Anesthetic quality during cesarean section following subarachnoid or epidural administration of bupivacaine with or without fentanyl

Intrathecal Opioid Dosing During Spinal Anesthesia for Cesarean Section: An Integrative Review

Approximately one in three women in the United States deliver via Cesarean section (CS), making it one of the most common surgical procedures in the country. Neuraxial (spinal or epidural) anesthesia is the most effective and common anesthetic approach for pain relief during a CS in the United States and often associated with adverse effects such as nausea, vomiting, and pruritus. While recommended dose ranges exist to protect patient safety, there are a lack of guidelines for opioid doses that both optimize postoperative pain management and minimize side effects. This integrative review synthesizes the evidence regarding best practice of opioid dosing in neuraxial anesthesia for planned CS. Evidence supports the use of lower doses of intrathecal (IT) opioids, specifically 0.1 morphine, to achieve optimal pain management with minimal nausea, vomiting, and pruritus. Lower IT doses have potential to achieve pain management and to alleviate preventable side effects in women delivering via CS.

The decision to delivery interval in emergency caesarean sections: Impact of anaesthetic technique and work shift

Background: One important task of the emergency anaesthesia service is to provide rapid, safe and effective anaesthesia for emergency caesarean sections (ECS). A Decision to Delivery Interval (DDI) <30 minutes for ECS is a quality indicator for this service. The aim of this study was to assess the DDI and the impact of chosen anaesthetic technique (general anaesthesia (GA), spinal anaesthesia (SPA) with opioid supplementation, or "top-up" of labour epidural analgesia (tEDA) with local anaesthesia and fentanyl mixture) and work shift for ECS at Danderyds Hospital, Sweden. Methods: A retrospective chart review of ECS at Danderyds Hospital was performed between January and October 2016. Time between decision for CS, start of anaesthesia, time for incision and delivery, type of anaesthetic technique, and time of day, working hours or on call and day of week, Monday - Friday, and weekend was compiled and analysed. Time events are presented as mean ± standard deviation. Non-parametric tests were used. Results: In total, 135 ECS were analysed: 92% of the cases were delivered within 30 minutes and mean DDI for all cases was 17.3±8.1 minutes. GA shortened the DDI by 10 and 13 minutes compared to SPA and tEDA (p<0.0005). DDI for SPA and tEDA did not differ. There was no difference in DDI regarding time of day or weekday. Apgar <7 at 5' was more commonly seen in ECS having GA (11 out of 64) compared to SPA (2/30) and tEDA (1/41) (p<0.05). Conclusion: GA shortens the DDI for ECS, but the use of SPA as well as tEDA with opioid supplementation maintains a short DDI and should be considered when time allows. Top-up epidural did not prolong the DDI compared to SPA. The day of week or time of ECS had no influence on the anaesthesia service as measured by the DDI.

The decision to delivery interval in emergency caesarean sections: Impact of anaesthetic technique and work shift

Background: One important task of the emergency anaesthesia service is to provide rapid, safe and effective anaesthesia for emergency caesarean sections (ECS). A Decision to Delivery Interval (DDI) <30 minutes for ECS is a quality indicator for this service. The aim of this study was to assess the DDI and the impact of chosen anaesthetic technique (general anaesthesia (GA), spinal anaesthesia (SPA) with opioid supplementation, or "top-up" of labour epidural analgesia (tEDA) with local anaesthesia and fentanyl mixture) and work shift for ECS at Danderyds Hospital, Sweden. Methods: A retrospective chart review of ECS at Danderyds Hospital was performed between January and October 2016. Time between decision for CS, start of anaesthesia, time for incision and delivery, type of anaesthetic technique, and time of day, working hours or on call and day of week, Monday - Friday, and weekend was compiled and analysed. Time events are presented as mean ± standard deviation. Non-parametric tests were used. Results: In total, 135 ECS were analysed: 92% of the cases were delivered within 30 minutes and mean DDI for all cases was 17.3±8.1 minutes. GA shortened the DDI by 10 and 13 minutes compared to SPA and tEDA (p<0.0005). DDI for SPA and tEDA did not differ. There was no difference in DDI regarding time of day or weekday. Apgar <7 at 5' was more commonly seen in ECS having GA (11 out of 64) compared to SPA (2/30) and tEDA (1/41) (p<0.05). Conclusion: GA shortens the DDI for ECS, but the use of SPA as well as tEDA with opioid supplementation maintains a short DDI and should be considered when time allows. Top-up epidural did not prolong the DDI compared to SPA. The day of week or time of ECS had no influence on the anaesthesia service as measured by the DDI.

