Intrathecal sufentanil for labor analgesia--sensory changes, side effects, and fetal heart rate changes

Plasmatic catecholamines after neuraxial labour analgesia: A randomised controlled trial comparing epidural versus combined spinal-epidural

BACKGROUND

Combined spinal-epidural technique (CSE) for labour analgesia has been associated with fetal bradycardia and uterine hypertonia when compared with epidural analgesia (EA), possibly due to a decrease in epinephrine levels following neuraxial anaesthesia. However, there are no recent studies comparing plasmatic catecholamines levels between those two techniques. This study aimed to compare CSE versus EA regarding pre- and post-analgesia catecholamines levels, uterine tone and fetal heart rate.

PATIENTS AND METHODS

Randomised clinical trial with 47 labouring patients divided in two groups (CSE and EA). Primary outcome was plasmatic catecholamine measurements before and after neuraxial block. Secondary outcomes were fetal heart rate changes, uterine hypertonia, hypotension episodes, pain relief and fetal outcomes.

RESULTS

For CSE group, the median decrease of plasmatic epinephrine was 0 pg/mL [(-) 480-(+) 41] and for norepinephrine was -21 pg/mL [(-) 2507-(+) 94]. For EA group, the median decrease for epinephrine was 0 pg/mL [(-) 326-(+) 15] and for norepinephrine was -5 pg/mL [(-) 190-(+76)]. There were no differences between groups (p = 0.96 and p = 0.63 for epinephrine and norepinephrine, respectively). There were no differences for secondary outcomes.

CONCLUSIONS

There was no evidence of a more significant decrease of catecholamines with CSE when compared with EA. Catecholamines decrease theory may not be valid for modern labour analgesia techniques.

[Spinal Analgesia - Cleverly Used for Vaginal Delivery]

Neuroaxial procedures are among the most effective ways of relieving pain during childbirth. Especially in the late phase of vaginal delivery, surprising moments, instrumental methods or special maneuvers require quick and sufficient analgesia. This refers to situations with a sudden, often unexpected and particularly pronounced intensity of pain. Here the advantages of spinal analgesia over the gold standard of obstetric analgesia, catheter epidural analgesia, can be used. Spinal analgesia is characterized by a fast onset of pain relief, a profound blockage and simple technical feasibility and, like other neuroaxial procedures, is comparatively uncomplicated in pregnant women. However, it is only effective if the delivery situation is well assessed. There is no possibility of repetition without re-puncture, so that limited duration of action is a significant disadvantage. Applied drugs correspond to those described for combined spinal and epidural analgesia, such as a mixture of low-dose bupivacaine and sufentanil, and can be adapted to local conditions. In the future, longer acting substances could overcome the main limitation (temporary effect) of spinal analgesia and suitable adjuvants could further increase the attractiveness of the procedure.

Transient lower cranial nerve palsies following spinal anesthesia with bupivacaine-fentanyl combination for transurethral resection of the prostate

Spinal anesthesia is a widely used regional anesthesia for many infra-umbilical surgical procedures with proven efficacy and safety. However, although rare, some neurologic complications can occur with potentially life threatening consequences. Among them, lower cranial nerve palsies have been rarely reported in the literature. We report such a case in a 75-year-old man with transient dysphagia, dysphonia and spinal accessory nerve palsy occurring four days after spinal anesthesia for transurethral resection of the prostate. His symptoms completely resolved spontaneously within 2 weeks. The possibility of lower cranial nerve palsies should be added to the potential complications during or following spinal anesthesia with bupivacaine-fentanyl combination. Although transitional, this complication may occur few days after the procedure and need to be promptly recognized, carefully evaluated and treated by conservative measures.

Uterine hypertonus and fetal bradycardia occurred after combined spinal-epidural analgesia during induction of labor with oxytocin infusion: A case report

RATIONALE

Pain management is an essential part of good obstetrical care. The rapid onset of pain relief after combined spinal-epidural (CSE) analgesia may cause a transient imbalance in maternal catecholamine level, leading to uterine hyperactivity and fetal heart rate (FHR) abnormalities. How to manage the uterine basal tone and FHR abnormalities after labor analgesia still remains controversial.

PATIENT CONCERNS

A 33-year-old nulliparous woman at 40 weeks' gestation underwent induction of labor after premature rupture of membranes. CSE analgesia was provided when the patient described her pain as the top on a scale of 10 during induction of labor with oxytocin infusion.

DIAGNOSES

Uterine hypertonus and fetal bradycardia were diagnosed within 10 minutes after CSE analgesia.

INTERVENTIONS

Oxytocin infusion and CSE analgesia were immediately suspended, and measures of staying in left lateral decubitus position and giving supplemental oxygen were attempted to resuscitating the baby. Because of suspicious fetal distress, the baby was rapidly delivered by emergency cesarean section.

OUTCOMES

The Apgar score of the baby was 8 and 10 at 1 and 5 minutes after birth. Subsequent follow-up confirmed that both mother and baby were in good condition.

