ketoprofen group, criteria to discontinue epidural sufentanil were achieved more often (14 vs. 6 children) before the end of the 72 h study period. Less children in the ketoprofen group suffered pruritus (13 vs. 4). The incidence of nausea/retching and vomiting was similar (11 vs. 12) in both groups. CONCLUSION: In this study, ketoprofen as a background analgesic to epidural sufentanil provided improved postoperative analgesia and reduced incidence of adverse effects of the epidural opioid.     

General anaesthesia versus epidural anaesthesia for primary caesarean section--a comparative study.

Forty-seven healthy parturients undergoing elective Caesarean section were randomly allocated to either general anaesthesia (n = 24) or epidural anaesthesia (n = 23) under standardized anaesthetic and surgical conditions. Seven women of the epidural group required additional systemic analgesia or sedation following delivery of the neonate. Nine of 24 newborns obtained 1-min Apgar scores below 7 after general anaesthesia compared to only 3/23 after epidural anaesthesia. The time period to establish normal colour in the babies was 2.2 min after epidural and 4.9 min after general anaesthesia. Three of the 24 general-anaesthesia newborns demonstrated a tendency to hypotonia compared to only one in the epidural group. Twenty-four hours and 7 days after delivery all infants of both groups were completely normal. At the time of delivery maternal PO2 was higher in the general anaesthesia compared to the epidural group, due to higher inspired oxygen concentrations. Comparable results were obtained in umbilical PO2 venous values; lower pH values, however, were observed in the umbilical artery after general anaesthesia. There were no significant differences in the glucose levels between the groups. A significant correlation was established between uterine incision-delivery interval and 1-min neonatal Apgar scores in the general-anaesthesia group, but not in the epidural group. Our investigation did not show either the incision-delivery interval or the start of operation-delivery interval to play a role in neonatal outcome. Epidural anaesthesia is superior to general anaesthesia in Caesarean section under normal conditions with regard to neonatal outcome. Whether this is also true for critical conditions cannot be concluded from this study.     

Epidural and spinal (subarachnoid) anaesthesia for Caesarean section

Regional anaesthesia for Caesarean section is increasing in popularity — a trend encouraged by obstetric anaesthetists because of its greater safety and the emotional benefits tomother and baby. Such anaesthesia is easier to provide for elective cases, but even in the case of many emergency or semi-emergency Caesarean sections there may be time to extend an epidural already in use, or to use spinal anaesthesia.The reason for the difficulty in providing effective epidural anaesthesia in some cases has been clarified with the identification of variable bands and septa in the epidural space. Spinal block gives more reliable anaesthesia but carries a higher risk of hypotension so that monitoring to detect, and measures to prevent it must be particularly rigorous.Two new developments which are likely to play a part in improving regional anaesthesia for Caesarean section and post-operative pain relief are continuous spinal and combined spinal-epidural techniques. In the case of the former, particular interest is being focused on very fine microcatheters, but the incidence of post-spinal headache with larger catheters is also being reassessed. The combined technique gives the speed of onset and reliability of the spinal block with the flexibility of analgesia provided by the epidural catheter, as well as the advantage of the Tuohy needle acting as guide for the very fine spinal needles.     

Paraesthesia during the needle-through-needle and the double segment technique for combined spinal epidural anaesthesia

Paraesthesia during regional anaesthesia is an unpleasant sensation for patients and, more importantly, in some cases it is related to neurological injury. Relatively few studies have been conducted on the frequency of paraesthesia during combined spinal epidural anaesthesia. We compared two combined spinal epidural anaesthesia techniques: the needle-through-needle technique and the double segment technique in this respect. We randomly allocated 116 parturients undergoing elective Caesarean section to receive anaesthesia using one of these techniques. Both techniques were performed using a 27G pencil point needle, an 18G Tuohy needle, and a 20G multiport epidural catheter from the same manufacturer. The overall frequency of paraesthesia was higher in the needle-through-needle technique group (56.9% vs. 31.6%, p = 0.011). The frequency of paraesthesia at spinal needle insertion was 20.7% in the needle-through-needle technique group and 8.8% in the double segment technique group; whereas the frequency of paraesthesia at epidural catheter insertion was 46.6% in the needle-through-needle technique group and 24.6% in the double segment technique group.     

Cardiovascular collapse following epidural anaesthesia for Caesarean section in a patient with aortic incompetence

A death following epidural anaesthesia for Caesarean section in a patient with aortic incompetence and pre-eclampsia is described. Possible hazards of epidural anaesthesia in aortic incompetence are described and it is suggested that reduction of total peripheral resistance is contraindicated in such patients.     

Comparison of epidural anaesthesia with ropivacaine 0.5% and bupivacaine 0.5% for Caesarean section

PURPOSE: To compare ropivacaine 0.5% with bupivacaine 0.5% for epidural anaesthesia for Caesarean section. METHODS: Healthy pregnant women, scheduled for elective Caesarean section were enrolled into this randomized, double-blind, parallel-group study. Epidural block was obtained with 20-30 ml of ropivacaine (group R) or bupivacaine (group B) and surgery started when anaesthesia was reached T6. Maternal heart rate and blood pressure and fetal heart rate were assessed before the test dose and at five minute intervals until the end of surgery. At the same intervals, sensory and motor block characteristics were determined. Apgar scores and Neurologic and Adaptive Capacity Scores (NACS) were determined after delivery. Adverse events were recorded. RESULTS: Sixty-five patients were enrolled and data from 61 were available for analysis; 30 ropivacaine and 31 bupivacaine. Time from the end of the last injection to the start of surgery was 46 +/- 13 min (mean +/- SD) in gp R and 53 +/- 25 min in gp B (P:NS). The median duration of analgesia varied between 1.7 and 4.2 hr in gp R and between 1.8 and 4.4 hr in gp B (P:NS). In patients who developed Bromage 4 block, it persisted longer in those in gp B (2.5 hr) than in gp R (0.9 hr) (P < 0.05). The quality of analgesia was satisfactory in 27/29 patients (93%) in gp R and 27/31 patients (87%) in gp B (P:NS), although supplemental i.v. opioid was required in ten and seven patients, respectively. The most common adverse events in the mother were hypotension (63% gp R and 61% in gp B) (NS) and nausea (30% and 58%, in group R and B, respectively) (P = 0.05). Apgar scores were 7 after five minutes in all neonates. CONCLUSION: Ropivacaine 0.5% and bupivacaine 0.5% provided effective epidural anaesthesia for Caesarean section although supplementation with i.v. opioid was commonly required.