[Recent standards in management of obstetric anesthesia]

The following article contains information not only for the clinical working anaesthesiologist, but also for other specialists involved in obstetric affairs. Besides a synopsis of a German translation of the current "Practice Guidelines for Obstetric Anaesthesia 2016" [1], written by the American Society of Anesthesiologists, the authors provide personal information regarding major topics of obstetric anaesthesia including pre-anaesthesia patient evaluation, equipment and staff at the delivery room, use of general anaesthesia, peridural analgesia, spinal anaesthesia, combined spinal-epidural anaesthesia, single shot spinal anaesthesia, and programmed intermittent epidural bolus.

Epidural local anaesthetics versus opioid-based analgesic regimens for postoperative gastrointestinal paralysis, vomiting and pain after abdominal surgery

BACKGROUND

Gastrointestinal paralysis, nausea and vomiting and pain are major clinical problems following abdominal surgery. Anaesthetic and analgesic techniques that reduce pain and postoperative nausea and vomiting (PONV), while preventing or reducing postoperative ileus, may reduce postoperative morbidity, duration of hospitalization and hospital costs. This review was first published in 2001 and was updated by new review authors in 2016.

OBJECTIVES

To compare effects of postoperative epidural analgesia with local anaesthetics versus postoperative systemic or epidural opioids in terms of return of gastrointestinal transit, postoperative pain control, postoperative vomiting, incidence of anastomotic leak, length of hospital stay and costs after abdominal surgery.

SEARCH METHODS

We identified trials by conducting computerized searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 12), MEDLINE (from 1950 to December 2014) and EMBASE (from 1974 to December 2014) and by checking the reference lists of trials retained. When we reran the search in February 2016, we added 16 potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate these studies into formal review findings during the next review update.

SELECTION CRITERIA

We included parallel randomized controlled trials comparing effects of postoperative epidural local anaesthetic versus regimens based on systemic or epidural opioids.

DATA COLLECTION AND ANALYSIS

We rated the quality of studies by using the Cochrane 'Risk of bias' tool. Two review authors independently extracted data and judged the quality of evidence according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation Working Group) scale.

MAIN RESULTS

We included 128 trials with 8754 participants in the review, and 94 trials with 5846 participants in the analysis. Trials included in the review were funded as follows: charity (n = 19), departmental resources (n = 8), governmental sources (n = 15) and industry (in part or in total) (n = 15). The source of funding was not specified for the other studies.Results of 22 trials including 1138 participants show that an epidural containing a local anaesthetic will decrease the time required for return of gastrointestinal transit as measured by time to first flatus after an abdominal surgery (standardized mean difference (SMD) -1.28, 95% confidence interval (CI) -1.71 to -0.86; high quality of evidence; equivalent to 17.5 hours). The effect is proportionate to the concentration of local anaesthetic used. A total of 28 trials including 1559 participants reported a decrease in time to first faeces (stool) (SMD -0.67, 95% CI -0.86 to -0.47; low quality of evidence; equivalent to 22 hours). Thirty-five trials including 2731 participants found that pain on movement at 24 hours after surgery was also reduced (SMD -0.89, 95% CI -1.08 to -0.70; moderate quality of evidence; equivalent to 2.5 on scale from 0 to 10). From findings of 22 trials including 1154 participants we did not find a difference in the incidence of vomiting within 24 hours (risk ratio (RR) 0.84, 95% CI 0.57 to 1.23; low quality of evidence). From investigators in 17 trials including 848 participants we did not find a difference in the incidence of gastrointestinal anastomotic leak (RR 0.74, 95% CI 0.41 to 1.32; low quality of evidence). Researchers in 30 trials including 2598 participants noted that epidural analgesia reduced length of hospital stay for an open surgery (SMD -0.20, 95% CI -0.35 to -0.04; very low quality of evidence; equivalent to one day). Data on costs were very limited.