LESSONS

The loss of the tocolytic effect of epinephrine after CSE analgesia and continuous oxytocin infusion may work together to form a totally synergistic function, finally leading to inevitable uterine hypertonus and fetal bradycardia. Both the obstetrical provider and anesthesiologist should carefully monitor all patients in the first 15 minutes after CES analgesia induction. Oxytocin administration in this critical period deserves attention. Additionally, intraprofessional collaboration is also necessary to ensure high quality and safe delivery for all childbearing women.

The comparative study of intravenous Ondansetron and sub-hypnotic Propofol dose in control and treatment of intrathecal Sufentanil-induced pruritus in elective caesarean surgery

Objective:

Pruritus is a common and disturbing side effect of neuraxial opioids after cesarean section. The purpose of this study was to compare the efficacy of intravenous ondansetron and sub-hypnotic dose of propofol in control and treatment of intrathecal sufentanil induced pruritus in cesarean surgery.

Methods:

Totally, 90 parturient with American Society of Anesthesiology physical status grade I-II, undergoing spinal anesthesia with 2.5 μg sufentanil and 10 mg bupivacaine 0.5% were enrolled to this randomized, prospective, double-blind study. The women were randomly assigned to two groups who received 8 mg ondansetron or 10 mg propofol to treat pruritus grade ≥3. The patient was evaluated after 5 min and in the lack of successful treatment, the doses of two drugs repeated and if the pruritus is on-going, the exact treatment with naloxone was done.

Findings:

The incidence of pruritus was 69.3%. Both groups were well-matched. The peak time pruritus was 30–75 min after injection. The percentage of individuals consumed naloxone were 6.8% and 15.9% in ondansetron and propofol groups, respectively (P = 0.18). The mean score of satisfaction (according to visual analog scale criteria) was 9.09 ± 1.1 in ondansetron group and 9.3 ± 1.07 in the propofol group (P = 0.39).

Conclusion:

Ondansetrone and sub-hypnotic dose of propofol are both safe and well-tolerated. Due to their same efficacy in the treatment of intrathecal sufentanil-induced pruritus, they can be widely used in clinical practice.

Intraoperative neurological event during cesarean section under spinal anesthesia with fentanyl and bupivacaine: Case report and review of literature

Neurological events similar to transient ischemic attack in a peripartum woman are uncommon. Cerebral complications of preeclampsia, thrombo-embolic phenomena, or high spinal can mimic such situations. Spinal anesthesia with local anesthetic and opioid is an established anesthetic technique for cesarean section. Although intrathecal opioids are safe for both the mother and fetus; some unusual complications such as dysphagia alone or associated with facial numbness, aphasia, have been reported. We report a case of transient aphonia and tingling sensation over the face without any dysphagia after intrathecal administration of bupivacaine and fentanyl for cesarean section.

On the ropivacaine-reducing effect of low-dose sufentanil in intrathecal labor analgesia

BACKGROUND

Combining ropivacaine with sufentanil for intrathecal (i.t.) analgesia in labor is well recognized, but information on dosing is limited. This study aimed to determine the ED 50 of i.t. ropivacaine and to assess the effect of adding defined low doses of sufentanil.

METHODS

This was a two-phase, double-blind, randomized and prospective study. One hundred and fifteen parturients receiving combined spinal epidural analgesia were allocated to one of four groups to receive ropivacaine or sufentanil alone or in combination. In phase one, sufentanil dose-response was calculated using logistic regression. In phase two, ED 50 of ropivacaine and of the combination with a fixed dosage of sufentanil at ED 20 and ED 40 was evaluated using the technique of up-down sequential allocation. Analgesic effectiveness was assessed 15 min after injection using a 100 mm visual analog scale, with <10 mm lasting for 45 min defined as effective. Furthermore, side effects and duration were recorded.

RESULTS

The ED 50 of i.t. ropivacaine was 4.6 mg [95% confidence intervals (95% CI) 4.28, 5.31]. Adding sufentanil at ED 20 significantly decreased the ED 50 of i.t. ropivacaine to 2.1 mg (95%CI 1.75, 2.5) (P<0.005); at ED 40, the reduction was similar (P<0.005). Combining sufentanil with ropivacaine resulted in a dose-independent prolongation of analgesia. Besides pruritus, which was well tolerated, there were no differences in side effects.

CONCLUSION

Adding sufentanil at ED 20 results in a more than 50% dose-sparing effect of ropivacaine and considerably prolongs analgesia. Increasing dosage implicates no clinical benefit.

Progress in analgesia for labor: focus on neuraxial blocks

Neuraxial analgesia is widely accepted as the most effective and the least depressant method of providing pain relief in labor. Over the last several decades neuraxial labor analgesia techniques and medications have progressed to the point now where they provide high quality pain relief with minimal side effects to both the mother and the fetus while maximizing the maternal autonomy possible for the parturient receiving neuraxial analgesia. The introduction of the combined spinal epidural technique for labor has allowed for the rapid onset of analgesia with minimal motor blockade, therefore allowing the comfortable parturient to ambulate. Patient-controlled epidural analgesia techniques have evolved to allow for more flexible analgesia that is tailored to the individual needs of the parturient and effective throughout the different phases of labor. Computer integrated systems have been studied to provide seamless analgesia from induction of neuraxial block to delivery. New adjuvant drugs that improve the effectiveness of neuraxial labor analgesia while decreasing the side effects that may occur due to high dose of a single drug are likely to be added to future labor analgesia practice. Bupivacaine still remains a popular choice of local anesthetic for labor analgesia. New local anesthetics with less cardiotoxicity have been introduced, but their cost effectiveness in the current labor analgesia practice has been questioned.

Modern neuraxial labor analgesia: options for initiation, maintenance and drug selection

In the present review we outline the state-of-the-art of neuraxial analgesia. As neuraxial analgesia remains the gold standar of analgesia during labor, we review the most recent literature on this topic. The neuraxial analgesia techniques, types of administration, drugs, adjuvants, and adverse effects are investigated from the references. Most authors would agree that central neuraxial analgesia is the best form to manage labor pain. When neuraxial analgesia is administered to the parturient in labor, different management choices must be made by the anesthetist: how will we initiate analgesia, how will analgesia be maintained, which local anesthetic will we use for neuraxial analgesia and which adjuvant drugs will we combine? The present manuscript tries to review the literature to answer these questions.

Adding sufentanil to levobupivacaine or ropivacaine intrathecal anaesthesia affects the minimum local anaesthetic dose required

BACKGROUND

We carried out this prospective, randomized, double-blind study in order to evaluate whether the intrathecal addition of sufentanil 3.3 mcg affects both the minimum local anaesthetic dose (MLAD) of spinal levobupivacaine and ropivacaine for a caesarean section and enhances the spinal block characteristics.

METHODS

One hundred and eighty women were randomly allocated into four groups: levobupivacaine (Group L), levobupivacaine plus sufentanil (Group L+S), ropivacaine (Group R) and ropivacaine plus sufentanil (Group R+S). Each received 3 ml of the study solution intrathecally as part of a combined spinal/epidural technique. The initial dose was 12 mg for Groups L and L+S, and 15 mg for Groups R and R+S. The test solution was required to achieve a visual analogue pain score (VAPS) of 30 mm or less to be considered effective at skin incision, uterine incision, birth, peritoneal closure and at the conclusion of surgery. Effective or ineffective responses determined a 0.5 mg decrease or increase of the same drug, respectively, for the next patient in the same group, using an up-down sequential allocation.

RESULTS

Using the Dixon and Massey formula, the MLAD was 10.65 mg [confidence interval (CI) 95%: 10.14-11.56] in Group L, 4.73 mg (CI 95%: 4.39-5.07) in Group L+S, 14.12 mg (CI 95%: 13.50-14.60) in Group R and 6.44 mg (CI 95%: 5.86-7.02) in Group R+S.

CONCLUSIONS

The addition of sufentanil reduced the MLAD of both the local anaesthetics. It did not affect their potency ratio significantly and resulted in enhanced spinal anaesthesia.

[30 microg intrathecal clonidine prolongs labour analgesia, but increases the incidence of hypotension and abnormal foetal heart rate patterns]

OBJECTIVE

To assess the efficacy of spinal clonidine combined with bupivacaine and sufentanil and its effects on maternal and foetal outcome.

STUDY DESIGN

Prospective double-blind randomized study.

PATIENTS AND METHODS

One hundred and five patients requesting labour analgesia had combined spinal epidural analgesia with intrathecal bupivacaine 2.5 mg and were randomly assigned to receive in addition either sufentanil 5 microg (S5), sufentanil 5 microg and clonidine 30 microg (C30), or sufentanil 10 microg (S10). Onset time, duration of analgesia, visual analogue scores, blood pressure, ephedrine requirements, heart rate, nausea, pruritus, sedation, motor block, foetal heart rate abnormalities, mode of delivery and Apgar scores were recorded.

RESULTS

Mean duration of spinal analgesia was significantly longer in patients receiving spinal clonidine compared to patients in S5 group (144+/-61 min versus 95+/-37 min). The onset time of analgesia was significantly shorter in S10 group (3+/-1 min) versus C30 group (4+/-1 min) and S5 group (4+/-1 min) (P=0.002). Hypotension was significantly more frequent in C30 group (29 versus 3% and 3% in S5 and S10 groups) (p=0,001). Foetal heart rate abnormalities and sedation were also significantly more frequent in C30 group. Mode of delivery (spontaneous, instrumental or caesarean delivery) and Apgar scores were unaffected by clonidine treatment.

CONCLUSION

Intrathecal clonidine 30 mug prolongs analgesia. However, it increases the incidence of hypotension, and abnormal foetal heart rate patterns. Thus, this study confirms that the use of 30 mug intrathecal clonidine for labour analgesia is not recommended.

Predicting prolonged fetal heart rate deceleration following intrathecal fentanyl/bupivacaine

BACKGROUND

Intrathecal opioids for labor analgesia are occasionally associated with fetal heart rate abnormalities. We wanted to identify risk factors for this occurrence.