AUTHORS' CONCLUSIONS

An epidural containing a local anaesthetic, with or without the addition of an opioid, accelerates the return of gastrointestinal transit (high quality of evidence). An epidural containing a local anaesthetic with an opioid decreases pain after abdominal surgery (moderate quality of evidence). We did not find a difference in the incidence of vomiting or anastomotic leak (low quality of evidence). For open surgery, an epidural containing a local anaesthetic would reduce the length of hospital stay (very low quality of evidence).

Practice Guidelines for Obstetric Anesthesia

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology present an updated report of the Practice Guidelines for Obstetric Anesthesia.

Supplemental Digital Content is available in the text.

Future of regional anaesthesia

The development and refinement of regional anaesthetic techniques for various types of surgery, mainly obstetric, ophthalmic and orthopaedic surgery, and of continuous regional analgesia continues. Suitable analgesic drug mixtures, and concentrations, will be further tested in order to find the ideal analgesic regimen for each type of surgery and for the individual patient. No new local anaesthetics or equipment for clinical use are expected in the near future. Improvement therefore depends much on how the anaesthesiologists use the present drugs, needles, nerve detection devices, catheters and pumps. During training in regional anaesthesia for the speciality of anaesthesiology and intensive care medicine, it may suffice to concentrate only on certain common techniques such as epidural block, spinal block, axillary brachial plexus block, intravenous regional anaesthesia and femoral nerve block. Rare regional anaesthetic blocks and invasive techniques should be mastered and taught by specially trained regional anaesthesiology experts. In chronic pain, regional anaesthetic blocks with local anesthetics are not expected to play any major therapeutic role. However, nerve blocks can be useful for diagnostic purposes and in order to facilitate rehabilitation in chronic pain syndromes.

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.

Efficacy of sufentanil addition to ropivacaine epidural anaesthesia for Caesarean section

BACKGROUND

This prospective double-blind trial evaluated the effect of sufentanil addition to epidural ropivacaine for elective Caesarean section.

METHODS

Sixty healthy parturients were randomly assigned to receive an initial dose of 90 mg of plain ropivacaine, or 90 mg of ropivacaine plus 10 or 20 microg of sufentanil (n = 20 each). Before surgery, if necessary, additional epidural ropivacaine was injected. Primary outcome parameter was time to achieve sensory block at T4.

RESULTS

Time to reach the sensory block was remarkably reduced (P < 0.001 each) by addition of 10 or 20 microg of sufentanil (21 +/- 8 min, 15 +/- 5 min, 11 +/- 4 min in the plain ropivacaine, the 10- and 20-microg sufentanil groups, respectively) whereas the visual analogue scale (VAS) scores at delivery were significantly reduced (P = 0.028) only by 20 microg of sufentanil (32 +/- 35 mm in the plain ropivacaine vs. 9 +/- 19 mm in the 20-microg sufentanil groups). The total dose of ropivacaine was significantly lower (P = 0.005) in patients receiving 20 microg of sufentanil (100.5 +/- 15.0 mg) compared with those treated with plain ropivacaine (118.5 +/- 17.3 mg). The incidence of maternal side-effects (hypotension, bradycardia, nausea, vomiting, shivering, pruritus) and neonatal outcome [APGAR score, neurologic and adaptive capacity (NAC) score, umbilical cord blood-gas values] did not differ between the groups.

CONCLUSION

Our results suggest that addition of 20 microg of sufentanil improved the epidural anaesthesia with ropivacaine 0.75% for Caesarean section.