METHODS

The fetal tracings of 151 consecutive patients were reviewed for the period including 30 min before and 60 min after combined spinal-epidural analgesia using intrathecal bupivacaine with fentanyl. Their progress of labor at injection was also recorded.

RESULTS

Lack of fetal head engagement (odds ratio 5.5, 95% CI 2.1-14.2) and the presence of variable fetal heart rate decelerations (odds ratio 3.6, 95% CI 1.6-8.4) were associated with prolonged fetal heart rate deceleration after combined spinal-epidural analgesia.

CONCLUSION

This case-control study suggests that if the fetal head is not engaged or if the fetus is experiencing variable decelerations, there is an increased risk of prolonged fetal heart rate deceleration following intrathecal fentanyl/bupivacaine. This finding must now be confirmed in a cohort study.

Two additional cases of excessive extension of sensory blockade after intrathecal sufentanil for labor analgesia

Combined spinal-epidural anesthesia (CSE) is an effective technique with rapid onset of labor analgesia. We describe two cases of excessive cephalad spread of sensory blockade without motor blockade in two parturients in spontaneous labor with CSE. The patients received sufentanil 5 microg intrathecally with 1.25 mg bupivacaine. Spinal injection produced dyspnea and extension of sensory blockade to cervical or facial level without fetal consequences. We conclude that the risk of these side-effects previously described with the 10 microg dose persists for lower sufentanil spinal doses.

Should epidural diamorphine be withheld after caesarean section from women who suffer severe pruritus following intrathecal fentanyl?

Pruritus following neuraxial opioids in 37 women undergoing caesarean section under combined epidural-spinal anaesthesia was investigated. All women received intrathecal fentanyl for intra-operative analgesia followed by epidural diamorphine for postoperative analgesia, when pain returned. Pruritus was assessed using a verbal rating scale at the end of surgery and again 24-36 h postoperatively. There was no relationship between pruritus experienced after intrathecal fentanyl and that experienced after epidural diamorphine. We conclude that there is no reason to withhold epidural diamorphine from women who have previously experienced severe itching after intrathecal fentanyl.

Intrathecal opioids for combined spinal-epidural analgesia during labour

In <25 years, intrathecal administration of opioids (i.e. spinal analgesia) has evolved from an experimental model into an important therapy for obstetric analgesia and anaesthesia. A small dose of opioid delivered into the CSF provides almost immediate relief from labour pain with minimal risks to the mother and fetus. Careful attention, and prompt treatment when needed, can ameliorate the adverse effects of fetal bradycardia, respiratory depression and pruritus. The major limitation of intrathecal opioids for labour analgesia is the short duration of effect: 90-180 minutes under ideal circumstances. To address this problem, and to increase flexibility for anaesthesia as well as analgesia, the combined spinal-epidural (CSE) technique was developed. The CSE technique involves injection of drugs into the CSF and placement of an epidural catheter. An intrathecally administered opioid provides a rapid onset of labour analgesia without motor block or significant haemodynamic perturbation. The epidural catheter allows ongoing administration of medications to maintain labour analgesia and provides a means of delivering anaesthesia for operative delivery. This review will focus on intrathecally administered opioids as used as part of CSE analgesia. Considerable research has focused on the optimum dose of opioids when delivered intrathecally, with or without adjuncts, in the CSE technique. Fentanyl and sufentanil, two of the lipophilic synthetic opioids, have emerged as the most useful. Bupivacaine, a long-acting local anaesthetic, is often added to prolong the duration of analgesia, although this tends to increase the likelihood of motor blockade of the lower extremities. Comparisons of the CSE technique with standard epidural practices have shown that both are effective means of providing analgesia during labour. Controversy revolves around the incidence of fetal bradycardia following CSE and whether this phenomenon increases the rate of operative deliveries. The rapid onset of analgesia with intrathecally administered opioids must be balanced against the added risks of dural puncture and considered in the context of the whole duration of labour. Ultimately, the decision to choose a CSE technique depends on the experience of the anaesthesia provider and the local availability of drugs, equipment and monitoring capabilities.

Single-shot intrathecal sufentanil with bupivacaine in late labour--analgesic quality and obstetric outcome

OBJECTIVES

To investigate the analgesic effect and obstetric outcome after single-shot intrathecal sufentanil with bupivacaine in late labour.

STUDY DESIGN

Forty multiparous women in advanced labour were given a spinal injection of sufentanil 7.5 microg and bupivacaine 2 mg. Pain intensity was recorded by the parturient on a visual analogue scale. The quality of pain relief was also rated with a verbal score directly after delivery. Side effects, such as hypotension, pruritus, sedation, nausea and motor block were noted. Obstetric parameters were followed and recorded. Apgar score and umbilical artery pH were noted.

RESULTS

Median visual analogue scores after 5, 15, 30, 60, 90, 120 and 150 min were 1.5, 0.5, 0, 1, 1.5, 2 and 3, respectively. Seventy-seven percent of the parturients scored the analgesic quality as excellent. Six parturients had hypotension. Motor block, sedation and nausea were rare. Pruritus was seen in 85% of the cases. No ceasarean section was performed. Vacuum extraction was done in six (15%) cases. Oxytocin augmentation was needed in 26 (65%) of the parturients. Fetal heart rate disturbances following the spinal block were seen in four cases. Apgar scores were high. No neonate had Apgar < 7.