Epidural ropivacaine 1% with and without sufentanil addition for Caesarean section

BACKGROUND

So far only ropivacaine concentrations of 0.5 and 0.75% have been used for Caesarean section. This prospective double-blind trial evaluated the anaesthetic quality of ropivacaine 1% with and without sufentanil addition.

METHODS

Three groups of patients (n=20 each) scheduled for an elective Caesarean section were studied. The patients received initially 120 mg ropivacaine, or 120 mg ropivacaine plus 10 microg or 20 microg sufentanil. Additional epidural ropivacaine was injected if necessary. Primary outcome parameter was time to achieve sensory block at T4. Moreover, pain intensity at delivery (visual analogue scale, VAS), incidence of maternal side-effects (hypotension, bradycardia, nausea, vomiting, shivering, pruritus), and neonatal outcome (Apgar score, neurologic and adaptive capacity score, umbilical cord blood-gas values) were recorded.

RESULTS

The onset time for the sensory block was not significantly different among the groups. Also, VAS scores at delivery did not differ significantly between the plain ropivacaine 1% group (18 +/- 29 mm), the 10-microg sufentanil group (1 +/- 5 mm), and the 20-microg sufentanil group (6 +/- 18 mm). The total dose of ropivacaine was significantly higher in the plain ropivacaine 1% group (145 +/- 19 mg) compared to the patients receiving additional 10 microg sufentanil (130 +/- 15 mg, P = 0.02) or 20 microg sufentanil (129 +/- 16 mg, P = 0.01). The incidence of maternal side-effects and neonatal outcome were similar in all groups.

CONCLUSION

Ropivacaine 1% alone provided sufficient analgesia. Sufentanil addition did not significantly improve the quality of epidural anaesthesia with ropivacaine 1.0% for Caesarean section.

Spinal versus epidural anaesthesia for caesarean section

BACKGROUND

Regional anaesthesia (spinal or epidural anaesthesia) for caesarean section is the preferred option when balancing risks and benefits to the mother and her fetus. Spinal anaesthesia for caesarean section is thought to be advantageous due to simplicity of technique, rapid administration and onset of anaesthesia, reduced risk of systemic toxicity and increased density of spinal anaesthetic block.

OBJECTIVES

To assess the relative efficacy and side-effects of spinal versus epidural anaesthesia in women having caesarean section.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Trials Register (February 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2003).

SELECTION CRITERIA

Types of studies considered for review include all published randomised controlled trials involving a comparison of spinal with epidural anaesthesia for caesarean section.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trials for inclusion. Review Manager software was used for calculation of the treatment effect represented by relative risk (RR) and weighted mean difference (WMD) using a random effects model with 95% confidence intervals (CI).

MAIN RESULTS

Ten trials (751 women) met our inclusion criteria. No difference was found between spinal and epidural techniques with regards to failure rate (RR 0.98, 95% CI 0.23 to 4.24; four studies), need for additional intraoperative analgesia (RR 0.88, 95% CI 0.59 to 1.32; five studies), need for conversion to general anaesthesia intraoperatively, maternal satisfaction, need for postoperative pain relief and neonatal intervention. Women receiving spinal anaesthesia for caesarean section showed reduced time from start of the anaesthetic to start of the operation (WMD 7.91 minutes less (95% CI -11.59 to -4.23; four studies), but increased need for treatment of hypotension RR 1.23 (95% CI 1.00 to 1.51; six studies).

REVIEWERS' CONCLUSIONS

Both spinal and epidural techniques are shown to provide effective anaesthesia for caesarean section. Both techniques are associated with moderate degrees of maternal satisfaction. Spinal anaesthesia has a shorter onset time, but treatment for hypotension is more likely if spinal anaesthesia is used. No conclusions can be drawn about intraoperative side-effects and postoperative complications because they were of low incidence and/or not reported.

Which administration route of fentanyl better enhances the spread of spinal anaesthesia: intravenous, intrathecal or both?

BACKGROUND

To enhance the spread of spinal anaesthesia, fentanyl may be administered intrathecally (i.t.) or intravenously (i.v.). The purpose of this prospective study was to investigate the effects of fentanyl administered i.v., i.t. or concurrently by both i.v. and spinal routes on the spread of spinal anaesthesia.

METHODS

Sixty patients were randomly assigned to one of three groups. In Groups I and II, spinal anaesthesia was performed with plain bupivacaine 10 mg plus 20 micro g fentanyl and in Group III with 10 mg of plain bupivacaine. The level of first peak sensory block was marked. In addition, fentanyl 50 micro g was administered i.v. in Groups II and III or by saline in Group I after the sensory blockade reached the highest dermatomal level. Ten minutes after i.v. administration, the level of the second peak sensory block was marked. The distance between the first- and second-highest levels of sensory block was measured.

RESULTS

The distance between the first- and second-highest level of sensory block was significantly different for the three groups: Group II (5.8 +/- 2.6 cm) > Group III (2.9 +/- 2.1 cm) > Group I (-0.15 +/- 1.7 cm). The peak dermatomal level of spinal block was significantly higher in Group II [T4 (T3-T7)] than in Group I [T6 (T4-T9)] and Group III [T6 (T4-T8)]. In Groups I and II the sensory block regressed to S2 for a longer period of time than it did in Group III.

CONCLUSION

Both the spinal and systemic administration of fentanyl enhanced the spread of spinal anaesthesia. The co-administration of spinal and i.v. fentanyl produced a greater increase in the cephalad spread of spinal block.

Mechanisms and management of an incomplete epidural block for cesarean section

Epidural blockade is an important option for anesthesia in parturients undergoing abdominal delivery. Despite the multiple benefits of this method, there is at least one significant downside--a relatively high occurrence of unsatisfactory anesthesia that requires intervention. Depending on the presumed mechanism of epidural block failure and other clinically relevant factors (e.g., timing of diagnosis, urgency of the procedure, and so forth), certain effective measures are recommended to successfully manage this demanding situation. In general, it is important to make every effort to make the pre-existing epidural effective or replace it with another regional technique, because overall, regional anesthesia is associated with significantly lower maternal mortality. It is important to identify a dysfunctional epidural block preoperatively before a maximum volume of local anesthetic has been administered. If catheter manipulation does not produce substantial improvement, and there is no time constraint, it is safe and reasonable to replace the epidural catheter. However, risks associated with excessive volume of local anesthetic should be kept in mind. Additional epidural injections or a second catheter placement might be considered under special circumstances. Single-shot spinal anesthesia after a failed epidural may provide fast onset and reliable surgical anesthesia. Available data, although limited and contradictory, suggest the possibility of unpredictably high or total spinal anesthesia. Many authors, however, believe that appropriate precautions and modifications in technique make this a safe alternative. These modifications include limiting the amount of epidural local anesthetic administered when diagnosing a nonfunctioning epidural and decreasing the dose of intrathecal local anesthetic by 20% to 30%. If there is no documented block when the spinal is inserted, and more than 30 minutes have passed from the last epidural dose, it is probably safe to use a normal dose of local anesthetic. Continuous spinal anesthesia with a macro catheter might be a dependable alternative, particularly if large amounts of local anesthetic have already been used or the patient's airway is a cause for concern. Although there are no reports of combined spinal epidural anesthesia being used in this context, it would appear to be an attractive alternative. It allows the anesthesiologist to give smaller doses intrathecally, while still offering the flexibility of augmenting the block if needed. When inadequate epidural block becomes apparent during surgery there are limited alternatives. Depending on the origin and the pattern of inadequate anesthesia, options may include psychological support, supplementation with a variety of inhalational and intravenous agents, and local anesthetic infiltration. Induction of general anesthesia is typically left as a backup option, but must be strongly considered if the patient continues to have pain/discomfort.

Pulmonary hypertension complicating twin pregnancy: continuous spinal anaesthesia for caesarean section

A case of secondary pulmonary hypertension complicating twin pregnancy and necessitating caesarean section is presented. A planned team approach involving senior consultants in obstetrics, cardiology, neonatology and cardiac and obstetric anaesthesia resulted in successful perioperative management. Continuous spinal anaesthesia was the chosen technique to give adequate operating conditions with least haemodynamic disturbance. This is the first report of continuous spinal anaesthesia in such a condition.