CONCLUSIONS

Intrathecal block with sufentanil 7.5 microg in combination with bupivacaine 2 mg is a very effective pain relief in late labour. Due to its limited duration it is important to select women in rapid progress of labour, and active obstetric management is necessary. It is also very important that the obstetrician is aware of the risk of non-reassuring fetal heart rate changes after intrathecal block.

The combined spinal–epidural technique

In recent years, the use of regional anaesthesia techniques for surgery, obstetrics and post operative pain management have increased in popularity. The combined spinal-epidural (CSE) technique has attained widespread popularity for patients undergoing major surgery below the umbilicus who may require prolonged and effective postoperative analgesia. The CSE technique is now well established in several institutions. This chapter includes the clinical experience, advantages and potential problems, and discusses future perspectives of the CSE technique.

A randomised double-blind evaluation of adenosine as adjunct to sufentanil in spinal labour analgesia

BACKGROUND

Intrathecal injection of sufentanil offers labour pain relief of short duration. This double-blind randomised study evaluates if the combination of adenosine to sufentanil could give relevant prolongation (40%) of the duration of sufentanil spinal analgesia.

METHODS

Twenty-five healthy parturients requesting labour analgesia were included. Patients received 10 micro g of sufentanil + 500 micro g of adenosine or 10 micro g of sufentanil intrathecally. Pain intensity and duration of pain relief were assessed.

RESULTS

Pain relief was equal between groups. Duration of analgesia was not increased by adenosine + sufentanil, 99 +/- 54 min, vs. sufentanil, 89 +/- 56 min.

CONCLUSION

Adding 500 micro g of adenosine to 10 micro g of sufentanil could not provide any prolongation of labour pain relief.

Newer techniques of labor analgesia

In maternity units in which central neuraxial techniques are frequently used, newer methods of epidural drug delivery (continuous infusion, patient-controlled) are well established and combined spinal-epidural analgesia is commonly used. Continuous spinal analgesia has reemerged as a useful approach after accidental dural puncture. Lumbar sympathetic block has been revisited and the safety of paracervical nerve block improved. The analgesic properties of systemic opioid in labor are poor, but PCIA at least has psychological benefits and allows rapid drug titration. PCIA is again under investigation because of the potent antinociceptive effects of the short-acting mu-opioid agonist, remifentanil. The premixing of nitrous oxide and a subanesthetic concentration of volatile anesthetic for patient-controlled administration has been tested under control of midwifery staff and without direct medical supervision.

Implantable devices for pain control: spinal cord stimulation and intrathecal therapies

Untreated chronic pain is costly to society and to the individual suffering from it. The treatment of chronic pain, a multidimensional disease, should rely on the expertise of varying health care providers and should focus not only on the neurobiological mechanisms of the process but also on the psychosocial aspects of the disease. Implantable devices are costly and invasive, and such efficacious therapies should be used only when more conservative and less costly therapies have failed to provide relief of pain and suffering. Spinal cord stimulation provides neuromodulation of neuropathic, but not nociceptive, pain signals and when used for appropriate indications in the right individuals provides approximately 60-80% long-term pain relief in 60-80% of patients trialled for efficacy. Intrathecal therapies with opioids such as morphine, fentanyl, sufentanil or meperidine--or non-opioids such as clonidine or bupivacaine--provide analgesia in patients with nociceptive or neuropathic pain syndromes. Baclofen, intrathecally, provides profound relief of muscle spasticity due to multiple sclerosis, spinal cord injuries, brain injuries or cerebral palsy.

Combined spinal-epidural analgesia for labor: breakthrough or unjustified invasion?

The combined spina-epidural (CSE) technique has become increasingly popular for labor analgesia. The advantages of the CSE include more rapid onset of analgesia, reduced total drug dosage, minimal or no motor blockade, and increased patient satisfaction. CSE has also been associated with more rapid cervical dilation when compared to epidural analgesia in nulliparous women in early labor. Despite these potential advantages, the indications for CSE versus epidural analgesia remain unclear and controversial. This review should allow better understanding of the benefits and risks of this technique, and bearing in mind that no ultimate neuraxial analgesic exists, it would seem that CSE should be considered a major breakthrough in the management of labor analgesia.

Effect of epidural analgesia on the fetal heart rate

Fetal heart rate (FHR) changes occasionally follow the use of labor epidurals. Most studies of the phenomenon have focused on specific techniques, but similar timing and appearance suggest a common cause. Induction of analgesia may transiently alter the balance between factors encouraging and inhibiting uterine contractions with subsequent changes of FHR patterns. Regardless the etiology, these changes are transient and do not produce maternal or fetal morbidity. However, they must be promptly recognized and treated if necessary.