Diclofenac in the treatment of pain after caesarean delivery. An opioid-saving strategy

OBJECTIVE

Pain relief of good quality after caesarean section (CS) results in early mobilization and good early mother-child interaction. Patient-controlled analgesia (PCA), with systemic opioids, gives a very high level of patient satisfaction. However, opioids have well documented side-effects i.e. sedation, nausea and respiratory depression. To minimize the risk of such negative effects we studied how far the required dose of opioid could be decreased with a multimodal strategy adding diclofenac.

STUDY DESIGN

In a randomized double-blind study, 50 parturients scheduled for elective CS under spinal anaesthesia, received rectally either diclofenac (Suppositorium diclofenac) 50 mgx3 or placebo 1x3 during the first 24 h postoperatively. All patients had PCA with the possibility of self-administered doses of ketobemidone 1 mg/6 min.

RESULTS

In the group receiving diclofenac rectally the consumption of ketobemidone was reduced with 39% compared to the placebo group.

CONCLUSION

A multimodal analgetic strategy with the addition of 150 mg diclofenac during the first 24 h after CS reduces the need for opioids significantly with maintained or improved analgetic effect. This is expected to reduce the risk of negative side-effects of systemic opioids.

Epidural local anaesthetics versus opioid-based analgesic regimens on postoperative gastrointestinal paralysis, PONV and pain after abdominal surgery

BACKGROUND

Gastrointestinal paralysis, nausea and vomiting, and pain, are major clinical problems following abdominal surgery. Anaesthetic and analgesic techniques that reduce pain and postoperative nausea and vomiting (PONV), and prevent or reduce postoperative ileus, may reduce postoperative morbidity, duration of hospitalisation and hospital costs.

OBJECTIVES

To compare effects of postoperative epidural local anaesthetic with regimens based on systemic or epidural opioids, on postoperative gastrointestinal function, postoperative pain, PONV and surgical/anaesthetic complications.

SEARCH STRATEGY

Trials were identified by computerised searches of the Cochrane Controlled Trials Register, MEDLINE, EMBASE and by checking the reference lists of trials and review articles.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of postoperative epidural local anaesthetic with systemic or epidural opioids.

DATA COLLECTION AND ANALYSIS

Collected data included treatment in active (local anaesthetic) and control (opioid based) groups, time to first postoperative stool, time to first postoperative flatus, gastric emptying measured by the paracetamol absorption test, duration of the passage of barium sulphate, pain assessments, use of supplementary analgesics, nausea, vomiting and surgical/anaesthetic complications.

MAIN RESULTS

Most studies in this review involved a small number of patients. Furthermore half of the studies indicated a poor level of methodology in particular regarding blinding and report of withdrawals. Heterogeneity of included studies was substantial. Results consistently showed reduced time to return of gastrointestinal function in the epidural local anaesthetic group compared with groups receiving systemic or epidural opioid (37 hours and 24 hours, respectively). Postoperative pain was comparable. Two studies compared the effect of epidural local anaesthetic with a combination of epidural local anaesthetic and opioid on gastrointestinal function. One study favoured epidural local anaesthetic and one study was indifferent. A meta analysis of five of eight studies comparing the effect of epidural local anaesthetic with a combination of epidural local anaesthetic and opioid on postoperative pain, yielded a reduction in VAS pain scores (0-100 mm) on the first postoperative day of 15 mm, in favour of the combination. No significant differences in PONV were observed between epidural local anaesthetic and opioid based regimens.

REVIEWER'S CONCLUSIONS

Administration of epidural local anaesthetics to patients undergoing laparotomy reduce gastrointestinal paralysis compared with systemic or epidural opioids, with comparable postoperative pain relief. Addition of opioid to epidural local anaesthetic may provide superior postoperative analgesia compared with epidural local anaesthetics alone. The effect of additional epidural opioid on gastrointestinal function is so far unsettled. Randomized, controlled trials comparing the effect of combinations of epidural local anaesthetic and opioid with epidural local anaesthetic alone on postoperative gastrointestinal function and pain are warranted.