A comparison of three doses of sufentanil in combination with bupivacaine-adrenaline in continuous epidural analgesia during labour

BACKGROUND

Sufentanil is now frequently added to local anaesthetic in labour epidural analgesia. However, this opioid has some side effects such as pruritus, and in higher doses could harm the neonate. The purpose of this study was to compare three doses of sufentanil combined with low-dose bupivacaine, to determine the lowest appropriate dose.

METHOD

In a prospective, randomized, double-blind study, 243 parturients were randomized, to receive A--0.5 microg/ml, or B--0.75 microg/ml or C--1 microg/ml sufentanil, in addition to bupivacaine 0.625 mg/ml+adrenaline 1.25 microg/ml. All were given an 8 ml bolus of the study solution, followed by continuous infusion at 6 ml/h. The analgetic effect was scored on a visual analogue scale (VAS). Onset quality was measured as VAS after 20 min, the total effect as VAS maximum during the first stage of labour. Overall maternal satisfaction was recorded within two hours post partum. Side effects were noted.

RESULTS

There were no differences between groups in VAS assessments after 20 min or in maximum registered VAS. In group A, 83% had VAS 0-4 after 20 min, in group B 77% and in group C 71%. Maximum VAS during the first stage was 0-4 for 60% of group A, 68% of group B and 61% of group C. Maternal satisfaction was also the same in the three groups. In group A, 70% reported excellent effect and 22% good effect. The corresponding figures in group B were 68% and 24% respectively, and in group C 62% and 24% respectively. Group A received a mean total dose of 21 microg sufentanil, group B 30 microg and group C 44 microg. Pruritus occurred in 51% of group A, 53% of group B and 65% of group C.

CONCLUSION

We found no difference in the analgesic effect between three different concentrations of sufentanil. We conclude that the lowest dose may be used. This should decrease the risk of adverse effects on mother and child.

The combined spinal-epidural technique

Epidural and spinal blocks are well-accepted regional techniques, but they have several disadvantages. The CSE technique can reduce or eliminate the risks of these disadvantages. CSE block combines the rapidity, density, and reliability of the subarachnoid block with the flexibility of continuous epidural block to extend duration of analgesia. The CSE technique is used routinely at many institutions, particularly for major orthopedic surgery and in obstetrics. It has been used in tens of thousands of patients without any reports of major problems. Although at first sight the CSE technique appears to be more complicated than epidural or spinal block alone, intrathecal drug administration and siting of the epidural catheter are both enhanced by the combined, single-space, needle-through-needle method. Concerns about the epidural catheter entering the theca via the small puncture hole are now considered to be unfounded, but as with all epidural catheter techniques, vigilant monitoring of the patient during and after any injection is paramount. CSE is an effective way to reduce the total drug dosage required for anesthesia or analgesia. The intrathecal injection achieves rapid onset with minimal doses of local anesthetics and opioids, and the block can be prolonged with low-dose epidural maintenance administration. In addition, the sequential CSE method can be used to extend the dermatomal block with minimal additional drugs or even saline. Reduction in total drug dosage has made truly selective blockade possible. Many studies have confirmed that low-dose CSE with local anesthetic and opioid, or low-dose epidural block alone, will provide effective analgesia with minimal motor and proprioceptive block. Such neurologic selective blockade has made it possible for most patients to walk and bear down normally in labor or postoperatively. There remains concern about the risk of infection being increased when the CSE technique is used in place of epidural block alone. Despite a recent flurry of reports of meningitis with CSE procedures, there is no evidence the CSE block is more hazardous than epidural or subarachnoid block alone. Arguably, the single-space, needle-through-needle CSE technique will continue to improve with new needle designs and other advances to improve further the success rate and reduce complications, such as neurotrauma, PDPH, and infection. Over the past decade it has become clear that the CSE technique is a significant advance in regional blockade.

Regional anesthesia for obstetrics

The practice of administration of labor analgesia has undergone dramatic changes this decade. This is largely attributable to unparalleled interest in the field by many dedicated and capable investigators around the world. Through their efforts, this decade has witnessed the introduction of new techniques (pencil point needles, CSE, PCEA, ultradilute epidural regimens) that have permitted us to come closer than ever to realizing the goal of complete relief from the pain and suffering of labor while safeguarding the well-being of mother and child and minimizing effects on the labor process. Neuraxial anesthetic techniques and modern multimodal analgesic approaches to postoperative pain relief now minimize the effects of cesarean delivery on maternal satisfaction and participation in the birth process.

Comparison of epidural lidocaine and fentanyl to intrathecal sufentanil for analgesia in early labour

A randomized, double-blind study was undertaken comparing an epidural test dose of lidocaine followed by 100 microg fentanyl (E-LF, n = 19) to combined spinal epidural sufentanil 10 microg (CSE-S, n = 21) in low risk women in early labour. The primary outcome measured was the duration of analgesia; secondary outcomes included the quality of analgesia, incidence and severity of pruritus, lower limb motor blockade, and the ability to ambulate. A P < 0.05 was considered statistically significant. Baseline demographic characteristics, including parity, were similar between groups. CSE-S provided analgesia of longer duration than E-LF (126 +/- 61 min versus 83 +/- 37 min, P < 0.01). Visual analog scores (VAS) for pain were higher with E-LF throughout the study period (P < 0.05) although patients in both groups had clinically acceptable analgesia. The VAS for pruritus were higher in the CSE-S group (P < 0.05) but no patient requested treatment for pruritus. Mild motor weakness was more frequent in the E-LF group (5/19 versus 20/21, P < 0.05) and fewer patients in the E-LF group met criteria for ambulation (13/19 versus 20/21, P < 0.05). While both E-LF and CSE-S provide effective analgesia for women in early labour, the more rapid onset of analgesia, lower VAS pain scores, longer duration of action and lesser impact on ability to ambulate suggest advantages of CSE-S over E-LF.

[Obstetric analgesia: peridural analgesia versus combined spinal and peridural analgesia]

OBJECTIVE

To compare the analgesic efficiency, side effects and obstetrical repercussions of epidural analgesia (EP) and combined spinal-epidural analgesia (CSE).

STUDY DESIGN

Prospective, randomized, double or single-blind studies as required, approved by the ethical committee of the institution.

PATIENTS

The study included 80 parturients, in active labour with a singleton in vertex presentation and a cervical dilatation of 3 cm or less, randomly allocated to receive either EP (n = 40) or CSE (n = 40).

METHOD

In the EP group, sufentanil (20 micrograms) and 0.25% bupivacaine (6-8 mL) were injected into the epidural space. In those of the CSE group, sufentanil (10 micrograms) was first injected into the subarachnoid space, followed by an epidural injection of the same agents at the same quantities as for the EP group. Additional analgesia was obtained in both groups by top-ups of 6-8 mL of 0.25% bupivacaine at the request of the patients. Analgesia, course of labour, obstetrical outcome, and neonatal status were assessed. Statistical analysis was performed using Anova, chi 2 analysis, Yates' correction or Fisher's exact test, with a P < 0.05 considered as significant.

RESULTS

Both groups had similar demographic and obstetric data. The onset of analgesia was more rapid in CSE group (8 +/- 11 min vs. 12 +/- 7 min, P < 0.05), however the duration was similar. Technical incidents were more frequent in the CSE group (30% vs. 7%, P < 0.05). The technique of analgesia did not influence the bupivacaine amounts required for its maintenance. The incidence of adverse effects were comparable with the exception of vertigo, which was more frequent in the EP group (57% vs. 28%, P < 0.05). The first stage of labour was increased by 30% in the CSE group (281 +/- 130 min vs. 216 +/- 97 min, P < 0.05), without significant prolongation of labour length. Durations of second stage and expulsion were similar in both groups, despite the administration of a lower dose of bupivacaine in the CSE group (33 +/- 17 mg vs. 46 +/- 12 mg, P < 0.05). The rates of instrumental deliveries and Caesarien sections were comparable. The Apgar scores were satisfactory at 5 min.

CONCLUSION

In the early phase of labour, the CSE technique using intrathecal sufentanil has no significant benefit when compared to the EP technique using bupivacaine and sufentanil. In the CSE group, technical incidents were more frequent and the length of the first stage of labour was increased.

Pain management in the critically ill obstetric patient

Safe and successful pain management in pregnant women requires an understanding of the normal physiologic changes of pregnancy. Some hemodynamic changes of labor and delivery are attenuated by effective epidural analgesia. The ideal analgesic agent for laboring parturients should produce a rapid onset of analgesia that lasts throughout labor without any adverse effect on the mother or fetus. There is no ideal analgesic for pain relief in labor. The physiologic changes of labor and delivery are reviewed, together with commonly used analgesic techniques. Special emphasis is placed on critically ill obstetric patients with concomitant cardiac disease.

Postoperative intrathecal patient-controlled analgesia with bupivacaine, sufentanil or a mixture of both

In a randomised double-blind study, 45 patients, scheduled for major orthopaedic surgery under continuous spinal anaesthesia, received for relief of postoperative pain patient-controlled analgesia with either sufentanil 2 micrograms.ml-1, bupivacaine 0.0625% or a mixture of both by the intrathecal route. The mean (SD) consumption of sufentanil and bupivacaine during the first 12 h was 65.5 (27.1) micrograms and 18.2 (4.8) mg, respectively. Combining bupivacaine and sufentanil reduced the consumption of both to approximately 40% as compared to the administration of each component separately. Pain relief was very good in all subjects, although this was obtained faster with the combined regimen. Moreover, more patients in this group remained completely painfree during the entire observation period (p < 0.05). The incidence of hypotension was low and not significantly different when the plain bupivacaine group was compared with the two other groups. Nausea and vomiting were significantly more frequently observed in both groups treated with sufentanil. Motor block was not a major problem and was noticed during the first 2 h of treatment only. Tachyphylaxis did not occur. It was concluded that the groups receiving plain bupivacaine and sufentanil alone experienced pain relief of good quality. The use of a mixture, however, accelerated the onset of analgesia, improved the analgesic quality and reduced the doses for both components by 60% but at the expense of a higher incidence of nausea and vomiting.