Regional blocks for cesarean section

Recent researches in the field of regional anesthesia for cesarean section have focused on spinal anesthesia, including prophylaxis of maternal hypotension, the use of opioids to improve intra- and postoperative analgesia and the use of ropivacaine.

Epidural fentanyl, adrenaline and clonidine as adjuvants to local anaesthetics for surgical analgesia: meta-analyses of analgesia and side-effects

BACKGROUND

The risk/benefit ratio of adding fentanyl, adrenaline and clonidine to epidural local anaesthetics for improving intraoperative analgesia is unclear. This meta-analysis was performed to clarify this issue.

METHODS

Trials retrieved by search were considered if they were prospective, controlled, epidural analgesia (without combining general anaesthesia) was planned and occurrence of pain during surgery or side-effects were reported. Papers entered meta-analysis if they reached a predefined minimum quality score. Pooled odds ratios (OR) and confidence intervals (CI) were computed. P < 0.05 was considered as significant.

RESULTS

Eighteen trials were included in the analysis for fentanyl. Fentanyl decreased the likelihood of pain (OR = 0.21, 95% CI = 0.15-0.30, P < 0.001) and increased the incidence of pruritus (OR = 5.59, 95% CI = 3.12-10.05, P < 0.001) and sedation (OR = 1.88, 95% CI = 1.19-2.98, P = 0.003), compared to control (local anaesthetic without fentanyl). Fentanyl had no effect on respiratory depression, nausea, vomiting and Apgar score. One case of respiratory depression of a newborn was observed. Because of the very low number of trials selected, evaluation of adrenaline and clonidine was not feasible.

CONCLUSION

The analysis of current literature shows that the addition of fentanyl to local anaesthetics for intraoperative epidural analgesia is safe and advantageous. The reduction in the incidence of pain during surgery is quantitatively high and therefore clinically significant. Side-effects are mild. Randomized, controlled trials have to be performed in order to clarify the role of adrenaline and clonidine as epidural adjuvants for surgical analgesia.

Ropivacaine 7.5 mg/ml for elective caesarean section. A clinical and pharmacokinetic comparison of 150 mg and 187.5 mg

BACKGROUND

The new, long-acting local anaesthetic ropivacaine has shown less systemic toxicity than bupivacaine and a concentration of 7.5 mg/ml can therefore be used for epidural anaesthesia in Caesarean section. The present pilot study was undertaken to find indications for an optimal dosage by comparing the clinical effects, quality of anaesthesia and pharmacokinetics of ropivacaine 150 mg (lower dose = LD) vs 187.5 mg (higher dose = HD) for women undergoing elective Caesarean section under epidural anaesthesia.

METHODS

Sixteen full-term women scheduled for elective Caesarean section in two equal-sized consecutive groups received 20 or 25 ml ropivacaine epidurally in this non-randomised, open study. Study parameters included sensory and motor blockade, circulatory response, intraoperative pain and discomfort, neonatal evaluation and pharmacokinetic determinations.

RESULTS

Block height varied between T5 and T2 in the LD group, whereas the HD group produced 4 unnecessarily high blocks (C8 in 3 women and C7 in 1 woman). Surgical anaesthesia was excellent in both groups. Circulatory stability was pronounced in the LD group (no ephedrine given), while 4 women required ephedrine in the HD group. Neonatal outcome as judged by Apgar scores; umbilical blood gas determinations and NACS scores were excellent in both groups. The plasma concentration-time profiles indicated linearity in the concentration range studied, with similar clearance values to those reported previously. Placental drug equilibrium was rapid; however, the foetal drug exposure depended on intrauterine exposure time.

CONCLUSIONS

20-25 ml ropivacaine 7.5 mg/ml produced very satisfactory conditions for elective Caesarean section under epidural anaesthesia. In this small population, 150 mg ropivacaine seemed optimal, while 187.5 mg produced unnecessarily extended block height in 50% of the women.