New epidural techniques for labour analgesia: patient-controlled epidural analgesia and combined spinal-epidural analgesia

Epidural analgesia in labour aims to provide high-quality pain relief of rapid onset and prolonged duration, while minimizing both maternal side-effects, particularly impairment of mobility, and impact on the fetus or on the outcome of labour. In conjunction with pharmacological research on spinal analgesics (local anaesthetics, opioids and other drug classes), refinement of new or established drug delivery techniques has allowed progress toward more reliable and improved pain relief at all stages of labour and childbirth, reduced individual drug doses with reduction of unwanted effects and greater safety and enhancement of maternal satisfaction. Patient-controlled epidural analgesia in labour has been in use for almost a decade, although is only now at a stage where its role is well defined and utility can be increased. Combined spinal-epidural analgesia is a more recent refinement which appears to be extremely promising but awaits further investigation.

An intravenous fluid bolus is not necessary before administration of intrathecal fentanyl for labor analgesia

STUDY OBJECTIVE

To determine if an intravenous (i.v.) fluid bolus is necessary to prevent any possible hemodynamic sequelae after administration of intrathecal fentanyl in laboring parturients.

DESIGN

Prospective, randomized study.

SETTING

Labor suite of a women's tertiary care hospital.

PATIENTS

30 ASA physical status I and II parturients in active labor requesting labor analgesia.

INTERVENTIONS

Patients were randomly divided into two groups of 15. One group received no i.v. fluid prior to the administration of 25 micrograms of intrathecal fentanyl, and the other group received 500 ml of lactated Ringer's solution before the block.

MEASUREMENTS AND MAIN RESULTS

Blood pressures [systolic (SBP), diastolic (DBP), mean (MAP)], heart rate (HR), cardiac index (CI; using impedance cardiography), and visual analog scores were measured before the block, after fluids, and then every 5 minutes for 45 minutes after the block. Prenatal baseline blood pressures before the onset of labor were obtained from the obstetrician's office records. Results were analyzed using analysis of variance. All patients reported good pain relief. No patient from either group required treatment for hypotension. In the no fluid group, SBP and MAP decreased 10% and 14%, respectively (p = 0.05), following intrathecal fentanyl administration compared with preblock values obtained during labor but not when compared with prelabor prenatal values. In the fluid group, no significant changes occurred in SBP after intrathecal fentanyl but MAP decreased approximately 12% only in comparison to preblock values. No significant changes were noted in CI in either group. Fluid infusion itself caused an increase in HR and CI of approximately 12% and 9.4%, respectively.

CONCLUSION

Intrathecal fentanyl produces only minimal hemodynamic changes with or without prior fluid administration.

Comparison of three different doses of intrathecal fentanyl and sufentanil for labor analgesia

STUDY OBJECTIVE

To compare the duration of analgesia and incidence of side effects of three doses of intrathecal fentanyl (25 micrograms, 37.5 micrograms, 50 micrograms) with three doses of intrathecal sufentanil (5 micrograms, 10 micrograms, 15 micrograms).

DESIGN

Randomized, double-blind study.

SETTING

Labor suite of the Hospital of the University of Pennsylvania.

PATIENTS

60 ASA physical status I and II parturients in active labor who requested analgesia.

INTERVENTIONS

Patients received one of the six doses of opioid diluted with normal saline to achieve a volume of 1.5 ml intrathecally.

MEASUREMENTS AND MAIN RESULTS

Duration of analgesia, contraction pain, degree of pruritus, maternal blood pressure, maternal heart rate, fetal heart rate, Apgar scores, and neurologic and adaptive capacity scores were measured. There was no statistical difference among the doses of fentanyl in duration of analgesia. In addition, there was no statistical difference among the doses of sufentanil. The durations of analgesia for all doses of sufentanil were statistically longer than that for all doses of fentanyl. There was no difference among all the groups for maximal pruritus score. The duration of pruritus did not differ among doses of fentanyl or sufentanil; the duration of pruritus was significantly longer for sufentanil. All groups had a decrease in blood pressure. There was no difference among the groups in regard to the effect on the systolic or diastolic blood pressure.

CONCLUSIONS

Intrathecal sufentanil produced analgesia of longer duration than fentanyl for all doses studied. The duration of pruritus with sufentanil was also longer.

Neuraxial opioids in labour

Neuraxial opioids were first used for labour analgesia in 1980 following the description of spinal cord opioid receptors in 1979. Via these receptors in the dorsal horn, opioids modulate both the visceral and the somatic pain of labour. The onset and duration of action of the individual opioid are determined primarily by its relative lipid solubility. Neuraxial opioids have a local anaesthetic sparing effect, allowing the use of lower concentrations of both agents while maintaining analgesia. As a sole agent, intrathecal opioids can be used to provide analgesia during the first stage of labour, especially in the high-risk parturient. They also have a role in the management of perineal pain and the provision of rapid-onset analgesia. Unfortunately maternal and neonatal side-effects can occur, the most important being respiratory depression.